diff --git a/published/201606/20151023 Mark Shuttleworth--The Man Behind Ubuntu Operating System.md b/published/201606/20151023 Mark Shuttleworth--The Man Behind Ubuntu Operating System.md new file mode 100644 index 0000000000..b5923ca86a --- /dev/null +++ b/published/201606/20151023 Mark Shuttleworth--The Man Behind Ubuntu Operating System.md @@ -0,0 +1,129 @@ +马克·沙特尔沃思 – Ubuntu 背后的那个男人 +================================================================================ + +![](http://www.unixmen.com/wp-content/uploads/2015/10/Mark-Shuttleworth-652x445.jpg) + +**马克·理查德·沙特尔沃思（Mark Richard Shuttleworth）** 是 Ubuntu 的创始人，也被称作 [Debian 背后的人][1]（[之一][2]）。他于 1973 年出生在南非的韦尔科姆（Welkom）。他不仅是个企业家，还是个太空游客——他是第一个前往太空旅行的非洲独立国家的公民。 + +马克曾在 1996 年成立了一家名为 **Thawte** 的互联网商务安全公司，那时他还在开普敦大学（ University of Cape Town）的学习金融和信息技术。 + +2000 年，马克创立了 HBD（Here be Dragons （此处有龙/危险）的缩写，所以其吉祥物是一只龙），这是一家投资公司，同时他还创立了沙特尔沃思基金会（Shuttleworth Foundation），致力于以奖金和投资等形式给社会中有创新性的领袖提供资助。 + +> “移动设备对于个人电脑行业的未来而言至关重要。比如就在这个月，相对于平板电脑的发展而言，传统 PC 行业很明显正在萎缩。所以如果我们想要涉足个人电脑产业，我们必须首先涉足移动行业。移动产业之所以有趣，是因为在这里没有盗版 Windows 操作系统的市场。所以如果你为你的操作系统赢得了一台设备的市场份额，这台设备会一直使用你的操作系统。在传统 PC 行业，我们时不时得和“免费”的 Windows 产生竞争，这是一种非常微妙的挑战。所以我们现在的重心是围绕 Ubuntu 和移动设备——手机和平板——以图与普通用户建立更深层次的联系。” +> +> — 马克·沙特尔沃思 + +2002 年，他在俄罗斯的星城（Star City）接受了为期一年的训练，随后作为联盟号 TM-34 任务组的一员飞往了国际空间站。再后来，在面向有志于航空航天或者其相关学科的南非学生群体发起了推广科学、编程及数学的运动后，马克 创立了 **Canonical Ltd**。此后直至2013年，他一直在领导 Ubuntu 操作系统的开发。 + +现今，沙特尔沃思拥有英国与南非双重国籍并和 18 只可爱的鸭子住在英国的 Isle of Man 小岛上的一处花园，一同的还有他可爱的女友 Claire，两条黑色母狗以及时不时经过的羊群。 + +> “电脑不仅仅是一台电子设备了。它现在是你思维的延续，以及通向他人的大门。” +> +> — 马克·沙特尔沃思 + +### 马克·沙特尔沃思的早年生活### + +正如我们之前提到的，马克出生在南非的奥兰治自由邦（Orange Free State）的韦尔科姆（Welkom）。他是一名外科医生和护士学校教师的孩子。他在西部省预科学校就读并在 1986 年成为了学生会主席，一个学期后就读于 Rondebosch 男子高中，再之后入学 Bishops Diocesan 学院并在 1991 年再次成为那里的学生会主席。 + +马克在开普敦大学（ University of Cape Town）拿到了金融和信息系统的商业科学双学士学位，他在学校就读时住在 Smuts Hall。作为学生，他也在那里帮助安装了学校的第一条宿舍互联网接入。 + +>“无数的企业和国家已经证明，引入开源政策能提高竞争力和效率。在不同层面上创造生产力对于公司和国家而言都是至关重要的。” +> +> — 马克·沙特尔沃思 + +### 马克·沙特尔沃思的职业生涯 ### + +马克在 1995 年创立了 Thawte，公司专注于数字证书和互联网安全，然后在 1999 年把公司卖给了 VeriSign，赚取了大约 5.75 亿美元。 + +2000 年，马克创立了 HBD 风险资本公司，成为了商业投资人和项目孵化器。2004 年，他创立了 Canonical Ltd. 以支持和鼓励自由软件开发项目的商业化，特别是 Ubuntu 操作系统的项目。直到 2009 年，马克才从 Canonical CEO 的位置上退下。 + +> “在 [DDC](https://en.wikipedia.org/wiki/DCC_Alliance) (LCTT 译注：一个 Debian GNU/Linux 开发者联盟) 的早期，我更倾向于让拥护者们放手去做，看看能发展出什么。” +> +> — 马克·沙特尔沃思 + +### Linux、自由开源软件与马克·沙特尔沃思 ### + +在 90 年代后期，马克曾作为一名开发者参与 Debian 操作系统项目。 + +2001 年，马克创立了沙特尔沃思基金会，这是个扎根南非的、非赢利性的基金会，专注于赞助社会创新、免费/教育用途开源软件，曾赞助过[自由烤面包机][3]（Freedom Toaster）（LCTT 译注：自由烤面包机是一个可以给用户带来的 CD/DVD 上刻录自由软件的公共信息亭）。 + +2004 年，马克通过出资开发基于 Debian 的 Ubuntu 操作系统返回了自由软件界，这一切也经由他的 Canonical 公司完成。 + +2005 年，马克出资建立了 Ubuntu 基金会并投入了一千万美元作为启动资金。在 Ubuntu 项目内，人们经常用一个朗朗上口的名字称呼他——“**SABDFL ：自封的生命之仁慈独裁者（Self-Appointed Benevolent Dictator for Life）**”。为了能够找到足够多的高手开发这个巨大的项目，马克花费了 6 个月的时间从 Debian 邮件列表里寻找，这一切都是在他乘坐在南极洲的一艘破冰船——赫列布尼科夫船长号（Kapitan Khlebnikov）——上完成的。同年，马克买下了 Impi Linux 65% 的股份。 + + +> “我呼吁电信公司的掌权者们尽快开发出跨洲际的高效信息传输服务。” +> +> — 马克·沙特尔沃思 + +2006 年，KDE 宣布沙特尔沃思成为 KDE 的**第一赞助人（first patron）**——彼时 KDE 最高级别的赞助。这一赞助协议在 2012 年终止，取而代之的是对 Kubuntu 的资金支持，这是一个使用 KDE 作为默认桌面环境的 Ubuntu 变种。 + +![](http://www.unixmen.com/wp-content/uploads/2015/10/shuttleworth-kde.jpg) + +2009 年，Shuttleworth 宣布他会从 Canonical 的 CEO 上退位以更好地关注合作关系、产品设计和客户。从 2004 年起担任公司 COO 的珍妮·希比尔（Jane Silber）晋升为 CEO。 + +2010 年，马克由于其贡献而被开放大学（Open University）授予了荣誉学位。 + +2012 年，马克和肯尼斯·罗格夫（Kenneth Rogoff）一同在牛津大学与彼得·蒂尔（Peter Thiel）和加里·卡斯帕罗夫（Garry Kasparov）就**创新悖论**（The Innovation Enigma）展开辩论。 + +2013 年，马克和 Ubuntu 一同被授予**澳大利亚反个人隐私大哥奖**（Austrian anti-privacy Big Brother Award），理由是默认情况下， Ubuntu 会把 Unity 桌面的搜索框的搜索结果发往 Canonical 服务器（LCTT 译注：因此侵犯了个人隐私）。而一年前，马克曾经申明过这一过程进行了匿名化处理。 + +> “所有主流 PC 厂家现在都提供 Ubuntu 预安装选项，所以我们和业界的合作已经相当紧密了。但那些 PC 厂家对于给买家推广新东西这件事都很紧张。如果我们可以让 PC 买家习惯 Ubuntu 的平板/手机操作系统的体验，那他们也应该更愿意买预装 Ubuntu 的 PC。没有哪个操作系统是通过抄袭模仿获得成功的，Android 很棒，但如果我们想成功的话我们必须给市场带去更新更好的东西（LCTT 译注：而不是改进或者模仿 Android）。如果我们中没有人追寻未来的话，我们将陷入停滞不前的危险。但如果你尝试去追寻未来了，那你必须接受不是所有人对未来的预见都和你一样这一事实。” +> +> — 马克·沙特尔沃思 + +### 马克·沙特尔沃思的太空之旅 ### + +马克在 2002 年作为世界第二名自费太空游客而闻名世界，同时他也是南非第一个旅行太空的人。这趟旅行中，马克作为俄罗斯联盟号 TM-34 任务的一名乘员加入，并为此支付了约两千万美元。2 天后，联盟号宇宙飞船抵达了国际空间站，在那里马克呆了 8 天并参与了艾滋病和基因组研究的相关实验。同年晚些时候，马克随联盟号 TM-33 任务返回了地球。为了参与这趟旅行，马克花了一年时间准备与训练，其中有 7 个月居住在俄罗斯的星城。 + +![](http://www.unixmen.com/wp-content/uploads/2015/10/Mark-Shuttleworth1.jpg) + +在太空中，马克与纳尔逊·曼德拉（Nelson Mandela）和另一个 14 岁的南非女孩米歇尔·福斯特（Michelle Foster） （她问马克要不要娶她）通过无线电进行了交谈。马克礼貌地回避了这个结婚问题，但在巧妙地改换话题之前他说他感到很荣幸。身患绝症的女孩福斯特通过梦想基金会（ Dream foundation）的赞助获得了与马克和纳尔逊·曼德拉交谈的机会。 + +归来后，马克在世界各地做了旅行，并和各地的学生就太空之旅发表了感言。 + +>“粗略的统计数据表明 Ubuntu 的实际用户依然在增长。而我们的合作方——戴尔、惠普、联想和其他硬件生产商，以及游戏厂商 EA、Valve 都在加入我们——这让我觉得我们在关键的领域继续领先。” +> +> — 马克·沙特尔沃思 + +### 马克·沙特尔沃思的交通工具 ### + +马克有他自己的私人客机庞巴迪全球特快（Bombardier Global Express），虽然它经常被称为 Canonical 一号，但事实上此飞机是通过 HBD 风险投资公司注册拥有的。涂画在飞机侧面的龙图案是 HBD 风投公司的吉祥物 ，名叫 Norman。 + +![](http://www.leader.co.za/leadership/logos/logomarkshuttleworthdirectory_31ce.gif) + +### 与南非储备银行的法律冲突 ### + +在从南非转移 25 亿南非兰特去往 Isle of Man 的过程中，南非储备银行征收了 2.5 亿南非兰特的税金。马克上诉了，经过冗长的法庭唇枪舌战，南非储备银行被勒令返还 2.5 亿征税，以及其利息。马克宣布他会把这 2.5 亿存入信托基金，以用于帮助那些上诉到宪法法院的案子。 + + +> “离境征税倒也不和宪法冲突。但离境征税的主要目的不是提高税收，而是通过监管资金流出来保护本国经济。” +> +> — Dikgang Moseneke 法官 + +2015 年，南非宪法法院修正了低级法院的判决结果，并宣布了上述对于离岸征税的理解。 + +### 马克·沙特尔沃思喜欢的东西 ### + +Cesária Évora、mp3、春天、切尔西（Chelsea）、“恍然大悟”（finally seeing something obvious for first time）、回家、辛纳屈（Sinatra）、白日梦、暮后小酌、挑逗、苔丝（d’Urberville）、弦理论、Linux、粒子物理、Python、转世、米格-29、雪、旅行、Mozilla、酸橙果酱、激情代价（body shots）、非洲丛林、豹、拉贾斯坦邦、俄罗斯桑拿、单板滑雪、失重、Iain m 银行、宽度、阿拉斯泰尔·雷诺兹（Alastair Reynolds）、化装舞会服装、裸泳、灵机一动、肾上腺素激情消退、莫名（the inexplicable）、活动顶篷式汽车、Clifton、国家公路、国际空间站、机器学习、人工智能、维基百科、Slashdot、风筝冲浪（kitesurfing）和 Manx lanes。 + + + +### 马克·沙特尔沃思不喜欢的东西 ### + +行政、涨工资、法律术语和公众演讲。 + +-------------------------------------------------------------------------------- + +via: http://www.unixmen.com/mark-shuttleworth-man-behind-ubuntu-operating-system/ + +作者：[M.el Khamlichi][a] +译者：[Moelf](https://github.com/Moelf) +校对：[PurlingNayuki](https://github.com/PurlingNayuki), [wxy](https://github.com/wxy) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]:http://www.unixmen.com/author/pirat9/ +[1]:https://wiki.debian.org/PeopleBehindDebian +[2]:https://raphaelhertzog.com/2011/11/17/people-behind-debian-mark-shuttleworth-ubuntus-founder/ +[3]:https://en.wikipedia.org/wiki/Freedom_Toaster \ No newline at end of file diff --git a/published/20151210 Getting started with Docker by Dockerizing this Blog.md.md b/published/201606/20151210 Getting started with Docker by Dockerizing this Blog.md.md similarity index 100% rename from published/20151210 Getting started with Docker by Dockerizing this Blog.md.md rename to published/201606/20151210 Getting started with Docker by Dockerizing this Blog.md.md diff --git a/published/20160214 How to Install MariaDB 10 on CentOS 7 CPanel Server.md b/published/201606/20160214 How to Install MariaDB 10 on CentOS 7 CPanel Server.md similarity index 100% rename from published/20160214 How to Install MariaDB 10 on CentOS 7 CPanel Server.md rename to published/201606/20160214 How to Install MariaDB 10 on CentOS 7 CPanel Server.md diff --git a/published/20160217 How to Enable Multiple PHP-FPM Instances with Nginx or Apache.md b/published/201606/20160217 How to Enable Multiple PHP-FPM Instances with Nginx or Apache.md similarity index 100% rename from published/20160217 How to Enable Multiple PHP-FPM Instances with Nginx or Apache.md rename to published/201606/20160217 How to Enable Multiple PHP-FPM Instances with Nginx or Apache.md diff --git a/published/20160218 7 Steps to Start Your Linux SysAdmin Career.md b/published/201606/20160218 7 Steps to Start Your Linux SysAdmin Career.md similarity index 100% rename from published/20160218 7 Steps to Start Your 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Linux File Permissions.md diff --git a/published/20160218 Linux Systems Patched for Critical glibc Flaw.md b/published/201606/20160218 Linux Systems Patched for Critical glibc Flaw.md similarity index 100% rename from published/20160218 Linux Systems Patched for Critical glibc Flaw.md rename to published/201606/20160218 Linux Systems Patched for Critical glibc Flaw.md diff --git a/published/20160218 Top 4 open source issue tracking tools.md b/published/201606/20160218 Top 4 open source issue tracking tools.md similarity index 100% rename from published/20160218 Top 4 open source issue tracking tools.md rename to published/201606/20160218 Top 4 open source issue tracking tools.md diff --git a/published/20160221 NXP unveils a tiny 64-bit ARM processor for the Internet of Things.md b/published/201606/20160221 NXP unveils a tiny 64-bit ARM processor for the Internet of Things.md similarity index 100% rename from published/20160221 NXP unveils a tiny 64-bit ARM processor for the Internet of Things.md rename to published/201606/20160221 NXP unveils a tiny 64-bit ARM processor for the Internet of Things.md diff --git a/published/20160223 New Docker Data Center Admin Suite Should Bring Order to Containerization.md b/published/201606/20160223 New Docker Data Center Admin Suite Should Bring Order to Containerization.md similarity index 100% rename from published/20160223 New Docker Data Center Admin Suite Should Bring Order to Containerization.md rename to published/201606/20160223 New Docker Data Center Admin Suite Should Bring Order to Containerization.md diff --git a/published/20160228 Two Outstanding All-in-One Linux Servers.md b/published/201606/20160228 Two Outstanding All-in-One Linux Servers.md similarity index 100% rename from published/20160228 Two Outstanding All-in-One Linux Servers.md rename to published/201606/20160228 Two Outstanding All-in-One Linux Servers.md diff --git a/published/20160304 Image processing at NASA with open source tools.md b/published/201606/20160304 Image processing at NASA with open source tools.md similarity index 100% rename from published/20160304 Image processing at NASA with open source tools.md rename to published/201606/20160304 Image processing at NASA with open source tools.md diff --git a/translated/talk/20160510 65% of companies are contributing to open source projects.md b/published/201606/20160510 65% of companies are contributing to open source projects.md similarity index 70% rename from translated/talk/20160510 65% of companies are contributing to open source projects.md rename to published/201606/20160510 65% of companies are contributing to open source projects.md index 03290b0e97..46939a4e3a 100644 --- a/translated/talk/20160510 65% of companies are contributing to open source projects.md +++ b/published/201606/20160510 65% of companies are contributing to open source projects.md @@ -3,11 +3,11 @@ ![](https://opensource.com/sites/default/files/styles/image-full-size/public/images/business/BUSINESS_openseries.png?itok=s7lXChId) -今年 Black Duck 和 North Bridge 发布了第十届年度开源软件前景调查，来检验开源软件的发展趋势。今年这份调查的亮点在于，当前主流社会对开源软件的接受程度以及过去的十年中人们对开源软件态度的变化。 +今年 Black Duck 和 North Bridge 发布了第十届年度开源软件前景调查，来调查开源软件的发展趋势。今年这份调查的亮点在于，当前主流社会对开源软件的接受程度以及过去的十年中人们对开源软件态度的变化。 -[2016 年的开源软件前景调查][1]，分析了来自约3400位专家的反馈。今年的调查中，开发者发表了他们的看法，包括了大约 70% 的参与者。数据显示，安全专家的参与人数呈指数级增长，增长超过 450% 。他们的参与表明，开源社区开始逐渐关注开源软件中存在的安全问题，以及当新的技术出现时确保它们的安全性。 +[2016 年的开源软件前景调查][1]，分析了来自约3400位专家的反馈。今年的调查中，开发者发表了他们的看法，大约 70% 的参与者是开发者。数据显示，安全专家的参与人数呈指数级增长，增长超过 450% 。他们的参与表明，开源社区开始逐渐关注开源软件中存在的安全问题，以及当新的技术出现时确保它们的安全性。 -Black Duck 的年度 [开源新秀奖][2] 涉及到一些新出现的技术，如 Docker 和 Kontena 容器。容器技术这一年有了巨大的发展 ———— 76% 的受访者表示，他们的企业有一些使用容器技术的规划。而 59% 的受访者正准备使用容器技术完成大量的部署，从开发与测试，到内部与外部的生产环境部署。开发者社区已经把容器技术作为一种简单快速开发的方法。 +Black Duck 的[年度开源新秀奖][2] 涉及到一些新出现的技术，如容器方面的 Docker 和 Kontena。容器技术这一年有了巨大的发展 ———— 76% 的受访者表示，他们的企业有一些使用容器技术的规划。而 59% 的受访者正准备使用容器技术完成大量的部署，从开发与测试，到内部与外部的生产环境部署。开发者社区已经把容器技术作为一种简单快速开发的方法。 调查显示，几乎每个组织都有开发者致力于开源软件，这一点毫不惊讶。当像微软和苹果这样的大公司将它们的一些解决方案开源时，开发者就获得了更多的机会来参与开源项目。我非常希望这样的趋势会延续下去，让更多的软件开发者无论在工作中，还是工作之余都可以致力于开源项目。 @@ -30,11 +30,11 @@ Black Duck 的年度 [开源新秀奖][2] 涉及到一些新出现的技术， #### 安全和管理 -一流的开源安全与管理实践的发展，并没有跟上人们使用开源不断增长的步伐。尽管备受关注的开源项目近年来爆炸式地增长，调查结果却指出： +一流的开源安全与管理实践的发展，也没有跟上人们使用开源不断增长的步伐。尽管备受关注的开源项目近年来爆炸式地增长，调查结果却指出： * 50% 的企业在选择和批准开源代码这方面没有出台正式的政策。 * 47% 的企业没有正式的流程来跟踪开源代码，这就限制了它们对开源代码的了解，以及控制开源代码的能力。 -* 超过三分之一的企业没有用于识别，跟踪，和修复重大开源安全漏洞的流程。 +* 超过三分之一的企业没有用于识别、跟踪和修复重大开源安全漏洞的流程。 #### 不断增长的开源参与者 @@ -45,16 +45,17 @@ Black Duck 的年度 [开源新秀奖][2] 涉及到一些新出现的技术， * 约三分之一的企业有专门为开源项目设置的全职岗位。 * 59% 的受访者参与开源项目以获得竞争优势。 -Black Duck 和 North Bridge 从今年的调查中了解了很多，如安全，政策，商业模式等。我们很兴奋能够分享这些新发现。感谢我们的合作者，以及所有参与我们调查的受访者。这是一个伟大的十年，我很高兴我们可以肯定地说，开源的未来充满了无限可能。 +Black Duck 和 North Bridge 从今年的调查中了解到了很多，如安全，政策，商业模式等。我们很兴奋能够分享这些新发现。感谢我们的合作者，以及所有参与我们调查的受访者。这是一个伟大的十年，我很高兴我们可以肯定地说，开源的未来充满了无限可能。 想要了解更多内容，可以查看完整的[调查结果][3]。 + -------------------------------------------------------------------------------- via: https://opensource.com/business/16/5/2016-future-open-source-survey 作者：[Haidee LeClair][a] 译者：[Cathon](https://github.com/Cathon) -校对：[校对者ID](https://github.com/校对者ID) +校对：[wxy](https://github.com/wxy) [a]: https://opensource.com/users/blackduck2016 [1]: http://www.slideshare.net/blackducksoftware/2016-future-of-open-source-survey-results diff --git a/published/20160513 How to Set Up 2-Factor Authentication for Login and sudo.md b/published/201606/20160513 How to Set Up 2-Factor Authentication for Login and sudo.md similarity index 100% rename from published/20160513 How to Set Up 2-Factor Authentication for Login and sudo.md rename to published/201606/20160513 How to Set Up 2-Factor Authentication for Login and sudo.md diff --git a/published/20160514 NODEOS - LINUX DISTRIBUTION FOR NODE LOVERS.md b/published/201606/20160514 NODEOS - LINUX DISTRIBUTION FOR NODE LOVERS.md similarity index 100% rename from published/20160514 NODEOS - LINUX DISTRIBUTION FOR NODE LOVERS.md rename to published/201606/20160514 NODEOS - LINUX DISTRIBUTION FOR NODE LOVERS.md diff --git a/published/20160516 4 BEST MODERN OPEN SOURCE CODE EDITORS FOR LINUX.md b/published/201606/20160516 4 BEST MODERN OPEN SOURCE CODE EDITORS FOR LINUX.md similarity index 100% rename from published/20160516 4 BEST MODERN OPEN SOURCE CODE EDITORS FOR LINUX.md rename to published/201606/20160516 4 BEST MODERN OPEN SOURCE CODE EDITORS FOR LINUX.md diff --git a/translated/talk/20160518 Android Use Apps Even Without Installing Them.md b/published/201606/20160518 Android Use Apps Even Without Installing Them.md similarity index 68% rename from translated/talk/20160518 Android Use Apps Even Without Installing Them.md rename to published/201606/20160518 Android Use Apps Even Without Installing Them.md index a8aecc1d19..40cf217035 100644 --- a/translated/talk/20160518 Android Use Apps Even Without Installing Them.md +++ b/published/201606/20160518 Android Use Apps Even Without Installing Them.md @@ -3,23 +3,23 @@ 谷歌安卓的一项新创新将可以让你无需安装即可在你的设备上使用应用程序。现在已经初具雏形。 -还记得那时候吗，某人发给你了一个链接，要求你通过安装来查看应用。 +还记得那时候吗，某人发给你了一个链接，要求你通过安装一个应用才能查看。 -是否要安装这个应用来查看一个一次性的链接，这种进退两难的选择一定让你感到很沮丧。而且，应用安装本身也会消耗你不少宝贵的时间。 +是否要安装这个应用就为了看一下链接，这种进退两难的选择一定让你感到很沮丧。而且，安装应用这个事也会消耗你不少宝贵的时间。 -上述场景可能大多数人都经历过，或者说大多数现代科技用户都经历过。尽管如此，我们都接受这是正确且合理的过程。 +上述场景可能大多数人都经历过，或者说大多数现代科技用户都经历过。尽管如此，我们都接受，认为这是天经地义的事情。 事实真的如此吗？ -针对这个问题谷歌的安卓部门给出了一个全新的，开箱即用的答案： +针对这个问题谷歌的安卓部门给出了一个全新的、开箱即用的答案： -### Android Instant Apps +### Android Instant Apps （AIA） -Android Instant Apps 声称第一时间帮你摆脱这样的两难境地，让你简单地点击链接（见打开链接的示例）然后直接开始使用这个应用。 +Android Instant Apps 声称可以从一开始就帮你摆脱这样的两难境地，让你简单地点击链接（见打开链接的示例）然后直接开始使用这个应用。 -另一个真实生活场景的例子，如果你想停车但是没有停车码表的配对应用，有了 Instant Apps 在这种情况下就方便多了。 +另一个真实生活场景的例子，如果你想停车但是没有停车码表的相应应用，有了 Instant Apps 在这种情况下就方便多了。 -根据谷歌的信息，你可以简单地将你的手机和码表触碰，停车应用就会直接显示在你的屏幕上，并且准备就绪可以使用。 +根据谷歌提供的信息，你可以简单地将你的手机和码表触碰，停车应用就会直接显示在你的屏幕上，并且准备就绪可以使用。 #### 它是怎么工作的？ @@ -30,21 +30,25 @@ Instant Apps 和你已经熟悉的应用基本相同，只有一个不同—— 这样应用就可以快速打开，让你可以完成你的目标任务。 ![](http://www.iwillfolo.com/wordpress/wp-content/uploads/2016/05/AIA-demo.jpg) ->AIA 示例 + +*AIA 示例* ![](https://4.bp.blogspot.com/-p5WOrD6wVy8/VzyIpsDqULI/AAAAAAAADD0/xbtQjurJZ6EEji_MPaY1sLK5wVkXSvxJgCKgB/s800/B%2526H%2B-%2BDevice%2B%2528Final%2529.gif) ->B&H 图片（通过谷歌搜索） + +*B&H 图片（通过谷歌搜索）* ![](https://2.bp.blogspot.com/-q5ApCzECuNA/VzyKa9l0t2I/AAAAAAAADEI/nYhhMClDl5Y3qL5-wiOb2J2QjtGWwbF2wCLcB/s800/BuzzFeed-Device-Install%2B%2528Final%2529.gif) ->BuzzFeedVideo（通过一个共享链接） + +*BuzzFeedVideo（通过一个共享链接）* ![](https://2.bp.blogspot.com/-mVhKMMzhxms/VzyKg25ihBI/AAAAAAAADEM/dJN6_8H7qkwRyulCF7Yr2234-GGUXzC6ACLcB/s800/Park%2Band%2BPay%2B-%2BDevice%2Bwith%2BMeter%2B%2528Final%2529.gif) ->停车与支付（例）（通过 NFC） + +*停车与支付（例）（通过 NFC）* 听起来很棒，不是吗？但是其中还有很多技术方面的问题需要解决。 -比如，从安全的观点来说：如果任何应用从理论上来说都能在你的设备上运行，甚至你都不用安装它——你要怎么保证设备远离恶意软件攻击？ +比如，从安全的观点来说：从理论上来说，如果任何应用都能在你的设备上运行，甚至你都不用安装它——你要怎么保证设备远离恶意软件攻击？ 因此，为了消除这类威胁，谷歌还在这个项目上努力，目前只有少数合作伙伴，未来将逐步扩展。 diff --git a/translated/tech/20160520 ORB - NEW GENERATION OF LINUX APPS ARE HERE.md b/published/201606/20160520 ORB - NEW GENERATION OF LINUX APPS ARE HERE.md similarity index 62% rename from translated/tech/20160520 ORB - NEW GENERATION OF LINUX APPS ARE HERE.md rename to published/201606/20160520 ORB - NEW GENERATION OF LINUX APPS ARE HERE.md index cc212e7a4c..4f31e9ed63 100644 --- a/translated/tech/20160520 ORB - NEW GENERATION OF LINUX APPS ARE HERE.md +++ b/published/201606/20160520 ORB - NEW GENERATION OF LINUX APPS ARE HERE.md @@ -5,19 +5,19 @@ ORB：新一代 Linux 应用 我们之前讨论过[在 Ubuntu 上离线安装应用][1]。我们现在要再次讨论它。 -[Orbital Apps][2] 给我们带来了新的软件包类型，**ORB**，它带有便携软件，交互式安装向导支持，以及离线使用的能力。 +[Orbital Apps][2] 给我们带来了一种新的软件包类型 **ORB**，它具有便携软件、交互式安装向导支持，以及离线使用的能力。 -便携软件很方便。主要是因为它们能够无需任何管理员权限直接运行，也能够带着所有的设置和数据随U盘存储。而交互式的安装向导也能让我们轻松地安装应用。 +便携软件很方便。主要是因为它们能够无需任何管理员权限直接运行，也能够带着所有的设置和数据随 U 盘存储。而交互式的安装向导也能让我们轻松地安装应用。 -### 开放可运行包 OPEN RUNNABLE BUNDLE (ORB) +### 开放式可运行的打包（OPEN RUNNABLE BUNDLE） (ORB) -ORB 是一个免费和开源的包格式，它和其它包格式在很多方面有所不同。ORB 的一些特性： +ORB 是一个自由开源的包格式，它和其它包格式在很多方面有所不同。ORB 的一些特性： -- **压缩**：所有的包经过压缩，使用 squashfs，体积最多减少 60%。 -- **便携模式**：如果一个便携 ORB 应用是从可移动设备运行的，它会把所有设置和数据存储在那之上。 +- **压缩**：所有的包都经过 squashfs 压缩，体积最多可减少 60%。 +- **便携模式**：如果一个便携 ORB 应用是在可移动设备上运行的，它会把所有设置和数据存储在那之上。 - **安全**：所有的 ORB 包使用 PGP/RSA 签名，通过 TLS 1.2 分发。 - **离线**：所有的依赖都打包进软件包，所以不再需要下载依赖。 -- **开放包**：ORB 包可以作为 ISO 镜像挂载。 +- **开放式软件包**：ORB 软件包可以作为 ISO 镜像挂载。 ### 种类 @@ -26,77 +26,69 @@ ORB 应用现在有两种类别： - 便携软件 - SuperDEB -#### 1. 便携 ORB 软件 +### 1. 便携 ORB 软件 -便携 ORB 软件可以立即运行而不需要任何的事先安装。那意味着它不需要管理员权限和依赖！你可以直接从 Orbital Apps 网站下载下来就能使用。 +便携 ORB 软件可以立即运行而不需要任何的事先安装。这意味着它不需要管理员权限，也没有依赖！你可以直接从 Orbital Apps 网站下载下来就能使用。 -并且由于它支持便携模式，你可以将它拷贝到U盘携带。它所有的设置和数据会和它一起存储在U盘。只需将U盘连接到任何运行 Ubuntu 16.04 的机器上就行了。 +并且由于它支持便携模式，你可以将它拷贝到 U 盘携带。它所有的设置和数据会和它一起存储在 U 盘。只需将 U 盘连接到任何运行 Ubuntu 16.04 的机器上就行了。 -##### 可用便携软件 +#### 可用便携软件 目前有超过 35 个软件以便携包的形式提供，包括一些十分流行的软件，比如：[Deluge][3]，[Firefox][4]，[GIMP][5]，[Libreoffice][6]，[uGet][7] 以及 [VLC][8]。 完整的可用包列表可以查阅 [便携 ORB 软件列表][9]。 -##### 使用便携软件 +#### 使用便携软件 按照以下步骤使用便携 ORB 软件： - 从 Orbital Apps 网站下载想要的软件包。 -- 将其移动到想要的位置（本地磁盘/U盘）。 +- 将其移动到想要的位置（本地磁盘/U 盘）。 - 打开存储 ORB 包的目录。 -![](http://itsfoss.com/wp-content/uploads/2016/05/using-portable-orb-app-1-1024x576.jpg) - + ![](http://itsfoss.com/wp-content/uploads/2016/05/using-portable-orb-app-1-1024x576.jpg) - 打开 ORB 包的属性。 -![](http://itsfoss.com/wp-content/uploads/2016/05/using-portable-orb-app-2.jpg) ->给 ORB 包添加运行权限 + ![给 ORB 包添加运行权限](http://itsfoss.com/wp-content/uploads/2016/05/using-portable-orb-app-2.jpg) - 在权限标签页添加运行权限。 - 双击打开它。 等待几秒，让它准备好运行。大功告成。 -#### 2. SuperDEB +### 2. SuperDEB 另一种类型的 ORB 软件是 SuperDEB。SuperDEB 很简单，交互式安装向导能够让软件安装过程顺利得多。如果你不喜欢从终端或软件中心安装软件，superDEB 就是你的菜。 最有趣的部分是你安装时不需要一个互联网连接，因为所有的依赖都由安装向导打包了。 -##### 可用的 SuperDEB +#### 可用的 SuperDEB 超过 60 款软件以 SuperDEB 的形式提供。其中一些流行的有：[Chromium][10]，[Deluge][3]，[Firefox][4]，[GIMP][5]，[Libreoffice][6]，[uGet][7] 以及 [VLC][8]。 完整的可用 SuperDEB 列表，参阅 [SuperDEB 列表][11]。 -##### 使用 SuperDEB 安装向导 +#### 使用 SuperDEB 安装向导 - 从 Orbital Apps 网站下载需要的 SuperDEB。 - 像前面一样给它添加**运行权限**（属性 > 权限）。 - 双击 SuperDEB 安装向导并按下列说明操作： -![](http://itsfoss.com/wp-content/uploads/2016/05/Using-SuperDEB-Installer-1.png) ->点击 OK + ![点击 OK](http://itsfoss.com/wp-content/uploads/2016/05/Using-SuperDEB-Installer-1.png) -![](http://itsfoss.com/wp-content/uploads/2016/05/Using-SuperDEB-Installer-2.png) ->输入你的密码并继续 + ![输入你的密码并继续](http://itsfoss.com/wp-content/uploads/2016/05/Using-SuperDEB-Installer-2.png) -![](http://itsfoss.com/wp-content/uploads/2016/05/Using-SuperDEB-Installer-3.png) ->它会开始安装… + ![它会开始安装…](http://itsfoss.com/wp-content/uploads/2016/05/Using-SuperDEB-Installer-3.png) -![](http://itsfoss.com/wp-content/uploads/2016/05/Using-SuperDEB-Installer-4.png) ->一会儿他就完成了… + ![一会儿它就完成了…](http://itsfoss.com/wp-content/uploads/2016/05/Using-SuperDEB-Installer-4.png) - 完成安装之后，你就可以正常使用了。 ### ORB 软件兼容性 -从 Orbital Apps 可知，它们完全适配 Ubuntu 16.04 [64 bit]。 +从 Orbital Apps 可知，它们完全适配 Ubuntu 16.04 [64 位]。 ->阅读建议：[如何在 Ubuntu 获知你的是电脑 32 位还是 64 位的][12]。 - -至于其它发行版兼容性不受保证。但我们可以说，它在所有 Ubuntu 16.04 衍生版（UbuntuMATE，UbuntuGNOME，Lubuntu，Xubuntu 等）以及基于 Ubuntu 16.04 的发行版（比如即将到来的 Linux Mint 18）上都适用。我们现在还不清楚 Orbital Apps 是否有计划拓展它的支持到其它版本 Ubuntu 或 Linux 发行版上。 +至于其它发行版兼容性则不受保证。但我们可以说，它在所有 Ubuntu 16.04 衍生版（UbuntuMATE，UbuntuGNOME，Lubuntu，Xubuntu 等）以及基于 Ubuntu 16.04 的发行版（比如即将到来的 Linux Mint 18）上都适用。我们现在还不清楚 Orbital Apps 是否有计划拓展它的支持到其它版本 Ubuntu 或 Linux 发行版上。 如果你在你的系统上经常使用便携 ORB 软件，你可以考虑安装 ORB 启动器。它不是必需的，但是推荐安装它以获取更佳的体验。最简短的 ORB 启动器安装流程是打开终端输入以下命令： @@ -116,11 +108,11 @@ wget -O - https://www.orbital-apps.com/orb.sh | bash ---------------------------------- -via: http://itsfoss.com/orb-linux-apps/?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+ItsFoss+%28Its+FOSS%21+An+Open+Source+Blog%29 +via: http://itsfoss.com/orb-linux-apps/ 作者：[Munif Tanjim][a] 译者：[alim0x](https://github.com/alim0x) -校对：[校对者ID](https://github.com/校对者ID) +校对：[wxy](https://github.com/wxy) 本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创翻译，[Linux中国](https://linux.cn/) 荣誉推出 diff --git a/published/201606/20160523 Driving cars into the future with Linux.md b/published/201606/20160523 Driving cars into the future with Linux.md new file mode 100644 index 0000000000..fad7ca99f2 --- /dev/null +++ b/published/201606/20160523 Driving cars into the future with Linux.md @@ -0,0 +1,106 @@ +与 Linux 一同驾车奔向未来 +=========================================== + +![](https://opensource.com/sites/default/files/styles/image-full-size/public/images/life/open-snow-car-osdc-lead.png?itok=IgYZ6mNY) + +当我驾车的时候并没有这么想过，但是我肯定喜欢一个配有这样系统的车子，它可以让我按下几个按钮就能与我的妻子、母亲以及孩子们语音通话。这样的系统也可以让我选择是否从云端、卫星广播、以及更传统的 AM/FM 收音机收听音乐流媒体。我也会得到最新的天气情况，以及它可以引导我的车载 GPS 找到抵达下一个目的地的最快路线。[车载娱乐系统（In-vehicle infotainment）][1]，业界常称作 IVI，它已经普及出现在最新的汽车上了。 + +前段时间，我乘坐飞机跨越了数百英里，然后租了一辆汽车。令人愉快的是，我发现我租赁的汽车上配置了类似我自己车上同样的 IVI 技术。毫不犹豫地，我就通过蓝牙连接把我的联系人上传到了系统当中，然后打电话回家给我的家人，让他们知道我已经安全抵达了，然后我的主机会让他们知道我正在去往他们家的路上。 + +在最近的[新闻综述][2]中，Scott Nesbitt 引述了一篇文章，说福特汽车公司因其开源的[智能设备连接（Smart Device Link）][3]（SDL）从竞争对手汽车制造商中得到了足够多的回报，这个中间件框架可以用于支持移动电话。 SDL 是 [GENIVI 联盟][4]的一个项目，这个联盟是一个非营利性组织，致力于建设支持开源车载娱乐系统的中间件。据 GENIVI 的执行董事 [Steven Crumb][5] 称，他们的[成员][6]有很多，包括戴姆勒集团、现代、沃尔沃、日产、本田等等 170 个企业。 + +为了在同行业间保持竞争力，汽车生产企业需要一个中间设备系统，以支持现代消费者所使用的各种人机界面技术。无论您使用的是 Android、iOS 还是其他设备，汽车 OEM 厂商都希望自己的产品能够支持这些。此外，这些的 IVI 系统必须有足够适应能力以支持日益变化的移动技术。OEM 厂商希望提供有价值的服务，并可以在他们的 IVI 之上增加服务，以满足他们客户的各种需求。 + +### 步入 Linux 和开源软件 + +除了 GENIVI 在努力之外，[Linux 基金会][7]也赞助支持了[车载 Linux（Automotive Grade Linux）][8]（AGL）工作组，这是一个致力于为汽车应用寻求开源解决方案的软件基金会。虽然 AGL 初期将侧重于 IVI 系统，但是未来他们希望发展到不同的方向，包括[远程信息处理（telematics）][9]、抬头显示器（HUD）及其他控制系统等等。 现在 AGL 已经有超过 50 名成员，包括捷豹、丰田、日产，并在其[最近发布的一篇公告][10]中宣称福特、马自达、三菱、和斯巴鲁也加入了。 + +为了了解更多信息，我们采访了这一新兴领域的两位领导人。具体来说，我们想知道 Linux 和开源软件是如何被使用的，并且它们是如何事实上改变了汽车行业的面貌。首先，我们将与 [Alison Chaiken][11] 谈谈，她是一位任职于 Peloton Technology 的软件工程师，也是一位在车载 Linux 、网络安全和信息透明化方面的专家。她曾任职于 [Alison Chaiken][11] 公司、诺基亚和斯坦福直线性加速器。然后我们和 [Steven Crumb][12] 进行了交谈，他是 GENIVI 执行董事，他之前从事于高性能计算环境（超级计算机和早期的云计算）的开源工作。他说，虽然他再不是一个程序员了，但是他乐于帮助企业解决在使用开源软件时的实际业务问题。 + +### 采访 Alison Chaiken (by [Deb Nicholson][13]) + +#### 你是如何开始对汽车软件领域感兴趣的？ + +我曾在诺基亚从事于手机上的 [MeeGo][14] 产品，2009 年该项目被取消了。我想，我下一步怎么办？其时，我的一位同事正在从事于 [MeeGo-IVI][15]，这是一个早期的车载 Linux 发行版。 “Linux 在汽车方面将有很大发展，” 我想，所以我就朝着这个方向努力。 + +#### 你能告诉我们你在这些日子里工作在哪些方面吗？ + +我目前正在启动一个高级巡航控制系统的项目，它用在大型卡车上，使用实时 Linux 以提升安全性和燃油经济性。我喜欢在这方面的工作，因为没有人会反对提升货运的能力。 + +#### 近几年有几则汽车被黑的消息。开源代码方案可以帮助解决这个问题吗？ + +我恰好针对这一话题准备了一次讲演，我会在南加州 Linux 2016 博览会上就 Linux 能否解决汽车上的安全问题做个讲演 （[讲演稿在此][16]）。值得注意的是，GENIVI 和车载 Linux 项目已经公开了他们的代码，这两个项目可以通过 Git 提交补丁。（如果你有补丁的话），请给上游发送您的补丁！许多眼睛都盯着，bug 将无从遁形。 + +#### 执法机构和保险公司可以找到很多汽车上的数据的用途。他们获取这些信息很容易吗？ + +好问题。IEEE-1609 专用短程通信标准（Dedicated Short Range Communication Standard）就是为了让汽车的 WiFi 消息可以安全、匿名地传递。不过，如果你从你的车上发推，那可能就有人能够跟踪到你。 + +#### 开发人员和公民个人可以做些什么，以在汽车技术进步的同时确保公民自由得到保护？ + +电子前沿基金会（ Electronic Frontier Foundation）（EFF）在关注汽车问题方面做了出色的工作，包括对哪些数据可以存储在汽车 “黑盒子”里通过官方渠道发表了看法，以及 DMCA 规定 1201 如何应用于汽车上。 + +#### 在未来几年，你觉得在汽车方面会发生哪些令人激动的发展？ + +可以拯救生命的自适应巡航控制系统和防撞系统将取得长足发展。当它们大量进入汽车里面时，我相信这会使得（因车祸而导致的）死亡人数下降。如果这都不令人激动，我不知道还有什么会更令人激动。此外，像自动化停车辅助功能，将会使汽车更容易驾驶，减少汽车磕碰事故。 + +#### 我们需要做什么？人们怎样才能参与？ + +车载 Linux 开发是以开源的方式开发，它运行在每个人都能买得起的廉价硬件上（如树莓派 2 和中等价位的 Renesas Porter 主板）。 GENIVI 汽车 Linux 中间件联盟通过 Git 开源了很多软件。此外，还有很酷的 [OSVehicle 开源硬件][17]汽车平台。 + +只需要不太多的预算，人们就可以参与到 Linux 软件和开放硬件中。如果您感兴趣，请加入我们在 Freenode 上的IRC #automotive 吧。 + +### 采访 Steven Crumb (by Don Watkins) + +#### GENIVI 在 IVI 方面做了哪些巨大贡献？ + +GENIVI 率先通过使用自由开源软件填补了汽车行业的巨大空白，这包括 Linux、非安全关键性汽车软件（如车载娱乐系统（IVI））等。作为消费者，他们很期望在车辆上有和智能手机一样的功能，对这种支持 IVI 功能的软件的需求量成倍地增长。不过不断提升的软件数量也增加了建设 IVI 系统的成本，从而延缓了其上市时间。 + +GENIVI 使用开源软件和社区开发的模式为汽车制造商及其软件提供商节省了大量资金，从而显著地缩短了产品面市时间。我为 GENIVI 而感到激动，我们有幸引导了一场革命，在缓慢进步的汽车行业中，从高度结构化和专有的解决方案转换为以社区为基础的开发方式。我们还没有完全达成目标，但是我们很荣幸在这个可以带来实实在在好处的转型中成为其中的一份子。 + +#### 你们的主要成员怎样推动了 GENIVI 的发展方向？ + +GENIVI 有很多成员和非成员致力于我们的工作。在许多开源项目中，任何公司都可以通过通过技术输出而发挥影响，包括简单地贡献代码、补丁、花点时间测试。前面说过，宝马、奔驰、现代汽车、捷豹路虎、标致雪铁龙、雷诺/日产和沃尔沃都是 GENIVI 积极的参与者和贡献者，其他的许多 OEM 厂商也在他们的汽车中采用了 IVI 解决方案，广泛地使用了 GENIVI 的软件。 + +#### 这些贡献的代码使用了什么许可证？ + +GENIVI 采用了一些许可证，包括从（L）GPLv2 到 MPLv2 和 Apache2.0。我们的一些工具使用的是 Eclipse 许可证。我们有一个[公开许可策略][18]，详细地说明了我们的许可证偏好。 + +#### 个人或团体如何参与其中？社区的参与对于这个项目迈向成功有多重要？ + +GENIVI 的开发完全是开放的（[projects.genivi.org][19]），因此，欢迎任何有兴趣在汽车中使用开源软件的人参加。也就是说，公司可以通过成员的方式[加入该联盟][20]，联盟以开放的方式资助其不断进行开发。GENIVI 的成员可以享受各种各样的便利，在过去六年中，已经有多达 140 家公司参与到这个全球性的社区当中。 + +社区对于 GENIVI 是非常重要的，没有一个活跃的贡献者社区，我们不可能在这些年开发和维护了这么多有价值的软件。我们努力让参与到 GENIVI 更加简单，现在只要加入一个[邮件列表][21]就可以接触到各种软件项目中的人们。我们使用了许多开源项目采用的标准做法，并提供了高品质的工具和基础设施，以帮助开发人员宾至如归而富有成效。 + +无论你是否熟悉汽车软件，都欢迎你加入我们的社区。人们已经对汽车改装了许多年，所以对于许多人来说，在汽车上修修改改是自热而然的做法。对于汽车来说，软件是一个新的领域，GENIVI 希望能为对汽车和开源软件有兴趣的人打开这扇门。 + +------------------------------- +via: https://opensource.com/business/16/5/interview-alison-chaiken-steven-crumb + +作者：[Don Watkins][a] +译者：[erlinux](https://github.com/erlinux) +校对：[wxy](https://github.com/wxy) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创翻译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://opensource.com/users/don-watkins +[1]: https://en.wikipedia.org/wiki/In_car_entertainment +[2]: https://opensource.com/life/16/1/weekly-news-jan-9 +[3]: http://projects.genivi.org/smartdevicelink/home +[4]: http://www.genivi.org/ +[5]: https://www.linkedin.com/in/stevecrumb +[6]: http://www.genivi.org/genivi-members +[7]: http://www.linuxfoundation.org/ +[8]: https://www.automotivelinux.org/ +[9]: https://en.wikipedia.org/wiki/Telematics +[10]: https://www.automotivelinux.org/news/announcement/2016/01/ford-mazda-mitsubishi-motors-and-subaru-join-linux-foundation-and +[11]: https://www.linkedin.com/in/alison-chaiken-3ba456b3 +[12]: https://www.linkedin.com/in/stevecrumb +[13]: https://opensource.com/users/eximious +[14]: https://en.wikipedia.org/wiki/MeeGo +[15]: http://webinos.org/deliverable-d026-target-platform-requirements-and-ipr/automotive/ +[16]: http://she-devel.com/Chaiken_automotive_cybersecurity.pdf +[17]: https://www.osvehicle.com/ +[18]: http://projects.genivi.org/how +[19]: http://projects.genivi.org/ +[20]: http://genivi.org/join +[21]: http://lists.genivi.org/mailman/listinfo/genivi-projects diff --git a/published/20160524 Test Fedora 24 Beta in an OpenStack cloud.md b/published/201606/20160524 Test Fedora 24 Beta in an OpenStack cloud.md similarity index 100% rename from published/20160524 Test Fedora 24 Beta in an OpenStack cloud.md rename to published/201606/20160524 Test Fedora 24 Beta in an OpenStack cloud.md diff --git a/published/20160526 BEST LINUX PHOTO MANAGEMENT SOFTWARE IN 2016.md b/published/201606/20160526 BEST LINUX PHOTO MANAGEMENT SOFTWARE IN 2016.md similarity index 100% rename from published/20160526 BEST LINUX PHOTO MANAGEMENT SOFTWARE IN 2016.md rename to published/201606/20160526 BEST LINUX PHOTO MANAGEMENT SOFTWARE IN 2016.md diff --git a/published/20160529 LAMP Stack Installation Guide on Ubuntu Server 16.04 LTS.md b/published/201606/20160529 LAMP Stack Installation Guide on Ubuntu Server 16.04 LTS.md similarity index 100% rename from published/20160529 LAMP Stack Installation Guide on Ubuntu Server 16.04 LTS.md rename to published/201606/20160529 LAMP Stack Installation Guide on Ubuntu Server 16.04 LTS.md diff --git a/published/20160601 Apps to Snaps.md b/published/201606/20160601 Apps to Snaps.md similarity index 100% rename from published/20160601 Apps to Snaps.md rename to published/201606/20160601 Apps to Snaps.md diff --git a/published/20160601 scp command in Linux.md b/published/201606/20160601 scp command in Linux.md similarity index 100% rename from published/20160601 scp command in Linux.md rename to published/201606/20160601 scp command in Linux.md diff --git a/published/201606/20160605 How to Add Cron Jobs in Linux and Unix.md b/published/201606/20160605 How to Add Cron Jobs in Linux and Unix.md new file mode 100644 index 0000000000..139084225a --- /dev/null +++ b/published/201606/20160605 How to Add Cron Jobs in Linux and Unix.md @@ -0,0 +1,212 @@ +如何在 Linux 及 Unix 系统中添加定时任务 +====================================== + +![](https://www.unixmen.com/wp-content/uploads/2016/05/HOW-TO-ADD-CRON-JOBS-IN-LINUX-AND-UNIX-696x334.png) + +### 导言 + +![](http://www.unixmen.com/wp-content/uploads/2016/05/cronjob.gif) + +定时任务 (cron job) 被用于安排那些需要被周期性执行的命令。利用它，你可以配置某些命令或者脚本，让它们在某个设定的时间周期性地运行。`cron` 是 Linux 或者类 Unix 系统中最为实用的工具之一。cron 服务（守护进程）在系统后台运行，并且会持续地检查 `/etc/crontab` 文件和 `/etc/cron.*/ `目录。它同样也会检查 `/var/spool/cron/` 目录。 + +### crontab 命令 + +`crontab` 是用来安装、卸载或者列出定时任务列表的命令。cron 配置文件则用于驱动 `Vixie Cron` 的 [cron(8)][1] 守护进程。每个用户都可以拥有自己的 crontab 文件，虽然这些文件都位于 `/var/spool/cron/crontabs` 目录中，但并不意味着你可以直接编辑它们。你需要通过 `crontab` 命令来编辑或者配置你自己的定时任务。 + +### 定时配置文件的类型 + +配置文件分为以下不同的类型： + +- **UNIX 或 Linux 系统的 crontab** : 此类型通常由那些需要 root 或类似权限的系统服务和重要任务使用。第六个字段（见下方的字段介绍）为用户名，用来指定此命令以哪个用户身份来执行。如此一来，系统的 `crontab` 就能够以任意用户的身份来执行操作。 + +- **用户的 crontab**: 用户可以使用 `crontab` 命令来安装属于他们自己的定时任务。 第六个字段为需要运行的命令, 所有的命令都会以创建该 crontab 任务的用户的身份运行。 + +**注意**: 这种问答形式的 `Cron` 实现由 Paul Vixie 所编写，并且被包含在许多 [Linux][2] 发行版本和类 Unix 系统（如广受欢迎的第四版 BSD）中。它的语法被各种 crond 的实现所[兼容][3]。 + +那么我该如何安装、创建或者编辑我自己的定时任务呢？ + +要编辑你的 crontab 文件，需要在 Linux 或 Unix 的 shell 提示符后键入以下命令： + +``` +$ crontab -e +``` + +`crontab` 语法（字段介绍） + +语法为： + +``` +1 2 3 4 5 /path/to/command arg1 arg2 +``` + +或者 + +``` +1 2 3 4 5 /root/ntp_sync.sh +``` + +其中： + +- 第1个字段：分钟 (0-59) +- 第2个字段：小时 (0-23) +- 第3个字段：日期 (0-31) +- 第4个字段：月份 (0-12 [12 代表 December]) +- 第5个字段：一周当中的某天 (0-7 [7 或 0 代表星期天]) +- /path/to/command - 计划执行的脚本或命令的名称 + +便于记忆的格式： + +``` +* * * * * 要执行的命令 +---------------- +| | | | | +| | | | ---- 周当中的某天 (0 - 7) (周日为 0 或 7) +| | | ------ 月份 (1 - 12) +| | -------- 一月当中的某天 (1 - 31) +| ---------- 小时 (0 - 23) +------------ 分钟 (0 - 59) +``` + +简单的 `crontab` 示例： + +```` +## 每隔 5 分钟运行一次 backupscript 脚本 ## +*/5 * * * * /root/backupscript.sh + +## 每天的凌晨 1 点运行 backupscript 脚本 ## + +0 1 * * * /root/backupscript.sh + +## 每月的第一个凌晨 3:15 运行 backupscript 脚本 ## + +15 3 1 * * /root/backupscript.sh +``` + +### 如何使用操作符 + +操作符允许你为一个字段指定多个值，这里有三个操作符可供使用： + +- **星号 (*)** : 此操作符为字段指定所有可用的值。举个例子，在小时字段中，一个星号等同于每个小时；在月份字段中，一个星号则等同于每月。 + +- **逗号 (,)** : 这个操作符指定了一个包含多个值的列表，例如：`1,5,10,15,20,25`. + +- **横杠 (-)** : 此操作符指定了一个值的范围，例如：`5-15` ，等同于使用逗号操作符键入的 `5,6,7,8,9,...,13,14,15`。 + +- **分隔符 (/)** : 此操作符指定了一个步进值，例如： `0-23/` 可以用于小时字段来指定某个命令每小时被执行一次。步进值也可以跟在星号操作符后边，如果你希望命令行每 2 小时执行一次，则可以使用 `*/2`。 + +### 如何禁用邮件输出 + +默认情况下，某个命令或者脚本的输出内容（如果有的话）会发送到你的本地邮箱账户中。若想停止收到 `crontab` 发送的邮件，需要添加 `>/dev/null 2>&1` 这段内容到执行的命令的后面，例如： + +``` +0 3 * * * /root/backup.sh >/dev/null 2>&1 +``` + +如果想将输出内容发送到特定的邮件账户中，比如说 vivek@nixcraft.in 这个邮箱， 则你需要像下面这样定义一个 MAILTO 变量： + +``` +MAILTO="vivek@nixcraft.in" +0 3 * * * /root/backup.sh >/dev/null 2>&1 +``` + +访问 “[禁用 Crontab 命令的邮件提示](http://www.cyberciti.biz/faq/disable-the-mail-alert-by-crontab-command/)” 查看更多信息。 + + +### 任务：列出你所有的定时任务 + +键入以下命令： + +``` +# crontab -l +# crontab -u username -l +``` + +要删除所有的定时任务，可以使用如下命令： + +``` +# 删除当前定时任务 # +crontab -r +``` + +``` +## 删除某用户名下的定时任务，此命令需以 root 用户身份执行 ## +crontab -r -u username +``` + +### 使用特殊字符串来节省时间 + +你可以使用以下 8 个特殊字符串中的其中一个替代头五个字段，这样不但可以节省你的时间，还可以提高可读性。 + +特殊字符 |含义 +|:-- |:-- +@reboot | 在每次启动时运行一次 +@yearly | 每年运行一次,等同于 “0 0 1 1 *”. +@annually | (同 @yearly) +@monthly | 每月运行一次, 等同于 “0 0 1 * *”. +@weekly | 每周运行一次, 等同于 “0 0 * * 0”. +@daily | 每天运行一次, 等同于 “0 0 * * *”. +@midnight | (同 @daily) +@hourly | 每小时运行一次, 等同于 “0 * * * *”. + +示例： + +#### 每小时运行一次 ntpdate 命令 #### + +``` +@hourly /path/to/ntpdate +``` + +### 关于 `/etc/crontab` 文件和 `/etc/cron.d/*` 目录的更多内容 + +** /etc/crontab ** 是系统的 crontab 文件。通常只被 root 用户或守护进程用于配置系统级别的任务。每个独立的用户必须像上面介绍的那样使用 `crontab` 命令来安装和编辑自己的任务。`/var/spool/cron/` 或者 `/var/cron/tabs/` 目录存放了个人用户的 crontab 文件，它必定会备份在用户的家目录当中。 + +###理解默认的 `/etc/crontab` 文件 + +典型的 `/etc/crontab` 文件内容是这样的： + +``` +SHELL=/bin/bash +PATH=/sbin:/bin:/usr/sbin:/usr/bin +MAILTO=root +HOME=/ +# run-parts +01 * * * * root run-parts /etc/cron.hourly +02 4 * * * root run-parts /etc/cron.daily +22 4 * * 0 root run-parts /etc/cron.weekly +42 4 1 * * root run-parts /etc/cron.monthly +``` + +首先，环境变量必须被定义。如果 SHELL 行被忽略，cron 会使用默认的 sh shell。如果 PATH 变量被忽略，就没有默认的搜索路径，所有的文件都需要使用绝对路径来定位。如果 HOME 变量被忽略，cron 会使用调用者（用户）的家目录替代。 + +另外，cron 会读取 `/etc/cron.d/`目录中的文件。通常情况下，像 sa-update 或者 sysstat 这样的系统守护进程会将他们的定时任务存放在此处。作为 root 用户或者超级用户，你可以使用以下目录来配置你的定时任务。你可以直接将脚本放到这里。`run-parts`命令会通过 `/etc/crontab` 文件来运行位于某个目录中的脚本或者程序。 + +目录 |描述 +|:-- |:-- +/etc/cron.d/ | 将所有的脚本文件放在此处，并从 /etc/crontab 文件中调用它们。 +/etc/cron.daily/ | 运行需要 每天 运行一次的脚本 +/etc/cron.hourly/ | 运行需要 每小时 运行一次的脚本 +/etc/cron.monthly/ | 运行需要 每月 运行一次的脚本 +/etc/cron.weekly/ | 运行需要 每周 运行一次的脚本 + +### 备份定时任务 + +``` +# crontab -l > /path/to/file + +# crontab -u user -l > /path/to/file +``` + +-------------------------------------------------------------------------------- + +via: https://www.unixmen.com/add-cron-jobs-linux-unix/ + +作者：[Duy NguyenViet][a] +译者：[mr-ping](https://github.com/mr-ping) +校对：[FSSlc](https://github.com/FSSlc) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://www.unixmen.com/author/duynv/ +[1]: http://www.manpager.com/linux/man8/cron.8.html +[2]: http://www.linuxsecrets.com/ +[3]: http://www.linuxsecrets.com/linux-hardware/ \ No newline at end of file diff --git a/translated/talk/20160605 Will Google Replace Passwords With A New Trust-Based Authentication Method.md b/published/201606/20160605 Will Google Replace Passwords With A New Trust-Based Authentication Method.md similarity index 96% rename from translated/talk/20160605 Will Google Replace Passwords With A New Trust-Based Authentication Method.md rename to published/201606/20160605 Will Google Replace Passwords With A New Trust-Based Authentication Method.md index 7e0e85d688..ba14bf8742 100644 --- a/translated/talk/20160605 Will Google Replace Passwords With A New Trust-Based Authentication Method.md +++ b/published/201606/20160605 Will Google Replace Passwords With A New Trust-Based Authentication Method.md @@ -14,7 +14,8 @@ 基于这个信任分，一个需要登录认证的应用可以验证你确实可以授权登录，从而不会提示需要密码。 ![](http://www.iwillfolo.com/wordpress/wp-content/uploads/2016/05/Abacus-to-Trust-API.jpg) ->Abacus 到 Trust API + +*Abacus 到 Trust API* ### 需要思考的地方 @@ -31,7 +32,7 @@ via: http://www.iwillfolo.com/will-google-replace-passwords-with-a-new-trust-bas 作者：[iWillFolo][a] 译者：[alim0x](https://github.com/alim0x) -校对：[校对者ID](https://github.com/校对者ID) +校对：[wxy](https://github.com/wxy) 本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 diff --git a/published/201606/20160611 vlock – A Smart Way to Lock User Virtual Console or Terminal in Linux.md b/published/201606/20160611 vlock – A Smart Way to Lock User Virtual Console or Terminal in Linux.md new file mode 100644 index 0000000000..99c1da66ab --- /dev/null +++ b/published/201606/20160611 vlock – A Smart Way to Lock User Virtual Console or Terminal in Linux.md @@ -0,0 +1,102 @@ +vlock – 一个锁定 Linux 用户虚拟控制台或终端的好方法 +======================================================================= + +虚拟控制台是 Linux 上非常重要的功能，它们给系统用户提供了 shell 提示符，以保证用户在登录和远程登录一个未安装图形界面的系统时仍能使用。 + +一个用户可以同时操作多个虚拟控制台会话，只需在虚拟控制台间来回切换即可。 + +![](http://www.tecmint.com/wp-content/uploads/2016/05/vlock-Lock-User-Terminal-in-Linux.png) + +*用 vlock 锁定 Linux 用户控制台或终端* + +这篇使用指导旨在教会大家如何使用 vlock 来锁定用户虚拟控制台和终端。 + +### vlock 是什么？ + +vlock 是一个用于锁定一个或多个用户虚拟控制台用户会话的工具。在多用户系统中 vlock 扮演着重要的角色，它让用户可以在锁住自己会话的同时不影响其他用户通过其他虚拟控制台操作同一个系统。必要时，还可以锁定所有的控制台，同时禁止在虚拟控制台间切换。 + +vlock 的主要功能面向控制台会话方面，同时也支持非控制台会话的锁定，但该功能的测试还不完全。 + +### 在 Linux 上安装 vlock + +根据你的 Linux 系统选择 vlock 安装指令： + +``` +# yum install vlock [On RHEL / CentOS / Fedora] +$ sudo apt-get install vlock [On Ubuntu / Debian / Mint] +``` + +### 在 Linux 上使用 vlock + +vlock 操作选项的常规语法： + +``` +# vlock option +# vlock option plugin +# vlock option -t plugin +``` + +#### vlock 常用选项及用法： + +1、 锁定用户的当前虚拟控制台或终端会话，如下： + +``` +# vlock --current +``` + +![](http://www.tecmint.com/wp-content/uploads/2016/05/Lock-User-Terminal-Session-in-Linux.png) + +*锁定 Linux 用户终端会话* + +选项 -c 或 --current，用于锁定当前的会话，该参数为运行 vlock 时的默认行为。 + +2、 锁定所有你的虚拟控制台会话，并禁用虚拟控制台间切换，命令如下： + +``` +# vlock --all +``` + +![](http://www.tecmint.com/wp-content/uploads/2016/05/Lock-All-Linux-Terminal-Sessions.png) + +*锁定所有 Linux 终端会话* + +选项 -a 或 --all，用于锁定所有用户的控制台会话，并禁用虚拟控制台间切换。 + +其他的选项只有在编译 vlock 时编入了相关插件支持和引用后，才能发挥作用： + +3、 选项 -n 或 --new，调用时后，会在锁定用户的控制台会话前切换到一个新的虚拟控制台。 + +``` +# vlock --new +``` + +4、 选项 -s 或 --disable-sysrq，在禁用虚拟控制台的同时禁用 SysRq 功能，只有在与 -a 或 --all 同时使用时才起作用。 + +``` +# vlock -sa +``` + +5、 选项 -t 或 --timeout ，用以设定屏幕保护插件的 timeout 值。 + +``` +# vlock --timeout 5 +``` + +你可以使用 `-h` 或 `--help` 和 `-v` 或 `--version` 分别查看帮助消息和版本信息。 + +我们的介绍就到这了，提示一点，你可以将 vlock 的 `~/.vlockrc` 文件包含到系统启动中，并参考入门手册[添加环境变量][1]，特别是 Debian 系的用户。 + +想要找到更多或是补充一些这里没有提及的信息，可以直接在写在下方评论区。 + +-------------------------------------------------------------------------------- + +via: http://www.tecmint.com/vlock-lock-user-virtual-console-terminal-linux/ + +作者：[Aaron Kili][a] +译者：[martin2011qi](https://github.com/martin2011qi) +校对：[wxy](https://github.com/wxy) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: http://www.tecmint.com/author/aaronkili/ +[1]: http://www.tecmint.com/set-path-variable-linux-permanently/ diff --git a/published/201606/20160621 Building Serverless App with Docker.md b/published/201606/20160621 Building Serverless App with Docker.md new file mode 100644 index 0000000000..0b5409fc89 --- /dev/null +++ b/published/201606/20160621 Building Serverless App with Docker.md @@ -0,0 +1,98 @@ +用 Docker 创建 serverless 应用 +====================================== + +当今世界会时不时地出现一波波科技浪潮，将以前的技术拍死在海滩上。针对 serverless 应用的概念我们已经谈了很多，它是指将你的应用程序按功能来部署，这些功能在被用到时才会启动。你不用费心去管理服务器和程序规模，因为它们会在需要的时候在一个集群中启动并运行。 + +但是 serverless 并不意味着没有 Docker 什么事儿，事实上 Docker 就是 serverless 的。你可以使用 Docker 来容器化这些功能，然后在 Swarm 中按需求来运行它们。serverless 是一项构建分布式应用的技术，而 Docker 是它们完美的构建平台。 + +### 从 servers 到 serverless + +那如何才能写一个 serverless 应用呢？来看一下我们的例子，[5个服务组成的投票系统][1]： + +![](https://blog.docker.com/wp-content/uploads/Picture1.png) + +投票系统由下面5个服务组成： + +- 两个 web 前端 +- 一个后台处理投票的进程 +- 一个计票的消息队列 +- 一个数据库 + +后台处理投票的进程很容易转换成 serverless 构架，我们可以使用以下代码来实现： + +``` +import dockerrun +client = dockerrun.from_env() +client.run("bfirsh/serverless-record-vote-task", [voter_id, vote], detach=True) +``` + +这个投票处理进程和消息队列可以用运行在 Swarm 上的 Docker 容器来代替，并实现按需自动部署。 + +我们也可以用容器替换 web 前端，使用一个轻量级 HTTP 服务器来触发容器响应一个 HTTP 请求。Docker 容器代替长期运行的 HTTP 服务器来挑起响应请求的重担，这些容器可以自动扩容来支撑更大访问量。 + +新的架构就像这样： + +![](https://blog.docker.com/wp-content/uploads/Picture2.png) + +红色框内是持续运行的服务，绿色框内是按需启动的容器。这个架构里需要你来管理的长期运行服务更少，并且可以自动扩容（最大容量由你的 Swarm 决定）。 + +### 我们可以做点什么？ + +你可以在你的应用中使用3种技术： + +1. 在 Docker 容器中按需运行代码。 +2. 使用 Swarm 来部署集群。 +3. 通过使用 Docker API 套接字在容器中运行容器。 + +结合这3种技术，你可以有很多方法搭建你的应用架构。用这种方法来部署后台环境真是非常有效，而在另一些场景，也可以这么玩，比如说： + +- 由于存在延时，使用容器实现面向用户的 HTTP 请求可能不是很合适，但你可以写一个负载均衡器，使用 Swarm 来对自己的 web 前端进行自动扩容。 +- 实现一个 MongoDB 容器，可以自检 Swarm 并且启动正确的分片和副本（LCTT 译注：分片技术为大规模并行检索提供支持，副本技术则是为数据提供冗余）。 + +### 下一步怎么做 + +我们提供了这些前卫的工具和概念来构建应用，并没有深入发掘它们的功能。我们的架构里还是存在长期运行的服务，将来我们需要使用 Swarm 来把所有服务都用按需扩容的方式实现。 + +希望本文能在你搭建架构时给你一些启发，但我们还是需要你的帮助。我们提供了所有的基本工具，但它们还不是很完善，我们需要更多更好的工具、库、应用案例、文档以及其他资料。 + +[我们在这里发布了工具、库和文档][3]。如果想了解更多，请贡献给我们一些你知道的资源，以便我们能够完善这篇文章。 + +玩得愉快。 + +### 更多关于 Docker 的资料 + +- New to Docker? Try our 10 min [online tutorial][4] +- Share images, automate builds, and more with [a free Docker Hub account][5] +- Read the Docker [1.12 Release Notes][6] +- Subscribe to [Docker Weekly][7] +- Sign up for upcoming [Docker Online Meetups][8] +- Attend upcoming [Docker Meetups][9] +- Watch [DockerCon EU 2015 videos][10] +- Start [contributing to Docker][11] + + +-------------------------------------------------------------------------------- + +via: https://blog.docker.com/2016/06/building-serverless-apps-with-docker/ + +作者：[Ben Firshman][a] +译者：[bazz2](https://github.com/bazz2) +校对：[wxy](https://github.com/wxy) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://blog.docker.com/author/bfirshman/ + +[1]: https://github.com/docker/example-voting-app +[3]: https://github.com/bfirsh/serverless-docker +[4]: https://docs.docker.com/engine/understanding-docker/ +[5]: https://hub.docker.com/ +[6]: https://docs.docker.com/release-notes/ +[7]: https://www.docker.com/subscribe_newsletter/ +[8]: http://www.meetup.com/Docker-Online-Meetup/ +[9]: https://www.docker.com/community/meetup-groups +[10]: https://www.youtube.com/playlist?list=PLkA60AVN3hh87OoVra6MHf2L4UR9xwJkv +[11]: https://docs.docker.com/contributing/contributing/ + + + diff --git a/published/20160602 How to build and deploy a Facebook Messenger bot with Python and Flask.md b/published/20160602 How to build and deploy a Facebook Messenger bot with Python and Flask.md new file mode 100644 index 0000000000..e2191b88c1 --- /dev/null +++ b/published/20160602 How to build and deploy a Facebook Messenger bot with Python and Flask.md @@ -0,0 +1,392 @@ +如何用 Python 和 Flask 建立部署一个 Facebook Messenger 机器人 +========================================================================== + +这是我建立一个简单的 Facebook Messenger 机器人的记录。功能很简单，它是一个回显机器人，只是打印回用户写了什么。 + +回显服务器类似于服务器的“Hello World”例子。 + +这个项目的目的不是建立最好的 Messenger 机器人，而是让你了解如何建立一个小型机器人和每个事物是如何整合起来的。 + +- [技术栈][1] +- [机器人架构][2] +- [机器人服务器][3] +- [部署到 Heroku][4] +- [创建 Facebook 应用][5] +- [结论][6] + +### 技术栈 + +使用到的技术栈: + +- [Heroku][7] 做后端主机。免费级足够这个等级的教程。回显机器人不需要任何种类的数据持久，所以不需要数据库。 +- [Python][8] 是我们选择的语言。版本选择 2.7，虽然它移植到 Pyhton 3 很容易，只需要很少的改动。 +- [Flask][9] 作为网站开发框架。它是非常轻量的框架，用在小型工程或微服务是非常完美的。 +- 最后 [Git][10] 版本控制系统用来维护代码和部署到 Heroku。 +- 值得一提：[Virtualenv][11]。这个 python 工具是用来创建清洁的 python 库“环境”的，这样你可以只安装必要的需求和最小化应用的大小。 + +### 机器人架构 + +Messenger 机器人是由一个响应两种请求的服务器组成的： + +- GET 请求被用来认证。他们与你注册的 FaceBook 认证码一同被 Messenger 发出。 +- POST 请求被用来实际的通信。典型的工作流是，机器人将通过用户发送带有消息数据的 POST 请求而建立通信，然后我们将处理这些数据，并发回我们的 POST 请求。如果这个请求完全成功（返回一个 200 OK 状态码），我们也将响应一个 200 OK 状态码给初始的 Messenger请求。 + +这个教程应用将托管到 Heroku，它提供了一个优雅而简单的部署应用的接口。如前所述，免费级可以满足这个教程。 + +在应用已经部署并且运行后，我们将创建一个 Facebook 应用然后连接它到我们的应用，以便 Messenger 知道发送请求到哪，这就是我们的机器人。 + +### 机器人服务器 + +基本的服务器代码可以在 Github 用户 [hult(Magnus Hult)][13] 的 [Chatbot][12] 项目上获取，做了一些只回显消息的代码修改和修正了一些我遇到的错误。最终版本的服务器代码如下： + +``` +from flask import Flask, request +import json +import requests + +app = Flask(__name__) + +### 这需要填写被授予的页面通行令牌（PAT） +### 它由将要创建的 Facebook 应用提供。 +PAT = '' + +@app.route('/', methods=['GET']) +def handle_verification(): + print "Handling Verification." + if request.args.get('hub.verify_token', '') == 'my_voice_is_my_password_verify_me': + print "Verification successful!" + return request.args.get('hub.challenge', '') + else: + print "Verification failed!" + return 'Error, wrong validation token' + +@app.route('/', methods=['POST']) +def handle_messages(): + print "Handling Messages" + payload = request.get_data() + print payload + for sender, message in messaging_events(payload): + print "Incoming from %s: %s" % (sender, message) + send_message(PAT, sender, message) + return "ok" + +def messaging_events(payload): + """Generate tuples of (sender_id, message_text) from the + provided payload. + """ + data = json.loads(payload) + messaging_events = data["entry"][0]["messaging"] + for event in messaging_events: + if "message" in event and "text" in event["message"]: + yield event["sender"]["id"], event["message"]["text"].encode('unicode_escape') + else: + yield event["sender"]["id"], "I can't echo this" + + +def send_message(token, recipient, text): + """Send the message text to recipient with id recipient. + """ + + r = requests.post("https://graph.facebook.com/v2.6/me/messages", + params={"access_token": token}, + data=json.dumps({ + "recipient": {"id": recipient}, + "message": {"text": text.decode('unicode_escape')} + }), + headers={'Content-type': 'application/json'}) + if r.status_code != requests.codes.ok: + print r.text + +if __name__ == '__main__': + app.run() +``` + +让我们分解代码。第一部分是引入所需的依赖： + +``` +from flask import Flask, request +import json +import requests +``` + +接下来我们定义两个函数（使用 Flask 特定的 app.route 装饰器），用来处理到我们的机器人的 GET 和 POST 请求。 + +``` +@app.route('/', methods=['GET']) +def handle_verification(): + print "Handling Verification." + if request.args.get('hub.verify_token', '') == 'my_voice_is_my_password_verify_me': + print "Verification successful!" + return request.args.get('hub.challenge', '') + else: + print "Verification failed!" + return 'Error, wrong validation token' +``` + +当我们创建 Facebook 应用时，verify_token 对象将由我们声明的 Messenger 发送。我们必须自己来校验它。最后我们返回“hub.challenge”给 Messenger。 + +处理 POST 请求的函数更有意思一些： + +``` +@app.route('/', methods=['POST']) +def handle_messages(): + print "Handling Messages" + payload = request.get_data() + print payload + for sender, message in messaging_events(payload): + print "Incoming from %s: %s" % (sender, message) + send_message(PAT, sender, message) + return "ok" +``` + +当被调用时，我们抓取消息载荷，使用函数 messaging_events 来拆解它，并且提取发件人身份和实际发送的消息，生成一个可以循环处理的 python 迭代器。请注意 Messenger 发送的每个请求有可能多于一个消息。 + +``` +def messaging_events(payload): + """Generate tuples of (sender_id, message_text) from the + provided payload. + """ + data = json.loads(payload) + messaging_events = data["entry"][0]["messaging"] + for event in messaging_events: + if "message" in event and "text" in event["message"]: + yield event["sender"]["id"], event["message"]["text"].encode('unicode_escape') + else: + yield event["sender"]["id"], "I can't echo this" +``` + +对每个消息迭代时，我们会调用 send_message 函数，然后我们使用 Facebook Graph messages API 对 Messenger 发回 POST 请求。在这期间我们一直没有回应我们阻塞的原始 Messenger请求。这会导致超时和 5XX 错误。 + +上述情况是我在解决遇到错误时发现的，当用户发送表情时实际上是发送的 unicode 标识符，但是被 Python 错误的编码了，最终我们发回了一些乱码。 + +这个发回 Messenger 的 POST 请求将永远不会完成，这会导致给初始请求返回 5xx 状态码，显示服务不可用。 + +通过使用 `encode('unicode_escape')` 封装消息，然后在我们发送回消息前用 `decode('unicode_escape')` 解码消息就可以解决。 + +``` +def send_message(token, recipient, text): + """Send the message text to recipient with id recipient. + """ + + r = requests.post("https://graph.facebook.com/v2.6/me/messages", + params={"access_token": token}, + data=json.dumps({ + "recipient": {"id": recipient}, + "message": {"text": text.decode('unicode_escape')} + }), + headers={'Content-type': 'application/json'}) + if r.status_code != requests.codes.ok: + print r.text +``` + +### 部署到 Heroku + +一旦代码已经建立成我想要的样子时就可以进行下一步。部署应用。 + +那么，该怎么做？ + +我之前在 Heroku 上部署过应用（主要是 Rails），然而我总是遵循某种教程做的，所用的配置是创建好了的。而在本文的情况下，我就需要从头开始。 + +幸运的是有官方 [Heroku 文档][14]来帮忙。这篇文档很好地说明了运行应用程序所需的最低限度。 + +长话短说，我们需要的除了我们的代码还有两个文件。第一个文件是“requirements.txt”，它列出了运行应用所依赖的库。 + +需要的第二个文件是“Procfile”。这个文件通知 Heroku 如何运行我们的服务。此外这个文件只需要一点点内容： + +``` +web: gunicorn echoserver:app +``` + +Heroku 对它的解读是，我们的应用通过运行 echoserver.py 启动，并且应用将使用 gunicorn 作为 Web 服务器。我们使用一个额外的网站服务器是因为与性能相关，在上面的 Heroku 文档里对此解释了： + +> Web 应用程序并发处理传入的 HTTP 请求比一次只处理一个请求的 Web 应用程序会更有效利地用测试机的资源。由于这个原因，我们建议使用支持并发请求的 Web 服务器来部署和运行产品级服务。 + +> Django 和 Flask web 框架提供了一个方便的内建 Web 服务器，但是这些阻塞式服务器一个时刻只能处理一个请求。如果你部署这种服务到 Heroku 上，你的测试机就会资源利用率低下，应用会感觉反应迟钝。 + +> Gunicorn 是一个纯 Python 的 HTTP 服务器，用于 WSGI 应用。允许你在单独一个测试机内通过运行多 Python 进程的方式来并发的运行各种 Python 应用。它在性能、灵活性和配置简易性方面取得了完美的平衡。 + +回到我们之前提到过的“requirements.txt”文件，让我们看看它如何结合 Virtualenv 工具。 + +很多情况下，你的开发机器也许已经安装了很多 python 库。当部署应用时你不想全部加载那些库，但是辨认出你实际使用哪些库很困难。 + +Virtualenv 可以创建一个新的空白虚拟环境，以便你可以只安装你应用所需要的库。 + +你可以运行如下命令来检查当前安装了哪些库： + +``` +kostis@KostisMBP ~ $ pip freeze +cycler==0.10.0 +Flask==0.10.1 +gunicorn==19.6.0 +itsdangerous==0.24 +Jinja2==2.8 +MarkupSafe==0.23 +matplotlib==1.5.1 +numpy==1.10.4 +pyparsing==2.1.0 +python-dateutil==2.5.0 +pytz==2015.7 +requests==2.10.0 +scipy==0.17.0 +six==1.10.0 +virtualenv==15.0.1 +Werkzeug==0.11.10 +``` + +注意：pip 工具应该已经与 Python 一起安装在你的机器上。如果没有，查看[官方网站][15]如何安装它。 + +现在让我们使用 Virtualenv 来创建一个新的空白环境。首先我们给我们的项目创建一个新文件夹，然后进到目录下： + +``` +kostis@KostisMBP projects $ mkdir echoserver +kostis@KostisMBP projects $ cd echoserver/ +kostis@KostisMBP echoserver $ +``` + +现在来创建一个叫做 echobot 的新环境。运行下面的 source 命令激活它，然后使用 pip freeze 检查，我们能看到现在是空的。 + +``` +kostis@KostisMBP echoserver $ virtualenv echobot +kostis@KostisMBP echoserver $ source echobot/bin/activate +(echobot) kostis@KostisMBP echoserver $ pip freeze +(echobot) kostis@KostisMBP echoserver $ +``` + +我们可以安装需要的库。我们需要是 flask、gunicorn 和 requests，它们被安装后我们就创建 requirements.txt 文件： + +``` +(echobot) kostis@KostisMBP echoserver $ pip install flask +(echobot) kostis@KostisMBP echoserver $ pip install gunicorn +(echobot) kostis@KostisMBP echoserver $ pip install requests +(echobot) kostis@KostisMBP echoserver $ pip freeze +click==6.6 +Flask==0.11 +gunicorn==19.6.0 +itsdangerous==0.24 +Jinja2==2.8 +MarkupSafe==0.23 +requests==2.10.0 +Werkzeug==0.11.10 +(echobot) kostis@KostisMBP echoserver $ pip freeze > requirements.txt +``` + +上述完成之后，我们用 python 代码创建 echoserver.py 文件，然后用之前提到的命令创建 Procfile，我们最终的文件/文件夹如下： + +``` +(echobot) kostis@KostisMBP echoserver $ ls +Procfile echobot echoserver.py requirements.txt +``` + +我们现在准备上传到 Heroku。我们需要做两件事。第一是如果还没有安装 Heroku toolbet，就安装它（详见 [Heroku][16]）。第二是通过 Heroku [网页界面][17]创建一个新的 Heroku 应用。 + +点击右上的大加号然后选择“Create new app”。 + +![](http://tsaprailis.com/assets/create_app.png) + +为你的应用选择一个名字，然后点击“Create App”。 + +![](http://tsaprailis.com/assets/create.png) + +你将会重定向到你的应用的控制面板，在那里你可以找到如何部署你的应用到 Heroku 的细节说明。 + +``` +(echobot) kostis@KostisMBP echoserver $ heroku login +(echobot) kostis@KostisMBP echoserver $ git init +(echobot) kostis@KostisMBP echoserver $ heroku git:remote -a +(echobot) kostis@KostisMBP echoserver $ git add . +(echobot) kostis@KostisMBP echoserver $ git commit -m "Initial commit" +(echobot) kostis@KostisMBP echoserver (master) $ git push heroku master +... +remote: https://.herokuapp.com/ deployed to Heroku +... +(echobot) kostis@KostisMBP echoserver (master) $ heroku config:set WEB_CONCURRENCY=3 +``` + +如上，当你推送你的修改到 Heroku 之后，你会得到一个用于公开访问你新创建的应用的 URL。保存该 URL，下一步需要它。 + +### 创建这个 Facebook 应用 + +让我们的机器人可以工作的最后一步是创建这个我们将连接到其上的 Facebook 应用。Facebook 通常要求每个应用都有一个相关页面，所以我们来[创建一个][18]。 + +接下来我们去 [Facebook 开发者专页][19]，点击右上角的“My Apps”按钮并选择“Add a New App”。不要选择建议的那个，而是点击“basic setup”。填入需要的信息并点击“Create App Id”，然后你会重定向到新的应用页面。 + +![](http://tsaprailis.com/assets/facebook_app.png) + + +在 “Products” 菜单之下，点击“+ Add Product” ，然后在“Messenger”下点击“Get Started”。跟随这些步骤设置 Messenger，当完成后你就可以设置你的 webhooks 了。Webhooks 简单的来说是你的服务所用的 URL 的名称。点击 “Setup Webhooks” 按钮，并添加该 Heroku 应用的 URL （你之前保存的那个）。在校验元组中写入 ‘my_voice_is_my_password_verify_me’。你可以写入任何你要的内容，但是不管你在这里写入的是什么内容，要确保同时修改代码中 handle_verification 函数。然后勾选 “messages” 选项。 + +![](http://tsaprailis.com/assets/webhooks.png) + +点击“Verify and Save” 就完成了。Facebook 将访问该 Heroku 应用并校验它。如果不工作，可以试试运行： + +``` +(echobot) kostis@KostisMBP heroku logs -t +``` + +然后看看日志中是否有错误。如果发现错误， Google 搜索一下可能是最快的解决方法。 + +最后一步是取得页面访问元组（PAT），它可以将该 Facebook 应用于你创建好的页面连接起来。 + +![](http://tsaprailis.com/assets/PAT.png) + +从下拉列表中选择你创建好的页面。这会在“Page Access Token”（PAT）下面生成一个字符串。点击复制它，然后编辑 echoserver.py 文件，将其贴入 PAT 变量中。然后在 Git 中添加、提交并推送该修改。 + +``` +(echobot) kostis@KostisMBP echoserver (master) $ git add . +(echobot) kostis@KostisMBP echoserver (master) $ git commit -m "Initial commit" +(echobot) kostis@KostisMBP echoserver (master) $ git push heroku master +``` + +最后，在 Webhooks 菜单下再次选择你的页面并点击“Subscribe”。 + +![](http://tsaprailis.com/assets/subscribe.png) + +现在去访问你的页面并建立会话： + +![](http://tsaprailis.com/assets/success.png) + +成功了，机器人回显了！ + +注意：除非你要将这个机器人用在 Messenger 上测试，否则你就是机器人唯一响应的那个人。如果你想让其他人也试试它，到 [Facebook 开发者专页][19]中，选择你的应用、角色，然后添加你要添加的测试者。 + +###总结 + +这对于我来说是一个非常有用的项目，希望它可以指引你找到开始的正确方向。[官方的 Facebook 指南][20]有更多的资料可以帮你学到更多。 + +你可以在 [Github][21] 上找到该项目的代码。 + +如果你有任何评论、勘误和建议，请随时联系我。 + + +-------------------------------------------------------------------------------- + +via: http://tsaprailis.com/2016/06/02/How-to-build-and-deploy-a-Facebook-Messenger-bot-with-Python-and-Flask-a-tutorial/ + +作者：[Konstantinos Tsaprailis][a] +译者：[wyangsun](https://github.com/wyangsun) +校对：[wxy](https://github.com/wxy) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创翻译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://github.com/kostistsaprailis +[1]: http://tsaprailis.com/2016/06/02/How-to-build-and-deploy-a-Facebook-Messenger-bot-with-Python-and-Flask-a-tutorial/#tech-stack +[2]: http://tsaprailis.com/2016/06/02/How-to-build-and-deploy-a-Facebook-Messenger-bot-with-Python-and-Flask-a-tutorial/#bot-architecture +[3]: http://tsaprailis.com/2016/06/02/How-to-build-and-deploy-a-Facebook-Messenger-bot-with-Python-and-Flask-a-tutorial/#the-bot-server +[4]: http://tsaprailis.com/2016/06/02/How-to-build-and-deploy-a-Facebook-Messenger-bot-with-Python-and-Flask-a-tutorial/#deploying-to-heroku +[5]: http://tsaprailis.com/2016/06/02/How-to-build-and-deploy-a-Facebook-Messenger-bot-with-Python-and-Flask-a-tutorial/#creating-the-facebook-app +[6]: http://tsaprailis.com/2016/06/02/How-to-build-and-deploy-a-Facebook-Messenger-bot-with-Python-and-Flask-a-tutorial/#conclusion +[7]: https://www.heroku.com +[8]: https://www.python.org +[9]: http://flask.pocoo.org +[10]: https://git-scm.com +[11]: https://virtualenv.pypa.io/en/stable +[12]: https://github.com/hult/facebook-chatbot-python +[13]: https://github.com/hult +[14]: https://devcenter.heroku.com/articles/python-gunicorn +[15]: https://pip.pypa.io/en/stable/installing +[16]: https://toolbelt.heroku.com +[17]: https://dashboard.heroku.com/apps +[18]: https://www.facebook.com/pages/create +[19]: https://developers.facebook.com/ +[20]: https://developers.facebook.com/docs/messenger-platform/implementation +[21]: https://github.com/kostistsaprailis/messenger-bot-tutorial \ No newline at end of file diff --git a/published/201607/20151117 How bad a boss is Linus Torvalds.md b/published/201607/20151117 How bad a boss is Linus Torvalds.md new file mode 100644 index 0000000000..b35ba67827 --- /dev/null +++ b/published/201607/20151117 How bad a boss is Linus Torvalds.md @@ -0,0 +1,80 @@ +Linus Torvalds 是一个糟糕的老板吗？ +================================================================================ + +![linus torvalds](http://images.techhive.com/images/article/2015/08/linus_torvalds-100600260-primary.idge.jpg) + +*1999 年 8 月 10 日，加利福尼亚州圣何塞市，在 LinuxWorld Show 上 Linus Torvalds 在一个坐满 Linux 爱好者的礼堂中发表了一篇演讲。图片来自：James Niccolai* + +**这取决于所处的领域。在软件开发的世界中，他也是个普通人。问题是，这种情况是否应该继续下去？** + +Linus Torvalds 是 Linux 的发明者，我认识他超过 20 年了。我们不是密友，但是我们欣赏彼此。 + +最近，因为 Linus Torvalds 的管理风格，他正遭到严厉的炮轰。Linus 无法忍受胡来的人。“代码的质量有多好？”是他在 Linux 内核的开发过程中评判人的一种方式。 + +没有什么比这个更重要了。正如 Linus 今年（2015年）早些时候在 Linux.conf.au 会议上说的那样，“我不是一个友好的人，我也不在意你。对我重要的是『[我所关心的技术和内核][1]』。” + +现在我也可以和这种只关心技术的人打交道了。如果你不能，你应当避免参加 Linux 内核会议，因为在那里你会遇到许多有这种精英思想的人。这不代表我认为在 Linux 领域所有东西都是极好的，并且不应该受到其他影响而带来改变。我能够和一个精英待在一起；而在一个男性做主导的大城堡中遇到的问题是，女性经常受到蔑视和无礼的对待。 + +这就是我看到的最近关于 Linus 管理风格所引发争论的原因 -- 或者更准确的说，他对于个人管理方面是完全冷漠的 -- 就像是在软件开发世界的标准操作流程一样。与此同时，我看到了揭示了这个事情需要改变的另外一个证据。 + +第一次是在 [Linux 4.3 发布][2]的时候出现的这个情况，Linus 使用 Linux 内核邮件列表来狠狠的数落了一个插入了一些网络方面的代码的开发者——这些代码很“烂”，“[生成了如此烂的代码][3]。这看起来太糟糕了，并且完全没有理由这样做。”他继续咆哮了半天。这里使用“烂”这个词，相对他早期使用的“愚蠢的”这个同义词来说还算好的。 + +但是，事情就是这样。Linus 是对的。我读了代码后，发现代码确实很烂，并且开发者只是为了用新的“overflow_usub()” 函数而用的。 + +现在，一些人把 Linus 的这种谩骂的行为看作他脾气不好而且恃强凌弱的证据。我见过一个完美主义者，在他的领域中，他无法忍受这种糟糕。 + +许多人告诉我，这不是一个专业的程序员应当有的行为。群众们，你曾经和最优秀的开发者一起工作过吗？据我所知道的，在 Apple，Microsoft，Oracle 这就是他们的行为。 + +我曾经听过 Steve Jobs 攻击一个开发者，就像要把他撕成碎片那样。我也被一个 Oracle 的高级开发者攻击一屋子的新开发者吓到过，就像食人鱼穿过一群金鱼那样。 + +在 Robert X. Cringely 关于 PC 崛起的经典书籍《[意外帝国（Accidental Empires）][5]》，中，他这样描述了微软的软件管理风格，比尔·盖茨像计算机系统一样管理他们，“比尔·盖茨的是最高等级，从他开始每一个等级依次递减，上级会向下级叫嚷，刺激他们，甚至羞辱他们。” + +Linus 和所有大型的商业软件公司的领导人不同的是，Linus 说在这里所有的东西是向全世界公开的。而其他人是在自己的会议室中做东西的。我听有人说 Linus 在那种公司中可能会被开除。这是不可能的。他会处于他现在所处的地位，他在编程世界的最顶端。 + +但是，这里有另外一个不同。如果 Larry Ellison （Oracle 的首席执行官）向你发火，你就别想在这里干了。如果 Linus 向你发火，你会在邮件中收到他的责骂。这就是差别。 + +你知道的，Linus 不是任何人的老板。他完全没有雇佣和解聘的权利，他只是负责着有 10000 个贡献者的一个项目而已。他仅仅能做的就是从心理上伤害你。 + +这说明，在开源软件开发圈和商业软件开发圈中同时存在一个非常严重的问题。不管你是一个多么好的编程者，如果你是一个女性，你的这个身份就是对你不利的。 + +这种情况并没有在 Sarah Sharp 的身上有任何好转，她现在是一个 Intel 的开发者，以前是一个顶尖的 Linux 程序员。[在她博客上10月份的一个帖子中][4]，她解释道：“我最终发现，我不能够再为 Linux 社区做出贡献了。因为在那里，我虽然能够得到技术上的尊重，却得不到个人的尊重……我不想专职于同那些有着轻微的性别歧视或开同性恋玩笑的人一起工作。” + +谁会责怪她呢？我不会。很抱歉，我必须说，Linus 就像所有我见过的软件经理一样，是他造成了这种不利的工作环境。 + +他可能会说，确保 Linux 的贡献者都表现出专业精神和相互尊重不应该是他的工作。除了代码以外，他不关心任何其他事情。 + +就像 Sarah Sharp 写的那样： + + +> 我对于 Linux 内核社区做出的技术努力表示最大尊重。他们在那维护一些最高标准的代码，以此来平衡并且发展一个项目。他们专注于优秀的技术，以及超过负荷的维护人员，他们有不同的文化背景和社会规范，这些意味着这些 Linux 内核维护者说话非常直率、粗鲁，或者为了完成他们的任务而不讲道理。顶尖的 Linux 内核开发者经常为了使别人改正行为而向他们大喊大叫。 +> +> 这种事情发生在我身上，但它不是一种有效的沟通方式。 +> +> 许多高级的 Linux 内核开发者支持那些技术上和人性上不讲道理的维护者的权利。即使他们自己是非常友好的人，他们不想看到 Linux 内核交流方式改变。 + +她是对的。 + +我和其他观察者不同的是，我不认为这个问题对于 Linux 或开源社区在任何方面有特殊之处。作为一个从事技术商业工作超过五年和有着 25 年技术工作经历的记者，我见多了这种不成熟的小孩子行为。 + +这不是 Linus 的错误。他不是一个经理，他是一个有想象力的技术领导者。看起来真正的问题是，在软件开发领域没有人能够用一种支持的语气来对待团队和社区。 + +展望未来，我希望像 Linux 基金会这样的公司和组织，能够找到一种方式去授权社区经理或其他经理来鼓励并且强制实施民主的行为。 + +非常遗憾的是，我们不能够在我们这种纯技术或纯商业的领导人中找到这种管理策略。它不存在于这些人的基因中。 + +-------------------------------------------------------------------------------- + +via: http://www.computerworld.com/article/3004387/it-management/how-bad-a-boss-is-linus-torvalds.html + +作者：[Steven J. Vaughan-Nichols][a] +译者：[FrankXinqi](https://github.com/FrankXinqi) +校对：[wxy](https://github.com/wxy) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]:http://www.computerworld.com/author/Steven-J.-Vaughan_Nichols/ +[1]:http://www.computerworld.com/article/2874475/linus-torvalds-diversity-gaffe-brings-out-the-best-and-worst-of-the-open-source-world.html +[2]:http://www.zdnet.com/article/linux-4-3-released-after-linus-torvalds-scraps-brain-damage-code/ +[3]:http://lkml.iu.edu/hypermail/linux/kernel/1510.3/02866.html +[4]:http://sarah.thesharps.us/2015/10/05/closing-a-door/ +[5]:https://www.amazon.cn/Accidental-Empires-Cringely-Robert-X/dp/0887308554/479-5308016-9671450?ie=UTF8&qid=1447101469&ref_=sr_1_1&tag=geo-23 \ No newline at end of file diff --git a/translated/tech/20151215 Securi-Pi--Using the Raspberry Pi as a Secure Landing Point.md b/published/201607/20151215 Securi-Pi--Using the Raspberry Pi as a Secure Landing Point.md similarity index 50% rename from translated/tech/20151215 Securi-Pi--Using the Raspberry Pi as a Secure Landing Point.md rename to published/201607/20151215 Securi-Pi--Using the Raspberry Pi as a Secure Landing Point.md index fc489163ef..7038dfd87a 100644 --- a/translated/tech/20151215 Securi-Pi--Using the Raspberry Pi as a Secure Landing Point.md +++ b/published/201607/20151215 Securi-Pi--Using the Raspberry Pi as a Secure Landing Point.md @@ -1,25 +1,27 @@ -Securi-Pi: 使用树莓派作为安全跳板 +Securi-Pi：使用树莓派作为安全跳板 ================================================================================ -像很多 LinuxJournal 的读者一样，我也过上了当今非常普遍的“科技游牧”生活，在网络到网络间，从一个接入点到另一个接入点，我们身处现实世界的不同地方却始终保持统一的互联网接入端。近来我发现越来越多的网络环境开始屏蔽对外的常用端口比如 SMTP（端口25），SSH（端口22）之类的。当你走进一家咖啡馆然后想 SSH 到你的一台服务器上做点事情的时候发现端口22被屏蔽了是一件很烦的事情。 +像很多 LinuxJournal 的读者一样，我也过上了当今非常普遍的“科技游牧”生活，在网络之间，从一个接入点到另一个接入点，我们身处现实世界的不同地方却始终保持连接到互联网和日常使用的其它网络上。近来我发现越来越多的网络环境开始屏蔽对外的常用端口比如 SMTP（端口25），SSH（端口22）之类的。当你走进一家咖啡馆然后想 SSH 到你的一台服务器上做点事情的时候发现端口 22 被屏蔽了是一件很烦的事情。 -不过，我到目前为止还没发现有什么网络环境会把 HTTPS 给墙了（端口443）。在稍微配置了一下家中的树莓派 2之后，我成功地让自己能通过接入树莓派的443接口充当跳板从而让我在各种网络环境下连上想要的目标端口。简而言之，我把家中的树莓派设置成了一个 OpenVPN 的端点，SSH 端点同时也是一个 Apache 服务器——用于监听443端口上的我的接入活动并执行我预先设置好的网络策略。 +不过，我到目前为止还没发现有什么网络环境会把 HTTPS 给墙了（端口443）。在稍微配置了一下家中的树莓派 2 之后，我成功地让自己通过接入树莓派的 443 端口充当跳板，从而让我在各种网络环境下都能连上想要的目标端口。简而言之，我把家中的树莓派设置成了一个 OpenVPN 的端点和 SSH 端点，同时也是一个 Apache 服务器，所有这些服务都监听在 443 端口上，以便可以限制我不想暴露的网络服务。 -### 笔记 -此解决方案能搞定大多数有限制的网络环境，但有些防火墙会对外部流量调用深度包检查（Deep packet inspection），它们时常能屏蔽掉用本篇文章里的方式传输的信息。不过我到目前为止还没在这样的防火墙后测试过。同时，尽管我使用了很多基于密码学的工具（OpenVPN，HTTPS，SSH），我并没有非常严格地审计过这套配置方案（译者注：作者的意思是指这套方案能帮你绕过端口限制，但不代表你就是完全安全地连接上了树莓派）。有时候甚至 DNS 服务都会泄露你的信息，很可能在我没有考虑周到的角落里会有遗漏。我强烈不推荐把此跳板配置方案当作是万无一失的隐藏网络流量的办法，此配置只是希望能绕过一些端口限制连上网络，而不是做一些危险的事情。 +### 备注 + +此解决方案能搞定大多数有限制的网络环境，但有些防火墙会对外部流量调用深度包检查（Deep packet inspection），它们时常能屏蔽掉用本篇文章里的方式传输的信息。不过我到目前为止还没在这样的防火墙后测试过。同时，尽管我使用了很多基于密码学的工具（OpenVPN，HTTPS，SSH），我并没有非常严格地审计过这套配置方案（LCTT 译注：作者的意思是指这套方案能帮你绕过端口限制，但不代表你的活动就是完全安全的）。有时候甚至 DNS 服务都会泄露你的信息，很可能在我没有考虑周到的角落里会有遗漏。我强烈不推荐把此跳板配置方案当作是万无一失的隐藏网络流量的办法，此配置只是希望能绕过一些端口限制连上网络，而不是做一些危险的事情。 ### 起步 -让我们先从你需要什么说起，我用的是树莓派 2，装载了最新版本的 Raspbian，不过这个配置也应该能在树莓派 Model B 上运行；512MB 的内存对我们来说绰绰有余了，虽然性能可能没有树莓派 2这么好，毕竟Model B只有一颗单核心 CPU 相比于四核心的树莓派 2。我的树莓派在家里的防火墙和路由器之后，所以我还能用这个树莓派作为跳板访问家里的其他电子设备。同时这也意味着我的流量在互联网上看起来仿佛来自我家的ip地址，所以这也算某种意义上保护了我的匿名性。如果你没有树莓派，或者不想从家里运行这个服务，那你完全可以把这个配置放在一台小型云服务器上（译者：比如 IPS ）。你只要确保服务器运行着基于 Debian 的 Linux 发行版即可，这份指南依然可用。 +让我们先从你需要什么说起，我用的是树莓派 2，装载了最新版本的 Raspbian，不过这个配置也应该能在树莓派 Model B 上运行；512MB 的内存对我们来说绰绰有余了，虽然性能可能没有树莓派 2这么好，毕竟相比于四核心的树莓派 2， Model B 只有一颗单核心 CPU。我的树莓派放置在家里的防火墙和路由器的后面，所以我还能用这个树莓派作为跳板访问家里的其他电子设备。同时这也意味着我的流量在互联网上看起来仿佛来自我家的 ip 地址，所以这也算某种意义上保护了我的匿名性。如果你没有树莓派，或者不想从家里运行这个服务，那你完全可以把这个配置放在一台小型云服务器上（LCTT 译注：比如 IPS ）。你只要确保服务器运行着基于 Debian 的 Linux 发行版即可，这份指南依然可用。 ![](http://www.linuxjournal.com/files/linuxjournal.com/ufiles/imagecache/large-550px-centered/u1002061/11913f1.jpg) -图 1 树莓派，即将成为我们的加密网络端点 +*图 1 树莓派，即将成为我们的加密网络端点* ### 安装并配置 BIND -无论你是用树莓派还是一台服务器，当你成功启动之后你就可以安装 BIND 了，驱动了互联网相当一部分的域名服务软件。你将会把 BIND 仅仅作为缓存域名服务使用，而不用把它配置为用来处理来自互联网的域名请求。安装 BIND 会让你拥有一个可以被 OpenVPN 使用的 DNS 服务器。安装 BIND 十分简单，`apt-get` 就可以直接搞定: + +无论你是用树莓派还是一台服务器，当你成功启动之后你就可以安装 BIND 了，这是一个驱动了互联网相当一部分的域名服务软件。你将会把 BIND 仅仅作为缓存域名服务使用，而不用把它配置为用来处理来自互联网的域名请求。安装 BIND 会让你拥有一个可以被 OpenVPN 使用的 DNS 服务器。安装 BIND 十分简单，`apt-get` 就可以直接搞定: ``` root@test:~# apt-get install bind9 @@ -32,15 +34,13 @@ Suggested packages: bind9-doc resolvconf ufw The following NEW packages will be installed: bind9 bind9utils -0 upgraded, 2 newly installed, 0 to remove and - ↪0 not upgraded. +0 upgraded, 2 newly installed, 0 to remove and 0 not upgraded. Need to get 490 kB of archives. -After this operation, 1,128 kB of additional disk - ↪space will be used. +After this operation, 1,128 kB of additional disk space will be used. Do you want to continue [Y/n]? y ``` -在我们能把 BIND 当做缓存域名服务器之前，还有一些小细节需要配置。两个修改都在`/etc/bind/named.conf.options`里完成。首先你要反注释掉 forwarders 这一节内容，同时你还要增加一个可以转发域名请求的目标服务器。作为例子我会用 Google 的 DNS 服务器（8.8.8.8）（译者：国内的话需要找一个替代品）；文件的 forwarders 节看上去大致是这样的： +在我们把 BIND 作为缓存域名服务器之前，还有一些小细节需要配置。两个修改都在`/etc/bind/named.conf.options`里完成。首先你要取消注释掉 forwarders 这一节内容，同时你还要增加一个可以转发域名请求的目标服务器。作为例子我会用 Google 的 DNS 服务器（8.8.8.8）（LCTT 译注：国内的话需要找一个替代品）；文件的 forwarders 节看上去大致是这样的： ``` @@ -49,19 +49,18 @@ forwarders { }; ``` -第二点你需要做的更改是允许来自互联网和本地局域网的 query，直接把这一行加入配置文件的低端，最后一个`}`之前就可以了： +第二点你需要做的更改是允许来自内网和本机的查询请求，直接把这一行加入配置文件的后面，记得放在最后一个`};`之前就可以了： ``` allow-query { 192.168.1.0/24; 127.0.0.0/16; }; ``` -上面那行配置会允许此 DNS 服务器接收来自网络和局域网的请求。下一步，你需要重启一下 BIND 的服务： +上面那行配置会允许此 DNS 服务器接收来自其所在的网络（在本例中，我的网络就在我的防火墙之后）和本机的请求。下一步，你需要重启一下 BIND 的服务： ``` root@test:~# /etc/init.d/bind9 restart -[....] Stopping domain name service...: bind9waiting - ↪for pid 13209 to die +[....] Stopping domain name service...: bind9waiting for pid 13209 to die . ok [ ok ] Starting domain name service...: bind9. ``` @@ -91,12 +90,12 @@ Name: www.google.com Address: 173.194.33.180 ``` -完美！现在你的系统里已经有一个正常的域名服务在允许了，下一步我们来配置一下OpenVPN。 +完美！现在你的系统里已经有一个正常的域名服务在工作了，下一步我们来配置一下OpenVPN。 ### 安装并配置 OpenVPN -OpenVPN 是一个运用 SSL/TLS 作为密钥交换的开源 VPN 解决方案。同时它也非常便于在 Linux 环境下部署。配置 OpenVPN 可能有一点艰巨，不过在此其实你也不需要在默认的配置文件里做太多修改。首先你会需要运行一下 `apt-get` 来安装 OpenVPN： +OpenVPN 是一个运用 SSL/TLS 作为密钥交换的开源 VPN 解决方案。同时它也非常便于在 Linux 环境下部署。配置 OpenVPN 可能有一点点难，不过其实你也不需要在默认的配置文件里做太多修改。首先你需要运行一下 `apt-get` 来安装 OpenVPN： ``` @@ -110,22 +109,18 @@ Suggested packages: resolvconf The following NEW packages will be installed: liblzo2-2 libpkcs11-helper1 openvpn -0 upgraded, 3 newly installed, 0 to remove and - ↪0 not upgraded. +0 upgraded, 3 newly installed, 0 to remove and 0 not upgraded. Need to get 621 kB of archives. -After this operation, 1,489 kB of additional disk - ↪space will be used. +After this operation, 1,489 kB of additional disk space will be used. Do you want to continue [Y/n]? y ``` -现在 OpenVPN 已经安装好了，你需要去配置它了。OpenVPN 是基于 SSL 的，并且它同时依赖于服务端和客户端两方的证书来工作。为了生成这些证书，你需要配置机器上的证书签发（CA）。幸运地，OpenVPN 在安装中自带了一些用于生成证书的脚本比如 “easy-rsa” 来帮助你加快这个过程。你将要创建一个文件目录用于放置 easy-rsa 脚本的模板： +现在 OpenVPN 已经安装好了，你需要去配置它了。OpenVPN 是基于 SSL 的，并且它同时依赖于服务端和客户端两方的证书来工作。为了生成这些证书，你需要在机器上配置一个证书签发（CA）。幸运地，OpenVPN 在安装中自带了一些用于生成证书的脚本比如 “easy-rsa” 来帮助你加快这个过程。你将要创建一个文件目录用于放置 easy-rsa 脚本，从模板目录复制过来： ``` root@test:~# mkdir /etc/openvpn/easy-rsa -root@test:~# cp -rpv - ↪/usr/share/doc/openvpn/examples/easy-rsa/2.0/* - ↪/etc/openvpn/easy-rsa/ +root@test:~# cp -rpv /usr/share/doc/openvpn/examples/easy-rsa/2.0/* /etc/openvpn/easy-rsa/ ``` 下一步，把 vars 文件复制一个备份： @@ -137,7 +132,6 @@ root@test:/etc/openvpn/easy-rsa# cp vars vars.bak 接下来，编辑一下 vars 以让其中的信息符合你的状态。我将以我需要编辑的信息作为例子： - ``` KEY_SIZE=4096 KEY_COUNTRY="US" @@ -147,19 +141,17 @@ KEY_ORG="Linux Journal" KEY_EMAIL="bill.childers@linuxjournal.com" ``` -下一步是 source 一下 vars ，这样系统就能把其中的信息当作环境变量处理了： +下一步是导入（source）一下 vars 中的环境变量，这样系统就能把其中的信息当作环境变量处理了： ``` root@test:/etc/openvpn/easy-rsa# source ./vars -NOTE: If you run ./clean-all, I will be doing a - ↪rm -rf on /etc/openvpn/easy-rsa/keys +NOTE: If you run ./clean-all, I will be doing a rm -rf on /etc/openvpn/easy-rsa/keys ``` -### 搭建CA（证书签发） +### 搭建 CA（证书签发） - -接下来你要允许一下 `clean-all` 来确保有一个清理干净的系统工作环境，紧接着你也就要做证书签发了。注意一下我修改了一些 changeme 的跳出的交互提示内容以符合我需要的安装情况： +接下来你要运行一下 `clean-all` 来确保有一个清理干净的系统工作环境，紧接着你就要做证书签发了。注意一下我修改了一些 changeme 的所提示修改的内容以符合我需要的安装情况： ``` @@ -182,10 +174,8 @@ Country Name (2 letter code) [US]: State or Province Name (full name) [CA]: Locality Name (eg, city) [Silicon Valley]: Organization Name (eg, company) [Linux Journal]: -Organizational Unit Name (eg, section) - ↪[changeme]:SecTeam -Common Name (eg, your name or your server's hostname) - ↪[changeme]:test.linuxjournal.com +Organizational Unit Name (eg, section) [changeme]:SecTeam +Common Name (eg, your name or your server's hostname) [changeme]:test.linuxjournal.com Name [changeme]:test.linuxjournal.com Email Address [bill.childers@linuxjournal.com]: ``` @@ -193,12 +183,11 @@ Email Address [bill.childers@linuxjournal.com]: ### 生成服务端证书 -一旦CA创建好了，你接着就可以生成客户端的　OpenVPN 证书了： +一旦 CA 创建好了，你接着就可以生成客户端的 OpenVPN 证书了： ``` -root@test:/etc/openvpn/easy-rsa# - ↪./build-key-server test.linuxjournal.com +root@test:/etc/openvpn/easy-rsa# ./build-key-server test.linuxjournal.com Generating a 4096 bit RSA private key ...................................................++ writing new private key to 'test.linuxjournal.com.key' @@ -215,10 +204,8 @@ Country Name (2 letter code) [US]: State or Province Name (full name) [CA]: Locality Name (eg, city) [Silicon Valley]: Organization Name (eg, company) [Linux Journal]: -Organizational Unit Name (eg, section) - ↪[changeme]:SecTeam -Common Name (eg, your name or your server's hostname) - ↪[test.linuxjournal.com]: +Organizational Unit Name (eg, section) [changeme]:SecTeam +Common Name (eg, your name or your server's hostname) [test.linuxjournal.com]: Name [changeme]:test.linuxjournal.com Email Address [bill.childers@linuxjournal.com]: @@ -226,8 +213,7 @@ Please enter the following 'extra' attributes to be sent with your certificate request A challenge password []: An optional company name []: -Using configuration from - ↪/etc/openvpn/easy-rsa/openssl-1.0.0.cnf +Using configuration from /etc/openvpn/easy-rsa/openssl-1.0.0.cnf Check that the request matches the signature Signature ok The Subject's Distinguished Name is as follows @@ -238,10 +224,8 @@ organizationName :PRINTABLE:'Linux Journal' organizationalUnitName:PRINTABLE:'SecTeam' commonName :PRINTABLE:'test.linuxjournal.com' name :PRINTABLE:'test.linuxjournal.com' -emailAddress - ↪:IA5STRING:'bill.childers@linuxjournal.com' -Certificate is to be certified until Sep 1 - ↪06:23:59 2025 GMT (3650 days) +emailAddress :IA5STRING:'bill.childers@linuxjournal.com' +Certificate is to be certified until Sep 1 06:23:59 2025 GMT (3650 days) Sign the certificate? [y/n]:y 1 out of 1 certificate requests certified, commit? [y/n]y @@ -249,13 +233,12 @@ Write out database with 1 new entries Data Base Updated ``` -下一步需要用掉一些时间来生成 OpenVPN 服务器需要的 Diffie-Hellman 密钥。这个步骤在一般的桌面级 CPU 上会需要几分钟的时间，但在 ARM 构架的树莓派上，会用掉超级超级长的时间。耐心点，只要终端上的点还在跳，那么一切就在按部就班运行： +下一步需要用掉一些时间来生成 OpenVPN 服务器需要的 Diffie-Hellman 密钥。这个步骤在一般的桌面级 CPU 上会需要几分钟的时间，但在 ARM 构架的树莓派上，会用掉超级超级长的时间。耐心点，只要终端上的点还在跳，那么一切就在按部就班运行（下面的示例省略了不少的点）： ``` root@test:/etc/openvpn/easy-rsa# ./build-dh -Generating DH parameters, 4096 bit long safe prime, - ↪generator 2 +Generating DH parameters, 4096 bit long safe prime, generator 2 This is going to take a long time ....................................................+ @@ -263,11 +246,10 @@ This is going to take a long time ### 生成客户端证书 -现在你要生成一下客户端用于登陆 OpenVPN 的密钥。通常来说 OpenVPN 都会被配置成使用证书验证的加密方式，在这个配置下客户端需要持有由服务端签发的一份证书： +现在你要生成一下客户端用于登录 OpenVPN 的密钥。通常来说 OpenVPN 都会被配置成使用证书验证的加密方式，在这个配置下客户端需要持有由服务端签发的一份证书： ``` -root@test:/etc/openvpn/easy-rsa# ./build-key - ↪bills-computer +root@test:/etc/openvpn/easy-rsa# ./build-key bills-computer Generating a 4096 bit RSA private key ...................................................++ ...................................................++ @@ -285,10 +267,8 @@ Country Name (2 letter code) [US]: State or Province Name (full name) [CA]: Locality Name (eg, city) [Silicon Valley]: Organization Name (eg, company) [Linux Journal]: -Organizational Unit Name (eg, section) - ↪[changeme]:SecTeam -Common Name (eg, your name or your server's hostname) - ↪[bills-computer]: +Organizational Unit Name (eg, section) [changeme]:SecTeam +Common Name (eg, your name or your server's hostname) [bills-computer]: Name [changeme]:bills-computer Email Address [bill.childers@linuxjournal.com]: @@ -296,8 +276,7 @@ Please enter the following 'extra' attributes to be sent with your certificate request A challenge password []: An optional company name []: -Using configuration from - ↪/etc/openvpn/easy-rsa/openssl-1.0.0.cnf +Using configuration from /etc/openvpn/easy-rsa/openssl-1.0.0.cnf Check that the request matches the signature Signature ok The Subject's Distinguished Name is as follows @@ -308,30 +287,26 @@ organizationName :PRINTABLE:'Linux Journal' organizationalUnitName:PRINTABLE:'SecTeam' commonName :PRINTABLE:'bills-computer' name :PRINTABLE:'bills-computer' -emailAddress - ↪:IA5STRING:'bill.childers@linuxjournal.com' -Certificate is to be certified until - ↪Sep 1 07:35:07 2025 GMT (3650 days) +emailAddress :IA5STRING:'bill.childers@linuxjournal.com' +Certificate is to be certified until Sep 1 07:35:07 2025 GMT (3650 days) Sign the certificate? [y/n]:y -1 out of 1 certificate requests certified, - ↪commit? [y/n]y +1 out of 1 certificate requests certified, commit? [y/n]y Write out database with 1 new entries Data Base Updated root@test:/etc/openvpn/easy-rsa# ``` -现在你需要再生成一个 HMAC 代码作为共享密钥来进一步增加整个加密提供的安全性： +现在你需要再生成一个 HMAC 码作为共享密钥来进一步增加整个加密提供的安全性： ``` -root@test:~# openvpn --genkey --secret - ↪/etc/openvpn/easy-rsa/keys/ta.key +root@test:~# openvpn --genkey --secret /etc/openvpn/easy-rsa/keys/ta.key ``` ### 配置服务器 -最后，你来到了需要配置 OpenVPN 服务的时候了。你需要创建一个 `/etc/openvpn/server.conf` 文件；这个配置文件的大多数地方都可以套用模板解决。设置 OpenVPN 服务的主要修改在于让它只用 TCP 而不是 UDP 链接。这是下一步所必需的---如果不是 TCP 链接那么你的服务将不能通过 端口443 运作。创建 `/etc/openvpn/server.conf` 然后把下述配置丢进去： +最后，我们到了配置 OpenVPN 服务的时候了。你需要创建一个 `/etc/openvpn/server.conf` 文件；这个配置文件的大多数地方都可以套用模板解决。设置 OpenVPN 服务的主要修改在于让它只用 TCP 而不是 UDP 链接。这是下一步所必需的---如果不是 TCP 连接那么你的服务将不能工作在端口 443 上。创建 `/etc/openvpn/server.conf` 然后把下述配置丢进去： ``` @@ -339,23 +314,15 @@ port 1194 proto tcp dev tun ca easy-rsa/keys/ca.crt -cert easy-rsa/keys/test.linuxjournal.com.crt ## or whatever - ↪your hostname was -key easy-rsa/keys/test.linuxjournal.com.key ## Hostname key - ↪- This file should be kept secret +cert easy-rsa/keys/test.linuxjournal.com.crt ## or whatever your hostname was +key easy-rsa/keys/test.linuxjournal.com.key ## Hostname key - This file should be kept secret management localhost 7505 dh easy-rsa/keys/dh4096.pem tls-auth /etc/openvpn/certs/ta.key 0 -server 10.8.0.0 255.255.255.0 # The server will use this - ↪subnet for clients connecting to it +server 10.8.0.0 255.255.255.0 # The server will use this subnet for clients connecting to it ifconfig-pool-persist ipp.txt -push "redirect-gateway def1 bypass-dhcp" # Forces clients - ↪to redirect all traffic through the VPN -push "dhcp-option DNS 192.168.1.1" # Tells the client to - ↪use the DNS server at 192.168.1.1 for DNS - - ↪replace with the IP address of the OpenVPN - ↪machine and clients will use the BIND - ↪server setup earlier +push "redirect-gateway def1 bypass-dhcp" # Forces clients to redirect all traffic through the VPN +push "dhcp-option DNS 192.168.1.1" # Tells the client to use the DNS server at 192.168.1.1 for DNS - replace with the IP address of the OpenVPN machine and clients will use the BIND server setup earlier keepalive 30 240 comp-lzo # Enable compression persist-key @@ -364,14 +331,12 @@ status openvpn-status.log verb 3 ``` -最后，你将需要在服务器上启用 IP 转发，配置 OpenVPN 为开机启动并立刻启动 OpenVPN 服务： +最后，你将需要在服务器上启用 IP 转发，配置 OpenVPN 为开机启动，并立刻启动 OpenVPN 服务： ``` -root@test:/etc/openvpn/easy-rsa/keys# echo - ↪"net.ipv4.ip_forward = 1" >> /etc/sysctl.conf -root@test:/etc/openvpn/easy-rsa/keys# sysctl -p - ↪/etc/sysctl.conf +root@test:/etc/openvpn/easy-rsa/keys# echo "net.ipv4.ip_forward = 1" >> /etc/sysctl.conf +root@test:/etc/openvpn/easy-rsa/keys# sysctl -p /etc/sysctl.conf net.core.wmem_max = 12582912 net.core.rmem_max = 12582912 net.ipv4.tcp_rmem = 10240 87380 12582912 @@ -387,61 +352,48 @@ net.ipv4.tcp_wmem = 10240 87380 12582912 net.ipv4.ip_forward = 0 net.ipv4.ip_forward = 1 -root@test:/etc/openvpn/easy-rsa/keys# update-rc.d - ↪openvpn defaults +root@test:/etc/openvpn/easy-rsa/keys# update-rc.d openvpn defaults update-rc.d: using dependency based boot sequencing -root@test:/etc/openvpn/easy-rsa/keys# - ↪/etc/init.d/openvpn start +root@test:/etc/openvpn/easy-rsa/keys# /etc/init.d/openvpn start [ ok ] Starting virtual private network daemon:. ``` ### 配置 OpenVPN 客户端 +客户端的安装取决于客户端的操作系统，但你需要将之前生成的证书和密钥复制到你的客户端上，并导入你的 OpenVPN 客户端并新建一个配置文件。每种操作系统下的 OpenVPN 客户端在操作上会有些稍许不同，这也不在这篇文章的覆盖范围内，所以你最好去看看特定操作系统下的 OpenVPN 文档来获取更多信息。请参考本文档里的资源那一节。 -客户端的安装取决于客户端的操作系统，但你总会需要之前生成的证书和密钥，并导入你的 OpenVPN 客户端并新建一个配置文件。每种操作系统下的 OpenVPN 客户端在操作上会有些稍许不同，这也不在这篇文章的覆盖范围内，所以你最好去看看特定操作系统下的 OpenVPN 文档来获取更多信息。参考文档里的 Resources 章节。 +### 安装 SSLH —— "魔法"多协议切换工具 -### 安装 SSLH —— "魔法"多协议工具 - -本文章介绍的解决方案最有趣的部分就是运用 SSLH 了。SSLH 是一个多重协议工具——它可以监听443端口的流量，然后分析他们是以SSH，HTTPS 还是 OpenVPN 的通讯包，并把他们分别转发给正确的系统服务。这就是为何本解决方案可以让你绕过大多数端口封杀——你可以一直使用HTTPS通讯，介于它几乎从来不会被封杀。 +本文章介绍的解决方案最有趣的部分就是运用 SSLH 了。SSLH 是一个多重协议工具——它可以监听 443 端口的流量，然后分析他们是 SSH，HTTPS 还是 OpenVPN 的通讯包，并把它们分别转发给正确的系统服务。这就是为何本解决方案可以让你绕过大多数端口封杀——你可以一直使用 HTTPS 通讯，因为它几乎从来不会被封杀。 同样，直接 `apt-get` 安装： ``` -root@test:/etc/openvpn/easy-rsa/keys# apt-get - ↪install sslh +root@test:/etc/openvpn/easy-rsa/keys# apt-get install sslh Reading package lists... Done Building dependency tree Reading state information... Done The following extra packages will be installed: - apache2 apache2-mpm-worker apache2-utils - ↪apache2.2-bin apache2.2-common - libapr1 libaprutil1 libaprutil1-dbd-sqlite3 - ↪libaprutil1-ldap libconfig9 + apache2 apache2-mpm-worker apache2-utils apache2.2-bin apache2.2-common + libapr1 libaprutil1 libaprutil1-dbd-sqlite3 libaprutil1-ldap libconfig9 Suggested packages: - apache2-doc apache2-suexec apache2-suexec-custom - ↪openbsd-inetd inet-superserver + apache2-doc apache2-suexec apache2-suexec-custom openbsd-inetd inet-superserver The following NEW packages will be installed: - apache2 apache2-mpm-worker apache2-utils - ↪apache2.2-bin apache2.2-common - libapr1 libaprutil1 libaprutil1-dbd-sqlite3 - ↪libaprutil1-ldap libconfig9 sslh -0 upgraded, 11 newly installed, 0 to remove - ↪and 0 not upgraded. + apache2 apache2-mpm-worker apache2-utils apache2.2-bin apache2.2-common + libapr1 libaprutil1 libaprutil1-dbd-sqlite3 libaprutil1-ldap libconfig9 sslh +0 upgraded, 11 newly installed, 0 to remove and 0 not upgraded. Need to get 1,568 kB of archives. -After this operation, 5,822 kB of additional - ↪disk space will be used. +After this operation, 5,822 kB of additional disk space will be used. Do you want to continue [Y/n]? y ``` -在 SSLH 被安装之后，包管理器会询问要在 inetd 还是 standalone 模式下允许。选择 standalone 模式，因为你希望 SSLH 在它自己的进程里运行。如果你没有安装 Apache，apt包管理器会自动帮你下载并安装的，尽管它也不是完全不可或缺。如果你已经有 Apache 了，那你需要确保它只监听 localhost 端口而不是所有的端口（不然的话 SSLH 会无法运行因为 443 端口已经被 Apache 监听占用）。安装后，你会看到一个如下所示的错误信息： +在 SSLH 被安装之后，包管理器会询问要在 inetd 还是 standalone 模式下允许。选择 standalone 模式，因为你希望 SSLH 在它自己的进程里运行。如果你没有安装 Apache，apt 包管理器会自动帮你下载并安装的，尽管它也不是完全不可或缺。如果你已经有 Apache 了，那你需要确保它只监听 localhost 端口而不是所有的端口（不然的话 SSLH 会无法运行，因为 443 端口已经被 Apache 监听占用）。安装后，你会看到一个如下所示的错误信息： ``` -[....] Starting ssl/ssh multiplexer: sslhsslh disabled, - ↪please adjust the configuration to your needs -[FAIL] and then set RUN to 'yes' in /etc/default/sslh - ↪to enable it. ... failed! +[....] Starting ssl/ssh multiplexer: sslhsslh disabled, please adjust the configuration to your needs +[FAIL] and then set RUN to 'yes' in /etc/default/sslh to enable it. ... failed! failed! ``` @@ -461,20 +413,16 @@ failed! RUN=yes -# binary to use: forked (sslh) or single-thread - ↪(sslh-select) version +# binary to use: forked (sslh) or single-thread (sslh-select) version DAEMON=/usr/sbin/sslh -DAEMON_OPTS="--user sslh --listen 0.0.0.0:443 --ssh - ↪127.0.0.1:22 --ssl 127.0.0.1:443 --openvpn - ↪127.0.0.1:1194 --pidfile /var/run/sslh/sslh.pid" +DAEMON_OPTS="--user sslh --listen 0.0.0.0:443 --ssh 127.0.0.1:22 --ssl 127.0.0.1:443 --openvpn 127.0.0.1:1194 --pidfile /var/run/sslh/sslh.pid" ``` 保存编辑并启动 SSLH： ``` - root@test:/etc/openvpn/easy-rsa/keys# - ↪/etc/init.d/sslh start + root@test:/etc/openvpn/easy-rsa/keys# /etc/init.d/sslh start [ ok ] Starting ssl/ssh multiplexer: sslh. ``` @@ -485,26 +433,21 @@ $ ssh -p 443 root@test.linuxjournal.com root@test:~# ``` -SSLH 现在开始监听端口443 并且可以转发流量信息到 SSH，Apache 或者 OpenVPN 取决于抵达流量包的类型。这套系统现已整装待发了！ +SSLH 现在开始监听端口 443 并且可以转发流量信息到 SSH、Apache 或者 OpenVPN ，这取决于抵达流量包的类型。这套系统现已整装待发了！ ### 结论 -现在你可以启动 OpenVPN 并且配置你的客户端连接到服务器的 443 端口了，然后 SSLH 会从那里把流量转发到服务器的 1194 端口。但介于你正在和服务器的 443 端口通信，你的 VPN 流量不会被封锁。现在你可以舒服地坐在陌生小镇的咖啡店里，畅通无阻地通过树莓派上的 OpenVPN 浏览互联网。你顺便还给你的链接增加了一些安全性，这个额外作用也会让你的链接更安全和私密一些。享受通过安全跳板浏览互联网把！ +现在你可以启动 OpenVPN 并且配置你的客户端连接到服务器的 443 端口了，然后 SSLH 会从那里把流量转发到服务器的 1194 端口。但鉴于你正在和服务器的 443 端口通信，你的 VPN 流量不会被封锁。现在你可以舒服地坐在陌生小镇的咖啡店里，畅通无阻地通过你的树莓派上的 OpenVPN 浏览互联网。你顺便还给你的链接增加了一些安全性，这个额外作用也会让你的链接更安全和私密一些。享受通过安全跳板浏览互联网把！ -资源： +### 参考资源 -安装与配置 OpenVPN: [https://wiki.debian.org/OpenVPN](https://wiki.debian.org/OpenVPN) and [http://cryptotap.com/articles/openvpn](http://cryptotap.com/articles/openvpn) - -OpenVPN 客户端下载: [https://openvpn.net/index.php/open-source/downloads.html](https://openvpn.net/index.php/open-source/downloads.html) - -OpenVPN Client for iOS: [https://itunes.apple.com/us/app/openvpn-connect/id590379981?mt=8](https://itunes.apple.com/us/app/openvpn-connect/id590379981?mt=8) - -OpenVPN Client for Android: [https://play.google.com/store/apps/details?id=net.openvpn.openvpn&hl=en](https://play.google.com/store/apps/details?id=net.openvpn.openvpn&hl=en) - -Tunnelblick for Mac OS X (OpenVPN client): [https://tunnelblick.net](https://tunnelblick.net) - -SSLH 介绍: [http://www.rutschle.net/tech/sslh.shtml](http://www.rutschle.net/tech/sslh.shtml) 和 [https://github.com/yrutschle/sslh](https://github.com/yrutschle/sslh) +- 安装与配置 OpenVPN: [https://wiki.debian.org/OpenVPN](https://wiki.debian.org/OpenVPN) 和 [http://cryptotap.com/articles/openvpn](http://cryptotap.com/articles/openvpn) +- OpenVPN 客户端下载: [https://openvpn.net/index.php/open-source/downloads.html](https://openvpn.net/index.php/open-source/downloads.html) +- OpenVPN iOS 客户端: [https://itunes.apple.com/us/app/openvpn-connect/id590379981?mt=8](https://itunes.apple.com/us/app/openvpn-connect/id590379981?mt=8) +- OpenVPN Android 客户端: [https://play.google.com/store/apps/details?id=net.openvpn.openvpn&hl=en](https://play.google.com/store/apps/details?id=net.openvpn.openvpn&hl=en) +- Tunnelblick for Mac OS X (OpenVPN 客户端): [https://tunnelblick.net](https://tunnelblick.net) +- SSLH 介绍: [http://www.rutschle.net/tech/sslh.shtml](http://www.rutschle.net/tech/sslh.shtml) 和 [https://github.com/yrutschle/sslh](https://github.com/yrutschle/sslh) ---------- @@ -512,7 +455,7 @@ via: http://www.linuxjournal.com/content/securi-pi-using-raspberry-pi-secure-lan 作者：[Bill Childers][a] 译者：[Moelf](https://github.com/Moelf) -校对：[校对者ID](https://github.com/校对者ID) +校对：[wxy](https://github.com/wxy) 本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创翻译，[Linux中国](https://linux.cn/) 荣誉推出 diff --git a/published/201607/20160104 What is good stock portfolio management software on Linux.md b/published/201607/20160104 What is good stock portfolio management software on Linux.md new file mode 100644 index 0000000000..15c5091b6a --- /dev/null +++ b/published/201607/20160104 What is good stock portfolio management software on Linux.md @@ -0,0 +1,111 @@ +JStock：Linux 上不错的股票投资组合管理软件 +================================================================================ + +如果你在股票市场做投资，那么你可能非常清楚投资组合管理计划有多重要。管理投资组合的目标是依据你能承受的风险，时间层面的长短和资金盈利的目标去为你量身打造的一种投资计划。鉴于这类软件的重要性，因此从来不会缺乏商业性的 app 和股票行情检测软件，每一个都可以兜售复杂的投资组合以及跟踪报告功能。 + +对于我们这些 Linux 爱好者们，我也找到了一些**好用的开源投资组合管理工具**，用来在 Linux 上管理和跟踪股票的投资组合，这里高度推荐一个基于 java 编写的管理软件 [JStock][1]。如果你不是一个 java 粉，也许你会放弃它，JStock 需要运行在沉重的 JVM 环境上。但同时，在每一个安装了 JRE 的环境中它都可以马上运行起来，在你的 Linux 环境中它会运行的很顺畅。 + +“开源”就意味着免费或标准低下的时代已经过去了。鉴于 JStock 只是一个个人完成的产物，作为一个投资组合管理软件它最令人印象深刻的是包含了非常多实用的功能，以上所有的荣誉属于它的作者 Yan Cheng Cheok！例如，JStock 支持通过监视列表去监控价格，多种投资组合，自选/内置的股票指标与相关监测，支持27个不同的股票市场和跨平台的云端备份/还原。JStock 支持多平台部署（Linux, OS X, Android 和 Windows），你可以通过云端保存你的 JStock 投资组合，并通过云平台无缝的备份/还原到其他的不同平台上面。 + +现在我将向你展示如何安装以及使用过程的一些具体细节。 + +### 在 Linux 上安装 JStock ### + +因为 JStock 使用Java编写，所以必须[安装 JRE][2]才能让它运行起来。小提示，JStock 需要 JRE1.7 或更高版本。如你的 JRE 版本不能满足这个需求，JStock 将会运行失败然后出现下面的报错。 + + Exception in thread "main" java.lang.UnsupportedClassVersionError: org/yccheok/jstock/gui/JStock : Unsupported major.minor version 51.0 + + +在你的 Linux 上安装好了 JRE 之后，从其官网下载最新的发布的 JStock，然后加载启动它。 + + $ wget https://github.com/yccheok/jstock/releases/download/release_1-0-7-13/jstock-1.0.7.13-bin.zip + $ unzip jstock-1.0.7.13-bin.zip + $ cd jstock + $ chmod +x jstock.sh + $ ./jstock.sh + +教程的其他部分，让我来给大家展示一些 JStock 的实用功能 + +### 监视监控列表中股票价格的波动 ### + +使用 JStock 你可以创建一个或多个监视列表，它可以自动的监视股票价格的波动并给你提供相应的通知。在每一个监视列表里面你可以添加多个感兴趣的股票进去。之后在“Fall Below”和“Rise Above”的表格里添加你的警戒值，分别设定该股票的最低价格和最高价格。 + +![](https://c2.staticflickr.com/2/1588/23795349969_37f4b0f23c_c.jpg) + +例如你设置了 AAPL 股票的最低/最高价格分别是 $102 和 $115.50，只要在价格低于 $102 或高于 $115.50 时你就得到桌面通知。 + +你也可以设置邮件通知，这样你将收到一些价格信息的邮件通知。设置邮件通知在“Options”菜单里，在“Alert”标签中国，打开“Send message to email(s)”，填入你的 Gmail 账户。一旦完成 Gmail 认证步骤，JStock 就会开始发送邮件通知到你的 Gmail 账户（也可以设置其他的第三方邮件地址）。 + +![](https://c2.staticflickr.com/2/1644/24080560491_3aef056e8d_b.jpg) + +### 管理多个投资组合 ### + +JStock 允许你管理多个投资组合。这个功能对于你使用多个股票经纪人时是非常实用的。你可以为每个经纪人创建一个投资组合去管理你的“买入/卖出/红利”用来了解每一个经纪人的业务情况。你也可以在“Portfolio”菜单里面选择特定的投资组合来切换不同的组合项目。下面是一张截图用来展示一个假设的投资组合。 + +![](https://c2.staticflickr.com/2/1646/23536385433_df6c036c9a_c.jpg) + +你也可以设置付给中介费，你可以为每个买卖交易设置中介费、印花税以及结算费。如果你比较懒，你也可以在选项菜单里面启用自动费用计算，并提前为每一家经济事务所设置费用方案。当你为你的投资组合增加交易之后，JStock 将自动的计算并计入费用。 + +![](https://c2.staticflickr.com/2/1653/24055085262_0e315c3691_b.jpg) + +### 使用内置/自选股票指标来监控 ### + +如果你要做一些股票的技术分析，你可能需要基于各种不同的标准来监控股票（这里叫做“股票指标”）。对于股票的跟踪，JStock提供多个[预设的技术指示器][3] 去获得股票上涨/下跌/逆转指数的趋势。下面的列表里面是一些可用的指标。 + +- 平滑异同移动平均线（MACD） +- 相对强弱指标 (RSI) +- 资金流向指标 (MFI) +- 顺势指标 (CCI) +- 十字线 +- 黄金交叉线，死亡交叉线 +- 涨幅/跌幅 + +开启预设指示器能需要在 JStock 中点击“Stock Indicator Editor”标签。之后点击右侧面板中的安装按钮。选择“Install from JStock server”选项，之后安装你想要的指示器。 + +![](https://c2.staticflickr.com/2/1476/23867534660_b6a9c95a06_c.jpg) + +一旦安装了一个或多个指示器，你可以用他们来扫描股票。选择“Stock Indicator Scanner”标签，点击底部的“Scan”按钮，选择需要的指示器。 + +![](https://c2.staticflickr.com/2/1653/24137054996_e8fcd10393_c.jpg) + +当你选择完需要扫描的股票（例如， NYSE, NASDAQ）以后，JStock 将执行该扫描，并将该指示器捕获的结果通过列表展现。 + +![](https://c2.staticflickr.com/2/1446/23795349889_0f1aeef608_c.jpg) + +除了预设指示器以外，你也可以使用一个图形化的工具来定义自己的指示器。下面这张图例用于监控当前价格小于或等于60天平均价格的股票。 + +![](https://c2.staticflickr.com/2/1605/24080560431_3d26eac6b5_c.jpg) + +### 通过云在 Linux 和 Android JStock 之间备份/恢复### + +另一个非常棒的功能是 JStock 支持云备份恢复。Jstock 可以通过 Google Drive 把你的投资组合/监视列表在云上备份和恢复，这个功能可以实现在不同平台上无缝穿梭。如果你在两个不同的平台之间来回切换使用 Jstock，这种跨平台备份和还原非常有用。我在 Linux 桌面和 Android 手机上测试过我的 Jstock 投资组合，工作的非常漂亮。我在 Android 上将 Jstock 投资组合信息保存到 Google Drive 上，然后我可以在我的 Linux 版的 Jstock 上恢复它。如果能够自动同步到云上，而不用我手动地触发云备份/恢复就更好了，十分期望这个功能出现。 + +![](https://c2.staticflickr.com/2/1537/24163165565_bb47e04d6c_c.jpg) + +![](https://c2.staticflickr.com/2/1556/23536385333_9ed1a75d72_c.jpg) + +如果你在从 Google Drive 还原之后不能看到你的投资信息以及监视列表，请确认你的国家信息与“Country”菜单里面设置的保持一致。 + +JStock 的安卓免费版可以从 [Google Play Store][4] 获取到。如果你需要完整的功能（比如云备份，通知，图表等），你需要一次性支付费用升级到高级版。我认为高级版物有所值。 + +![](https://c2.staticflickr.com/2/1687/23867534720_18b917028c_c.jpg) + +写在最后，我应该说一下它的作者，Yan Cheng Cheok，他是一个十分活跃的开发者，有bug及时反馈给他。这一切都要感谢他！！！ + +关于 JStock 这个投资组合跟踪软件你有什么想法呢？ + +-------------------------------------------------------------------------------- + +via: http://xmodulo.com/stock-portfolio-management-software-Linux.html + +作者：[Dan Nanni][a] +译者：[ivo-wang](https://github.com/ivo-wang) +校对：[wxy](https://github.com/wxy) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://Linux.cn/) 荣誉推出 + +[a]:http://xmodulo.com/author/nanni +[1]:http://jstock.org/ +[2]:http://ask.xmodulo.com/install-java-runtime-Linux.html +[3]:http://jstock.org/ma_indicator.html +[4]:https://play.google.com/store/apps/details?id=org.yccheok.jstock.gui diff --git a/published/201607/20160218 How to Best Manage Encryption Keys on Linux.md b/published/201607/20160218 How to Best Manage Encryption Keys on Linux.md new file mode 100644 index 0000000000..fa0e559ff9 --- /dev/null +++ b/published/201607/20160218 How to Best Manage Encryption Keys on Linux.md @@ -0,0 +1,104 @@ +在 Linux 上管理加密密钥的最佳体验 +============================================= + +存储 SSH 的加密秘钥和记住密码一直是一个让人头疼的问题。但是不幸的是，在当前这个充满了恶意黑客和攻击的世界中，基本的安全预防是必不可少的。对于许多普通用户来说，大多数人只能是记住密码，也可能寻找到一个好程序去存储密码，正如我们提醒这些用户不要在每个网站采用相同的密码。但是对于在各个 IT 领域的人们，我们需要将这个事情提高一个层面。我们需要使用像 SSH 密钥这样的加密秘钥，而不只是密码。 + +设想一个场景：我有一个运行在云上的服务器，用作我的主 git 库。我有很多台工作电脑，所有这些电脑都需要登录到这个中央服务器去做 push 与 pull 操作。这里我设置 git 使用 SSH。当 git 使用 SSH 时，git 实际上是以 SSH 的方式登录到服务器，就好像你通过 SSH 命令打开一个服务器的命令行一样。为了把这些配置好，我在我的 .ssh 目录下创建一个配置文件，其中包含一个有服务器名字、主机名、登录用户、密钥文件路径等信息的主机项。之后我可以通过输入如下命令来测试这个配置是否正确。 + + ssh gitserver + +很快我就可以访问到服务器的 bash shell。现在我可以配置 git 使用相同配置项以及存储的密钥来登录服务器。这很简单，只是有一个问题：对于每一个我要用它登录服务器的电脑，我都需要有一个密钥文件，那意味着需要密钥文件会放在很多地方。我会在当前这台电脑上存储这些密钥文件，我的其他电脑也都需要存储这些。就像那些有特别多的密码的用户一样，我们这些 IT 人员也被这些特别多的密钥文件淹没。怎么办呢？ + +### 清理 + +在我们开始帮助你管理密钥之前，你需要有一些密钥应该怎么使用的基础知识，以及明白我们下面的提问的意义所在。同时，有个前提，也是最重要的，你应该知道你的公钥和私钥该放在哪里。然后假设你应该知道： + +1. 公钥和私钥之间的差异； +2. 为什么你不可以从公钥生成私钥，但是反之则可以？ +3. `authorized_keys` 文件的目的以及里面包含什么内容； +4. 如何使用私钥去登录一个你的对应公钥存储在其上的 `authorized_keys` 文件中的服务器。 + +![](http://www.linux.com/images/stories/41373/key-management-diagram.png) + +这里有一个例子。当你在亚马逊的网络服务上创建一个云服务器，你必须提供一个用于连接你的服务器的 SSH 密钥。每个密钥都有一个公开的部分（公钥）和私密的部分（私钥）。你要想让你的服务器安全，乍看之下你可能应该将你的私钥放到服务器上，同时你自己带着公钥。毕竟，你不想你的服务器被公开访问，对吗？但是实际上的做法正好是相反的。 + +你应该把自己的公钥放到 AWS 服务器，同时你持有用于登录服务器的私钥。你需要保护好私钥，并让它处于你的控制之中，而不是放在一些远程服务器上，正如上图中所示。 + +原因如下：如果公钥被其他人知道了，它们不能用于登录服务器，因为他们没有私钥。进一步说，如果有人成功攻入你的服务器，他们所能找到的只是公钥，他们不可以从公钥生成私钥。同时，如果你在其他的服务器上使用了相同的公钥，他们不可以使用它去登录别的电脑。 + +这就是为什么你要把你自己的公钥放到你的服务器上以便通过 SSH 登录这些服务器。你持有这些私钥，不要让这些私钥脱离你的控制。 + +但是还有一点麻烦。试想一下我 git 服务器的例子。我需要做一些抉择。有时我登录架设在别的地方的开发服务器，而在开发服务器上，我需要连接我的 git 服务器。如何使我的开发服务器连接 git 服务器？显然是通过使用私钥，但这样就会有问题。在该场景中，需要我把私钥放置到一个架设在别的地方的服务器上，这相当危险。 + +一个进一步的场景：如果我要使用一个密钥去登录许多的服务器，怎么办？如果一个入侵者得到这个私钥，这个人就能用这个私钥得到整个服务器网络的权限，这可能带来一些严重的破坏，这非常糟糕。 + +同时，这也带来了另外一个问题，我真的应该在这些其他服务器上使用相同的密钥吗？因为我刚才描述的，那会非常危险的。 + +最后，这听起来有些混乱，但是确实有一些简单的解决方案。让我们有条理地组织一下。 + +（注意，除了登录服务器，还有很多地方需要私钥密钥，但是我提出的这个场景可以向你展示当你使用密钥时你所面对的问题。） + +### 常规口令 + +当你创建你的密钥时，你可以选择是否包含一个密钥使用时的口令。有了这个口令，私钥文件本身就会被口令所加密。例如，如果你有一个公钥存储在服务器上，同时你使用私钥去登录服务器的时候，你会被提示输入该口令。没有口令，这个密钥是无法使用的。或者你也可以配置你的密钥不需要口令，然后只需要密钥文件就可以登录服务器了。 + +一般来说，不使用口令对于用户来说是更方便的，但是在很多情况下我强烈建议使用口令，原因是，如果私钥文件被偷了，偷密钥的人仍然不可以使用它，除非他或者她可以找到口令。在理论上，这个将节省你很多时间，因为你可以在攻击者发现口令之前，从服务器上删除公钥文件，从而保护你的系统。当然还有一些使用口令的其它原因，但是在很多场合这个原因对我来说更有价值。（举一个例子，我的 Android 平板上有 VNC 软件。平板上有我的密钥。如果我的平板被偷了之后，我会马上从服务器上删除公钥，使得它的私钥没有作用，无论有没有口令。）但是在一些情况下我不使用口令，是因为我正在登录的服务器上没有什么有价值的数据，这取决于情境。 + +### 服务器基础设施 + +你如何设计自己服务器的基础设施将会影响到你如何管理你的密钥。例如，如果你有很多用户登录，你将需要决定每个用户是否需要一个单独的密钥。（一般来说，应该如此；你不会想在用户之间共享私钥。那样当一个用户离开组织或者失去信任时，你可以删除那个用户的公钥，而不需要必须给其他人生成新的密钥。相似地，通过共享密钥，他们能以其他人的身份登录，这就更糟糕了。）但是另外一个问题是你如何配置你的服务器。举例来说，你是否使用像 Puppet 这样工具配置大量的服务器？你是否基于你自己的镜像创建大量的服务器？当你复制你的服务器，是否每一个的密钥都一样？不同的云服务器软件允许你配置如何选择；你可以让这些服务器使用相同的密钥，也可以给每一个服务器生成一个新的密钥。 + +如果你在操作这些复制的服务器，如果用户需要使用不同的密钥登录两个不同但是大部分都一样的系统，它可能导致混淆。但是另一方面，服务器共享相同的密钥会有安全风险。或者，第三，如果你的密钥有除了登录之外的需要（比如挂载加密的驱动），那么你会在很多地方需要相同的密钥。正如你所看到的，你是否需要在不同的服务器上使用相同的密钥不是我能为你做的决定；这其中有权衡，你需要自己去决定什么是最好的。 + +最终，你可能会有： + +- 需要登录的多个服务器 +- 多个用户登录到不同的服务器，每个都有自己的密钥 +- 每个用户使用多个密钥登录到不同的服务器 + +（如果你正在别的情况下使用密钥，这个同样的普适理论也能应用于如何使用密钥，需要多少密钥，它们是否共享，你如何处理公私钥等方面。） + +### 安全方法 + +了解你的基础设施和特有的情况，你需要组合一个密钥管理方案，它会指导你如何去分发和存储你的密钥。比如，正如我之前提到的，如果我的平板被偷了，我会从我服务器上删除公钥，我希望这在平板在用于访问服务器之前完成。同样的，我会在我的整体计划中考虑以下内容： + +1. 私钥可以放在移动设备上，但是必须包含口令； +2. 必须有一个可以快速地从服务器上删除公钥的方法。 + +在你的情况中，你可能决定你不想在自己经常登录的系统上使用口令；比如，这个系统可能是一个开发者一天登录多次的测试机器。这没有问题，但是你需要调整一点你的规则。你可以添加一条规则：不可以通过移动设备登录该机器。换句话说，你需要根据自己的状况构建你的准则，不要假设某个方案放之四海而皆准。 + +### 软件 + +至于软件，令人吃惊的是，现实世界中并没有很多好的、可靠的存储和管理私钥的软件解决方案。但是应该有吗？考虑下这个，如果你有一个程序存储你所有服务器的全部密钥，并且这个程序被一个快捷的密钥锁住，那么你的密钥就真的安全了吗？或者类似的，如果你的密钥被放置在你的硬盘上，用于 SSH 程序快速访问，密钥管理软件是否真正提供了任何保护吗？ + +但是对于整体基础设施和创建/管理公钥来说，有许多的解决方案。我已经提到了 Puppet，在 Puppet 的世界中，你可以创建模块以不同的方式管理你的服务器。这个想法是服务器是动态的，而且不需要精确地复制彼此。[这里有一个聪明的方法](http://manuel.kiessling.net/2014/03/26/building-manageable-server-infrastructures-with-puppet-part-4/)，在不同的服务器上使用相同的密钥，但是对于每一个用户使用不同的 Puppet 模块。这个方案可能适合你，也可能不适合你。 + +或者，另一个选择就是完全换个不同的档位。在 Docker 的世界中，你可以采取一个不同的方式，正如[关于 SSH 和 Docker 博客](http://blog.docker.com/2014/06/why-you-dont-need-to-run-sshd-in-docker/)所描述的那样。 + +但是怎么样管理私钥？如果你搜索过的话，你无法找到很多可以选择的软件，原因我之前提到过；私钥存放在你的硬盘上，一个管理软件可能无法提到更多额外的安全。但是我使用这种方法来管理我的密钥： + +首先，我的 `.ssh/config` 文件中有很多的主机项。我要登录的都有一个主机项，但是有时我对于一个单独的主机有不止一项。如果我有很多登录方式，就会出现这种情况。对于放置我的 git 库的服务器来说，我有两个不同的登录项；一个限制于 git，另一个用于一般用途的 bash 访问。这个为 git 设置的登录选项在机器上有极大的限制。还记得我之前说的我存储在远程开发机器上的 git 密钥吗？好了。虽然这些密钥可以登录到我其中一个服务器，但是使用的账号是被严格限制的。 + +其次，大部分的私钥都包含口令。（对于需要多次输入口令的情况，考虑使用 [ssh-agent](http://blog.docker.com/2014/06/why-you-dont-need-to-run-sshd-in-docker/)。） + +再次，我有一些我想要更加小心地保护的服务器，我不会把这些主机项放在我的 host 文件中。这更加接近于社会工程方面，密钥文件还在，但是可能需要攻击者花费更长的时间去找到这个密钥文件，分析出来它们对应的机器。在这种情况下，我就需要手动打出来一条长长的 SSH 命令。（没那么可怕。） + +同时你可以看出来我没有使用任何特别的软件去管理这些私钥。 + +## 无放之四海而皆准的方案 + +我们偶尔会在 linux.com 收到一些问题，询问管理密钥的好软件的建议。但是退一步看，这个问题事实上需要重新思考，因为没有一个普适的解决方案。你问的问题应该基于你自己的状况。你是否简单地尝试找到一个位置去存储你的密钥文件？你是否寻找一个方法去管理多用户问题，其中每个人都需要将他们自己的公钥插入到 `authorized_keys` 文件中？ + +通过这篇文章，我已经囊括了这方面的基础知识，希望到此你明白如何管理你的密钥，并且，只有当你问出了正确的问题，无论你寻找任何软件（甚至你需要另外的软件），它都会出现。 + +------------------------------------------------------------------------------ + +via: http://www.linux.com/learn/tutorials/838235-how-to-best-manage-encryption-keys-on-linux + +作者：[Jeff Cogswell][a] +译者：[mudongliang](https://github.com/mudongliang) +校对：[wxy](https://github.com/wxy) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创翻译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]:http://www.linux.com/community/forums/person/62256 diff --git a/published/201607/20160218 What do Linux developers think of Git and GitHub.md b/published/201607/20160218 What do Linux developers think of Git and GitHub.md new file mode 100644 index 0000000000..1824c6e19e --- /dev/null +++ b/published/201607/20160218 What do Linux developers think of Git and GitHub.md @@ -0,0 +1,110 @@ +Linux 开发者如何看待 Git 和 Github？ +===================================================== + +### Linux 开发者如何看待 Git 和 Github？ + +Git 和 Github 在 Linux 开发者中有很高的知名度。但是开发者如何看待它们呢？另外，Github 是不是真的和 Git 是一个意思？一个 Linux reddit 用户最近问到了这个问题，并且得到了很有意思的答案。 + +Dontwakemeup46 提问： + +> 我正在学习 Git 和 Github。我感兴趣社区如何看待两者？据我所知，Git 和 Github 应用十分广泛。但是 Git 或 Github 有没有严重的不足？社区喜欢去改变些什么呢？ + +[更多见 Reddit](https://www.reddit.com/r/linux/comments/45jy59/the_popularity_of_git_and_github/) + +与他志同道合的 Linux reddit 用户回答了他们对于 Git 和 Github的观点： + +>**Derenir**: “Github 并不附属于 Git。 + +> Git 是由 Linus Torvalds 开发的。 + +> Github 几乎不支持 Linux。 + +> Github 是一家企图借助 Git 赚钱的公司。 + +> https://desktop.github.com/ 并没有支持 Linux。” + +--- +>**Bilog78**: “一个小的补充： Linus Torvalds 已经不再维护 Git了。维护者是 Junio C Hamano，以及 在他之后的主要贡献者是 Jeff King 和 Shawn O. Pearce。” + +--- + +>**Fearthefuture**: “我喜欢 Git，但是不明白人们为什么还要使用 Github。从我的角度，Github 比 Bitbucket 好的一点是用户统计和更大的用户基础。Bitbucket 有无限的免费私有库，更好的 UI，以及更好地集成了其他服务，比如说 Jenkins。” + +--- + +>**Thunger**: “Gitlab.com 也很不错，特别是你可以在自己的服务器上架设自己的实例。” + +--- + +>**Takluyver**: “很多人熟悉 Github 的 UI 以及相关联的服务，比如说 Travis 。并且很多人都有 Github 账号，所以它是存储项目的一个很好的地方。人们也使用他们的 Github 个人信息页作为一种求职用的作品选辑，所以他们很积极地将更多的项目放在这里。Github 是一个存放开源项目的事实标准。” + +--- + +>**Tdammers**: “Git 严重问题在于 UI，它有些违反直觉，以至于很多用户只能达到使用一些容易记住的咒语的程度。” + +> Github：最严重的问题在于它是商业托管的解决方案；你买了方便，但是代价是你的代码在别人的服务器上面，已经不在你的掌控范围之内了。另一个对于 Github 的普遍批判是它的工作流和 Git 本身的精神不符，特别是 pull requests 工作的方式。最后， Github 垄断了代码的托管环境，同时对于多样性是很不好的，这反过来对于旺盛的免费软件社区很重要。” + +--- + +>**Dies**: “更重要的是，如果一旦是这样，按照现状来说，我猜我们会被 Github 所困，因为它们控制如此多的项目。” + +--- + +>**Tdammers**: “代码托管在别人的服务器上，这里"别人"指的是 Github。这对于开源项目来说，并不是什么太大的问题，但是尽管如此，你无法控制它。如果你在 Github 上有私有项目，“它将保持私有”的唯一的保险只是 Github 的承诺而已。如果你决定删除东西，你不能确定东西是否被删除了，或者只是隐藏了。 + +Github 并不自己控制这些项目（你总是可以拿走你的代码，然后托管到别的地方，声明新位置是“官方”的），它只是有比开发者本身有更深的使用权。” + +--- + +>**Drelos**: “我已经读了大量的关于 Github 的赞美与批评。（这里有一个[例子](http://www.wired.com/2015/06/problem-putting-worlds-code-github/)），但是我的幼稚问题是为什么不向一个免费开源的版本努力呢？” + +--- + +>**Twizmwazin**: “Gitlab 的源码就存在这里” + +--- + +[更多见 Reddit](https://www.reddit.com/r/linux/comments/45jy59/the_popularity_of_git_and_github/) + +### DistroWatch 评估 XStream 桌面 153 版本 + +XStreamOS 是一个由 Sonicle 创建的 Solaris 的一个版本。XStream 桌面将 Solaris 的强大带给了桌面用户，同时新手用户很可能有兴趣体验一下。DistroWatch 对于 XStream 桌面 153 版本做了一个很全面的评估，并且发现它运行相当好。 + +Jesse Smith 为 DistroWatch 报道: + +> 我认为 XStream 桌面做好了很多事情。诚然，当操作系统无法在我的硬件上启动，同时当运行在 VirtualBox 中时我无法使得桌面使用我显示器的完整分辨率，我的开端并不很成功。不过，除此之外，XStream 表现的很好。安装器工作的很好，该系统自动设置和使用了引导环境（boot environments），这让我们可以在发生错误时恢复该系统。包管理器有工作的不错， XStream 带了一套有用的软件。 + +> 我确实在播放多媒体文件时遇见一些问题，特别是使声卡工作。我不确定这是不是又一个硬件兼容问题，或者是该操作系统自带的多媒体软件的问题。另一方面，像 Web 浏览器，电子邮件，生产工具套件以及配置工具这样的工作的很好。 + +> 我最欣赏 XStream 的地方是这个操作系统是 OpenSolaris 家族的一个使用保持最新的分支。OpenSolaris 的其他衍生系统有落后的倾向，但是至少在桌面软件上，XStream 搭载最新版本的火狐和 LibreOffice。 + +> 对我个人来说，XStream 缺少一些组件，比如打印机管理器，多媒体支持和我的特定硬件的驱动。这个操作系统的其他方面也是相当吸引人的。我喜欢开发者搭配了 LXDE，也喜欢它的默认软件集，以及我最喜欢文件系统快照和启动环境开箱即用的方式。大多数的 Linux 发行版，openSUSE 除外，并没有利用好引导环境（boot environments）的用途。我希望它是一个被更多项目采用的技术。 + +[更多见 DistroWatch](http://distrowatch.com/weekly.php?issue=20160215#xstreamos) + +### 街头霸王 V 和 SteamOS + +街头霸王是最出名的游戏之一，并且 [Capcom 已经宣布](http://steamcommunity.com/games/310950/announcements/detail/857177755595160250) 街头霸王 V 将会在这个春天进入 Linux 和 StreamOS。这对于 Linux 游戏者是非常好的消息。 + +Joe Parlock 为 Destructoid 报道： + +> 你是不足 1% 的那些在 Linux 系统上玩游戏的 Stream 用户吗？你是更少数的那些在 Linux 平台上玩游戏，同时也很喜欢街头霸王 V 的人之一吗？是的话，我有一些好消息要告诉你。 + +> Capcom 已经宣布，这个春天街头霸王 V 通过 Stream 进入 StreamOS 以及其他 Linux 发行版。它无需任何额外的花费，所以那些已经在自己的个人电脑上安装了该游戏的人可以很容易在 Linux 上安装它并玩了。 + +[更多 Destructoid](https://www.destructoid.com/street-fighter-v-is-coming-to-linux-and-steamos-this-spring-341531.phtml) + +你是否错过了摘要？检查 [开源之眼的主页](http://www.infoworld.com/blog/eye-on-open/) 来获得关于 Linux 和开源的最新的新闻。 + +------------------------------------------------------------------------------ + +via: http://www.infoworld.com/article/3033059/linux/what-do-linux-developers-think-of-git-and-github.html + +作者：[Jim Lynch][a] +译者：[mudongliang](https://github.com/mudongliang) +校对：[wxy](https://github.com/wxy) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创翻译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]:http://www.infoworld.com/author/Jim-Lynch/ + diff --git a/published/201607/20160219 How to Setup Lighttpd Web server on Ubuntu 15.04 or CentOS 7.md b/published/201607/20160219 How to Setup Lighttpd Web server on Ubuntu 15.04 or CentOS 7.md new file mode 100644 index 0000000000..3db9318138 --- /dev/null +++ b/published/201607/20160219 How to Setup Lighttpd Web server on Ubuntu 15.04 or CentOS 7.md @@ -0,0 +1,213 @@ +如何在 Ubuntu 15.04/CentOS 7 中安装 Lighttpd Web 服务器 +================================================================================= + +Lighttpd 是一款开源 Web 服务器软件。Lighttpd 安全快速，符合行业标准，适配性强并且针对高配置环境进行了优化。相对于其它的 Web 服务器而言，Lighttpd 占用内存更少；因其对 CPU 占用小和对处理速度的优化而在效率和速度方面从众多 Web 服务器中脱颖而出。而 Lighttpd 诸如 FastCGI、CGI、认证、输出压缩、URL 重写等高级功能更是那些面临性能压力的服务器的福音。 + +以下便是我们在运行 Ubuntu 15.04 或 CentOS 7 Linux 发行版的机器上安装 Lighttpd Web 服务器的简要流程。 + +### 安装Lighttpd + +#### 使用包管理器安装 + +这里我们通过使用包管理器这种最简单的方法来安装 Lighttpd。只需以 sudo 模式在终端或控制台中输入下面的指令即可。 + +**CentOS 7** + +由于 CentOS 7.0 官方仓库中并没有提供 Lighttpd，所以我们需要在系统中安装额外的软件源 epel 仓库。使用下面的 yum 指令来安装 epel。 + + # yum install epel-release + +然后，我们需要更新系统及为 Lighttpd 的安装做前置准备。 + + # yum update + # yum install lighttpd + +![Install Lighttpd Centos](http://blog.linoxide.com/wp-content/uploads/2016/02/install-lighttpd-centos.png) + +**Ubuntu 15.04** + +Ubuntu 15.04 官方仓库中包含了 Lighttpd，所以只需更新本地仓库索引并使用 apt-get 指令即可安装 Lighttpd。 + + # apt-get update + # apt-get install lighttpd + +![Install lighttpd ubuntu](http://blog.linoxide.com/wp-content/uploads/2016/02/install-lighttpd-ubuntu.png) + +#### 从源代码安装 Lighttpd + +如果想从 Lighttpd 源码安装最新版本（例如 1.4.39），我们需要在本地编译源码并进行安装。首先我们要安装编译源码所需的依赖包。 + + # cd /tmp/ + # wget http://download.lighttpd.net/lighttpd/releases-1.4.x/lighttpd-1.4.39.tar.gz + +下载完成后，执行下面的指令解压缩。 + + # tar -zxvf lighttpd-1.4.39.tar.gz + +然后使用下面的指令进行编译。 + + # cd lighttpd-1.4.39 + # ./configure + # make + +**注：**在这份教程中，我们安装的是默认配置的 Lighttpd。其他拓展功能，如对 SSL 的支持，mod_rewrite，mod_redirect 等，需自行配置。 + +当编译完成后，我们就可以把它安装到系统中了。 + + # make install + +### 设置 Lighttpd + +如果有更高的需求，我们可以通过修改默认设置文件，如`/etc/lighttpd/lighttpd.conf`，来对 Lighttpd 进行进一步设置。 而在这份教程中我们将使用默认设置，不对设置文件进行修改。如果你曾做过修改并想检查设置文件是否出错，可以执行下面的指令。 + + # lighttpd -t -f /etc/lighttpd/lighttpd.conf + +#### 使用 CentOS 7 + +在 CentOS 7 中，我们需创建一个在 Lighttpd 默认配置文件中设置的 webroot 文件夹，例如`/src/www/htdocs`。 + + # mkdir -p /srv/www/htdocs/ + +而后将默认欢迎页面从`/var/www/lighttpd`复制至刚刚新建的目录中： + + # cp -r /var/www/lighttpd/* /srv/www/htdocs/ + +### 开启服务 + +现在，通过执行 systemctl 指令来重启 Web 服务。 + + # systemctl start lighttpd + +然后我们将它设置为伴随系统启动自动运行。 + + # systemctl enable lighttpd + +### 设置防火墙 + +如要让我们运行在 Lighttpd 上的网页或网站能在 Internet 或同一个网络内被访问，我们需要在防火墙程序中设置打开 80 端口。由于 CentOS 7 和 Ubuntu15.04 都附带 Systemd 作为默认初始化系统，所以我们默认用的都是 firewalld。如果要打开 80 端口或 http 服务，我们只需执行下面的命令： + + # firewall-cmd --permanent --add-service=http + success + # firewall-cmd --reload + success + +### 连接至 Web 服务器 + +在将 80 端口设置为默认端口后，我们就可以直接访问 Lighttpd 的默认欢迎页了。我们需要根据运行 Lighttpd 的设备来设置浏览器的 IP 地址和域名。在本教程中，我们令浏览器访问 [http://lighttpd.linoxide.com/](http://lighttpd.linoxide.com/) ，同时将该子域名指向上述 IP 地址。如此一来，我们就可以在浏览器中看到如下的欢迎页面了。 + +![Lighttpd Welcome Page](http://blog.linoxide.com/wp-content/uploads/2016/02/lighttpd-welcome-page.png) + +此外，我们可以将网站的文件添加到 webroot 目录下，并删除 Lighttpd 的默认索引文件，使我们的静态网站可以在互联网上访问。 + +如果想在 Lighttpd Web 服务器中运行 PHP 应用，请参考下面的步骤： + +### 安装 PHP5 模块 + +在 Lighttpd 成功安装后，我们需要安装 PHP 及相关模块，以在 Lighttpd 中运行 PHP5 脚本。 + +#### 使用 Ubuntu 15.04 + + # apt-get install php5 php5-cgi php5-fpm php5-mysql php5-curl php5-gd php5-intl php5-imagick php5-mcrypt php5-memcache php-pear + +#### 使用 CentOS 7 + + # yum install php php-cgi php-fpm php-mysql php-curl php-gd php-intl php-pecl-imagick php-mcrypt php-memcache php-pear lighttpd-fastcgi + +### 设置 Lighttpd 的 PHP 服务 + +如要让 PHP 与 Lighttpd 协同工作，我们只要根据所使用的发行版执行如下对应的指令即可。 + +#### 使用 CentOS 7 + +首先要做的便是使用文件编辑器编辑 php 设置文件（例如`/etc/php.ini`）并取消掉对**cgi.fix_pathinfo=1**这一行的注释。 + + # nano /etc/php.ini + +完成上面的步骤之后，我们需要把 PHP-FPM 进程的所有权从 Apache 转移至 Lighttpd。要完成这些，首先用文件编辑器打开`/etc/php-fpm.d/www.conf`文件。 + + # nano /etc/php-fpm.d/www.conf + +然后在文件中增加下面的语句： + + user = lighttpd + group = lighttpd + +做完这些，我们保存并退出文本编辑器。然后从`/etc/lighttpd/modules.conf`设置文件中添加 FastCGI 模块。 + + # nano /etc/lighttpd/modules.conf + +然后，去掉下面语句前面的`#`来取消对它的注释。 + + include "conf.d/fastcgi.conf" + +最后我们还需在文本编辑器设置 FastCGI 的设置文件。 + + # nano /etc/lighttpd/conf.d/fastcgi.conf + +在文件尾部添加以下代码： + + fastcgi.server += ( ".php" => + (( + "host" => "127.0.0.1", + "port" => "9000", + "broken-scriptfilename" => "enable" + )) + ) + +在编辑完成后保存并退出文本编辑器即可。 + +#### 使用 Ubuntu 15.04 + +如需启用 Lighttpd 的 FastCGI，只需执行下列代码： + + # lighttpd-enable-mod fastcgi + + Enabling fastcgi: ok + Run /etc/init.d/lighttpd force-reload to enable changes + + # lighttpd-enable-mod fastcgi-php + + Enabling fastcgi-php: ok + Run `/etc/init.d/lighttpd` force-reload to enable changes + +然后，执行下列命令来重启 Lighttpd。 + + # systemctl force-reload lighttpd + +### 检测 PHP 工作状态 + +如需检测 PHP 是否按预期工作，我们需在 Lighttpd 的 webroot 目录下新建一个 php 文件。本教程中，在 Ubuntu 下 /var/www/html 目录，CentOS 下 /src/www/htdocs 目录下使用文本编辑器创建并打开 info.php。 + +**使用 CentOS 7** + + # nano /var/www/info.php + +**使用 Ubuntu 15.04** + + # nano /srv/www/htdocs/info.php + +然后只需将下面的语句添加到文件里即可。 + + + +在编辑完成后保存并推出文本编辑器即可。 + +现在，我们需根据路径 [http://lighttpd.linoxide.com/info.php](http://lighttpd.linoxide.com/info.php) 下的 info.php 文件的 IP 地址或域名，来让我们的网页浏览器指向系统上运行的 Lighttpd。如果一切都按照以上说明进行，我们将看到如下图所示的 PHP 页面信息。 + +![phpinfo lighttpd](http://blog.linoxide.com/wp-content/uploads/2016/02/phpinfo-lighttpd.png) + +### 总结 + +至此，我们已经在 CentOS 7 和 Ubuntu 15.04 Linux 发行版上成功安装了轻巧快捷并且安全的 Lighttpd Web 服务器。现在，我们已经可以上传网站文件到网站根目录、配置虚拟主机、启用 SSL、连接数据库，在我们的 Lighttpd Web 服务器上运行 Web 应用等功能了。 如果你有任何疑问，建议或反馈请在下面的评论区中写下来以让我们更好的改良 Lighttpd。谢谢！ + +-------------------------------------------------------------------------------- + +via: http://linoxide.com/linux-how-to/setup-lighttpd-web-server-ubuntu-15-04-centos-7/ + +作者：[Arun Pyasi][a] +译者：[HaohongWANG](https://github.com/HaohongWANG) +校对：[wxy](https://github.com/wxy) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]:http://linoxide.com/author/arunp/ diff --git a/translated/tech/20160220 Best Cloud Services For Linux To Replace Copy.md b/published/201607/20160220 Best Cloud Services For Linux To Replace Copy.md similarity index 76% rename from translated/tech/20160220 Best Cloud Services For Linux To Replace Copy.md rename to published/201607/20160220 Best Cloud Services For Linux To Replace Copy.md index ce9380b600..a43c5776e8 100644 --- a/translated/tech/20160220 Best Cloud Services For Linux To Replace Copy.md +++ b/published/201607/20160220 Best Cloud Services For Linux To Replace Copy.md @@ -3,9 +3,9 @@ ![](http://itsfoss.com/wp-content/uploads/2016/02/Linux-cloud-services.jpg) -云存储服务 Copy 即将关闭，我们 Linux 用户是时候该寻找其他优秀的** Copy 之外的 Linux 云存储服务**。 +云存储服务 Copy 已经关闭，我们 Linux 用户是时候该寻找其他优秀的** Copy 之外的 Linux 云存储服务**。 -全部文件将会在 2016年5月1号 被删除。如果你是 Copy 的用户，你应该保存你的文件并将它们移至其他地方。 +全部文件会在 2016年5月1号 被删除。如果你是 Copy 的用户，你应该保存你的文件并将它们移至其他地方。 在过去的两年里，Copy 已经成为了我最喜爱的云存储。它为我提供了大量的免费空间并且带有桌面平台的原生应用程序，包括 Linux 和移动平台如 iOS 和 Android。 @@ -13,16 +13,16 @@ 当我从 Copy.com 看到它即将关闭的消息，我的担忧成真了。事实上，Copy 并不孤独。它的母公司 [Barracuda Networks](https://www.barracuda.com/)正经历一段困难时期并且已经[雇佣 Morgan Stanely 寻找 合适的卖家](http://www.bloomberg.com/news/articles/2016-02-01/barracuda-networks-said-to-work-with-morgan-stanley-to-seek-sale)(s) -无论什么理由，我们所知道的是 Copy 将会成为历史，我们需要寻找相似的**优秀的 Linux 云服务**。我之所以强调 Linux 是因为其他流行的云存储服务，如[微软的OneDrive](https://onedrive.live.com/about/en-us/) 和 [Google Drive](https://www.google.com/drive/) 都没有提供本地 Linux 客户端。这是微软预计的事情，但是谷歌对 Linux 的冷漠令人震惊。 +无论什么理由，我们所知道的是 Copy 将会成为历史，我们需要寻找相似的**优秀的 Linux 云服务**。我之所以强调 Linux 是因为其他流行的云存储服务，如[微软的 OneDrive](https://onedrive.live.com/about/en-us/) 和 [Google Drive](https://www.google.com/drive/) 都没有提供本地 Linux 客户端。微软并没有出乎我们的预料，但是[谷歌对 Linux 的冷漠][1]令人震惊。 ## Linux 下 Copy 的最佳替代者 -现在，作为一个 Linux 存储，在云存储中你需要什么？让我们猜猜： +什么样的云服务才适合作为 Linux 下的存储服务？让我们猜猜： -- 大量的免费空间。毕竟，个人用户无法每月支付巨额款项。 -- 原生的 Linux 客户端。因此你能够使用提供的服务，方便地同步文件，而不用做一些特殊的调整或者定时执行脚本。 -- 其他桌面系统的客户端，比如 Windows 和 OS X。便携性是必要的，并且同步设备间的文件是一种很好的缓解。 -- Android 和 iOS 的移动应用程序。在今天的现代世界里，你需要连接所有设备。 +- 大量的免费空间。毕竟，个人用户无法支付每月的巨额款项。 +- 原生的 Linux 客户端。以便你能够方便的在服务器之间同步文件，而不用做一些特殊的调整或者定时执行脚本。 +- 其他桌面系统的客户端，比如 Windows 和 OS X。移动性是必要的，并且同步设备间的文件也很有必要。 +- 基于 Android 和 iOS 的移动应用程序。在今天的现代世界里，你需要连接所有设备。 我不将自托管的云服务计算在内，比如 OwnCloud 或 [Seafile](https://www.seafile.com/en/home/) ，因为它们需要自己建立和运行一个服务器。这不适合所有想要类似 Copy 的云服务的家庭用户。 @@ -32,7 +32,7 @@ ![](http://itsfoss.com/wp-content/uploads/2016/02/Mega-Linux.jpg) -如果你是一个 It’s FOSS 的普通读者，你可能已经看过我之前的一篇有关[Mega on Linux](http://itsfoss.com/install-mega-cloud-storage-linux/)的文章。这种云服务由[Megaupload scandal](https://en.wikipedia.org/wiki/Megaupload) 公司下臭名昭著的[Kim Dotcom](https://en.wikipedia.org/wiki/Kim_Dotcom)提供。这也使一些用户怀疑它，因为 Kim Dotcom 已经很长一段时间成为美国当局的目标。 +如果你是一个 It’s FOSS 的普通读者，你可能已经看过我之前的一篇有关 [Mega on Linux](http://itsfoss.com/install-mega-cloud-storage-linux/)的文章。这种云服务由 [Megaupload scandal](https://en.wikipedia.org/wiki/Megaupload) 公司下臭名昭著的 [Kim Dotcom](https://en.wikipedia.org/wiki/Kim_Dotcom) 提供。这也使一些用户怀疑它，因为 Kim Dotcom 已经很长一段时间成为美国当局的目标。 Mega 拥有方便免费云服务下你所期望的一切。它给每个个人用户提供 50 GB 的免费存储空间。提供Linux 和其他平台下的原生客户端，并带有端到端的加密。原生的 Linux 客户端运行良好，可以无缝地跨平台同步。你也能在浏览器上查看操作你的文件。 @@ -74,7 +74,7 @@ Hubic 拥有一些不错的功能。除了简单的用户界面、文件共享 ![](http://itsfoss.com/wp-content/uploads/2016/02/pCloud-Linux.jpeg) -pCloud 是另一款欧洲的发行软件，但这一次从瑞士横跨法国边境。专注于加密和安全，pCloud 为每一个注册者提供 10 GB 的免费存储空间。你可以通过邀请好友、在社交媒体上分享链接等方式将空间增加至 20 GB。 +pCloud 是另一款欧洲的发行软件，但这一次跨过了法国边境，它来自瑞士。专注于加密和安全，pCloud 为每一个注册者提供 10 GB 的免费存储空间。你可以通过邀请好友、在社交媒体上分享链接等方式将空间增加至 20 GB。 它拥有云服务的所有标准特性，例如文件共享、同步、选择性同步等等。pCloud 也有跨平台原生客户端，当然包括 Linux。 @@ -128,8 +128,9 @@ via: http://itsfoss.com/cloud-services-linux/ 作者：[ABHISHEK][a] 译者：[cposture](https://github.com/cposture) -校对：[校对者ID](https://github.com/校对者ID) +校对：[wxy](https://github.com/wxy) 本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创翻译，[Linux中国](https://linux.cn/) 荣誉推出 [a]:http://itsfoss.com/author/abhishek/ +[1]:https://itsfoss.com/google-hates-desktop-linux/ \ No newline at end of file diff --git a/published/201607/20160301 The Evolving Market for Commercial Software Built On Open Source.md b/published/201607/20160301 The Evolving Market for Commercial Software Built On Open Source.md new file mode 100644 index 0000000000..fa3448b1bb --- /dev/null +++ b/published/201607/20160301 The Evolving Market for Commercial Software Built On Open Source.md @@ -0,0 +1,37 @@ +构建在开源之上的商业软件市场持续成长 +===================================================================== + +![](https://www.linux.com/images/stories/41373/Structure-event-photo.jpg) + +*与会者在 Structure 上听取演讲，Structure Data 2016 也将在 UCSF Mission Bay 会议中心举办。图片来源：Structure Events。* + +如今真的很难低估开源项目对于企业软件市场的影响；开源软件的集成如此快速地形成了业界常态，我们没能捕捉到转折点也情有可原。 + +举个例子，Hadoop，改变的不止是数据分析界，它引领了新一代数据公司，它们围绕开源项目创造自己的软件，按需调整和支持那些代码，更像红帽在上世纪 90 年代和本世纪早期拥抱 Linux 那样。软件越来越多地通过公有云交付，而不是运行在购买者自己的服务器，拥有了令人惊奇的操作灵活性，但同时也带来了一些关于授权、支持以及价格之类的新问题。 + +我们多年来持续追踪这个趋势，这些话题充斥了我们的 Structure Data 会议，而今年的 Structure Data 2016 也不例外。三家围绕 Hadoop 最重要的大数据公司——Hortonworks、Cloudera 和 MapR ——的 CEO 们将会共同讨论它们是如何销售他们围绕开源项目的企业软件和服务，获利的同时回报社区项目。 + +以前在企业软件上获利是很容易的事情。一个客户购买了之后，企业供应商的一系列软件就变成了收银机，从维护合同和阶段性升级中获得近乎终生的收入，软件也越来越难以被替代，因为它已经成为了客户的业务核心。客户抱怨这种绑定，但如果它们想提高工作队伍的生产力也确实没有多少选择。 + +而现在的情况不再是这样了。尽管无数的公司还陷于在他们的基础设施上运行至关重要的巨型软件包，新的项目被部署到使用开源技术的云服务器上。这让升级功能不再需要去掉大量软件包再重新安装别的，同时也让公司按需付费，而不是为一堆永远用不到的特性买单。 + +有很多客户想要利用开源项目的优势，而又不想建立和支持一支工程师队伍来调整那些开源项目以满足自己的需求。这些客户愿意为开源项目和在这之上的专有特性之间的差异付费。 + +这对于基础设施相关的软件来说格外正确。当然，你的客户们可以自己对项目进行调整，比如 Hadoop，Spark 或 Node.js，但付费可以帮助他们自定义地打包部署如今这些重要的开源技术，而不用自己干这些活儿。只需看看 Structure Data 2016 的发言者就明白了，比如 Confluent（Kafka），Databricks（Spark），以及 Cloudera-Hortonworks-MapR（Hadoop）三人组。 + +当然还有一个值得提到的是在出错的时候有个供应商给你背锅。如果你的工程师弄糟了开源项目的实现，那你只能怪你自己了。但是如果你和一个愿意提供服务级品质、能确保性能和正常运行时间指标的公司签订了合同，你实际上就是为得到支持、指导，以及有人背锅而买单。 + +构建在开源之上的商业软件市场的持续成长是我们在 Structure Data 上追踪多年的内容，如果这个话题正合你意，我们鼓励你加入我们，在旧金山，3 月 9 日和 10 日。 + + +-------------------------------------------------------------------------------- + +via: https://www.linux.com/news/enterprise/cloud-computing/889564-the-evolving-market-for-commercial-software-built-on-open-source- + +作者：[Tom Krazit][a] +译者：[alim0x](https://github.com/alim0x) +校对：[wxy](https://github.com/wxy) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://www.linux.com/community/forums/person/70513 diff --git a/published/201607/20160303 Top 5 open source command shells for Linux.md b/published/201607/20160303 Top 5 open source command shells for Linux.md new file mode 100644 index 0000000000..ec6aa3517a --- /dev/null +++ b/published/201607/20160303 Top 5 open source command shells for Linux.md @@ -0,0 +1,86 @@ +Linux 下五个顶级的开源命令行 Shell +=============================================== + +![](https://opensource.com/sites/default/files/styles/image-full-size/public/images/business/terminal_blue_smoke_command_line_0.jpg?itok=u2mRRqOa) + +这个世界上有两种 Linux 用户：敢于冒险的和态度谨慎的。 + +其中一类用户总是本能的去尝试任何能够戳中其痛点的新选择。他们尝试过不计其数的窗口管理器、系统发行版和几乎所有能找到的桌面插件。 + +另一类用户找到他们喜欢的东西后，会一直使用下去。他们往往喜欢所使用的系统发行版的默认配置。最先熟练掌握的文本编辑器会成为他们最钟爱的那一个。 + +作为一个使用桌面版和服务器版十五年之久的 Linux 用户，比起第一类来，我无疑属于第二类用户。我更倾向于使用现成的东西，如此一来，很多时候我就可以通过文档和示例方便地找到我所需要的使用案例。如果我决定选择使用非费标准的东西，这个切换过程一定会基于细致的研究，并且前提是来自好基友的大力推荐。 + +但这并不意味着我不喜欢尝试新事物并且查漏补失。所以最近一段时间，在我不假思索的使用了 bash shell 多年之后，决定尝试一下另外四个 shell 工具：ksh、tcsh、zsh 和 fish。这四个 shell 都可以通过我所用的 Fedora 系统的默认库轻松安装，并且他们可能已经内置在你所使用的系统发行版当中了。 + +这里对它们每个选择都稍作介绍，并且阐述下它适合做为你的下一个 Linux 命令行解释器的原因所在。 + +### bash + +首先，我们回顾一下最为熟悉的一个。 [GNU Bash][1]，又名 Bourne Again Shell，它是我这些年使用过的众多 Linux 发行版的默认选择。它最初发布于 1989 年，并且轻松成长为 Linux 世界中使用最广泛的 shell，甚至常见于其他一些类 Unix 系统当中。 + +Bash 是一个广受赞誉的 shell，当你通过互联网寻找各种事情解决方法所需的文档时，总能够无一例外的发现这些文档都默认你使用的是 bash shell。但 bash 也有一些缺点存在，如果你写过 Bash 脚本就会发现我们写的代码总是得比真正所需要的多那么几行。这并不是说有什么事情是它做不到的，而是说它读写起来并不总是那么直观，至少是不够优雅。 + +如上所述，基于其巨大的安装量，并且考虑到各类专业和非专业系统管理员已经适应了它的使用方式和独特之处，至少在将来一段时间内，bash 或许会一直存在。 + +### ksh + +[KornShell][4]，或许你对这个名字并不熟悉，但是你一定知道它的调用命令 ksh。这个替代性的 shell 于 80 年代起源于贝尔实验室，由 David Korn 所写。虽然最初是一个专有软件，但是后期版本是在 [Eclipse Public 许可][5]下发布的。 + +ksh 的拥趸们列出了他们觉得其优越的诸多理由，包括更好的循环语法，清晰的管道退出代码，处理重复命令和关联数组的更简单的方式。它能够模拟 vi 和 emacs 的许多行为，所以如果你是一个重度文本编辑器患者，它值得你一试。最后，我发现它虽然在高级脚本方面拥有不同的体验，但在基本输入方面与 bash 如出一辙。 + +### tcsh + +[tcsh][6] 衍生于 csh（Berkely Unix C shell），并且可以追溯到早期的 Unix 和计算机时代开始。 + +tcsh 最大的卖点在于它的脚本语言，对于熟悉 C 语言编程的人来说，看起来会非常亲切。tcsh 的脚本编写有人喜欢，有人憎恶。但是它也有其他的技术特色，包括可以为 aliases 添加参数，各种可能迎合你偏好的默认行为，包括 tab 自动完成和将 tab 完成的工作记录下来以备后查。 + +tcsh 以 [BSD 许可][7]发布。 + +### zsh + +[zsh][8] 是另外一个与 bash 和 ksh 有着相似之处的 shell。诞生于 90 年代初，zsh 支持众多有用的新技术，包括拼写纠正、主题化、可命名的目录快捷键，在多个终端中共享同一个命令历史信息和各种相对于原来的 bash 的轻微调整。 + +虽然部分需要遵照 GPL 许可，但 zsh 的代码和二进制文件可以在一个类似 MIT 许可证的许可下进行分发； 你可以在 [actual license][9] 中查看细节。 + +### fish + +之前我访问了 [fish][10] 的主页，当看到 “好了，这是一个为 90 后而生的命令行 shell” 这条略带调侃的介绍时（fish 完成于 2005 年），我就意识到我会爱上这个交互友好的 shell 的。 + +fish 的作者提供了若干切换过来的理由，这些理由有点小幽默并且能戳中笑点，不过还真是那么回事。这些特性包括自动建议（“注意， Netscape Navigator 4.0 来了”，LCTT 译注：NN4 是一个重要版本。），支持“惊人”的 256 色 VGA 调色，不过也有真正有用的特性，包括根据你机器上的 man 页面自动补全命令，清除脚本和基于 web 界面的配置方式。 + +fish 的许可主要基于 GPLv2，但有些部分是在其他许可下的。你可以查看资源库来了解[完整信息][11]。 + +*** + +如果你想要寻找关于每个选择确切不同之处的详尽纲要，[这个网站][12]应该可以帮到你。 + +我的立场到底是怎样的呢？好吧，最终我应该还是会重新投入 bash 的怀抱，因为对于大多数时间都在使用命令行交互的人来说，切换过程对于编写高级的脚本能带来的好处微乎其微，并且我已经习惯于使用 bash 了。 + +但是我很庆幸做出了敞开大门并且尝试新选择的决定。我知道门外还有许许多多其他的东西。你尝试过哪些 shell，更中意哪一个？请在评论里告诉我们。 + +--- + +via: https://opensource.com/business/16/3/top-linux-shells + +作者：[Jason Baker][a] +译者：[mr-ping](https://github.com/mr-ping) +校对：[wxy](https://github.com/wxy) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]:https://opensource.com/users/jason-baker + +[1]: https://www.gnu.org/software/bash/ +[2]: http://mywiki.wooledge.org/BashPitfalls +[3]: http://www.gnu.org/licenses/gpl.html +[4]: http://www.kornshell.org/ +[5]: https://www.eclipse.org/legal/epl-v10.html +[6]: http://www.tcsh.org/Welcome +[7]: https://en.wikipedia.org/wiki/BSD_licenses +[8]: http://www.zsh.org/ +[9]: https://sourceforge.net/p/zsh/code/ci/master/tree/LICENCE +[10]: https://fishshell.com/ +[11]: https://github.com/fish-shell/fish-shell/blob/master/COPYING +[12]: http://hyperpolyglot.org/unix-shells + diff --git a/published/201607/20160304 Microservices with Python RabbitMQ and Nameko.md b/published/201607/20160304 Microservices with Python RabbitMQ and Nameko.md new file mode 100644 index 0000000000..d70afff960 --- /dev/null +++ b/published/201607/20160304 Microservices with Python RabbitMQ and Nameko.md @@ -0,0 +1,284 @@ +用 Python、 RabbitMQ 和 Nameko 实现微服务 +============================================== + +>"微服务是一股新浪潮" - 现如今，将项目拆分成多个独立的、可扩展的服务是保障代码演变的最好选择。在 Python 的世界里，有个叫做 “Nameko” 的框架，它将微服务的实现变得简单并且强大。 + + +### 微服务 + +> 在最近的几年里，“微服务架构”如雨后春笋般涌现。它用于描述一种特定的软件应用设计方式，这种方式使得应用可以由多个独立部署的服务以服务套件的形式组成。 - M. Fowler + +推荐各位读一下 [Fowler 的文章][1] 以理解它背后的原理。 + +#### 好吧，那它究竟意味着什么呢？ + +简单来说，**微服务架构**可以将你的系统拆分成多个负责不同任务的小的（单一上下文内）功能块（responsibilities blocks），它们彼此互无感知，各自只提供用于通讯的通用指向（common point）。这个指向通常是已经将通讯协议和接口定义好的消息队列。 + +#### 这里给大家提供一个真实案例 + +> 案例的代码可以通过 github: 访问，查看 service 和 api 文件夹可以获取更多信息。 + +想象一下，你有一个 REST API ，这个 API 有一个端点（LCTT 译注：REST 风格的 API 可以有多个端点用于处理对同一资源的不同类型的请求）用来接受数据，并且你需要将接收到的数据进行一些运算工作。那么相比阻塞接口调用者的请求来说，异步实现此接口是一个更好的选择。你可以先给用户返回一个 "OK - 你的请求稍后会处理" 的状态，然后在后台任务中完成运算。 + +同样，如果你想要在不阻塞主进程的前提下，在计算完成后发送一封提醒邮件，那么将“邮件发送”委托给其他服务去做会更好一些。 + + +#### 场景描述 + +![](http://brunorocha.org/static/media/microservices/micro_services.png) + + +### 用代码说话 + +让我们将系统创建起来，在实践中理解它： + +#### 环境 + +我们需要的环境： + +- 运行良好的 RabbitMQ（LCTT 译注：[RabbitMQ][2] 是一个流行的消息队列实现） +- 由 VirtualEnv 提供的 Services 虚拟环境 +- 由 VirtualEnv 提供的 API　虚拟环境 + +#### Rabbit + +在开发环境中使用 RabbitMQ 最简单的方式就是运行其官方的 docker 容器。在你已经拥有 Docker 的情况下，运行： + +``` +docker run -d --hostname my-rabbit --name some-rabbit -p 15672:15672 -p 5672:5672 rabbitmq:3-management +``` + +在浏览器中访问 ，如果能够使用 guest:guest 验证信息登录 RabbitMQ 的控制面板，说明它已经在你的开发环境中运行起来了。 + +![](http://brunorocha.org/static/media/microservices/RabbitMQManagement.png) + +#### 服务环境 + +现在让我们创建微服务来满足我们的任务需要。其中一个服务用来执行计算任务，另一个用来发送邮件。按以下步骤执行： + +在 Shell 中创建项目的根目录 + +``` +$ mkdir myproject +$ cd myproject +``` + +用 virtualenv 工具创建并且激活一个虚拟环境(你也可以使用virtualenv-wrapper) + +``` +$ virtualenv service_env +$ source service_env/bin/activate +``` + +安装 nameko 框架和 yagmail + +``` +(service_env)$ pip install nameko +(service_env)$ pip install yagmail +``` + +#### 服务的代码 + +现在我们已经准备好了 virtualenv 所提供的虚拟环境（可以想象成我们的服务是运行在一个独立服务器上的，而我们的 API 运行在另一个服务器上），接下来让我们编码，实现 nameko 的 RPC 服务。 + +我们会将这两个服务放在同一个 python 模块中，当然如果你乐意，也可以把它们放在单独的模块里并且当成不同的服务运行： + +在名为 `service.py` 的文件中 + +```python +import yagmail +from nameko.rpc import rpc, RpcProxy + + +class Mail(object): + name = "mail" + + @rpc + def send(self, to, subject, contents): + yag = yagmail.SMTP('myname@gmail.com', 'mypassword') + # 以上的验证信息请从安全的地方进行读取 + # 贴士: 可以去看看 Dynaconf 设置模块 + yag.send(to=to.encode('utf-8), + subject=subject.encode('utf-8), + contents=[contents.encode('utf-8)]) + + +class Compute(object): + name = "compute" + mail = RpcProxy('mail') + + @rpc + def compute(self, operation, value, other, email): + operations = {'sum': lambda x, y: int(x) + int(y), + 'mul': lambda x, y: int(x) * int(y), + 'div': lambda x, y: int(x) / int(y), + 'sub': lambda x, y: int(x) - int(y)} + try: + result = operations[operation](value, other) + except Exception as e: + self.mail.send.async(email, "An error occurred", str(e)) + raise + else: + self.mail.send.async( + email, + "Your operation is complete!", + "The result is: %s" % result + ) + return result +``` + +现在我们已经用以上代码定义好了两个服务，下面让我们将 Nameko RPC service 运行起来。 + +> 注意：我们会在控制台中启动并运行它。但在生产环境中，建议大家使用 supervisord 替代控制台命令。 + +在 Shell 中启动并运行服务 + +``` +(service_env)$ nameko run service --broker amqp://guest:guest@localhost +starting services: mail, compute +Connected to amqp://guest:**@127.0.0.1:5672// +Connected to amqp://guest:**@127.0.0.1:5672// +``` + + +#### 测试 + +在另外一个 Shell 中（使用相同的虚拟环境），用 nameko shell 进行测试： + +``` +(service_env)$ nameko shell --broker amqp://guest:guest@localhost +Nameko Python 2.7.9 (default, Apr 2 2015, 15:33:21) +[GCC 4.9.2] shell on linux2 +Broker: amqp://guest:guest@localhost +>>> +``` + +现在你已经处在 RPC 客户端中了，Shell 的测试工作是通过 n.rpc 对象来进行的，它的使用方法如下： + +``` +>>> n.rpc.mail.send("name@email.com", "testing", "Just testing") +``` + +上边的代码会发送一封邮件，我们同样可以调用计算服务对其进行测试。需要注意的是，此测试还会附带进行异步的邮件发送。 + +``` +>>> n.rpc.compute.compute('sum', 30, 10, "name@email.com") +40 +>>> n.rpc.compute.compute('sub', 30, 10, "name@email.com") +20 +>>> n.rpc.compute.compute('mul', 30, 10, "name@email.com") +300 +>>> n.rpc.compute.compute('div', 30, 10, "name@email.com") +3 +``` + +### 在 API 中调用微服务 + +在另外一个 Shell 中（甚至可以是另外一台服务器上），准备好 API 环境。 + +用 virtualenv 工具创建并且激活一个虚拟环境（你也可以使用 virtualenv-wrapper） + +``` +$ virtualenv api_env +$ source api_env/bin/activate +``` + +安装 Nameko、 Flask 和 Flasgger + +``` +(api_env)$ pip install nameko +(api_env)$ pip install flask +(api_env)$ pip install flasgger +``` + +>注意： 在 API 中并不需要 yagmail ，因为在这里，处理邮件是服务的职责 + +创建含有以下内容的 `api.py` 文件： + +```python +from flask import Flask, request +from flasgger import Swagger +from nameko.standalone.rpc import ClusterRpcProxy + +app = Flask(__name__) +Swagger(app) +CONFIG = {'AMQP_URI': "amqp://guest:guest@localhost"} + + +@app.route('/compute', methods=['POST']) +def compute(): + """ + Micro Service Based Compute and Mail API + This API is made with Flask, Flasgger and Nameko + --- + parameters: + - name: body + in: body + required: true + schema: + id: data + properties: + operation: + type: string + enum: + - sum + - mul + - sub + - div + email: + type: string + value: + type: integer + other: + type: integer + responses: + 200: + description: Please wait the calculation, you'll receive an email with results + """ + operation = request.json.get('operation') + value = request.json.get('value') + other = request.json.get('other') + email = request.json.get('email') + msg = "Please wait the calculation, you'll receive an email with results" + subject = "API Notification" + with ClusterRpcProxy(CONFIG) as rpc: + # asynchronously spawning and email notification + rpc.mail.send.async(email, subject, msg) + # asynchronously spawning the compute task + result = rpc.compute.compute.async(operation, value, other, email) + return msg, 200 + +app.run(debug=True) +``` + +在其他的 shell 或者服务器上运行此文件 + +``` +(api_env) $ python api.py + * Running on http://127.0.0.1:5000/ (Press CTRL+C to quit) +``` + +然后访问 这个 url，就可以看到 Flasgger 的界面了，利用它可以进行 API 的交互并可以发布任务到队列以供服务进行消费。 + +![](http://brunorocha.org/static/media/microservices/Flasgger_API_documentation.png) + +> 注意： 你可以在 shell 中查看到服务的运行日志，打印信息和错误信息。也可以访问 RabbitMQ 控制面板来查看消息在队列中的处理情况。 + +Nameko 框架还为我们提供了很多高级特性，你可以从 获取更多的信息。 + +别光看了，撸起袖子来，实现微服务! + + +-------------------------------------------------------------------------------- + +via: http://brunorocha.org/python/microservices-with-python-rabbitmq-and-nameko.html + +作者: [Bruno Rocha][a] +译者: [mr-ping](http://www.mr-ping.com) +校对: [wxy](https://github.com/wxy) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]:http://facebook.com/rochacbruno +[1]:http://martinfowler.com/articles/microservices.html +[2]:http://rabbitmq.mr-ping.com/description.html diff --git a/published/201607/20160425 How to Use Awk to Print Fields and Columns in File.md b/published/201607/20160425 How to Use Awk to Print Fields and Columns in File.md new file mode 100644 index 0000000000..94b914cd3d --- /dev/null +++ b/published/201607/20160425 How to Use Awk to Print Fields and Columns in File.md @@ -0,0 +1,107 @@ +如何使用 Awk 打印文件中的字段和列 +=================================================== + +在 [Linux Awk 命令系列介绍][1] 的这部分，我们来看一下 awk 最重要的功能之一，字段编辑。 + +首先我们要知道 Awk 会自动把输入的行切分为字段，字段可以定义为是一些字符集，这些字符集和其它字段被内部字段分隔符分离。 + +![](http://www.tecmint.com/wp-content/uploads/2016/04/Awk-Print-Fields-and-Columns.png) +>Awk 输出字段和列 + +如果你熟悉 Unix/Linux 或者懂得 [bash shell 编程][2]，那么你也应该知道内部字段分隔符（IFS）变量。Awk 默认的 IFS 是 tab 和空格。 + +Awk 字段切分的工作原理如下：当获得一行输入时，根据定义的 IFS，第一个字符集是字段一，用 $1 表示，第二个字符集是字段二，用 $2 表示，第三个字符集是字段三，用 $3 表示，以此类推直到最后一个字符集。 + +为了更好的理解 Awk 的字段编辑，让我们来看看下面的例子： + +**事例 1:**： 我创建了一个名为 tecmintinfo.txt 的文件。 + +``` +# vi tecmintinfo.txt +# cat tecmintinfo.txt +``` + +![](http://www.tecmint.com/wp-content/uploads/2016/04/Create-File-in-Linux.png) +>在 Linux 中创建文件 + +然后在命令行中使用以下命令打印 tecmintinfo.txt 文件中的第一、第二和第三个字段。 + +``` +$ awk '//{print $1 $2 $3 }' tecmintinfo.txt +TecMint.comisthe +``` +从上面的输出中你可以看到，三个字段中的第一个是按照定义的 IFS，也就是空格，打印的。 + +- 字段一 “TecMint.com” 使用 $1 访问。 +- 字段二 “is” 通过 $2 访问。 +- 字段三 “the” 通过 $3 访问。 + +如果你注意打印的输出，可以看到字段值之间并没有分隔开，这是 print 默认的方式。 + +为了在字段值之间加入空格，你需要像下面这样添加（,）分隔符： + +``` +$ awk '//{print $1, $2, $3; }' tecmintinfo.txt + +TecMint.com is the +``` + +很重要而且必须牢记的一点是，Awk 中 （$） 的使用和在 shell 脚本中不一样。 + +在 shell 脚本中 （$） 用于获取变量的值，而在 Awk 中 （$） 只用于获取一个字段的内容，而不能用于获取变量的值。 + +**事例2**： 让我们再看一个使用多行文件 my_shoping.list 的例子。 + +``` +No Item_Name Unit_Price Quantity Price +1 Mouse #20,000 1 #20,000 +2 Monitor #500,000 1 #500,000 +3 RAM_Chips #150,000 2 #300,000 +4 Ethernet_Cables #30,000 4 #120,000 +``` + +假设你只想打印购物清单中每个物品的 Unit_Price，你需要允许下面的命令： + +``` +$ awk '//{print $2, $3 }' my_shopping.txt + +Item_Name Unit_Price +Mouse #20,000 +Monitor #500,000 +RAM_Chips #150,000 +Ethernet_Cables #30,000 +``` + +Awk 也有一个 printf 命令，它能帮助你用更好的方式格式化输出，正如你可以看到上面的输出并不清晰。 + +使用 printf 格式化输出 Item_Name 和 Unit_Price： + +``` +$ awk '//{printf "%-10s %s\n",$2, $3 }' my_shopping.txt + +Item_Name Unit_Price +Mouse #20,000 +Monitor #500,000 +RAM_Chips #150,000 +Ethernet_Cables #30,000 +``` + +### 总结 + +使用 Awk 进行文本和字符串过滤时字段编辑功能非常重要，它能帮助你从列表中获取列的特定数据。同时需要记住 Awk 中 （$） 操作符和 shell 脚本中不一样。 + +我希望这篇文章能对你有所帮助，如果你需要获取其它信息或者有任何疑问，都可以在下面的评论框中告诉我们。 + +-------------------------------------------------------------------------------- + +via: http://www.tecmint.com/awk-print-fields-columns-with-space-separator/?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+tecmint+%28Tecmint%3A+Linux+Howto%27s+Guide%29 + +作者：[Aaron Kili][a] +译者：[ictlyh](https://github.com/ictlyh) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: http://www.tecmint.com/author/aaronkili/ +[1]: http://www.tecmint.com/tag/awk-command/ +[2]: http://www.tecmint.com/category/bash-shell/ diff --git a/published/201607/20160511 An introduction to data processing with Cassandra and Spark.md b/published/201607/20160511 An introduction to data processing with Cassandra and Spark.md new file mode 100644 index 0000000000..bec55c2e7c --- /dev/null +++ b/published/201607/20160511 An introduction to data processing with Cassandra and Spark.md @@ -0,0 +1,45 @@ +Cassandra 和 Spark 数据处理一窥 +============================================================== + +![](https://opensource.com/sites/default/files/styles/image-full-size/public/images/life/osdc_520x292_opendata_0613mm.png?itok=mzC0Tb28) + +Apache Cassandra 数据库近来引起了很多的兴趣，这主要源于现代云端软件对于可用性及性能方面的要求。 + +那么，Apache Cassandra 是什么？它是一种为高可用性及线性可扩展性优化的分布式的联机交易处理 (OLTP) 数据库。具体说到 Cassandra 的用途时，可以想想你希望贴近用户的系统，比如说让我们的用户进行交互的系统、需要保证实时可用的程序等等，如：产品目录，物联网，医疗系统，以及移动应用。对这些程序而言，下线时间意味着利润降低甚至导致其他更坏的结果。Netfilix 是这个在 2008 年开源的项目的早期使用者，他们对此项目的贡献以及带来的成功让这个项目名声大噪。 + +Cassandra 于2010年成为了 Apache 软件基金会的顶级项目，并从此之后就流行起来。现在，只要你有 Cassadra 的相关知识，找工作时就能轻松不少。想想看，NoSQL 语言和开源技术能达到企业级 SQL 技术的高度，真让人觉得十分疯狂而又不可思议的。这引出了一个问题。是什么让它如此的流行？ + +因为采用了[亚马逊发表的 Dynamo 论文][1]中率先提出的设计，Cassandra 有能力在大规模的硬件及网络故障时保持实时在线。由于采用了点对点模式，在没有单点故障的情况下，我们能幸免于机架故障甚至全网中断。我们能在不影响用户体验的前提下处理数据中心故障。一个能考虑到故障的分布式系统才是一个没有后顾之忧的分布式系统，因为老实说，故障是迟早会发生的。有了 Cassandra， 我们可以直面残酷的生活并将之融入数据库的结构和功能中。 + +我们能猜到你现在在想什么，“但我只有关系数据库相关背景，难道这样的转变不会很困难吗？”这问题的答案介于是和不是之间。使用 Cassandra 建立数据模型对有关系数据库背景的开发者而言是轻车熟路。我们使用表格来建立数据模型，并使用 CQL （ Cassandra 查询语言）来查询数据库。然而，与 SQL 不同的是，Cassandra 支持更加复杂的数据结构，例如嵌套和用户自定义类型。举个例子，当要储存对一个小猫照片的点赞数目时，我们可以将整个数据储存在一个包含照片本身的集合之中从而获得更快的顺序查找而不是建立一个独立的表。这样的表述在 CQL 中十分的自然。在我们照片表中，我们需要记录名字，URL以及给此照片点赞过的人。 + +![](https://opensource.com/sites/default/files/resize/screen_shot_2016-05-06_at_7.17.33_am-350x198.png) + +在一个高性能系统中，毫秒级处理都能对用户体验和客户维系产生影响。昂贵的 JOIN 操作制约了我们通过增加不可预见的网络调用而扩容的能力。当我们将数据反范式化使其能通过尽可能少的请求就可获取时，我们即可从磁盘空间成本的降低中获益并获得可预期的、高性能应用。我们将反范式化同 Cassandra 一同介绍是因为它提供了很有吸引力的的折衷方案。 + +很明显，我们不会局限于对于小猫照片的点赞数量。Canssandra 是一款为高并发写入优化的方案。这使其成为需要时常吞吐数据的大数据应用的理想解决方案。实时应用和物联网方面的应用正在稳步增长，无论是需求还是市场表现，我们也会不断的利用我们收集到的数据来寻求改进技术应用的方式。 + +这就引出了我们的下一步，我们已经提到了如何以一种现代的、性价比高的方式储存数据，但我们应该如何获得更多的动力呢？具体而言，当我们收集到了所需的数据，我们应该怎样处理呢？如何才能有效的分析几百 TB 的数据呢？如何才能实时的对我们所收集到的信息进行反馈，并在几秒而不是几小时的时间利作出决策呢？Apache Spark 将给我们答案。 + +Spark 是大数据变革中的下一步。 Hadoop 和 MapReduce 都是革命性的产品，它们让大数据界获得了分析所有我们所取得的数据的机会。Spark 对性能的大幅提升及对代码复杂度的大幅降低则将大数据分析提升到了另一个高度。通过 Spark，我们能大批量的处理计算，对流处理进行快速反应，通过机器学习作出决策，并通过图遍历来理解复杂的递归关系。这并非只是为你的客户提供与快捷可靠的应用程序连接（Cassandra 已经提供了这样的功能），这更是能洞悉 Canssandra 所储存的数据，作出更加合理的商业决策并同时更好地满足客户需求。 + +你可以看看 [Spark-Cassandra Connector][2] (开源) 并动手试试。若想了解更多关于这两种技术的信息，我们强烈推荐名为 [DataStax Academy][3] 的自学课程 + +-------------------------------------------------------------------------------- + +via: https://opensource.com/life/16/5/basics-cassandra-and-spark-data-processing + +作者：[Jon Haddad][a],[Dani Traphagen][b] +译者：[KevinSJ](https://github.com/KevinSJ) +校对：[wxy](https://github.com/wxy) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://twitter.com/rustyrazorblade +[b]: https://opensource.com/users/dtrapezoid +[1]: http://www.allthingsdistributed.com/files/amazon-dynamo-sosp2007.pdf +[2]: https://github.com/datastax/spark-cassandra-connector +[3]: https://academy.datastax.com/ +[4]: http://conferences.oreilly.com/oscon/open-source-us/public/schedule/detail/49162 +[5]: https://twitter.com/dtrapezoid +[6]: https://twitter.com/rustyrazorblade diff --git a/published/201607/20160519 The future of sharing integrating Pydio and ownCloud.md b/published/201607/20160519 The future of sharing integrating Pydio and ownCloud.md new file mode 100644 index 0000000000..5c1b998508 --- /dev/null +++ b/published/201607/20160519 The future of sharing integrating Pydio and ownCloud.md @@ -0,0 +1,65 @@ +共享的未来：Pydio 与 ownCloud 的联合 +========================================================= + +![](https://opensource.com/sites/default/files/styles/image-full-size/public/images/business/BIZ_darwincloud_520x292_0311LL.png?itok=5yWIaEDe) + +*图片来源 : opensource.com* + +开源共享生态圈内容纳了许多各异的项目，它们每一个都给出了自己的解决方案，且每一个都不按套路来。有很多原因导致你选择开源的解决方案，而非 Dropbox、Google Drive、iCloud 或 OneDrive 这些商业的解决方案。这些商业的解决方案虽然能让你不必为如何管理数据担心，但也理所应当的带着种种限制，其中就包括对于原有基础结构的控制和整合不足。 + +对于用户而言仍有相当一部分可供选择的文件分享和同步的替代品，其中就包括了 Pydio 和 ownCloud。 + +### Pydio + +Pydio （Put your data in orbit 把你的数据放上轨道） 项目由一位作曲家 Charles du Jeu 发起，起初他只是需要一种与乐队成员分享大型音频文件的方法。[Pydio][1] 是一种文件分享与同步的解决方案，综合了多存储后端，设计时还同时考虑了开发者和系统管理员两方面。在世界各地有逾百万的下载量，已被翻译成 27 种语言。 + +项目在刚开始的时候便开源了，先是在 [SourceForge][2] 上茁壮的成长，现在已在 [GitHub][3] 上安了家。 + +用户界面基于 Google 的 [Material 设计风格][4]。用户可以使用现有的传统文件基础结构或是根据预估的需求部署 Pydio，并通过 web、桌面和移动端应用随时随地地管理自己的东西。对于管理员来说，细粒度的访问权限绝对是配置访问时的利器。 + +在 [Pydio 社区][5]，你可以找到许多让你增速的资源。Pydio 网站 [对于如何为 Pydio GitHub 仓库贡献][6] 给出了明确的指导方案。[论坛][7]中也包含了开发者板块和社区。 + +### ownCloud + +[ownCloud][8] 在世界各地拥有逾 8 百万的用户，它是一个开源、自行管理的文件同步共享技术。同步客户端支持所有主流平台并支持 WebDAV 通过 web 界面实现。ownCloud 拥有简单的使用界面，强大的管理工具，和大规模的共享及协作功能——以满足用户管理数据时的需求。 + +ownCloud 的开放式架构是通过 API 和为应用提供平台来实现可扩展性的。迄今已有逾 300 款应用，功能包括处理像日历、联系人、邮件、音乐、密码、笔记等诸多数据类型。ownCloud 由一个数百位贡献者的国际化的社区开发，安全，并且能做到为小到一个树莓派大到好几百万用户的 PB 级存储集群量身定制。 + +### 联合共享 （Federated sharing） + +文件共享开始转向团队合作时代，而标准化为合作提供了坚实的土壤。 + +联合共享（Federated sharing）——一个由 [OpenCloudMesh][9] 项目提供的新的开放标准，就是在这个方向迈出的一步。先不说别的，在支持该标准的服务器之间分享文件和文件夹，比如说 Pydio 和 ownCloud。 + +ownCloud 7 率先引入该标准，这种服务器到服务器的分享方式可以让你挂载远程服务器上共享的文件，实际上就是创建你自己的云上之云。你可以直接为其它支持联合共享的服务器上的用户创建共享链接。 + +实现这个新的 API 允许存储解决方案之间更深层次的集成，同时保留了原有平台的安全，控制和特性。 + +“交换和共享文件是当下和未来不可或缺的东西。”ownCloud 的创始人 Frank Karlitschek 说道：“正因如此，采用联合和分布的方式而非集中的数据孤岛就显得至关重要。联合共享的设计初衷便是在保证安全和用户隐私的同时追求分享的无缝、至简之道。” + +### 下一步是什么呢？ + +正如 OpenCloudMesh 做的那样，将会通过像 Pydio 和 ownCloud 这样的机构和公司，合作推广这一文件共享的新开放标准。ownCloud 9 已经引入联合的服务器之间交换用户列表的功能，让你的用户们在你的服务器上享有和你同样的无缝体验。将来，一个中央地址簿服务（联合的）集合，用以检索其他联合云 ID 的构想可能会把云间合作推向一个新的高度。 + +这一举措无疑有助于日益开放的技术社区中的那些成员方便地讨论，开发，并推动“OCM 分享 API”作为一个厂商中立协议。所有领导 OCM 项目的合作伙伴都全心致力于开放 API 的设计原则，并欢迎其他开源的文件分享和同步社区参与并加入其中。 + +-------------------------------------------------------------------------------- + +via: https://opensource.com/business/16/5/sharing-files-pydio-owncloud + +作者：[ben van 't ende][a] +译者：[martin2011qi](https://github.com/martin2011qi) +校对：[wxy](https://github.com/wxy) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://opensource.com/users/benvantende +[1]: https://pydio.com/ +[2]: https://sourceforge.net/projects/ajaxplorer/ +[3]: https://github.com/pydio/ +[4]: https://www.google.com/design/spec/material-design/introduction.html +[5]: https://pydio.com/en/community +[6]: https://pydio.com/en/community/contribute +[7]: https://pydio.com/forum/f +[8]: https://owncloud.org/ +[9]: https://wiki.geant.org/display/OCM/Open+Cloud+Mesh diff --git a/translated/tech/20160527 Turn Your Old Laptop into a Chromebook.md b/published/201607/20160527 Turn Your Old Laptop into a Chromebook.md similarity index 91% rename from translated/tech/20160527 Turn Your Old Laptop into a Chromebook.md rename to published/201607/20160527 Turn Your Old Laptop into a Chromebook.md index 3c7038a2a2..df776e73b5 100644 --- a/translated/tech/20160527 Turn Your Old Laptop into a Chromebook.md +++ b/published/201607/20160527 Turn Your Old Laptop into a Chromebook.md @@ -2,7 +2,8 @@ ======================================== ![](https://www.linux.com/sites/lcom/files/styles/rendered_file/public/cloud-ready-main.jpg?itok=gtzJVSq0) ->学习如何用 CloudReady 在你的旧电脑上安装 Chrome OS + +*学习如何用 CloudReady 在你的旧电脑上安装 Chrome OS* Linux 之年就在眼前。根据[报道][1]，Google 在 2016 年第一季度卖出了比苹果卖出的 Macbook 更多的 Chromebook。并且，Chromebook 即将变得更加激动人心。在 Google I/O 大会上，Google 宣布安卓 Google Play 商店将在 6 月中旬来到 Chromebook，这让用户能够在他们的 Chrome OS 设备上运行安卓应用。 @@ -16,33 +17,35 @@ Linux 之年就在眼前。根据[报道][1]，Google 在 2016 年第一季度 在你开始在笔记本上安装 CloudReady 之前，你需要一些准备： -- 一个容量大于等于 4GB 的 USB 存储设备 - +- 一个容量不小于 4GB 的 USB 存储设备 - 打开 Chrome 浏览器，到 Google Chrome Store 去安装 [Chromebook Recovery Utility（Chrome 恢复工具）][3] - - 更改目标机器的 BIOS 设置以便能从 USB 启动 ### 开始 Neverware 提供两个版本的 CloudReady 镜像：32 位和 64 位。从下载页面[下载][4]合适你硬件的系统版本。 -解压下载的 zip 文件，你会得到一个 chromiumos_image.bin 文件。现在插入 U 盘并打开 Chromebook recovery utility。点击工具右上角的齿轮，选择 erase recovery media（擦除恢复媒介，如图 1）。 +解压下载的 zip 文件，你会得到一个 chromiumos_image.bin 文件。现在插入 U 盘并打开 Chromebook Recovery Utility。点击工具右上角的齿轮，选择 erase recovery media（擦除恢复媒介，如图 1）。 ![](https://www.linux.com/sites/lcom/files/styles/rendered_file/public/cloudready-erase.png?itok=1si1QrCL) ->图 1：选择 erase recovery media。[image:cloudready-erase] + +*图 1：选择 erase recovery media。[image:cloudready-erase]* 接下来，选择目标 USB 驱动器并把它格式化。格式化完成后，再次打开右上齿轮，这次选择 use local image（使用本地镜像）。浏览解压的 bin 文件并选中，选好 USB 驱动器，点击继续，然后点击创建按钮（图 2）。它会开始将镜像写入驱动器。 ![](https://www.linux.com/sites/lcom/files/styles/rendered_file/public/cloudready-create.png?itok=S1FGzRp-) ->图 2：创建 CloudReady 镜像。[Image:cloudready-create] + +*图 2：创建 CloudReady 镜像。[Image:cloudready-create]* 驱动器写好可启动的 CloudReady 之后，插到目标 PC 上并启动。系统启动进 Chromium OS 需要一小段时间。启动之后，你会看到图 3 中的界面。 ![](https://www.linux.com/sites/lcom/files/styles/rendered_file/public/cloud-ready-install-1.jpg?itok=D6SjlIQ4) ->图 3：准备好安装 CloudReady。 + +*图 3：准备好安装 CloudReady。* ![](https://www.linux.com/sites/lcom/files/styles/floated_images/public/cloud-ready-install-single_crop.jpg?itok=My2rUjYC) ->图 4：单系统选项。 + +*图 4：单系统选项。* 到任务栏选择 Install CloudReady（安装 CloudReady）。 @@ -53,7 +56,8 @@ Neverware 提供两个版本的 CloudReady 镜像：32 位和 64 位。从下载 按照下一步按钮说明选择安装。 ![](https://www.linux.com/sites/lcom/files/styles/floated_images/public/cloud-ready-install-dual_crop.jpg?itok=Daywck_s) ->图 5：双系统选项。 + +*图 5：双系统选项。* 整个过程最多 20 分钟左右，这取决于存储媒介和处理能力。安装完成后，电脑会关闭并重启。 @@ -62,17 +66,20 @@ Neverware 提供两个版本的 CloudReady 镜像：32 位和 64 位。从下载 你连上无线网络之后，系统会自动查找更新并提供 Adobe Flash 安装。安装完成后，你会看到 Chromium OS 登录界面。现在你只需登录你的 Gmail 账户，开始使用你的“Chromebook”即可。 ![](https://www.linux.com/sites/lcom/files/styles/rendered_file/public/cloud-ready-post-install-network.jpg?itok=gSX2fQZS) ->图 6：网络设置。 + +*图 6：网络设置。* ### 让 Netflix 正常工作 如果你想要播放 Netflix 或其它 DRM 保护流媒体站点，你需要做一些额外的工作。转到设置并点击安装 Widevine 插件（图 7）。 ![](https://www.linux.com/sites/lcom/files/styles/rendered_file/public/install_widevine.png?itok=bUJaRmyx0) ->图 7：安装 Widevine。 + +*图 7：安装 Widevine。* ![](https://www.linux.com/sites/lcom/files/styles/floated_images/public/user-agent-changer.jpg?itok=5QDCLrZk) ->图 8：安装 User Agent Switcher. + +*图 8：安装 User Agent Switcher。* 现在你需要使用 user agent switcher 这个伎俩（图 8）。 @@ -96,20 +103,20 @@ Indicator Flag: "IE" 点击“添加（Add）”。 ![](https://www.linux.com/sites/lcom/files/styles/rendered_file/public/spoof-netflix.png?itok=8DEZK4Pl) ->图 9：为 CloudReady 创建条目。 + +*图 9：为 CloudReady 创建条目。* 然后，到“permanent spoof list（永久欺骗列表）”选项中将 CloudReady Widevine 添加为 [www.netflix.com](http://www.netflix.com) 的永久 UA 串。 现在，重启机器，你就可以观看 Netflix 和其它一些服务了。 - -------------------------------------------------------------------------------- via: https://www.linux.com/learn/turn-your-old-laptop-chromebook 作者：[SWAPNIL BHARTIYA][a] 译者：[alim0x](https://github.com/alim0x) -校对：[校对者ID](https://github.com/校对者ID) +校对：[wxy](https://github.com/wxy) 本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 diff --git a/published/201607/20160530 Install LEMP with MariaDB 10, PHP 7 and HTTP 2.0 Support for Nginx on Ubuntu 16.04.md b/published/201607/20160530 Install LEMP with MariaDB 10, PHP 7 and HTTP 2.0 Support for Nginx on Ubuntu 16.04.md new file mode 100644 index 0000000000..0ff5f7a412 --- /dev/null +++ b/published/201607/20160530 Install LEMP with MariaDB 10, PHP 7 and HTTP 2.0 Support for Nginx on Ubuntu 16.04.md @@ -0,0 +1,322 @@ +在 Ubuntu 16.04 为 Nginx 服务器安装 LEMP 环境（MariaDB，PHP 7 并支持 HTTP 2.0） +===================== + +LEMP 是个缩写，代表一组软件包（L：Linux OS，E：Nginx 网络服务器，M：MySQL/MariaDB 数据库和 P：PHP 服务端动态编程语言)，它被用来搭建动态的网络应用和网页。 + +![](http://www.tecmint.com/wp-content/uploads/2016/05/Install-Nginx-with-FastCGI-on-Ubuntu-16.04.png) + +*在 Ubuntu 16.04 安装 Nginx 以及 MariaDB，PHP7 并且支持 HTTP 2.0* + +这篇教程会教你怎么在 Ubuntu 16.04 的服务器上安装 LEMP （Nginx 和 MariaDB 以及 PHP7）。 + +**前置准备** + +- [安装 Ubuntu 16.04 服务器版本][1] + +### 步骤 1：安装 Nginx 服务器 + +1、Nginx 是一个先进的、资源优化的 Web 服务器程序，用来向因特网上的访客展示网页。我们从 Nginx 服务器的安装开始介绍，使用 [apt 命令][2] 从 Ubuntu 的官方软件仓库中获取 Nginx 程序。 + +``` +$ sudo apt-get install nginx +``` + +![](http://www.tecmint.com/wp-content/uploads/2016/05/Install-Nginx-on-Ubuntu-16.04.png) + +*在 Ubuntu 16.04 安装 Nginx* + +2、 然后输入 [netstat][3] 和 [systemctl][4] 命令，确认 Nginx 进程已经启动并且绑定在 80 端口。 + +``` +$ netstat -tlpn +``` + +![](http://www.tecmint.com/wp-content/uploads/2016/05/Check-Nginx-Network-Port-Connection.png) + +*检查 Nginx 网络端口连接* + +``` +$ sudo systemctl status nginx.service +``` + +![](http://www.tecmint.com/wp-content/uploads/2016/05/Check-Nginx-Service-Status.png) + +*检查 Nginx 服务状态* + +当你确认服务进程已经启动了，你可以打开一个浏览器，使用 HTTP 协议访问你的服务器 IP 地址或者域名，浏览 Nginx 的默认网页。 + +``` +http://IP-Address +``` + +![](http://www.tecmint.com/wp-content/uploads/2016/05/Verify-Nginx-Webpage.png) + +*验证 Nginx 网页* + +### 步骤 2：启用 Nginx HTTP/2.0 协议 + +3、 对 HTTP/2.0 协议的支持默认包含在 Ubuntu 16.04 最新发行版的 Nginx 二进制文件中了，它只能通过 SSL 连接并且保证加载网页的速度有巨大提升。 + +要启用Nginx 的这个协议，首先找到 Nginx 提供的网站配置文件，输入下面这个命令备份配置文件。 + +``` +$ cd /etc/nginx/sites-available/ +$ sudo mv default default.backup +``` + +![](http://www.tecmint.com/wp-content/uploads/2016/05/Backup-Nginx-Sites-Configuration-File.png) + +*备份 Nginx 的网站配置文件* + +4、然后，用文本编辑器新建一个默认文件，输入以下内容： + +``` +server { + listen 443 ssl http2 default_server; + listen [::]:443 ssl http2 default_server; + + root /var/www/html; + + index index.html index.htm index.php; + + server_name 192.168.1.13; + + location / { + try_files $uri $uri/ =404; + } + + ssl_certificate /etc/nginx/ssl/nginx.crt; + ssl_certificate_key /etc/nginx/ssl/nginx.key; + + ssl_protocols TLSv1 TLSv1.1 TLSv1.2; + ssl_prefer_server_ciphers on; + ssl_ciphers EECDH+CHACHA20:EECDH+AES128:RSA+AES128:EECDH+AES256:RSA+AES256:EECDH+3DES:RSA+3DES:!MD5; + ssl_dhparam /etc/nginx/ssl/dhparam.pem; + ssl_session_cache shared:SSL:20m; + ssl_session_timeout 180m; + resolver 8.8.8.8 8.8.4.4; + add_header Strict-Transport-Security "max-age=31536000; + #includeSubDomains" always; + + + location ~ \.php$ { + include snippets/fastcgi-php.conf; + fastcgi_pass unix:/run/php/php7.0-fpm.sock; + } + + location ~ /\.ht { + deny all; + } + +} + +server { + listen 80; + listen [::]:80; + server_name 192.168.1.13; + return 301 https://$server_name$request_uri; +} +``` + +![](http://www.tecmint.com/wp-content/uploads/2016/05/Enable-Nginx-HTTP-2-Protocol.png) + +*启用 Nginx HTTP 2 协议* + +上面的配置片段向所有的 SSL 监听指令中添加 http2 参数来启用 `HTTP/2.0`。 + +上述添加到服务器配置的最后一段，是用来将所有非 SSL 的流量重定向到 SSL/TLS 默认主机。然后用你主机的 IP 地址或者 DNS 记录（最好用 FQDN 名称）替换掉 `server_name` 选项的参数。 + +5、 当你按照以上步骤编辑完 Nginx 的默认配置文件之后，用下面这些命令来生成、查看 SSL 证书和密钥。 + +用你自定义的设置完成证书的制作，注意 Common Name 设置成和你的 DNS FQDN 记录或者服务器 IP 地址相匹配。 + +``` +$ sudo mkdir /etc/nginx/ssl +$ sudo openssl req -x509 -nodes -days 365 -newkey rsa:2048 -keyout /etc/nginx/ssl/nginx.key -out /etc/nginx/ssl/nginx.crt +$ ls /etc/nginx/ssl/ +``` + +![](http://www.tecmint.com/wp-content/uploads/2016/05/Generate-SSL-Certificate-and-Key.png) + +*生成 Nginx 的 SSL 证书和密钥* + +6、 通过输入以下命令使用一个强 DH 加密算法，这会修改之前的配置文件 `ssl_dhparam` 所配置的文件。 + +``` +$ sudo openssl dhparam -out /etc/nginx/ssl/dhparam.pem 2048 +``` + +![](http://www.tecmint.com/wp-content/uploads/2016/05/Create-Diffie-Hellman-Key.png) + +*创建 Diffie-Hellman 密钥* + +7、 当 `Diffie-Hellman` 密钥生成之后，验证 Nginx 的配置文件是否正确、能否被 Nginx 网络服务程序应用。然后运行以下命令重启守护进程来观察有什么变化。 + +``` +$ sudo nginx -t +$ sudo systemctl restart nginx.service +``` + +![](http://www.tecmint.com/wp-content/uploads/2016/05/Check-Nginx-Configuration.png) + +*检查 Nginx 的配置* + +8、 键入下面的命令来测试 Nginx 使用的是 HTTP/2.0 协议。看到协议中有 `h2` 的话，表明 Nginx 已经成功配置使用 HTTP/2.0 协议。所有最新的浏览器默认都能够支持这个协议。 + +``` +$ openssl s_client -connect localhost:443 -nextprotoneg '' +``` + +![](http://www.tecmint.com/wp-content/uploads/2016/05/Test-Nginx-HTTP-2-Protocol.png) + +*测试 Nginx HTTP 2.0 协议* + +### 第 3 步：安装 PHP 7 解释器 + +通过 FastCGI 进程管理程序的协助，Nginx 能够使用 PHP 动态语言解释器生成动态网络内容。FastCGI 能够从 Ubuntu 官方仓库中安装 php-fpm 二进制包来获取。 + +9、 在你的服务器控制台里输入下面的命令来获取 PHP7.0 和扩展包，这能够让 PHP 与 Nginx 网络服务进程通信。 + +``` +$ sudo apt install php7.0 php7.0-fpm +``` + +![](http://www.tecmint.com/wp-content/uploads/2016/05/Install-PHP-7-PHP-FPM-for-Ngin.png) + +*安装 PHP 7 以及 PHP-FPM* + +10、 当 PHP7.0 解释器安装成功后，输入以下命令启动或者检查 php7.0-fpm 守护进程： + +``` +$ sudo systemctl start php7.0-fpm +$ sudo systemctl status php7.0-fpm +``` + +![](http://www.tecmint.com/wp-content/uploads/2016/05/Start-Verify-php-fpm-Service.png) + +*开启、验证 php-fpm 服务* + +11、 当前的 Nginx 配置文件已经配置了使用 PHP FPM 来提供动态内容。 + +下面给出的这部分服务器配置让 Nginx 能够使用 PHP 解释器，所以不需要对 Nginx 配置文件作别的修改。 + +``` +location ~ \.php$ { + include snippets/fastcgi-php.conf; + fastcgi_pass unix:/run/php/php7.0-fpm.sock; + } +``` + +下面是的截图是 Nginx 默认配置文件的内容。你可能需要对其中的代码进行修改或者取消注释。 + +![](http://www.tecmint.com/wp-content/uploads/2016/05/Enable-PHP-FastCGI-for-Nginx.png) + +*启用 PHP FastCGI* + +12、 要测试启用了 PHP-FPM 的 Nginx 服务器，用下面的命令创建一个 PHP 测试配置文件 `info.php`。接着用 `http://IP_or domain/info.php` 这个网址来查看配置。 + +``` +$ sudo su -c 'echo "" |tee /var/www/html/info.php' +``` + +![](http://www.tecmint.com/wp-content/uploads/2016/05/Create-PHP-Info-File.png) + +*创建 PHP Info 文件* + +![](http://www.tecmint.com/wp-content/uploads/2016/05/Verify-PHP-FastCGI-Info.png) + +*检查 PHP FastCGI 的信息* + +检查服务器是否宣告支持 HTTP/2.0 协议，定位到 PHP 变量区域中的 `$_SERVER[‘SERVER_PROTOCOL’]` 就像下面这张截图一样。 + +![](http://www.tecmint.com/wp-content/uploads/2016/05/Check-HTTP-2.0-Protocol-Info.png) + +*检查 HTTP2.0 协议信息* + +13、 为了安装其它的 PHP7.0 模块，使用 `apt search php7.0` 命令查找 php 的模块然后安装。 + +如果你想要 [安装 WordPress][5] 或者别的 CMS，需要安装以下的 PHP 模块，这些模块迟早有用。 + +``` +$ sudo apt install php7.0-mcrypt php7.0-mbstring +``` + +![](http://www.tecmint.com/wp-content/uploads/2016/05/Install-PHP-7-Modules.png) + +*安装 PHP 7 模块* + +14、 要注册这些额外的 PHP 模块，输入下面的命令重启 PHP-FPM 守护进程。 + +``` +$ sudo systemctl restart php7.0-fpm.service +``` + +### 第 4 步：安装 MariaDB 数据库 + +15、 最后，我们需要 MariaDB 数据库来存储、管理网站数据，才算完成 LEMP 的搭建。 + +运行下面的命令安装 MariaDB 数据库管理系统，重启 PHP-FPM 服务以便使用 MySQL 模块与数据库通信。 + +``` +$ sudo apt install mariadb-server mariadb-client php7.0-mysql +$ sudo systemctl restart php7.0-fpm.service +``` + +![](http://www.tecmint.com/wp-content/uploads/2016/05/Install-MariaDB-for-Nginx.png) + +*安装 MariaDB* + +16、 为了安全加固 MariaDB，运行来自 Ubuntu 软件仓库中的二进制包提供的安全脚本，这会询问你设置一个 root 密码，移除匿名用户，禁用 root 用户远程登录，移除测试数据库。 + +输入下面的命令运行脚本，并且确认所有的选择。参照下面的截图。 + +``` +$ sudo mysql_secure_installation +``` + +![](http://www.tecmint.com/wp-content/uploads/2016/05/Secure-MariaDB-Installation-for-Nginx.png) + +*MariaDB 的安全安装* + +17、 配置 MariaDB 以便普通用户能够不使用系统的 sudo 权限来访问数据库。用 root 用户权限打开 MySQL 命令行界面，运行下面的命令： + +``` +$ sudo mysql +MariaDB> use mysql; +MariaDB> update user set plugin=’‘ where User=’root’; +MariaDB> flush privileges; +MariaDB> exit +``` + +![](http://www.tecmint.com/wp-content/uploads/2016/05/MariaDB-User-Permissions.png) + +*MariaDB 的用户权限* + +最后通过执行以下命令登录到 MariaDB 数据库，就可以不需要 root 权限而执行任意数据库内的命令： + +``` +$ mysql -u root -p -e 'show databases' +``` + +![](http://www.tecmint.com/wp-content/uploads/2016/05/Check-MariaDB-Databases.png) + +*查看 MariaDB 数据库* + +好了！现在你拥有了配置在 **Ubuntu 16.04** 服务器上的 **LEMP** 环境，你能够部署能够与数据库交互的复杂动态网络应用。 + +-------------------------------------------------------------------------------- + +via: http://www.tecmint.com/install-nginx-mariadb-php7-http2-on-ubuntu-16-04/ + +作者：[Matei Cezar][a] +译者：[GitFuture](https://github.com/GitFuture) +校对：[wxy](https://github.com/wxy) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: http://www.tecmint.com/author/cezarmatei/ +[1]: http://www.tecmint.com/installation-of-ubuntu-16-04-server-edition/ +[2]: http://www.tecmint.com/apt-advanced-package-command-examples-in-ubuntu/ +[3]: http://www.tecmint.com/20-netstat-commands-for-linux-network-management/ +[4]: http://www.tecmint.com/manage-services-using-systemd-and-systemctl-in-linux/ +[5]: http://www.tecmint.com/install-wordpress-using-lamp-or-lemp-on-rhel-centos-fedora/ diff --git a/translated/tech/20160531 HOW TO USE WEBP IMAGES IN UBUNTU LINUX.md b/published/201607/20160531 HOW TO USE WEBP IMAGES IN UBUNTU LINUX.md similarity index 72% rename from translated/tech/20160531 HOW TO USE WEBP IMAGES IN UBUNTU LINUX.md rename to published/201607/20160531 HOW TO USE WEBP IMAGES IN UBUNTU LINUX.md index c08efbc683..e6287d62e9 100644 --- a/translated/tech/20160531 HOW TO USE WEBP IMAGES IN UBUNTU LINUX.md +++ b/published/201607/20160531 HOW TO USE WEBP IMAGES IN UBUNTU LINUX.md @@ -1,14 +1,15 @@ -在 Ubuntu Linux 中使用 WEBP 图片 +在 Ubuntu Linux 中使用 WebP 图片 ========================================= ![](http://itsfoss.com/wp-content/uploads/2016/05/support-webp-ubuntu-linux.jpg) ->简介：这篇指南会向你展示如何在 Linux 下查看 WebP 图片以及将 WebP 图片转换为 JPEG 或 PNG 格式。 -### 什么是 WEBP？ +> 简介：这篇指南会向你展示如何在 Linux 下查看 WebP 图片以及将 WebP 图片转换为 JPEG 或 PNG 格式。 -Google 为图片推出 [WebP 文件格式][0]已经超过五年了。Google 说，WebP 提供有损和无损压缩，相比 JPEG 压缩，WebP 压缩文件大小能更小约 25%。 +### 什么是 WebP？ -Google 的目标是让 WebP 成为 web 图片的新标准，但是我没能看到这一切发生。已经五年过去了，除了谷歌的生态系统以外它仍未被接受成为一个标准。但正如我们所知的，Google 对它的技术很有进取心。几个月前 Google 将 Google Plus 的所有图片改为了 WebP 格式。 +自从 Google 推出 [WebP 图片格式][0]，已经过去五年了。Google 说，WebP 提供有损和无损压缩，相比 JPEG 压缩，WebP 压缩文件大小，能更小约 25%。 + +Google 的目标是让 WebP 成为 web 图片的新标准，但是并没有成为现实。已经五年过去了，除了谷歌的生态系统以外它仍未被接受成为一个标准。但正如我们所知的，Google 对它的技术很有进取心。几个月前 Google 将 Google Plus 的所有图片改为了 WebP 格式。 如果你用 Google Chrome 从 Google Plus 上下载那些图片，你会得到 WebP 图片，不论你之前上传的是 PNG 还是 JPEG。这都不是重点。真正的问题在于当你尝试着在 Ubuntu 中使用默认的 GNOME 图片查看器打开它时你会看到如下错误： @@ -17,7 +18,8 @@ Google 的目标是让 WebP 成为 web 图片的新标准，但是我没能看 > **Unrecognized image file format（未识别文件格式）** ![](http://itsfoss.com/wp-content/uploads/2016/05/WebP-images-Ubuntu-Linux-1.png) ->GNOME 图片查看器不支持 WebP 图片 + +*GNOME 图片查看器不支持 WebP 图片* 在这个教程里，我们会看到 @@ -41,7 +43,8 @@ sudo apt-get install gthumb 一旦安装完成，你就可以简单地右键点击 WebP 图片，选择 gThumb 来打开它。你现在应该可以看到如下画面： ![](http://itsfoss.com/wp-content/uploads/2016/05/WebP-images-Ubuntu-Linux-2.jpeg) ->gThumb 中显示的 WebP 图片 + +*gThumb 中显示的 WebP 图片* ### 让 gThumb 成为 Ubuntu 中 WebP 图片的默认应用 @@ -50,28 +53,30 @@ sudo apt-get install gthumb #### 步骤 1：右键点击 WebP 文件选择属性。 ![](http://itsfoss.com/wp-content/uploads/2016/05/WebP-images-Ubuntu-Linux-3.png) ->从右键菜单中选择属性 + +*从右键菜单中选择属性* #### 步骤 2：转到打开方式标签，选择 gThumb 并点击设置为默认。 ![](http://itsfoss.com/wp-content/uploads/2016/05/WebP-images-Ubuntu-Linux-4.png) ->让 gThumb 成为 Ubuntu 中 WebP 图片的默认应用 + +*让 gThumb 成为 Ubuntu 中 WebP 图片的默认应用* ### 让 gThumb 成为所有图片的默认应用 -gThumb 的功能比图片查看器更多。举个例子，你可以做一些简单的编辑，给图片添加滤镜等。添加滤镜的效率没有 XnRetro（在[ Linux 下添加类似 Instagram 滤镜效果][5]的专用工具）那么高，但它还是有一些基础的滤镜可以用。 +gThumb 的功能比图片查看器更多。举个例子，你可以做一些简单的图片编辑，给图片添加滤镜等。添加滤镜的效率没有 XnRetro（在[ Linux 下添加类似 Instagram 滤镜效果][5]的专用工具）那么高，但它还是有一些基础的滤镜可以用。 -我非常喜欢 gThumb 并且决定让它成为默认的图片查看器。如果你也想在 Ubuntu 中让 gThumb 成为所有图片的默认默认应用，遵照以下步骤操作： +我非常喜欢 gThumb 并且决定让它成为默认的图片查看器。如果你也想在 Ubuntu 中让 gThumb 成为所有图片的默认应用，遵照以下步骤操作： -#### 步骤1：打开系统设置 +步骤1：打开系统设置 ![](http://itsfoss.com/wp-content/uploads/2014/04/System_Settings_ubuntu_1404.jpeg) -#### 步骤2：转到详情（Details） +步骤2：转到详情（Details） ![](http://itsfoss.com/wp-content/uploads/2013/11/System_settings_Ubuntu_1.jpeg) -#### 步骤3：在这里将 gThumb 设置为图片的默认应用 +步骤3：在这里将 gThumb 设置为图片的默认应用 ![](http://itsfoss.com/wp-content/uploads/2016/05/WebP-images-Ubuntu-Linux-5.png) @@ -100,7 +105,7 @@ sudo apt-get install webp ##### 将 JPEG/PNG 转换为 WebP -我们将使用 cwebp 命令（它代表压缩为 WebP 吗？）来将 JPEG 或 PNG 文件转换为 WebP。命令格式是这样的： +我们将使用 cwebp 命令（它代表转换为 WebP 的意思吗？）来将 JPEG 或 PNG 文件转换为 WebP。命令格式是这样的： ``` cwebp -q [图片质量] [JPEG/PNG_文件名] -o [WebP_文件名] @@ -132,7 +137,7 @@ dwebp example.webp -o example.png [下载 XnConvert][1] -XnConvert 是个强大的工具，你可以用它来批量修改图片尺寸。但在这个教程里，我们只能看到如何将单个 WebP 图片转换为 PNG/JPEG。 +XnConvert 是个强大的工具，你可以用它来批量修改图片尺寸。但在这个教程里，我们只介绍如何将单个 WebP 图片转换为 PNG/JPEG。 打开 XnConvert 并选择输入文件： @@ -148,24 +153,24 @@ XnConvert 是个强大的工具，你可以用它来批量修改图片尺寸。 也许你一点都不喜欢 WebP 图片格式，也不想在 Linux 仅仅为了查看 WebP 图片而安装一个新软件。如果你不得不将 WebP 文件转换以备将来使用，这会是件更痛苦的事情。 -一个解决这个问题更简单，不那么痛苦的途径是安装一个 Chrome 扩展 Save Image as PNG。有了这个插件，你可以右键点击 WebP 图片并直接存储为 PNG 格式。 +解决这个问题的一个更简单、不那么痛苦的途径是安装一个 Chrome 扩展 Save Image as PNG。有了这个插件，你可以右键点击 WebP 图片并直接存储为 PNG 格式。 ![](http://itsfoss.com/wp-content/uploads/2016/05/WebP-images-Ubuntu-Linux-8.png) ->在 Google Chrome 中将 WebP 图片保存为 PNG 格式 -[获取 Save Image as PNG 扩展][2] +*在 Google Chrome 中将 WebP 图片保存为 PNG 格式* + +- [获取 Save Image as PNG 扩展][2] ### 你的选择是？ -我希望这个详细的教程能够帮你在 Linux 上获取 WebP 支持并帮你转换 WebP 图片。你在 Linux 怎么处理 WebP 图片？你使用哪个工具？以上描述的方法中，你最喜欢哪一个？ - +我希望这个详细的教程能够帮你在 Linux 上支持 WebP 并帮你转换 WebP 图片。你在 Linux 怎么处理 WebP 图片？你使用哪个工具？以上描述的方法中，你最喜欢哪一个？ ---------------------- -via: http://itsfoss.com/webp-ubuntu-linux/?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+ItsFoss+%28Its+FOSS%21+An+Open+Source+Blog%29 +via: http://itsfoss.com/webp-ubuntu-linux/ 作者：[Abhishek Prakash][a] 译者：[alim0x](https://github.com/alim0x) -校对：[校对者ID](https://github.com/校对者ID) +校对：[wxy](https://github.com/wxy) 本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创翻译，[Linux中国](https://linux.cn/) 荣誉推出 diff --git a/published/201607/20160531 Why Ubuntu-based Distros Are Leaders.md b/published/201607/20160531 Why Ubuntu-based Distros Are Leaders.md new file mode 100644 index 0000000000..c909e753f7 --- /dev/null +++ b/published/201607/20160531 Why Ubuntu-based Distros Are Leaders.md @@ -0,0 +1,63 @@ +为什么 Ubuntu 家族会占据 Linux 发行版的主导地位？ +========================================= + +在过去的数年中，我体验了一些优秀的 Linux 发行版。给我印象最深刻的是那些由强大的社区维护的发行版，而流行的发行版比强大的社区给我的印象更深。流行的 Linux 发行版往往能吸引新用户，这通常是由于其流行而使得使用该发行版会更加容易。并非绝对如此，但一般来说是这样的。 + +说到这里，首先映入我脑海的一个发行版是 [Ubuntu][1]。其基于健壮的 [Debian][2] 发行版构建，它不仅成为了一个非常受欢迎的 Linux 发行版，而且它也衍生出了不可计数的其他分支，比如 Linux Mint 就是一个例子。在本文中，我会探讨为何我认为 Ubuntu 会赢得 Linux 发行版之战的原因，以及它是怎样影响到了整个 Linux 桌面领域。 + +### Ubuntu 易于使用 + +在我几年前首次尝试使用 Ubuntu 前，我更喜欢使用 KED 桌面。在那个时期，我接触的大多是这种 KDE 桌面环境。主要原因还是 KDE 是大多数新手容易入手的 Linux 发行版中最受欢迎的。这些新手友好的发行版有 Knoppix、Simply Mepis、Xandros、Linspire 以及其它的发行版等等，这些发行版都推荐他们的用户去使用广受欢迎的 KDE。 + +现在 KDE 能满足我的需求，我也没有什么理由去折腾其他的桌面环境。有一天我的 Debian 安装失败了（由于我个人的操作不当），我决定尝试开发代号为 Dapper Drake 的 Ubuntu 版本（LCTT 译注：Ubuntu 6.06 - Dapper Drake，发布日期：2006 年 6 月 1 日），每个人都对它赞不绝口。那个时候，我对于它的印象仅限于屏幕截图，但是我想试试也挺有趣的。 + +Ubuntu Dapper Drake 给我的最大的印象是它让我很清楚地知道每个东西都在哪儿。记住，我是来自于 KDE 世界的用户，在 KDE 上要想改变菜单的设置就有 15 种方法 ！而 Ubuntu 上的 GNOME 实现极具极简主义的。 + +时间来到 2016 年，最新的版本号是 16.04：我们有了好几种 Ubuntu 特色版本，也有一大堆基于 Ubuntu 的发行版。所有的 Ubuntu 特色版和衍生发行版的共同具有的核心都是为易用而设计。发行版想要增大用户基数时，这就是最重要的原因。 + +### Ubuntu LTS + +过去，我几乎一直坚持使用 LTS（Long Term Support）发行版作为我的主要桌面系统。10月份的发行版很适合我测试硬盘驱动器，甚至把它用在一个老旧的手提电脑上。我这样做的原因很简单——我没有兴趣在一个正式使用的电脑上折腾短期发行版。我是个很忙的家伙，我觉得这样会浪费我的时间。 + +对于我来说，我认为 Ubuntu 提供 LTS 发行版是 Ubuntu 能够变得流行的最大的原因。这样说吧———给普罗大众提供一个桌面 Linux 发行版，这个发行版能够得到长期的有效支持就是它的优势。事实上，不只 Ubuntu 是这样，其他的分支在这一点上也做的很好。长期支持策略以及对新手的友好环境，我认为这就为 Ubuntu 的普及带来了莫大的好处。 + +### Ubuntu Snap 软件包 + +以前，用户会夸赞可以在他们的系统上使用 PPA（personal package archive 个人软件包档案）获得新的软件。不好的是，这种技术也有缺点。当它用在各种软件名称时， PPA 经常会找不到，这种情况很常见。 + +现在有了 [Snap 软件包][3] 。当然这不是一个全新的概念，过去已经进行了类似的尝试。用户可以在一个长期支持版本上运行最新的软件，而不必去使用最新的 Ubuntu 发行版。虽然我认为目前还处于 Snap 软件包的早期，但是我很期待可以在一个稳定的发行版上运行的崭新的软件。 + +最明显的问题是，如果你要运行很多软件，那么 Snap 包实际会占用很多硬盘空间。不仅如此，大多数 Ubuntu 软件仍然需要由官方从 deb 包进行转换。第一个问题可以通过使用更大的硬盘空间得到解决，而后一个问题的解决则需要等待。 + +### Ubuntu 社区 + +首先，我承认大多数主要的 Linux 发行版都有强大的社区。然而，我坚信 Ubuntu 社区的成员是最多样化的，他们来自各行各业。例如，我们的论坛包括从苹果硬件支持到游戏等不同分类。特别是这些专业的讨论话题还非常广泛。 + +除过论坛，Ubuntu 也提供了一个很正式的社区组织。这个组织包括一个理事会、技术委员会、[本地社区团队][4]和开发者成员委员会。还有很多，但是这些都是我知道的社区组织部分。 + +我们还有一个 [Ubuntu 问答][5]版块。我认为，这种功能可以代替人们从论坛寻求帮助的方式，我发现在这个网站你得到有用信息的可能性更大。不仅如此，那些提供的解决方案中被选出的最精准的答案也会被写入到官方文档中。 + +### Ubuntu 的未来 + +我认为 Ubuntu 的 Unity 界面（LCTT 译注：Unity 是 Canonical 公司为 Ubuntu 操作系统的 GNOME 桌面环境开发的图形化界面）在提升桌面占有率上少有作为。我能理解其中的缘由，现在它主要做一些诸如可以使开发团队的工作更轻松的事情。但是最终，我还是认为 Unity 为 Ubuntu MATE 和 Linux Mint 的普及铺平道路。 + +我最好奇的一点是 Ubuntu's IRC 和邮件列表的发展（LCTT 译注：可以在 Ubuntu LoCo Teams 的 IRC Chat 上提问关于地方团队和计划的事件的问题，也可以和一些不同团队的成员进行交流）。事实是，他们都不能像 Ubuntu 问答板块那样文档化。至于邮件列表，我一直认为这对于合作是一种很痛苦的过时方法，但这仅仅是我的个人看法——其他人可能有不同的看法，也可能会认为它很好。 + +你怎么看？你认为 Ubuntu 将来会占据主要的份额吗？也许你会认为 Arch 和 Linux Mint 或者其他的发行版会在普及度上打败 Ubuntu？ 既然这样，那请大声说出你最喜爱的发行版。如果这个发行版是 Ubuntu 衍生版 ，说说你为什么更喜欢它而不是 Ubuntu 本身。如果不出意外，Ubuntu 会成为构建其他发行版的基础，我想很多人都是这样认为的。 + +-------------------------------------------------------------------------------- + +via: http://www.datamation.com/open-source/why-ubuntu-based-distros-are-leaders.html + +作者：[Matt Hartley][a] +译者：[vim-kakali](https://github.com/vim-kakali) +校对：[wxy](https://github.com/wxy) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: http://www.datamation.com/author/Matt-Hartley-3080.html +[1]: http://www.ubuntu.com/ +[2]: https://www.debian.org/ +[3]: http://www.datamation.com/open-source/ubuntu-snap-packages-the-good-the-bad-the-ugly.html +[4]: http://loco.ubuntu.com/ +[5]: http://askubuntu.com/ diff --git a/published/201607/20160602 How to mount your Google Drive on Linux with google-drive-ocamlfuse.md b/published/201607/20160602 How to mount your Google Drive on Linux with google-drive-ocamlfuse.md new file mode 100644 index 0000000000..e993dc5e58 --- /dev/null +++ b/published/201607/20160602 How to mount your Google Drive on Linux with google-drive-ocamlfuse.md @@ -0,0 +1,64 @@ +教你用 google-drive-ocamlfuse 在 Linux 上挂载 Google Drive +===================== + +> 如果你在找一个方便的方式在 Linux 机器上挂载你的 Google Drive 文件夹， Jack Wallen 将教你怎么使用 google-drive-ocamlfuse 来挂载 Google Drive。 + +![](http://tr4.cbsistatic.com/hub/i/2016/05/18/ee5d7b81-e5be-4b24-843d-d3ca99230a63/651be96ac8714698f8100afa6883e64d/linuxcloudhero.jpg) + +*图片来源: Jack Wallen* + +Google 还没有发行 Linux 版本的 Google Drive 应用，尽管现在有很多方法从 Linux 中访问你的 Drive 文件。 + +如果你喜欢界面化的工具，你可以选择 Insync。如果你喜欢用命令行，有很多像 Grive2 这样的工具，和更容易使用的以 Ocaml 语言编写的基于 FUSE 的文件系统。我将会用后面这种方式演示如何在 Linux 桌面上挂载你的 Google Drive。尽管这是通过命令行完成的，但是它的用法会简单到让你吃惊。它太简单了以至于谁都能做到。 + +这个系统的特点： + +- 对普通文件/文件夹有完全的读写权限 +- 对于 Google Docs，sheets，slides 这三个应用只读 +- 能够访问 Drive 回收站（.trash） +- 处理重复文件功能 +- 支持多个帐号 + +让我们接下来完成 google-drive-ocamlfuse 在 Ubuntu 16.04 桌面的安装，然后你就能够访问云盘上的文件了。 + +### 安装 + +1. 打开终端。 +2. 用 `sudo add-apt-repository ppa:alessandro-strada/ppa` 命令添加必要的 PPA +3. 出现提示的时候，输入你的 root 密码并按下回车。 +4. 用 `sudo apt-get update` 命令更新应用。 +5. 输入 `sudo apt-get install google-drive-ocamlfuse` 命令安装软件。 + +### 授权 + +接下来就是授权 google-drive-ocamlfuse，让它有权限访问你的 Google 账户。先回到终端窗口敲下命令 `google-drive-ocamlfuse`，这个命令将会打开一个浏览器窗口，它会提示你登陆你的 Google 帐号或者如果你已经登陆了 Google 帐号，它会询问是否允许 google-drive-ocamlfuse 访问 Google 账户。如果你还没有登录，先登录然后点击“允许”。接下来的窗口（在 Ubuntu 16.04 桌面上会出现，但不会出现在 Elementary OS Freya 桌面上）将会询问你是否授给 gdfuse 和 OAuth2 Endpoint 访问你的 Google 账户的权限，再次点击“允许”。然后出现的窗口就会告诉你等待授权令牌下载完成，这个时候就能最小化浏览器了。当你的终端提示如下图一样的内容，你就能知道令牌下载完了，并且你已经可以挂载 Google Drive 了。 + +![](http://tr4.cbsistatic.com/hub/i/r/2016/05/18/a493122b-445f-4aca-8974-5ec41192eede/resize/620x/6ae5907ad2c08dc7620b7afaaa9e389c/googledriveocamlfuse3.png) + +*应用已经得到授权，你可以进行后面的工作。* + +### 挂载 Google Drive + +在挂载 Google Drive 之前，你得先创建一个文件夹，作为挂载点。在终端里，敲下`mkdir ~/google-drive`命令在你的家目录下创建一个新的文件夹。最后敲下命令`google-drive-ocamlfuse ~/google-drive`将你的 Google Drive 挂载到 google-drive 文件夹中。 + +这时你可以查看本地 google-drive 文件夹中包含的 Google Drive 文件/文件夹。你可以把 Google Drive 当作本地文件系统来进行工作。 + +当你想卸载 google-drive 文件夹，输入命令 `fusermount -u ~/google-drive`。 + +### 没有 GUI，但它特别好用 + +我发现这个特别的系统非常容易使用，在同步 Google Drive 时它出奇的快，并且这可以作为一种本地备份你的 Google Drive 账户的巧妙方式。（LCTT 译注：然而首先你得能使用……） + +试试 google-drive-ocamlfuse，看看你能用它做出什么有趣的事。 + +-------------------------------------------------------------------------------- + +via: http://www.techrepublic.com/article/how-to-mount-your-google-drive-on-linux-with-google-drive-ocamlfuse/ + +作者：[Jack Wallen][a] +译者：[GitFuture](https://github.com/GitFuture) +校对：[wxy](https://github.com/wxy) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: http://www.techrepublic.com/search/?a=jack+wallen diff --git a/translated/tech/20160603 How To Install And Use VBoxManage On Ubuntu 16.04 And Use Its Command line Options.md b/published/201607/20160603 How To Install And Use VBoxManage On Ubuntu 16.04 And Use Its Command line Options.md similarity index 66% rename from translated/tech/20160603 How To Install And Use VBoxManage On Ubuntu 16.04 And Use Its Command line Options.md rename to published/201607/20160603 How To Install And Use VBoxManage On Ubuntu 16.04 And Use Its Command line Options.md index fec5b55c6c..b177995009 100644 --- a/translated/tech/20160603 How To Install And Use VBoxManage On Ubuntu 16.04 And Use Its Command line Options.md +++ b/published/201607/20160603 How To Install And Use VBoxManage On Ubuntu 16.04 And Use Its Command line Options.md @@ -1,17 +1,17 @@ -在 Ubuntu 16.04 上安装使用 VBoxManage 以及 VBoxManage 命令行选项的用法 +在 Linux 上安装使用 VirtualBox 的命令行管理界面 VBoxManage ================= -VirtualBox 拥有一套命令行工具，然后你可以使用 VirtualBox 的命令行界面 (CLI) 对远端无界面的服务器上的虚拟机进行管理操作。在这篇教程中，你将会学到如何在没有 GUI 的情况下使用 VBoxManage 创建、启动一个虚拟机。VBoxManage 是 VirtualBox 的命令行界面，你可以在你的主机操作系统的命令行中来用它实现对 VirtualBox 的所有操作。VBoxManage 拥有图形化用户界面所支持的全部功能，而且它支持的功能远不止这些。它提供虚拟引擎的所有功能，甚至包含 GUI 还不能实现的那些功能。如果你想尝试不同的用户界面而不仅仅是 GUI，或者更改虚拟机更多高级和实验性的配置，那么你就需要用到命令行。 +VirtualBox 拥有一套命令行工具，你可以使用 VirtualBox 的命令行界面 (CLI) 对远程无界面的服务器上的虚拟机进行管理操作。在这篇教程中，你将会学到如何在没有 GUI 的情况下使用 VBoxManage 创建、启动一个虚拟机。VBoxManage 是 VirtualBox 的命令行界面，你可以在你的主机操作系统的命令行中用它来实现对 VirtualBox 的所有操作。VBoxManage 拥有图形化用户界面所支持的全部功能，而且它支持的功能远不止这些。它提供虚拟引擎的所有功能，甚至包含 GUI 还不能实现的那些功能。如果你想尝试下不同的用户界面而不仅仅是 GUI，或者更改虚拟机更多高级和实验性的配置，那么你就需要用到命令行。 -当你想要在 VirtualBox 上创建或运行虚拟机时，你会发现 VBoxManage 非常有用，你只需要使用远程主机的终端就够了。这对于服务器来说是一种常见的情形，因为在服务器上需要进行虚拟机的远程操作。 +当你想要在 VirtualBox 上创建或运行虚拟机时，你会发现 VBoxManage 非常有用，你只需要使用远程主机的终端就够了。这对于需要远程管理虚拟机的服务器来说是一种常见的情形。 ### 准备工作 -在开始使用 VBoxManage 的命令行工具前，确保在运行着 Ubuntu 16.04 的服务器上，你拥有超级用户的权限或者你能够使用 sudo 命令，而且你已经在服务器上安装了 Oracle Virtual Box。 然后你需要安装 VirtualBox 扩展包，这是运行远程桌面环境，访问无界面启动虚拟机所必须的。（headless的翻译拿不准，翻译为无界面启动） +在开始使用 VBoxManage 的命令行工具前，确保在运行着 Ubuntu 16.04 的服务器上，你拥有超级用户的权限或者你能够使用 sudo 命令，而且你已经在服务器上安装了 Oracle Virtual Box。 然后你需要安装 VirtualBox 扩展包，这是运行 VRDE 远程桌面环境，访问无界面虚拟机所必须的。 ### 安装 VBoxManage -通过 [Virtual Box Download Page][1] 这个链接，你能够获取你所需要的软件扩展包的最新版本，扩展包的版本和你安装的 VirtualBox 版本需要一致！ +通过 [Virtual Box 下载页][1] 这个链接，你能够获取你所需要的软件扩展包的最新版本，扩展包的版本和你安装的 VirtualBox 版本需要一致！ ![](http://linuxpitstop.com/wp-content/uploads/2016/06/12.png) @@ -71,11 +71,11 @@ $ VBoxManage modifyvm Ubuntu10.10 --memory 512 $ VBoxManage storagectl Ubuntu16.04 --name IDE --add ide --controller PIIX4 --bootable on ``` -这里的 “storagect1” 是给虚拟机创建存储控制器的，“--name” 指定了虚拟机里需要创建、更改或者移除的存储控制器的名称。“--add” 选项指明系统总线类型，可选的选项有 ide / sata / scsi / floppy，存储控制器必须要连接到系统总线。“--controller” 选择主板的类型，主板需要根据需要的存储控制器选择，可选的选项有 LsiLogic / LSILogicSAS / BusLogic / IntelAhci / PIIX3 / PIIX4 / ICH6 / I82078。最后的 “--bootable” 表示控制器是否可以引导。 +这里的 “storagect1” 是给虚拟机创建存储控制器的，“--name” 指定了虚拟机里需要创建、更改或者移除的存储控制器的名称。“--add” 选项指明存储控制器所需要连接到的系统总线类型，可选的选项有 ide / sata / scsi / floppy。“--controller” 选择主板的类型，主板需要根据需要的存储控制器选择，可选的选项有 LsiLogic / LSILogicSAS / BusLogic / IntelAhci / PIIX3 / PIIX4 / ICH6 / I82078。最后的 “--bootable” 表示控制器是否可以引导系统。 -上面的命令创建了叫做 IDE 的存储控制器。然后虚拟设备就能通过 “storageattach” 命令连接到控制器。 +上面的命令创建了叫做 IDE 的存储控制器。之后虚拟介质就能通过 “storageattach” 命令连接到该控制器。 -然后运行下面这个命令来创建一个叫做 SATA 的存储控制器，它将会连接到硬盘镜像上。 +然后运行下面这个命令来创建一个叫做 SATA 的存储控制器，它将会连接到之后的硬盘镜像上。 ``` $ VBoxManage storagectl Ubuntu16.04 --name SATA --add sata --controller IntelAhci --bootable on @@ -87,7 +87,7 @@ $ VBoxManage storagectl Ubuntu16.04 --name SATA --add sata --controller IntelAhc $ VBoxManage storageattach Ubuntu16.04 --storagectl SATA --port 0 --device 0 --type hdd --medium "your_iso_filepath" ``` -用媒体把 SATA 存储控制器连接到 Ubuntu16.04 虚拟机中，也就是之前创建的虚拟硬盘镜像里。 +这将把 SATA 存储控制器及介质（比如之前创建的虚拟磁盘镜像）连接到 Ubuntu16.04 虚拟机中。 运行下面的命令添加像网络连接，音频之类的功能。 @@ -120,9 +120,9 @@ $VBoxManage controlvm ![](http://linuxpitstop.com/wp-content/uploads/2016/06/81.png) -完结！ +###完结 -从这篇文章中，我们了解了 Oracle Virtual Box 中一个十分实用的工具，就是 VBoxManage，包含了 VBoxManage 的安装和在 Ubuntu 16.04 系统上的使用。文章包含详细的教程， 通过 VBoxManage 中实用的命令来创建和管理虚拟机。希望这篇文章对你有帮助，另外别忘了分享你的评论或者建议。 +从这篇文章中，我们了解了 Oracle Virtual Box 中一个十分实用的工具 VBoxManage，文章包含了 VBoxManage 的安装和在 Ubuntu 16.04 系统上的使用，包括通过 VBoxManage 中实用的命令来创建和管理虚拟机。希望这篇文章对你有帮助，另外别忘了分享你的评论或者建议。 -------------------------------------------------------------------------------- @@ -130,7 +130,7 @@ via: http://linuxpitstop.com/install-and-use-command-line-tool-vboxmanage-on-ubu 作者：[Kashif][a] 译者：[GitFuture](https://github.com/GitFuture) -校对：[校对者ID](https://github.com/校对者ID) +校对：[wxy](https://github.com/wxy) 本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 diff --git a/translated/tech/20160606 Basic Git Commands You Must Know.md b/published/201607/20160606 Basic Git Commands You Must Know.md similarity index 75% rename from translated/tech/20160606 Basic Git Commands You Must Know.md rename to published/201607/20160606 Basic Git Commands You Must Know.md index dbaf78ad95..57aa6662e2 100644 --- a/translated/tech/20160606 Basic Git Commands You Must Know.md +++ b/published/201607/20160606 Basic Git Commands You Must Know.md @@ -5,15 +5,15 @@ *简介：这个快速指南将向你展示所有的基础 Git 命令以及用法。你可以下载这些命令作为快速参考。* -我们在早先一篇文章中已经见过快速指南和 [Vi cheat sheet 下载][1]了。在这篇文章里，我们将会看到开始使用 Git 所需要的基础命令。 +我们在早先一篇文章中已经快速介绍过 [Vi 速查表][1]了。在这篇文章里，我们将会介绍开始使用 Git 时所需要的基础命令。 -### GIT +### Git [Git][2] 是一个分布式版本控制系统，它被用在大量开源项目中。它是在 2005 年由 Linux 创始人 [Linus Torvalds][3] 写就的。这个程序允许非线性的项目开发，并且能够通过存储在本地服务器高效处理大量数据。在这个教程里，我们将要和 Git 愉快玩耍并学习如何开始使用它。 我在这个教程里使用 Ubuntu，但你可以使用你选择的任何发行版。除了安装以外，剩下的所有命令在任何 Linux 发行版上都是一样的。 -### 安装 GIT +### 安装 Git 要安装 git 执行以下命令： @@ -23,11 +23,11 @@ sudo apt-get install git-core 在它完成下载之后，你就安装好了 Git 并且可以使用了。 -### 设置 GIT： +### 设置 Git 在 Git 安装之后，不论是从 apt-get 还是从源码安装，你需要将你的用户名和邮箱地址复制到 gitconfig 文件。你可以访问 ~/.gitconfig 这个文件。 -全新安装 Git 之后打开它会是完全空白的页面： +全新安装 Git 之后打开它会是完全空白的： ``` sudo vim ~/.gitconfig @@ -42,7 +42,7 @@ git config --global user.email user@example.com 然后你就完成设置了。现在让我们开始 Git。 -### 仓库： +### 仓库 创建一个新目录，打开它并运行以下命令： @@ -52,13 +52,11 @@ git init ![](http://itsfoss.com/wp-content/uploads/2016/05/Playing-around-git-1-1024x173.png) -这个命令会创建一个新的 git 仓库。你的本地仓库由三个 git 维护的“树”组成。 +这个命令会创建一个新的 Git 仓库（repository）。你的本地仓库由三个 Git 维护的“树”组成。 -第一个是你的**工作目录**，保存实际的文件。第二个是索引，实际上扮演的是暂存区，最后一个是 HEAD，它指向你最后一个 commit 提交。 +第一个是你的工作目录（Working Directory），保存实际的文件。第二个是索引，实际上扮演的是暂存区（staging area），最后一个是 HEAD，它指向你最后一个 commit 提交。使用 git clone /path/to/repository 签出你的仓库（从你刚创建的仓库或服务器上已存在的仓库）。 -使用 git clone /path/to/repository 签出你的仓库（从你刚创建的仓库或服务器上已存在的仓库）。 - -### 添加文件并提交： +### 添加文件并提交 你可以用以下命令添加改动： @@ -98,7 +96,7 @@ git commit -a ### 推送你的改动 -你的改动在你本地工作副本的 HEAD 中。如果你还没有从一个已存在的仓库克隆或想将你的仓库连接到远程服务器，你需要先添加它： +你的改动在你本地工作副本的 HEAD 中。如果你还没有从一个已存在的仓库克隆，或想将你的仓库连接到远程服务器，你需要先添加它： ``` git remote add origin <服务器地址> @@ -110,9 +108,9 @@ git remote add origin <服务器地址> git push -u origin master ``` -### 分支： +### 分支 -分支用于开发特性，它们之间是互相独立的。主分支 master 是你创建一个仓库时的“默认”分支。使用其它分支用于开发，在完成时将它合并回主分支。 +分支用于开发特性，分支之间是互相独立的。主分支 master 是你创建一个仓库时的“默认”分支。使用其它分支用于开发，在完成时将它合并回主分支。 创建一个名为“mybranch”的分支并切换到它之上： @@ -144,19 +142,19 @@ git push origin <分支名> ### 更新和合并 -要将你本地仓库更新到最新提交，运行： +要将你本地仓库更新到最新的提交上，运行： ``` git pull ``` -在你的工作目录获取和合并远程变动。要合并其它分支到你的活动分支（如 master），使用： +在你的工作目录获取并合并远程变动。要合并其它分支到你的活动分支（如 master），使用： ``` git merge <分支> ``` -在这两种情况下，git 会尝试自动合并（auto-merge）改动。不幸的是，这不总是可能的，可能会导致冲突。你需要负责通过编辑 git 显示的文件，手动合并那些冲突。改动之后，你需要用以下命令将它们标记为已合并： +在这两种情况下，git 会尝试自动合并（auto-merge）改动。不幸的是，这不总是可能的，可能会导致冲突。你需要通过编辑 git 所显示的文件，手动合并那些冲突。改动之后，你需要用以下命令将它们标记为已合并： ``` git add <文件名> @@ -168,7 +166,7 @@ git add <文件名> git diff <源分支> <目标分支> ``` -### GIT 日志： +### Git 日志 你可以这么查看仓库历史： @@ -176,7 +174,7 @@ git diff <源分支> <目标分支> git log ``` -要查看每个提交一行样式的日志你可以用： +要以每个提交一行的样式查看日志，你可以用： ``` git log --pretty=oneline @@ -196,9 +194,9 @@ git log --name-status 在这整个过程中如果你需要任何帮助，你可以用 git --help。 -Git 棒不棒！！！祝贺你你已经会 git 基础了。如果你愿意的话，你可以从下面这个链接下载这些基础 Git 命令作为快速参考： +Git 棒不棒？！祝贺你你已经会 Git 基础了。如果你愿意的话，你可以从下面这个链接下载这些基础 Git 命令作为快速参考： -[下载 Git Cheat Sheet][4] +- [下载 Git 速查表][4] -------------------------------------------------------------------------------- @@ -207,7 +205,7 @@ via: http://itsfoss.com/basic-git-commands-cheat-sheet/ 作者：[Rakhi Sharma][a] 译者：[alim0x](https://github.com/alim0x) -校对：[校对者ID](https://github.com/校对者ID) +校对：[wxy](https://github.com/wxy) 本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 diff --git a/published/201607/20160609 How to record your terminal session on Linux.md b/published/201607/20160609 How to record your terminal session on Linux.md new file mode 100644 index 0000000000..f30e4db2dc --- /dev/null +++ b/published/201607/20160609 How to record your terminal session on Linux.md @@ -0,0 +1,98 @@ +如何在 Linux 上录制你的终端操作 +================================================= + +录制一个终端操作可能是一个帮助他人学习 Linux 、展示一系列正确命令行操作的和分享知识的通俗易懂方法。不管是出于什么目的，从终端复制粘贴文本需要重复很多次，而录制视频的过程也是相当麻烦，有时候还不能录制。在这次的文章中，我们将简单的了解一下以 gif 格式记录和分享终端会话的方法。 + +### 预先要求 + +如果你只是希望能记录你的终端会话，并且能在终端进行回放或者和他人分享，那么你只需要一个叫做：ttyrec 的软件。Ubuntu 用户可以通过运行这行代码进行安装： + +``` +sudo apt-get install ttyrec +``` + +如果你想将生成的视频转换成一个 gif 文件，这样能够和那些不使用终端的人分享，就可以发布到网站上去，或者你只是想做一个 gif 方便使用而不想写命令。那么你需要安装额外的两个软件包。第一个就是 imagemagick , 你可以通过以下的命令安装： + +``` +sudo apt-get install imagemagick +``` + +第二个软件包就是：tty2gif.py，访问其[项目网站][1]下载。这个软件包需要安装如下依赖: + +``` +sudo apt-get install python-opster +``` + +### 录制 + +开始录制终端操作，你需要的仅仅是键入 `ttyprec` ，然后回车。这个命令将会在后台运行一个实时的记录工具。我们可以通过键入`exit`或者`ctrl+d`来停止。ttyrec 默认会在主目录下创建一个`ttyrecord`的文件。 + +![](https://www.howtoforge.com/images/how-to-record-your-terminal-session-on-linux/pic_1.jpg) + +![](https://www.howtoforge.com/images/how-to-record-your-terminal-session-on-linux/pic_2.jpg) + +![](https://www.howtoforge.com/images/how-to-record-your-terminal-session-on-linux/pic_3.jpg) + +### 回放 + +回放这个文件非常简单。你只需要打开终端并且使用 `ttyplay` 命令打开 `ttyrecord` 文件即可。(在这个例子里，我们使用 ttyrecord 作为文件名，当然，你也可以改成你用的文件名) + +![](https://www.howtoforge.com/images/how-to-record-your-terminal-session-on-linux/pic_4.jpg) + +然后就可以开始播放这个文件。这个视频记录了所有的操作，包括你的删除，修改。这看起来像一个拥有自我意识的终端，但是这个命令执行的过程并不是只是为了给系统看，而是为了更好的展现给人。 + +注意一点，播放这个记录是完全可控的，你可以通过点击 `+` 或者 `-` 进行加速减速，或者 `0`和 `1` 暂停和恢复播放。 + +### 导出成 GIF + +为了方便，我们通常会将视频记录转换为 gif 格式，并且，这个非常容易做到。以下是方法： + +将之前下载的 tty2gif.py 这个文件拷贝到 ttyprecord 文件（或者你命名的那个视频文件）相同的目录，然后在这个目录下打开终端，输入命令： + +``` +python tty2gif.py typing ttyrecord +``` + +如果出现了错误，检查一下你是否有安装 python-opster 包。如果还是有错误，使用如下命令进行排除。 + +``` +sudo apt-get install xdotool +export WINDOWID=$(xdotool getwindowfocus) +``` + +然后重复这个命令 `python tty2gif.py` 并且你将会看到在 ttyrecord 目录下多了一些 gif 文件。 + +![](https://www.howtoforge.com/images/how-to-record-your-terminal-session-on-linux/pic_5.jpg) + +接下来的一步就是整合所有的 gif 文件，将他打包成一个 gif 文件。我们通过使用 imagemagick 工具。输入下列命令: + +``` +convert -delay 25 -loop 0 *.gif example.gif +``` + +![](https://www.howtoforge.com/images/how-to-record-your-terminal-session-on-linux/pic_6.jpg) + +你可以使用任意的文件名，我用的是 example.gif。 并且，你可以改变这个延时和循环时间。 Enjoy。 + +![](https://www.howtoforge.com/images/how-to-record-your-terminal-session-on-linux/example.gif) + +-------------------------------------------------------------------------------- + +via: https://www.howtoforge.com/tutorial/how-to-record-your-terminal-session-on-linux/ + +作者：[Bill Toulas][a] +译者：[MikeCoder](https://github.com/MikeCoder) +校对：[wxy](https://github.com/wxy) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://twitter.com/howtoforgecom +[1]: https://bitbucket.org/antocuni/tty2gif/raw/61d5596c916512ce5f60fcc34f02c686981e6ac6/tty2gif.py + + + + + + + + diff --git a/published/201607/20160609 INSTALL MATE 1.14 IN UBUNTU MATE 16.04 VIA PPA.md b/published/201607/20160609 INSTALL MATE 1.14 IN UBUNTU MATE 16.04 VIA PPA.md new file mode 100644 index 0000000000..a7932ee269 --- /dev/null +++ b/published/201607/20160609 INSTALL MATE 1.14 IN UBUNTU MATE 16.04 VIA PPA.md @@ -0,0 +1,62 @@ +在 Ubuntu Mate 16.04 上通过 PPA 升级 Mate 1.14 +================================================================= + +Mate 桌面环境 1.14 现在可以在 Ubuntu Mate 16.04 ("Xenial Xerus") 上使用了。根据这个[发布版本][1]的描述，为了全面测试 Mate 1.14，所以 Mate 桌面环境 1.14 已经在 PPA 上发布 2 个月了。因此，你不太可能遇到安装的问题。 + +![](https://2.bp.blogspot.com/-v38tLvDAxHg/V1k7beVd5SI/AAAAAAAAX7A/1X72bmQ3ia42ww6kJ_61R-CZ6yrYEBSpgCLcB/s400/mate114-ubuntu1604.png) + +**现在 PPA 提供 Mate 1.14.1 包含如下改变（Ubuntu Mate 16.04 默认安装的是 Mate 1.12.x）：** + +- 客户端的装饰应用现在可以正确的在所有主题中渲染； +- 触摸板配置现在支持边缘操作和双指滚动； +- 在 Caja 中的 Python 扩展可以被单独管理； +- 所有三个窗口焦点模式都是可选的； +- Mate Panel 中的所有菜单栏图标和菜单图标可以改变大小； +- 音量和亮度 OSD 目前可以启用和禁用； +- 更多的改进和 bug 修改； + +Mate 1.14 同时改进了整个桌面环境中对 GTK+ 3 的支持，包括各种 GTK+3 小应用。但是，Ubuntu MATE 的博客中提到：PPA 的发行包使用 GTK+ 2 编译是“为了确保对 Ubuntu MATE 16.04 还有各种各样的第三方 MATE 应用、插件、扩展的支持"。 + +MATE 1.14 的完整修改列表[点击此处][2]阅读。 + +### 在 Ubuntu MATE 16.04 中升级 MATE 1.14.x + +在 Ubuntu MATE 16.04 中打开终端，并且输入如下命令，来从官方的 Xenial MATE PPA 中升级最新的 MATE 桌面环境: + +``` +sudo apt-add-repository ppa:ubuntu-mate-dev/xenial-mate +sudo apt update +sudo apt dist-upgrade +``` + +**注意**: mate-netspeed 应用将会在升级中删除。因为该应用现在已经是 mate-applets 应用报的一部分，所以它依旧是可以使用的。 + +一旦升级完成，请重启你的系统，享受全新的 MATE! + +### 如何回滚这次升级 + +如果你并不满意 MATE 1.14, 比如你遭遇了一些 bug 。或者你想回到 MATE 的官方源版本，你可以使用如下的命令清除 PPA，并且下载降级包。 + +``` +sudo apt install ppa-purge +sudo ppa-purge ppa:ubuntu-mate-dev/xenial-mate +``` + +在所有的 MATE 包降级之后，重启系统。 + +via [Ubuntu MATE blog][3] + +-------------------------------------------------------------------------------- + +via: http://www.webupd8.org/2016/06/install-mate-114-in-ubuntu-mate-1604.html + +作者：[Andrew][a] +译者：[MikeCoder](https://github.com/MikeCoder) +校对：[wxy](https://github.com/wxy) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: http://www.webupd8.org/p/about.html +[1]: https://ubuntu-mate.org/blog/mate-desktop-114-for-xenial-xerus/ +[2]: http://mate-desktop.com/blog/2016-04-08-mate-1-14-released/ +[3]: https://ubuntu-mate.org/blog/mate-desktop-114-for-xenial-xerus/ diff --git a/translated/tech/20160610 Getting started with ReactOS.md b/published/201607/20160610 Getting started with ReactOS.md similarity index 92% rename from translated/tech/20160610 Getting started with ReactOS.md rename to published/201607/20160610 Getting started with ReactOS.md index ffeeb9021f..8d04902798 100644 --- a/translated/tech/20160610 Getting started with ReactOS.md +++ b/published/201607/20160610 Getting started with ReactOS.md @@ -1,9 +1,7 @@ ReactOS 新手指南 ==================================== - -ReactOS 是一个比较年轻的开源操作系统，它提供了一个和 Windows NT 类似的图形界面，并且它的目标也是提供一个与 NT 功能和应用程序兼容性差不多的系统。这个项目在没有使用任何 Unix 的情况下实现了一个类似 Wine 的用户模式。它的开发者们从头实现了 NT 的架构以及对于 FAT32 的兼容，因此它也不需要负任何法律责任。这也就是说，它不是又双叒叕一个 Linux 发行版，而是一个独特的类 Windows 系统，并且是开源世界的一部分。这份快速指南是给那些想要一个易于使用的 Windows 的开源替代品的人准备的。 - +ReactOS 是一个比较年轻的开源操作系统，它提供了一个和 Windows NT 类似的图形界面，并且它的目标也是提供一个与 NT 功能和应用程序兼容性差不多的系统。这个项目在没有使用任何 Unix 架构的情况下实现了一个类似 Wine 的用户模式。它的开发者们从头实现了 NT 的架构以及对于 FAT32 的兼容，因此它也不需要负任何法律责任。这也就是说，它不是又双叒叕一个 Linux 发行版，而是一个独特的类 Windows 系统，并且是开源世界的一部分。这份快速指南是给那些想要一个易于使用的 Windows 的开源替代品的人准备的。 ### 安装系统 @@ -31,7 +29,6 @@ ReactOS 是一个比较年轻的开源操作系统，它提供了一个和 Windo 下一步是选择分区的格式，不过现在我们只能选择 FAT32。 - ![](https://www.howtoforge.com/images/getting-started-with-eeactos/pic_6.png) 再下一步是选择安装文件夹。我就使用默认的“/ReactOS”了，应该没有问题。 @@ -96,7 +93,7 @@ ReactOS 是一个比较年轻的开源操作系统，它提供了一个和 Windo ![](https://www.howtoforge.com/images/getting-started-with-eeactos/pic_20.png) -ReactOS 还有一个好啊，就是我们可以通过“我的电脑”来操作注册表。 +ReactOS 还有一个好的地方，就是我们可以通过“我的电脑”来操作注册表。 ![](https://www.howtoforge.com/images/getting-started-with-eeactos/pic_21.png) diff --git a/published/201607/20160616 10 Basic Linux Commands That Every Linux Newbies Should Remember.md b/published/201607/20160616 10 Basic Linux Commands That Every Linux Newbies Should Remember.md new file mode 100644 index 0000000000..50ec85acaa --- /dev/null +++ b/published/201607/20160616 10 Basic Linux Commands That Every Linux Newbies Should Remember.md @@ -0,0 +1,141 @@ +Linux 新手必知必会的 10 条 Linux 基本命令 +===================================================================== + +![](http://www.linuxandubuntu.com/uploads/2/1/1/5/21152474/4225072_orig.png) + + +Linux 对我们的生活产生了巨大的冲击。至少你的安卓手机使用的就是 Linux 核心。尽管如此，在第一次开始使用 Linux 时你还是会感到难以下手。因为在 Linux 中，通常需要使用终端命令来取代 Windows 系统中的点击启动图标操作。但是不必担心，这里我们会介绍 10 个 Linux 基本命令来帮助你开启 Linux 神秘之旅。 + + +### 帮助新手走出第一步的 10 个 Linux 基本命令 + +当我们谈论 Linux 命令时，实质上是在谈论 Linux 系统本身。这短短的 10 个 Linux 基本命令不会让你变成天才或者 Linux 专家，但是能帮助你轻松开始 Linux 之旅。使用这些基本命令会帮助新手们完成 Linux 的日常任务，由于它们的使用频率如此至高，所以我更乐意称他们为 Linux 命令之王！ + +让我们开始学习这 10 条 Linux 基本命令吧。 + + +#### 1. sudo + +这条命令的意思是“以超级用户的身份执行”，是 SuperUserDo 的简写，它是新手将要用到的最重要的一条 Linux 命令。当一条单行命令需要 root 权限的时候，`sudo`命令就派上用场了。你可以在每一条需要 root 权限的命令前都加上`sudo`。 + +``` +$ sudo su +``` + + +#### 2. ls (list) + + +跟其他人一样，你肯定也经常想看看目录下都有些什么东西。使用列表命令，终端会把当前工作目录下所有的文件以及文件夹展示给你。比如说，我当前处在 /home 文件夹中，我想看看 /home 文件夹中都有哪些文件和目录。 + +``` +/home$ ls +``` + + +在 /home 中执行`ls`命令将会返回类似下面的内容： + +``` +imad lost+found +``` + + +#### 3. cd + +变更目录命令（cd）是终端中总会被用到的主要命令。它是最常用到的 Linux 基本命令之一。此命令使用非常简单，当你打算从当前目录跳转至某个文件夹时，只需要将文件夹键入此命令之后即可。如果你想跳转至上层目录，只需要在此命令之后键入两个点 (..) 就可以了。 +​ +举个例子，我现在处在 /home 目录中，我想移动到 /home 目录中的 usr 文件夹下，可以通过以下命令来完成操作。 + +``` +/home $ cd usr + +/home/usr $ +``` + + +#### 4. mkdir + +只是可以切换目录还是不够完美。有时候你会想要新建一个文件夹或子文件夹。此时可以使用 mkdir 命令来完成操作。使用方法很简单，只需要把新的文件夹名跟在 mkdir 命令之后就好了。 + +``` +~$ mkdir folderName +``` + + +#### 5. cp + +拷贝-粘贴（copy-and-paste）是我们组织文件需要用到的重要命令。使用 `cp` 命令可以帮助你在终端当中完成拷贝-粘贴操作。首先确定你想要拷贝的文件，然后键入打算粘贴此文件的目标位置。 + +``` +$ cp src des +``` + +注意：如果目标目录对新建文件需要 root 权限时，你可以使用 `sudo` 命令来完成文件拷贝操作。 + + +#### 6. rm + +rm 命令可以帮助你移除文件甚至目录。如果不希望每删除一个文件都提示确认一次，可以用`-f`参数来强制执行。也可以使用 `-r` 参数来递归的移除文件夹。 + +``` +$ rm myfile.txt +``` + + +#### 7. apt-get + +这个命令会依据发行版的不同而有所区别。在基于 Debian 的发行版中，我们拥有 Advanced Packaging Tool（APT）包管理工具来安装、移除和升级包。apt-get 命令会帮助你安装需要在 Linux 系统中运行的软件。它是一个功能强大的命令行，可以用来帮助你对软件执行安装、升级和移除操作。 + +在其他发行版中，例如 Fedora、Centos，都各自不同的包管理工具。Fedora 之前使用的是 yum，不过现在 dnf 成了它默认的包管理工具。 + +``` +$ sudo apt-get update + +$ sudo dnf update +``` + + +#### 8. grep + +当你需要查找一个文件，但是又忘记了它具体的位置和路径时，`grep` 命令会帮助你解决这个难题。你可以提供文件的关键字，使用`grep`命令来查找到它。 + +``` +$ grep user /etc/passwd +``` + + +#### 9. cat + +作为一个用户，你应该会经常需要浏览脚本内的文本或者代码。`cat`命令是 Linux 系统的基本命令之一，它的用途就是将文件的内容展示给你。 + +``` +$ cat CMakeLists.txt +``` + + +#### 10. poweroff + +最后一个命令是 `poweroff`。有时你需要直接在终端中执行关机操作。此命令可以完成这个任务。由于关机操作需要 root 权限，所以别忘了在此命令之前添加`sudo`。 + +``` +$ sudo poweroff +``` + + +### 总结 + +如我在文章开始所言，这 10 条命令并不会让你立即成为一个 Linux 大拿，但它们会让你在初期快速上手 Linux。以这些命令为基础，给自己设置一个目标，每天学习一到三条命令，这就是此文的目的所在。在下方评论区分享有趣并且有用的命令。别忘了跟你的朋友分享此文。 + + +-------------------------------------------------------------------------------- + +via: http://www.linuxandubuntu.com/home/10-basic-linux-commands-that-every-linux-newbies-should-remember + +作者：[Commenti][a] +译者：[mr-ping](https://github.com/mr-ping) +校对：[wxy](https://github.com/wxy) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: http://www.linuxandubuntu.com/home/10-basic-linux-commands-that-every-linux-newbies-should-remember#comments +[1]: http://linuxandubuntu.com/home/category/linux diff --git a/published/201607/20160616 6 Amazing Linux Distributions For Kids.md b/published/201607/20160616 6 Amazing Linux Distributions For Kids.md new file mode 100644 index 0000000000..79f3aff154 --- /dev/null +++ b/published/201607/20160616 6 Amazing Linux Distributions For Kids.md @@ -0,0 +1,113 @@ +惊艳！6款面向儿童的 Linux 发行版 +====================================== + +毫无疑问未来是属于 Linux 和开源的。为了实现这样的未来、使 Linux 占据一席之地，人们已经着手开发尽可能简单的、面向儿童的 Linux 发行版，并尝试教导他们如何使用 Linux 操作系统。 + +![](http://www.tecmint.com/wp-content/uploads/2016/05/Linux-Distros-For-Kids.png) +>面向儿童的 Linux 发行版 + +Linux 是一款非常强大的操作系统，原因之一便是它支撑了互联网上绝大多数的服务器。但出于对其用户友好性的担忧，坊间时常展开有关于 Linux 应如何取代 Mac OS X 或 Windows 的争论。而我认为用户应该接受 Linux 来见识它真正的威力。 + +如今，Linux 运行在绝大多数设备上，从智能手机到平板电脑，笔记本电脑，工作站，服务器，超级计算机，再到汽车，航空管制系统，电冰箱，到处都有 Linux 的身影。正如我在开篇所说，有了这一切， Linux 是未来的操作系统。 + +>参考阅读: [30 Big Companies and Devices Running on Linux][1] + +未来是属于孩子们的，教育要从娃娃抓起。所以，要让小孩子尽早地学习计算机，而 Linux 就是其中一个重要的部分。 + +对小孩来说，一个常见的现象是，当他们在一个适合他的环境中学习时，好奇心和早期学习的能力会使他自己养成喜好探索的性格。 + +说了这么多儿童应该学习 Linux 的原因，接下来我就列出这些令人激动的发行版。你可以把它们推荐给小孩子来帮助他们开始学习使用 Linux 。 + +### Sugar on a Stick + +Sugar on a Stick (译注：“糖棒”)是 Sugar 实验室旗下的工程，Sugar 实验室是一个由志愿者领导的非盈利组织。这一发行版旨在设计大量的免费工具来促进儿童在探索中学会技能，发现、创造，并将这些反映到自己的思想上。 + +![](http://www.tecmint.com/wp-content/uploads/2016/05/Sugar-Neighborhood-View.png) +>Sugar Neighborhood 界面 + +![](http://www.tecmint.com/wp-content/uploads/2016/05/Sugar-Activity-Library.png) +>Sugar 应用程序 + +你既可以将 Sugar 看作是普通的桌面环境，也可以把它当做是帮助鼓励孩子学习、提高参与活动的积极性的一款应用合集。 + +访问主页: + +### Edubuntu + +Edubuntu 是基于当下最流行的发行版 Ubuntu 而开发的一款非官方发行版。主要致力于降低学校、家庭和社区安装、使用 Ubuntu 自由软件的难度。 + +![](http://www.tecmint.com/wp-content/uploads/2016/05/Edubuntu-Apps.jpg) +>Edubuntu 桌面应用 + +它是由来自不同组织的学生、教师、家长、一些利益相关者甚至黑客支持的，这些人都坚信自由的学习和共享知识能够提高自己和社区的发展。 + +该项目的主要目标是通过组建一款能够降低安装、管理软件难度的操作系统来增强学习和教育水平。 + +访问主页: + +### Doudou Linux + +Doudou Linux 是专为方便孩子们在建设创新思维时使用计算机而设计的发行版。它提供了简单但是颇具教育意义的应用来使儿童在应用过程中学习发现新的知识。 + +![](http://www.tecmint.com/wp-content/uploads/2016/05/Doudou-Linux.png) +>Doudou Linux + +其最引人注目的一点便是内容过滤功能，顾名思义，它能够阻止孩童访问网络上的限制性内容。如果想要更进一步的儿童保护功能，Doudou Linux 还提供了互联网用户隐私功能，能够去除网页中的特定加载内容。 + +访问主页: + +### LinuxKidX + +这是一款整合了许多专为儿童设计的教育软件的基于 Slackware Linux 发行版的 LiveCD。它使用 KDE 作为默认桌面环境并配置了诸如 Ktouch 打字指导，Kstars 虚拟天文台，Kalzium 元素周期表和 KwordQuiz 单词测试等应用。 + +![](http://www.tecmint.com/wp-content/uploads/2016/05/LinuxKidX.jpg) +>LinuxKidX + +访问主页: + +### Ubermix + +Ubermix 基于 Ubuntu 构建，同样以教学为目的。默认配备了超过60款应用，帮助学生更好地学习，同时给教师教学提供便利。 + +![](http://www.tecmint.com/wp-content/uploads/2016/05/ubermix.png) +>Ubermix Linux + +Ubermix 还具有5分钟快速安装和快速恢复等功能，可以给小孩子更好的帮助。 + +访问主页: + +### Qimo + +因为很多读者曾向我询问过 Qimo 发行版的情况，所以我把它写进这篇文章。但是截止发稿时，Qimo 儿童版的开发已经终止，不再提供更新。 + +![](http://www.tecmint.com/wp-content/uploads/2016/05/Qimo-Linux.png) +>Qimo Linux + +你仍然可以在 Ubuntu 或者其他的 Linux 发行版中找到大多数儿童游戏。正如这些开发商所说，他们并不是要终止为孩子们开发教育软件，而是在开发能够提高儿童读写能力的 android 应用。 + +如果你想进一步了解，可以移步他们的官方网站。 + +访问主页: + +以上这些便是我所知道的面向儿童的Linux发行版，或有缺漏，欢迎评论补充。 + +如果你想让我们知道你对如何想儿童介绍 Linux 或者你对未来的 Linux ，特别是桌面计算机上的 Linux，欢迎与我联系。 + +-------------------------------------------------------------------------------- + +via: http://www.tecmint.com/best-linux-distributions-for-kids/?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+tecmint+%28Tecmint%3A+Linux+Howto%27s+Guide%29 + + +作者：[Aaron Kili][a] +译者：[HaohongWANG](https://github.com/HaohongWANG) +校对：[Ezio](https://github.com/oska874) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: http://www.tecmint.com/author/aaronkili/ +[1]: http://www.tecmint.com/big-companies-and-devices-running-on-gnulinux/ + + + + + diff --git a/published/201607/20160620 Detecting cats in images with OpenCV.md b/published/201607/20160620 Detecting cats in images with OpenCV.md new file mode 100644 index 0000000000..55b80cc51e --- /dev/null +++ b/published/201607/20160620 Detecting cats in images with OpenCV.md @@ -0,0 +1,227 @@ +使用 OpenCV 识别图片中的猫咪 +======================================= + +![](http://www.pyimagesearch.com/wp-content/uploads/2016/05/cat_face_detector_result_04.jpg) + +你知道 OpenCV 可以识别在图片中小猫的脸吗？而且是拿来就能用，不需要其它的库之类的。 + +之前我也不知道。 + +但是在 [Kendrick Tan 曝出这个功能][1]后，我需要亲自体验一下……去看看到 OpenCV 是如何在我没有察觉到的情况下，将这一个功能添加进了他的软件库（就像一只悄悄溜进空盒子的猫咪一样，等待别人发觉）。 + +下面，我将会展示如何使用 OpenCV 的猫咪检测器在图片中识别小猫的脸。同样的，该技术也可以用在视频流中。 + +### 使用 OpenCV 在图片中检测猫咪 + +如果你查找过 [OpenCV 的代码仓库][3]，尤其是在 [haarcascades 目录][4]里（OpenCV 在这里保存处理它预先训练好的 Haar 分类器，以检测各种物体、身体部位等）， 你会看到这两个文件: + +- haarcascade_frontalcatface.xml +- haarcascade\_frontalcatface\_extended.xml + +这两个 Haar Cascade 文件都将被用来在图片中检测小猫的脸。实际上，我使用了相同的 cascades 分类器来生成这篇博文顶端的图片。 + +在做了一些调查工作之后，我发现这些 cascades 分类器是由鼎鼎大名的 [Joseph Howse][5]训练和贡献给 OpenCV 仓库的，他写了很多很棒的教程和书籍，在计算机视觉领域有着很高的声望。 + +下面，我将会展示给你如何使用 Howse 的 Haar cascades 分类器来检测图片中的小猫。 + +### 猫咪检测代码 + +让我们开始使用 OpenCV 来检测图片中的猫咪。新建一个叫 cat_detector.py 的文件，并且输入如下的代码: + +``` +# import the necessary packages +import argparse +import cv2 + +# construct the argument parse and parse the arguments +ap = argparse.ArgumentParser() +ap.add_argument("-i", "--image", required=True, + help="path to the input image") +ap.add_argument("-c", "--cascade", + default="haarcascade_frontalcatface.xml", + help="path to cat detector haar cascade") +args = vars(ap.parse_args()) +``` + +第 2 和第 3 行主要是导入了必要的 python 包。6-12 行用于解析我们的命令行参数。我们仅要求一个必需的参数 `--image` ，它是我们要使用 OpenCV 检测猫咪的图片。 + +我们也可以（可选的）通过 `--cascade` 参数指定我们的 Haar cascade 分类器的路径。默认使用 `haarcascades_frontalcatface.xml`，假定这个文件和你的 `cat_detector.py` 在同一目录下。 + +注意：我已经打包了猫咪的检测代码，还有在这个教程里的样本图片。你可以在博文原文的 “下载” 部分下载到。如果你是刚刚接触 Python+OpenCV（或者 Haar cascade），我建议你下载这个 zip 压缩包，这个会方便你跟着教程学习。 + +接下来，就是检测猫的时刻了： + +``` +# load the input image and convert it to grayscale +image = cv2.imread(args["image"]) +gray = cv2.cvtColor(image, cv2.COLOR_BGR2GRAY) + +# load the cat detector Haar cascade, then detect cat faces +# in the input image +detector = cv2.CascadeClassifier(args["cascade"]) +rects = detector.detectMultiScale(gray, scaleFactor=1.3, + minNeighbors=10, minSize=(75, 75)) +``` + +在 15、16 行，我们从硬盘上读取了图片，并且进行灰度化（这是一个在将图片传给 Haar cascade 分类器之前的常用的图片预处理步骤，尽管不是必须的） + +20 行，从硬盘加载 Haar casacade 分类器，即猫咪检测器，并且实例化 `cv2.CascadeClassifier` 对象。 + +在 21、22 行通过调用 `detector` 的 `detectMultiScale` 方法使用 OpenCV 完成猫脸检测。我们给 `detectMultiScale` 方法传递了四个参数。包括： + +1. 图片 `gray`，我们要在该图片中检测猫脸。 +2. 检测猫脸时的[图片金字塔][6] 的检测粒度 `scaleFactor` 。更大的粒度将会加快检测的速度，但是会对检测准确性（ true-positive）产生影响。相反的，一个更小的粒度将会影响检测的时间，但是会增加准确性（ true-positive）。但是，细粒度也会增加误报率（false-positive）。你可以看这篇博文的“ Haar cascades 注意事项”部分来获得更多的信息。 +3. `minNeighbors` 参数控制了检定框的最少数量，即在给定区域内被判断为猫脸的最少数量。这个参数可以很好的排除误报（false-positive）结果。 +4. 最后，`minSize` 参数不言自明。这个值描述每个检定框的最小宽高尺寸（单位是像素），这个例子中就是 75\*75 + +`detectMultiScale` 函数会返回 `rects`，这是一个 4 元组列表。这些元组包含了每个检测到的猫脸的 (x,y) 坐标值，还有宽度、高度。 + +最后，让我们在图片上画下这些矩形来标识猫脸： + +``` +# loop over the cat faces and draw a rectangle surrounding each +for (i, (x, y, w, h)) in enumerate(rects): + cv2.rectangle(image, (x, y), (x + w, y + h), (0, 0, 255), 2) + cv2.putText(image, "Cat #{}".format(i + 1), (x, y - 10), + cv2.FONT_HERSHEY_SIMPLEX, 0.55, (0, 0, 255), 2) + +# show the detected cat faces +cv2.imshow("Cat Faces", image) +cv2.waitKey(0) +``` + +给我们这些框（比如，rects）的数据，我们在 25 行依次遍历它。 + +在 26 行，我们在每张猫脸的周围画上一个矩形。27、28 行展示了一个整数，即图片中猫咪的数量。 + +最后，31，32 行在屏幕上展示了输出的图片。 + +### 猫咪检测结果 + +为了测试我们的 OpenCV 猫咪检测器，可以在原文的最后，下载教程的源码。 + +然后，在你解压缩之后，你将会得到如下的三个文件/目录: + +1. cat_detector.py：我们的主程序 +2. haarcascade_frontalcatface.xml： 猫咪检测器 Haar cascade +3. images：我们将会使用的检测图片目录。 + +到这一步，执行以下的命令： + +``` +$ python cat_detector.py --image images/cat_01.jpg +``` + +![](http://www.pyimagesearch.com/wp-content/uploads/2016/05/cat_face_detector_result_01.jpg) + +*图 1. 在图片中检测猫脸，甚至是猫咪部分被遮挡了。* + +注意，我们已经可以检测猫脸了，即使它的其余部分是被遮挡的。 + +试下另外的一张图片: + +``` +python cat_detector.py --image images/cat_02.jpg +``` + +![](http://www.pyimagesearch.com/wp-content/uploads/2016/05/cat_face_detector_result_02.jpg) + +*图 2. 使用 OpenCV 检测猫脸的第二个例子，这次猫脸稍有不同。* + +这次的猫脸和第一次的明显不同，因为它正在发出“喵呜”叫声的当中。这种情况下，我们依旧能检测到正确的猫脸。 + +在下面这张图片的结果也是正确的： + +``` +$ python cat_detector.py --image images/cat_03.jpg +``` + +![](http://www.pyimagesearch.com/wp-content/uploads/2016/05/cat_face_detector_result_03.jpg) + +*图 3. 使用 OpenCV 和 python 检测猫脸* + +我们最后的一个样例就是在一张图中检测多张猫脸: + +``` +$ python cat_detector.py --image images/cat_04.jpg +``` + +![](http://www.pyimagesearch.com/wp-content/uploads/2016/05/cat_face_detector_result_04.jpg) + +*图 4. 在同一张图片中使用 OpenCV 检测多只猫* + +注意，Haar cascade 返回的检定框不一定是以你预期的顺序。这种情况下，中间的那只猫会被标记成第三只。你可以通过判断他们的 (x, y) 坐标来自己排序这些检定框。 + +#### 关于精度的说明 + +在这个 xml 文件中的注释非常重要，Joseph Hower 提到了这个猫脸检测器有可能会将人脸识别成猫脸。 + +这种情况下，他推荐使用两种检测器（人脸 & 猫脸），然后将出现在人脸识别结果中的结果剔除掉。 + +#### Haar cascades 注意事项 + +这个方法首先出现在 Paul Viola 和 Michael Jones 2001 年出版的 [Rapid Object Detection using a Boosted Cascade of Simple Features][7] 论文中。现在它已经成为了计算机识别领域引用最多的论文之一。 + +这个算法能够识别图片中的对象，无论它们的位置和比例。而且最令人感兴趣的或许是它能在现有的硬件条件下实现实时检测。 + +在他们的论文中，Viola 和 Jones 关注在训练人脸检测器；但是，这个框架也能用来检测各类事物，如汽车、香蕉、路标等等。 + +#### 问题是？ + +Haar cascades 最大的问题就是如何确定 `detectMultiScale` 方法的参数正确。特别是 `scaleFactor` 和 `minNeighbors` 参数。你很容易陷入一张一张图片调参数的坑，这个就是该对象检测器很难被实用化的原因。 + +这个 `scaleFactor` 变量控制了用来检测对象的图片的各种比例的[图像金字塔][8]。如果 `scaleFactor` 参数过大，你就只需要检测图像金字塔中较少的层，这可能会导致你丢失一些在图像金字塔层之间缩放时少了的对象。 + +换句话说，如果 `scaleFactor` 参数过低，你会检测过多的金字塔图层。这虽然可以能帮助你检测到更多的对象。但是他会造成计算速度的降低，还会**明显**提高误报率。Haar cascades 分类器就是这样。 + +为了避免这个，我们通常使用 [Histogram of Oriented Gradients + 线性 SVM 检测][9] 替代。 + +上述的 HOG + 线性 SVM 框架的参数更容易调优。而且更好的误报率也更低，但是唯一不好的地方是无法实时运算。 + +### 对对象识别感兴趣？并且希望了解更多？ + +![](http://www.pyimagesearch.com/wp-content/uploads/2016/05/custom_object_detector_example.jpg) + +*图 5. 在 PyImageSearch Gurus 课程中学习如何构建自定义的对象识别器。* + +如果你对学习如何训练自己的自定义对象识别器感兴趣，请务必要去了解下 PyImageSearch Gurus 课程。 + +在这个课程中，我提供了 15 节课，覆盖了超过 168 页的教程，来教你如何从 0 开始构建自定义的对象识别器。你会掌握如何应用 HOG + 线性 SVM 框架来构建自己的对象识别器来识别路标、面孔、汽车（以及附近的其它东西）。 + +要学习 PyImageSearch Gurus 课程（有 10 节示例免费课程），点此：https://www.pyimagesearch.com/pyimagesearch-gurus/?src=post-cat-detection + +### 总结 + +在这篇博文里，我们学习了如何使用 OpenCV 默认就有的 Haar cascades 分类器来识别图片中的猫脸。这些 Haar casacades 是由 [Joseph Howse][9] 训练兵贡献给 OpenCV 项目的。我是在 Kendrick Tan 的[这篇文章][10]中开始注意到这个。 + +尽管 Haar cascades 相当有用，但是我们也经常用 HOG + 线性 SVM 替代。因为后者相对而言更容易使用，并且可以有效地降低误报率。 + +我也会[在 PyImageSearch Gurus 课程中][11]详细的讲述如何构建定制的 HOG + 线性 SVM 对象识别器，来识别包括汽车、路标在内的各种事物。 + +不管怎样，我希望你喜欢这篇博文。 + +-------------------------------------------------------------------------------- + +via: http://www.pyimagesearch.com/2016/06/20/detecting-cats-in-images-with-opencv/ + +作者：[Adrian Rosebrock][a] +译者：[MikeCoder](https://github.com/MikeCoder) +校对：[wxy](https://github.com/wxy) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: http://www.pyimagesearch.com/author/adrian/ +[1]: http://kendricktan.github.io/find-cats-in-photos-using-computer-vision.html +[2]: http://www.pyimagesearch.com/2016/06/20/detecting-cats-in-images-with-opencv/# +[3]: https://github.com/Itseez/opencv +[4]: https://github.com/Itseez/opencv/tree/master/data/haarcascades +[5]: http://nummist.com/ +[6]: http://www.pyimagesearch.com/2015/03/16/image-pyramids-with-python-and-opencv/ +[7]: https://www.cs.cmu.edu/~efros/courses/LBMV07/Papers/viola-cvpr-01.pdf +[8]: http://www.pyimagesearch.com/2015/03/16/image-pyramids-with-python-and-opencv/ +[9]: http://www.pyimagesearch.com/2014/11/10/histogram-oriented-gradients-object-detection/ +[10]: http://kendricktan.github.io/find-cats-in-photos-using-computer-vision.html +[11]: https://www.pyimagesearch.com/pyimagesearch-gurus/ + + + diff --git a/published/201607/20160620 Monitor Linux With Netdata.md b/published/201607/20160620 Monitor Linux With Netdata.md new file mode 100644 index 0000000000..989abf0d66 --- /dev/null +++ b/published/201607/20160620 Monitor Linux With Netdata.md @@ -0,0 +1,118 @@ +用 Netdata 监控 Linux +======= + +![](https://cdn.fedoramagazine.org/wp-content/uploads/2016/06/netdata-945x400.png) + +Netdata 是一个实时的资源监控工具，它拥有基于 web 的友好界面，由 [FireHQL][1] 开发和维护。通过这个工具，你可以通过图表来了解 CPU，RAM，硬盘，网络，Apache， Postfix 等软硬件的资源使用情况。它很像 Nagios 等别的监控软件；但是，Netdata 仅仅支持通过 Web 界面进行实时监控。 + +### 了解 Netdata + +目前 Netdata 还没有验证机制，如果你担心别人能从你的电脑上获取相关信息的话，你应该设置防火墙规则来限制访问。UI 很简单，所以任何人看懂图形并理解他们看到的结果，至少你会对它的快速安装印象深刻。 + +它的 web 前端响应很快，而且不需要 Flash 插件。 UI 很整洁，保持着 Netdata 应有的特性。第一眼看上去，你能够看到很多图表，幸运的是绝大多数常用的图表数据（像 CPU，RAM，网络和硬盘）都在顶部。如果你想深入了解图形化数据，你只需要下滑滚动条，或者点击在右边菜单的项目。通过每个图表的右下方的按钮， Netdata 还能让你控制图表的显示，重置，缩放。 + +![](https://fedoramagazine.org/wp-content/uploads/2016/06/Capture-1.png) + +*Netdata 图表控制* + +Netdata 并不会占用多少系统资源，它占用的内存不会超过 40MB。因为这个软件是作者用 C 语言写的。 + +![](https://fedoramagazine.org/wp-content/uploads/2016/06/Capture.png) + +*Netdata 显示的内存使用情况* + +### 下载 Netdata + +要下载这个软件，你可以访问 [Netdata 的 GitHub 页面][2]，然后点击页面左边绿色的 "Clone or download" 按钮 。你应该能看到以下两个选项： + +#### 通过 ZIP 文件下载 + +一种方法是下载 ZIP 文件。它包含仓库里的所有东西。但是如果仓库更新了，你需要重新下载 ZIP 文件。下载完 ZIP 文件后，你要用 `unzip` 命令行工具来解压文件。运行下面的命令能把 ZIP 文件的内容解压到 `netdata` 文件夹。 + +``` +$ cd ~/Downloads +$ unzip netdata-master.zip +``` + +![](https://fedoramagazine.org/wp-content/uploads/2016/06/Capture-2.png) + +*解压 Netdata* + +没必要在 unzip 命令后加上 `-d` 选项，因为文件都是是放在 ZIP 文件的根文件夹里面。如果没有那个文件夹， unzip 会把所有东西都解压到当前目录下面（这会让文件非常混乱）。 + +#### 通过 Git 下载 + +还有一种方式是通过 git 下载整个仓库。当然，你的系统需要安装 git。Git 在 Fedora 系统是默认安装的。如果没有安装，你可以用下面的命令在命令行里安装 git。 + +``` +$ sudo dnf install git +``` + +安装好 git 后，你要把仓库 “clone” 到你的系统里。运行下面的命令。 + +``` +$ git clone https://github.com/firehol/netdata.git +``` + +这个命令会在当前工作目录克隆（或者说复制一份）仓库。 + +### 安装 Netdata + +有些软件包是你成功构造 Netdata 时候需要的。 还好，一行命令就可以安装你所需要的东西（[这写在它的安装文档中][3]）。在命令行运行下面的命令就能满足安装 Netdata 需要的所有依赖关系。 + +``` +$ dnf install zlib-devel libuuid-devel libmnl-devel gcc make git autoconf autogen automake pkgconfig +``` + +当所有需要的软件包都安装好了，你就 cd 到 netdata/ 目录，运行 netdata-installer.sh 脚本。 + +``` +$ sudo ./netdata-installer.sh +``` + +然后就会提示你按回车键，开始安装程序。如果要继续的话，就按下回车吧。 + +![](https://cdn.fedoramagazine.org/wp-content/uploads/2016/06/Capture-3-600x341.png) + +*Netdata 的安装* + +如果一切顺利，你的系统上就已经安装并且运行了 Netdata。安装脚本还会在相应的文件夹里添加一个卸载脚本，叫做 `netdata-uninstaller.sh`。如果你以后不想使用 Netdata，运行这个脚本可以从你的系统里面卸载掉 Netdata。 + +你可以通过 systemctl 查看它的运行状态。 + +``` +$ sudo systemctl status netdata +``` + +### 使用 Netdata + +既然我们已经安装并且运行了 Netdata，你就能够通过 19999 端口来访问 web 界面。下面的截图是我在一个测试机器上运行的 Netdata。 + +![](https://cdn.fedoramagazine.org/wp-content/uploads/2016/06/Capture-4-768x458.png) + +*关于 Netdata 运行时的概览* + +恭喜！你已经成功安装并且能够看到漂亮的外观和图形，以及你的机器性能的高级统计数据。无论是否是你个人的机器，你都可以向你的朋友们炫耀，因为你能够深入的了解你的服务器性能，Netdata 在任何机器上的性能报告都非常出色。 + +-------------------------------------------------------------------------------- + +via: https://fedoramagazine.org/monitor-linux-netdata/ + +作者：[Martino Jones][a] +译者：[GitFuture](https://github.com/GitFuture) +校对：[wxy](https://github.com/wxy) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://fedoramagazine.org/monitor-linux-netdata/ +[1]: https://firehol.org/ +[2]: https://github.com/firehol/netdata +[3]: https://github.com/firehol/netdata/wiki/Installation + + + + + + + + diff --git a/published/201607/20160620 PowerPC gains an Android 4.4 port with Big Endian support.md b/published/201607/20160620 PowerPC gains an Android 4.4 port with Big Endian support.md new file mode 100644 index 0000000000..7ad127370b --- /dev/null +++ b/published/201607/20160620 PowerPC gains an Android 4.4 port with Big Endian support.md @@ -0,0 +1,106 @@ +Android 4.4 移植到了 PowerPC 架构，支持大端架构 +=========================================================== + +eInfochips（一家软件厂商） 已将将 Android 4.4 系统移植到 PowerPC 架构，它将用于一家航空电子客户用来监视引擎的健康状况的人机界面（HMI:Human Machine Interface）。 + +eInfochips 已经开发了第一个面向 PowerPC 架构的 CPU 的 Android 移植版本，并支持大端（Big Endian）架构。此移植基于 Android 开源项目 [Android Open Source Project (AOSP)] 中 Android 4.4 (KitKat) 的代码，其功能内核的版本号为 3.12.19。 + +Android 开始兴起的时候，PowerPC 正在快速丢失和 ARM 架构共同角逐的市场。高端的网络客户和其它的企业级的嵌入式工具大多运行在诸如飞思卡尔（Freescale）的 PowerQUICC 和 QorIQ 这样的 PowerPC 处理器上，但是并不是 Linux 系统。不过，有几个 Android 的移植计划。在 2009 年，飞思卡尔和 Embedded Alley（一家软件厂商，当前是 Mentor Graphics 的 Linux 团队的一部分）[宣布了针对 PowerQUICC 和 QorIQ 芯片的移植版本][15]，当前由 NXP 公司构建。另一个名为 [Android-PowerPC][16] 的项目也作出了相似的工作。 + +这些努力来的都并不容易，然而，当航空公司找到 eInfochips，希望能够为他们那些基于 PowerPC 的引擎监控系统添加 Android 应用程序以改善人机界面。该公司找出了这些早期的移植版本，然而，它们都相距甚远。所以，他们不得不从头开始新的移植。 + +最主要的问题是这些移植的 Android 版本实在是太老了，和现在的 Android 差别太大了。Embedded Alley 移植的版本为 Android 1.5 (Cupcake)，它于 2009 年发布，Linux 内核版本为 2.6.28。而 Android-PowerPC 项目最后一版的移植是 Android 2.2 (Froyo)，它于 2010 年发布，内核版本为 2.6.32。此外，航空公司还有一些额外的技术诉求，例如对大端架构（Big Endian）的支持，这种老式的内存访问方式仍旧应用于网络通信和电信行业。然而那些早期的移植版本仅能够支持小端（Little Endian）的内存访问。 + +### 来自 eInfochips 的全新 PowerPC 架构移植 + +eInfochips, 它最为出名的应该是那些基于 ARM/骁龙处理器的模块计算机板卡，例如 [Eragon 600][17]。 它已经完成了基于 QorIQ 的 Android 4.4 系统移植，且发布了白皮书介绍了该项目。采用该项目的航空电子设备客户仍旧不愿透露名称，目前仍旧不清楚什么时候会公开此该移植版本。 + +![](http://files.linuxgizmos.com/einfochips_porting_android_on_powerpc.jpg) + +*图片来自 eInfochips 的博客日志* + +全新的 PowerPC Android 项目包括： + +- 基于 PowerPC [e5500][1] 仿生定制 +- 基于 Android KitKat 的大端支持 +- 使用 GCC 5.2 工具链开发 +- Android 4.4 框架的 PowerPC 支持 +- PowerPC e5500 的 Android 内核版本为 3.12.19 + +根据 eInfochips 的销售经理 Sooryanarayanan Balasubramanian 描述，该航空电子客户想要使用 Android 主要是因为熟悉的界面能够缩减培训的时间，并且让程序更新和增加新程序变得更加容易。他继续解释说：“这次成功的移植了 Android，使得今后的工作仅仅需要在应用层作出修修改改，而不再向以前一样需要在所有层面之间作相互的校验。”，“这是第一次在航空航天工业作出这些尝试，这需要在设计时尽量认真。” + +通过白皮书，可以知道将 Android 移植到 PowerPC 上需要对框架、核心库、开发工具链、运行时链接器、对象链接器和开源编译工具作出大量的修改。在字节码生成阶段，移植团队决定使用便携模式（portable mode）而不是快速解释模式（fast interpreter mode）。这是因为还没有 PowerPC 可用的快速解释模式，而使用开源的 [libffi][18] 的便携模式能够支持 PowerPC。 + +同时，团队还面临着在 Android 运行时 (ART) 环境和 Dalvik 虚拟机 (DVM) 环境之间的选择。他们发现，ART 环境下的便携模式还未经测试且缺乏良好的文档支持，所以最终选择了 DVM 环境下的便携模式。 + +白皮书中还提及了其它的一些在移植过程中遇到的困难，包括重新开发工具链，重写脚本以解决 AOSP 对编译器标志“非标准”使用的问题。最终完成的移植版本提供了 37 个服务，以及提供了无界面的 Android 部署，在前端使用用户空间的模拟 UI。 + + +### 目标硬件 + +感谢来自 [eInfochips 博客日志][2] 的图片（如下图所示），让我们能够确认此 PowerPC 的 Android 移植项目的硬件平台。这个板卡为 [X-ES Xpedite 6101][3]，它是一个加固级 XMC/PrPMC 夹层模组。 + +![](http://hackerboards.com/files/xes_xpedite6101-sm.jpg) + +*X-ES Xpedite 6101 照片和框图* + +X-ES Xpedite 6101 板卡拥有一个可选的 NXP 公司基于 QorIQ T 系列通信处理器（T2081、T1042 和 T1022），它们分别集成了 8 个、4 个和 2 个 e6500 核心，稍有不同的是，T2081 的处理器主频为 1.8GHz，T1042/22 的处理器主频为 1.4GHz。所有的核心都集成了 AltiVec SIMD 引擎，这也就意味着它能够提供 DSP 级别的浮点运算性能。所有以上 3 款 X-ES 板卡都能够支持最高 8GB 的 DDR3-1600 ECC SDRAM 内存。外加 512MB NOR 和 32GB 的 NAND 闪存。 + +![](http://hackerboards.com/files/nxp_qoriq_t2081_block-sm.jpg) + +*NXP T2081 框图* + +板卡的 I/O 包括一个 x4 PCI Express Gen2 通道，以及双工的千兆级网卡、 RS232/422/485 串口和 SATA 3.0 接口。此外，它可选 3 款 QorIQ 处理器，Xpedite 6101 提供了三种 [X-ES 加固等级][19]，分别是额定工作温度 0 ~ 55°C, -40 ~ 70°C, 或者是 -40 ~ 85°C，且包含 3 类冲击和抗振类别。 + +此外，我们已经介绍过的基于 X-ES QorIQ 的 XMC/PrPMC 板卡包括 [XPedite6401 和 XPedite6370][20]，它们支持已有的板卡级 Linux 、风河的 VxWorks（一种实时操作系统） 和 Green Hills 的 Integrity（也是一种操作系统）。 + + +### 更多信息 + +eInfochips Android PowerPC 移植白皮书可以[在此][4]下载(需要先免费注册)。 + +### 相关资料 + +- [Commercial embedded Linux distro boosts virtualization][5] +- [Freescale unveils first ARM-based QorIQ SoCs][6] +- [High-end boards run Linux on 64-bit ARM QorIQ SoCs][7] +- [Free, Open Enea Linux taps Yocto Project and Linaro code][8] +- [LynuxWorks reverts to its LynxOS roots, changes name][9] +- [First quad- and octa-core QorIQ SoCs unveiled][10] +- [Free white paper shows how Linux won embedded][11] +- [Quad-core Snapdragon COM offers three dev kit options][12] +- [Tiny COM runs Linux on quad-core 64-bit Snapdragon 410][13] +- [PowerPC based IoT gateway COM ships with Linux BSP][14] + + +-------------------------------------------------------------------------------- + +via: http://hackerboards.com/powerpc-gains-android-4-4-port-with-big-endian-support/ + +作者：[Eric Brown][a] +译者：[dongfengweixiao](https://github.com/dongfengweixiao) +校对：[wxy](https://github.com/wxy) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: http://hackerboards.com/powerpc-gains-android-4-4-port-with-big-endian-support/ +[1]: http://linuxdevices.linuxgizmos.com/low-cost-powerquicc-chips-offer-flexible-interconnect-options/ +[2]: https://www.einfochips.com/blog/k2-categories/aerospace/presenting-a-case-for-porting-android-on-powerpc-architecture.html +[3]: http://www.xes-inc.com/products/processor-mezzanines/xpedite6101/ +[4]: http://biz.einfochips.com/portingandroidonpowerpc +[5]: http://hackerboards.com/commercial-embedded-linux-distro-boosts-virtualization/ +[6]: http://hackerboards.com/freescale-unveils-first-arm-based-qoriq-socs/ +[7]: http://hackerboards.com/high-end-boards-run-linux-on-64-bit-arm-qoriq-socs/ +[8]: http://hackerboards.com/free-open-enea-linux-taps-yocto-and-linaro-code/ +[9]: http://hackerboards.com/lynuxworks-reverts-to-its-lynxos-roots-changes-name/ +[10]: http://hackerboards.com/first-quad-and-octa-core-qoriq-socs-unveiled/ +[11]: http://hackerboards.com/free-white-paper-shows-how-linux-won-embedded/ +[12]: http://hackerboards.com/quad-core-snapdragon-com-offers-three-dev-kit-options/ +[13]: http://hackerboards.com/tiny-com-runs-linux-and-android-on-quad-core-64-bit-snapdragon-410/ +[14]: http://hackerboards.com/powerpc-based-iot-gateway-com-ships-with-linux-bsp/ +[15]: http://linuxdevices.linuxgizmos.com/android-ported-to-powerpc/ +[16]: http://www.androidppc.com/ +[17]: http://hackerboards.com/quad-core-snapdragon-com-offers-three-dev-kit-options/ +[18]: https://sourceware.org/libffi/ +[19]: http://www.xes-inc.com/capabilities/ruggedization/ +[20]: http://hackerboards.com/high-end-boards-run-linux-on-64-bit-arm-qoriq-socs/ diff --git a/published/201607/20160621 Container technologies in Fedora - systemd-nspawn.md b/published/201607/20160621 Container technologies in Fedora - systemd-nspawn.md new file mode 100644 index 0000000000..69cbf688d8 --- /dev/null +++ b/published/201607/20160621 Container technologies in Fedora - systemd-nspawn.md @@ -0,0 +1,105 @@ +Fedora 中的容器技术：systemd-nspawn +=== + +欢迎来到“Fedora 中的容器技术”系列！本文是该系列文章中的第一篇，它将说明你可以怎样使用 Fedora 中各种可用的容器技术。本文将学习 `systemd-nspawn` 的相关知识。 + +### 容器是什么？ + +一个容器就是一个用户空间实例，它能够在与托管容器的系统（叫做宿主系统）相隔离的环境中运行一个程序或者一个操作系统。这和 `chroot` 或 [虚拟机][1] 的思想非常类似。运行在容器中的进程是由与宿主操作系统相同的内核来管理的，但它们是与宿主文件系统以及其它进程隔离开的。 + +### 什么是 systemd-nspawn？ + +systemd 项目认为应当将容器技术变成桌面的基础部分，并且应当和用户的其余系统集成在一起。为此，systemd 提供了 `systemd-nspawn`，这款工具能够使用多种 Linux 技术创建容器。它也提供了一些容器管理工具。 + +`systemd-nspawn` 和 `chroot` 在许多方面都是类似的，但是前者更加强大。它虚拟化了文件系统、进程树以及客户系统中的进程间通信。它的吸引力在于它提供了很多用于管理容器的工具，例如用来管理容器的 `machinectl`。由 `systemd-nspawn` 运行的容器将会与 systemd 组件一同运行在宿主系统上。举例来说，一个容器的日志可以输出到宿主系统的日志中。 + +在 Fedora 24 上，`systemd-nspawn` 已经从 systemd 软件包分离出来了，所以你需要安装 `systemd-container` 软件包。一如往常，你可以使用 `dnf install systemd-container` 进行安装。 + +### 创建容器 + +使用 `systemd-nspawn` 创建一个容器是很容易的。假设你有一个专门为 Debian 创造的应用，并且无法在其它发行版中正常运行。那并不是一个问题，我们可以创造一个容器！为了设置容器使用最新版本的 Debian（现在是 Jessie），你需要挑选一个目录来放置你的系统。我暂时将使用目录 `~/DebianJessie`。 + +一旦你创建完目录，你需要运行 `debootstrap`，你可以从 Fedora 仓库中安装它。对于 Debian Jessie，你运行下面的命令来初始化一个 Debian 文件系统。 + +``` +$ debootstrap --arch=amd64 stable ~/DebianJessie +``` + +以上默认你的架构是 x86_64。如果不是的话，你必须将架构的名称改为 `amd64`。你可以使用 `uname -m` 得知你的机器架构。 + +一旦设置好你的根目录，你就可以使用下面的命令来启动你的容器。 + +``` +$ systemd-nspawn -bD ~/DebianJessie +``` + +容器将会在数秒后准备好并运行，当你试图登录时就会注意到：你无法使用你的系统上任何账户。这是因为 `systemd-nspawn` 虚拟化了用户。修复的方法很简单：将之前的命令中的 `-b` 移除即可。你将直接进入容器的 root 用户的 shell。此时，你只能使用 `passwd` 命令为 root 设置密码，或者使用 `adduser` 命令添加一个新用户。一旦设置好密码或添加好用户，你就可以把 `-b` 标志添加回去然后继续了。你会进入到熟悉的登录控制台，然后你使用设置好的认证信息登录进去。 + +以上对于任意你想在容器中运行的发行版都适用，但前提是你需要使用正确的包管理器创建系统。对于 Fedora，你应使用 DNF 而非 `debootstrap`。想要设置一个最小化的 Fedora 系统，你可以运行下面的命令，要将“/absolute/path/”替换成任何你希望容器存放的位置。 + +``` +$ sudo dnf --releasever=24 --installroot=/absolute/path/ install systemd passwd dnf fedora-release +``` + +![](https://cdn.fedoramagazine.org/wp-content/uploads/2016/06/Screenshot-from-2016-06-17-15-04-14.png) + +### 设置网络 + +如果你尝试启动一个服务，但它绑定了你宿主机正在使用的端口，你将会注意到这个问题：你的容器正在使用和宿主机相同的网络接口。幸运的是，`systemd-nspawn` 提供了几种可以将网络从宿主机分开的方法。 + +#### 本地网络 + +第一种方法是使用 `--private-network` 标志，它默认仅创建一个回环设备。这对于你不需要使用网络的环境是非常理想的，例如构建系统和其它持续集成系统。 + +#### 多个网络接口 + +如果你有多个网络接口设备，你可以使用 `--network-interface` 标志给容器分配一个接口。想要给我的容器分配 `eno1`，我会添加选项 `--network-interface=eno1`。当某个接口分配给一个容器后，宿主机就不能同时使用那个接口了。只有当容器彻底关闭后，宿主机才可以使用那个接口。 + +#### 共享网络接口 + +对于我们中那些并没有额外的网络设备的人来说，还有其它方法可以访问容器。一种就是使用 `--port` 选项。这会将容器中的一个端口定向到宿主机。使用格式是 `协议:宿主机端口:容器端口`，这里的协议可以是 `tcp` 或者 `udp`，`宿主机端口` 是宿主机的一个合法端口，`容器端口` 则是容器中的一个合法端口。你可以省略协议，只指定 `宿主机端口:容器端口`。我通常的用法类似 `--port=2222:22`。 + +你可以使用 `--network-veth` 启用完全的、仅宿主机模式的网络，这会在宿主机和容器之间创建一个虚拟的网络接口。你也可以使用 `--network-bridge` 桥接二者的连接。 + +### 使用 systemd 组件 + +如果你容器中的系统含有 D-Bus，你可以使用 systemd 提供的实用工具来控制并监视你的容器。基础安装的 Debian 并不包含 `dbus`。如果你想在 Debian Jessie 中使用 `dbus`，你需要运行命令 `apt install dbus`。 + +#### machinectl + +为了能够轻松地管理容器，systemd 提供了 `machinectl` 实用工具。使用 `machinectl`，你可以使用 `machinectl login name` 登录到一个容器中、使用 `machinectl status name`检查状态、使用 `machinectl reboot name` 启动容器或者使用 `machinectl poweroff name` 关闭容器。 + +### 其它 systemd 命令 + +多数 systemd 命令，例如 `journalctl`, `systemd-analyze` 和 `systemctl`，都支持使用 `--machine` 选项来指定容器。例如，如果你想查看一个名为 “foobar” 的容器的日志，你可以使用 `journalctl --machine=foobar`。你也可以使用 `systemctl --machine=foobar status service` 来查看运行在这个容器中的服务状态。 + +![](https://cdn.fedoramagazine.org/wp-content/uploads/2016/06/Screenshot-from-2016-06-17-15-09-25.png) + +### 和 SELinux 一起工作 + +如果你要使用 SELinux 强制模式（Fedora 默认模式），你需要为你的容器设置 SELinux 环境。想要那样的话，你需要在宿主系统上运行下面两行命令。 + +``` +$ semanage fcontext -a -t svirt_sandbox_file_t "/path/to/container(/.*)?" +$ restorecon -R /path/to/container/ +``` + +确保使用你的容器路径替换 “/path/to/container”。对于我的容器 "DebianJessie"，我会运行下面的命令： + +``` +$ semanage fcontext -a -t svirt_sandbox_file_t "/home/johnmh/DebianJessie(/.*)?" +$ restorecon -R /home/johnmh/DebianJessie/ +``` + +-------------------------------------------------------------------------------- + +via: https://fedoramagazine.org/container-technologies-fedora-systemd-nspawn/ + +作者：[John M. Harris, Jr.][a] +译者：[ChrisLeeGit](https://github.com/chrisleegit) +校对：[wxy](https://github.com/wxy) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://fedoramagazine.org/container-technologies-fedora-systemd-nspawn/ +[1]: https://en.wikipedia.org/wiki/Virtual_machine diff --git a/published/201607/20160624 How to permanently mount a Windows share on Linux.md b/published/201607/20160624 How to permanently mount a Windows share on Linux.md new file mode 100644 index 0000000000..1782a76241 --- /dev/null +++ b/published/201607/20160624 How to permanently mount a Windows share on Linux.md @@ -0,0 +1,123 @@ +如何在 Linux 上永久挂载一个 Windows 共享 +================================================== + +> 如果你已经厌倦了每次重启 Linux 就得重新挂载 Windows 共享，读读这个让共享永久挂载的简单方法。 + +![](http://tr2.cbsistatic.com/hub/i/2016/06/02/e965310b-b38d-43e6-9eac-ea520992138b/68fd9ec5d6731cc405bdd27f2f42848d/linuxadminhero.jpg) + +*图片： Jack Wallen* + +在 Linux 上和一个 Windows 网络进行交互从来就不是件轻松的事情。想想多少企业正在采用 Linux，需要在这两个平台上彼此协作。幸运的是，有了一些工具的帮助，你可以轻松地将 Windows 网络驱动器映射到一台 Linux 机器上，甚至可以确保在重启 Linux 机器之后共享还在。 + +### 在我们开始之前 + +要实现这个，你需要用到命令行。过程十分简单，但你需要编辑 /etc/fstab 文件，所以小心操作。还有，我假设你已经让 Samba 正常工作了，可以手动从 Windows 网络挂载共享到你的 Linux 机器，还知道这个共享的主机 IP 地址。 + +准备好了吗？那就开始吧。 + +### 创建你的挂载点 + +我们要做的第一件事是创建一个文件夹，他将作为共享的挂载点。为了简单起见，我们将这个文件夹命名为 share，放在 /media 之下。打开你的终端执行以下命令： + +``` +sudo mkdir /media/share +``` + +### 安装一些软件 + +现在我们得安装允许跨平台文件共享的系统；这个系统是 cifs-utils。在终端窗口输入： + +``` +sudo apt-get install cifs-utils +``` + +这个命令同时还会安装 cifs-utils 所有的依赖。 + +安装完成之后，打开文件 /etc/nsswitch.conf 并找到这一行： + +``` +hosts: files mdns4_minimal [NOTFOUND=return] dns +``` + +编辑这一行，让它看起来像这样： + +``` +hosts: files mdns4_minimal [NOTFOUND=return] wins dns +``` + +现在你需要安装 windbind 让你的 Linux 机器可以在 DHCP 网络中解析 Windows 机器名。在终端里执行： + +``` +sudo apt-get install libnss-windbind windbind +``` + +用这个命令重启网络服务： + +``` +sudo service networking restart +``` + +### 挂载网络驱动器 + +现在我们要映射网络驱动器。这里我们必须编辑 /etc/fstab 文件。在你做第一次编辑之前，用这个命令备份以下这个文件： + +``` +sudo cp /etc/fstab /etc/fstab.old +``` + +如果你需要恢复这个文件，执行以下命令： + +``` +sudo mv /etc/fstab.old /etc/fstab +``` + +在你的主目录创建一个认证信息文件 .smbcredentials。在这个文件里添加你的用户名和密码，就像这样（USER 和 PASSWORD 替换为实际的用户名和密码）： + +``` +username=USER + +password=PASSWORD +``` + +你需要知道挂载这个驱动器的用户的组 ID（GID）和用户 ID（UID）。执行命令： + +``` +id USER +``` + +USER 是你的实际用户名，你应该会看到类似这样的信息： + +``` +uid=1000(USER) gid=1000(GROUP) +``` + +USER 是实际的用户名，GROUP 是组名。在（USER）和（GROUP）之前的数字将会被用在 /etc/fstab 文件之中。 + +是时候编辑 /etc/fstab 文件了。在你的编辑器中打开那个文件并添加下面这行到文件末尾（替换以下全大写字段以及远程机器的 IP 地址）： + +``` +//192.168.1.10/SHARE /media/share cifs credentials=/home/USER/.smbcredentials,iocharset=uft8,gid=GID,udi=UID,file_mode=0777,dir_mode=0777 0 0 +``` + +**注意**：上面这些内容应该在同一行上。 + +保存并关闭那个文件。执行 sudo mount -a 命令，共享将被挂载。检查一下 /media/share，你应该能看到那个网络共享上的文件和文件夹了。 + +### 共享很简单 + +有了 cifs-utils 和 Samba，映射网络共享在一台 Linux 机器上简单得让人难以置信。现在，你再也不用在每次机器启动的时候手动重新挂载那些共享了。 + +更多网络提示和技巧，订阅我们的 Data Center 消息吧。 +[订阅](https://secure.techrepublic.com/user/login/?regSource=newsletter-button&position=newsletter-button&appId=true&redirectUrl=http%3A%2F%2Fwww.techrepublic.com%2Farticle%2Fhow-to-permanently-mount-a-windows-share-on-linux%2F&) + +-------------------------------------------------------------------------------- + +via: http://www.techrepublic.com/article/how-to-permanently-mount-a-windows-share-on-linux/ + +作者：[Jack Wallen][a] +译者：[alim0x](https://github.com/alim0x) +校对：[wxy](https://github.com/wxy) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: http://www.techrepublic.com/search/?a=jack+wallen diff --git a/published/201607/20160624 IT runs on the cloud and the cloud runs on Linux. Any questions.md b/published/201607/20160624 IT runs on the cloud and the cloud runs on Linux. Any questions.md new file mode 100644 index 0000000000..17af8d85d9 --- /dev/null +++ b/published/201607/20160624 IT runs on the cloud and the cloud runs on Linux. Any questions.md @@ -0,0 +1,63 @@ +IT 运行在云端，而云运行在 Linux 上。你怎么看？ +=================================================================== + +> IT 正在逐渐迁移到云端。那又是什么驱动了云呢？答案是 Linux。 当连微软的 Azure 都开始拥抱 Linux 时，你就应该知道这一切都已经改变了。 + +![](http://zdnet1.cbsistatic.com/hub/i/r/2016/06/24/7d2b00eb-783d-4202-bda2-ca65d45c460a/resize/770xauto/732db8df725ede1cc38972788de71a0b/linux-owns-cloud.jpg) + +*图片： ZDNet* + +不管你接不接受， 云正在接管 IT 已经成为现实。 我们这几年见证了 [ 云在内部 IT 的崛起 ][1] 。 那又是什么驱动了云呢？ 答案是 Linux 。 + +[Uptime Institute][2] 最近对 1000 个 IT 决策者进行了调查，发现约 50% 左右的资深企业 IT 决策者认为在将来[大部分的 IT 工作应该放在云上 ][3] 或托管网站上。在这个调查中，23% 的人认为这种改变即将发生在明年，有 70% 的人则认为这种情况会在四年内出现。 + +这一点都不奇怪。 我们中的许多人仍热衷于我们的物理服务器和机架， 但一般运营一个自己的数据中心并不会产生任何的经济效益。 + +很简单， 只需要对比你[运行在你自己的硬件上的资本费用（CAPEX）和使用云的业务费用（OPEX）][4]即可。 但这并不是说你应该把所有的东西都一股脑外包出去，而是说在大多数情况下你应该把许多工作都迁移到云端。 + +相应地，如果你想充分地利用云，你就得了解 Linux 。 + +[亚马逊的 AWS][5]、 [Apache CloudStack][6]、 [Rackspace][7]、[谷歌的 GCP][8] 以及 [ OpenStack ][9] 的核心都是运行在 Linux 上的。那么结果如何？截至到 2014 年， [在 Linux 服务器上部署的应用达到所有企业的 79% ][10]，而 在 Windows 服务器上部署的则跌到 36%。从那时起， Linux 就获得了更多的发展动力。 + +即便是微软自身也明白这一点。 + +Azure 的技术主管 Mark Russinovich 曾说，仅仅在过去的几年内微软就从[四分之一的 Azure 虚拟机运行在 Linux 上][11] 变为[将近三分之一的 Azure 虚拟机运行在 Linux 上][12]。 + +试想一下。微软，一家正逐渐将[云变为自身财政收入的主要来源][13] 的公司，其三分之一的云产业依靠于 Linux 。 + +即使是到目前为止， 这些不论喜欢或者不喜欢微软的人都很难想象得到[微软会从一家以商业软件为基础的软件公司转变为一家开源的、基于云服务的企业][14] 。 + +Linux 对于这些专用服务器机房的渗透甚至比它刚开始的时候更深了。 举个例子， [Docker 最近发行了其在 Windows 10 和 Mac OS X 上的公测版本 ][15] 。 这难道是意味着 [Docker][16] 将会把其同名的容器服务移植到 Windows 10 和 Mac 上吗？ 并不是的。 + +在这两个平台上， Docker 只是运行在一个 Linux 虚拟机内部。 在 Mac OS 上是 HyperKit ，在 Windows 上则是 Hyper-V 。 在图形界面上可能看起来就像另一个 Mac 或 Windows 上的应用， 但在其内部的容器仍然是运行在 Linux 上的。 + +所以，就像大量的安卓手机和 Chromebook 的用户压根就不知道他们所运行的是 Linux 系统一样。这些 IT 用户也会随之悄然地迁移到 Linux 和云上。 + +-------------------------------------------------------------------------------- + +via: http://www.zdnet.com/article/it-runs-on-the-cloud-and-the-cloud-runs-on-linux-any-questions/ + +作者：[Steven J. Vaughan-Nichols][a] +译者：[chenxinlong](https://github.com/chenxinlong) +校对：[wxy](https://github.com/wxy) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: http://www.zdnet.com/meet-the-team/us/steven-j-vaughan-nichols/ +[1]: http://www.zdnet.com/article/2014-the-year-the-cloud-killed-the-datacenter/ +[2]: https://uptimeinstitute.com/ +[3]: http://www.zdnet.com/article/move-to-cloud-accelerating-faster-than-thought-survey-finds/ +[4]: http://www.zdnet.com/article/rethinking-capex-and-opex-in-a-cloud-centric-world/ +[5]: https://aws.amazon.com/ +[6]: https://cloudstack.apache.org/ +[7]: https://www.rackspace.com/en-us +[8]: https://cloud.google.com/ +[9]: http://www.openstack.org/ +[10]: http://www.zdnet.com/article/linux-foundation-finds-enterprise-linux-growing-at-windows-expense/ +[11]: http://news.microsoft.com/bythenumbers/azure-virtual +[12]: http://www.zdnet.com/article/microsoft-nearly-one-in-three-azure-virtual-machines-now-are-running-linux/ +[13]: http://www.zdnet.com/article/microsofts-q3-azure-commercial-cloud-strong-but-earnings-revenue-light/ +[14]: http://www.zdnet.com/article/why-microsoft-is-turning-into-an-open-source-company/ +[15]: http://www.zdnet.com/article/new-docker-betas-for-azure-windows-10-now-available/ +[16]: http://www.docker.com/ + diff --git a/published/201607/20160624 Industrial SBC builds on Raspberry Pi Compute Module.md b/published/201607/20160624 Industrial SBC builds on Raspberry Pi Compute Module.md new file mode 100644 index 0000000000..cf916044a6 --- /dev/null +++ b/published/201607/20160624 Industrial SBC builds on Raspberry Pi Compute Module.md @@ -0,0 +1,78 @@ +用树莓派计算模块搭建的工业单板计算机 +===================================================== + +![](http://hackerboards.com/files/embeddedmicro_mypi-thm.jpg) + +在 Kickstarter 众筹网站上，一个叫 “MyPi” 的项目用树莓派计算模块制作了一款 SBC（LCTT 译注： Single Board Computer 单板计算机），提供一个 mini-PCIe 插槽，串口，宽范围输入电源，以及模块扩展等功能。 + +你也许觉得奇怪，都 2016 年了，为什么还会有人发布这样一款长得有点像三明治，用过时的 ARM11 构建的 COM （LCTT 译注： Compuer on Module，模块化计算机）版本的树莓派单板计算机：[树莓派计算模块][1]。原因是这样的，首先，目前仍然有大量工业应用不需要太多 CPU 处理能力，第二，树莓派计算模块仍是目前仅有的基于树莓派硬件的 COM，虽然更便宜、有点像 COM 并采用同样的 700MHz 处理器的 [零号树莓派][2] 也很类似。 + +![](http://hackerboards.com/files/embeddedmicro_mypi-sm.jpg) + +*安装了 COM 和 I/O 组件的 MyPi* + +![](http://hackerboards.com/files/embeddedmicro_mypi_encl-sm.jpg) + +*装入了可选的工业外壳中* + +另外，Embedded Micro Technology 还表示它的 SBC 还设计成可升级替换为支持的树莓派计算模块 —— 采用了树莓派 3 的四核、Cortex-A53 博通 BCM2837处理器的 SoC。因为这个产品最近很快就会到货，不确定他们怎么能及时为 Kickstarter 赞助者处理好这一切。不过，以后能支持也挺不错，就算要为这个升级付费也可以接受。 + +MyPi 并不是唯一一款新的基于树莓派计算模块的商业嵌入式设备。Pigeon Computers 在五月份启动了 [Pigeon RB100][3] 的项目，是一个基于 COM 的工业自动化控制器。不过，包括 [Techbase Modberry][4] 在内的这一类设备大都出现在 2014 年 COM 发布之后的一小段时间内。 + +MyPi 的目标是 30 天内筹集 $21,696，目前已经实现了三分之一。早期参与包的价格 $119 起，九月份发货。其他选项有 $187 版本，里面包含了价值 $30 的树莓派计算模块，以及各种线缆。套件里还有各种插件板以及工业外壳可选。 + +![](http://hackerboards.com/files/embeddedmicro_mypi_baseboard-sm.jpg) + +*不带 COM 和插件板的 MyPi 主板* + +![](http://hackerboards.com/files/embeddedmicro_mypi_detail-sm.jpg) + +*以及它的接口定义* + +树莓派计算模块能给 MyPi 带来博通 BCM2835 Soc，512MB 内存，以及 4GB eMMC 存储空间。MyPi 主板扩展了一个 microSD 卡槽，一个 HDMI 接口，两个 USB 2.0 接口，一个 10/100M 以太网口，还有一个像网口的 RS232 端口（通过 USB 连接）。 + +![](http://hackerboards.com/files/embeddedmicro_mypi_angle1-sm.jpg) + +*插上树莓派计算模块和 mini-PCIe 模块的 MyPi 的两个视角* + +![](http://hackerboards.com/files/embeddedmicro_mypi_angle2.jpg) + +*插上树莓派计算模块和 mini-PCIe 模块的 MyPi 的两个视角* + +MyPi 还将配备一个 mini-PCIe 插槽，据说“只支持 USB，以及只适用 mPCIe 形式的调制解调器”。还带有一个 SIM 卡插槽。板上还有双标准的树莓派摄像头接口，一个音频输出接口，自带备用电池的 RTC，LED 灯。还支持宽范围的 9-23V 直流输入。 + +Embedded Micro 表示，MyPi 是为那些树莓派爱好者们设计的，他们拼接了太多 HAT 外接板，已经不能有效地工作了，或者不能很好地装入工业外壳里。MyPi 支持 HAT，另外还提供了公司自己定义的 “ASIO” （特定应用接口）插件模块，它会将自己的 I/O 扩展到载板上，载板再将它们连到载板边上的 8针的绿色凤凰式工业 I/O 连接器（标记了“ASIO Out”）上，在下面图片里有描述。 + +![](http://hackerboards.com/files/embeddedmicro_mypi_io-sm.jpg) + +*MyPi 的模块扩展接口* + +就像 Kickstarter 页面里描述的：“比起在板边插满带 IO 信号接头的 HAT 板，我们更愿意把同样的 IO 信号接到另一个接头，它直接接到绿色的工业接头上。” 另外，“通过简单地延长卡上的插脚长度（抬高），你将来可以直接扩展 IO 集 - 这些都不需要任何排线！”Embedded Micro 表示。 + +![](http://hackerboards.com/files/embeddedmicro_mypi_with_iocards-sm.jpg) + +*MyPi 和它的可选 I/O 插件板卡* + +像上面展示的，这家公司为 MyPi 提供了一系列可靠的 ASIO 插卡，。一开始这些会包括 CAN 总线，4-20mA 传感器信号，RS485，窄带 RF，等等。 + +### 更多信息 + +MyPi 在 Kickstarter 上提供了 7 月 23 日到期的 79 英镑（$119）早期参与包（不包括树莓派计算模块），预计九月份发货。更多信息请查看 [Kickstarter 上 MyPi 的页面][5] 以及 [Embedded Micro Technology 官网][6]。 + +-------------------------------------------------------------------------------- + +via: http://hackerboards.com/industrial-sbc-builds-on-rpi-compute-module/ + +作者：[Eric Brown][a] +译者：[zpl1025](https://github.com/zpl1025) +校对：[Ezio](https://github.com/oska874) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: http://hackerboards.com/industrial-sbc-builds-on-rpi-compute-module/ +[1]: http://hackerboards.com/raspberry-pi-morphs-into-30-dollar-com/ +[2]: http://hackerboards.com/pi-zero-tweak-adds-camera-connector-keeps-5-price/ +[3]: http://hackerboards.com/automation-controller-runs-linux-on-raspberry-pi-com/ +[4]: http://hackerboards.com/automation-controller-taps-raspberry-pi-compute-module/ +[5]: https://www.kickstarter.com/projects/410598173/mypi-industrial-strength-raspberry-pi-for-iot-proj +[6]: http://www.embeddedpi.com/ diff --git a/published/201607/20160625 How to Hide Linux Command Line History by Going Incognito.md b/published/201607/20160625 How to Hide Linux Command Line History by Going Incognito.md new file mode 100644 index 0000000000..14bcdc2c7b --- /dev/null +++ b/published/201607/20160625 How to Hide Linux Command Line History by Going Incognito.md @@ -0,0 +1,126 @@ +如何隐藏你的 Linux 的命令行历史 +================================================================ + +![](https://maketecheasier-2d0f.kxcdn.com/assets/uploads/2016/06/commandline-history-featured.jpg) + +如果你是 Linux 命令行的用户，有的时候你可能不希望某些命令记录在你的命令行历史中。原因可能很多，例如，你在公司担任某个职位，你有一些不希望被其它人滥用的特权。亦或者有些特别重要的命令，你不希望在你浏览历史列表时误执行。 + +然而，有方法可以控制哪些命令进入历史列表，哪些不进入吗？或者换句话说，我们在 Linux 终端中可以开启像浏览器一样的无痕模式吗？答案是肯定的，而且根据你想要的具体目标，有很多实现方法。在这篇文章中，我们将讨论一些行之有效的方法。 + +注意：文中出现的所有命令都在 Ubuntu 下测试过。 + +### 不同的可行方法 + +前面两种方法已经在之前[一篇文章][1]中描述了。如果你已经了解，这部分可以略过。然而，如果你不了解，建议仔细阅读。 + +#### 1. 在命令前插入空格 + +是的，没看错。在命令前面插入空格，这条命令会被 shell 忽略，也就意味着它不会出现在历史记录中。但是这种方法有个前提，只有在你的环境变量 `HISTCONTROL` 设置为 "ignorespace" 或者 "ignoreboth" 才会起作用。在大多数情况下，这个是默认值。 + +所以，像下面的命令（LCTT 译注：这里`[space]`表示输入一个空格）： + +``` +[space]echo "this is a top secret" +``` + +如果你之前执行过如下设置环境变量的命令，那么上述命令不会出现在历史记录中。 + +``` +export HISTCONTROL = ignorespace +``` + +下面的截图是这种方式的一个例子。 + +![](https://maketecheasier-2d0f.kxcdn.com/assets/uploads/2016/06/commandline-history-bash-command-space.png) + +第四个 "echo" 命令因为前面有空格，它没有被记录到历史中。 + +#### 2. 禁用当前会话的所有历史记录 + +如果你想禁用某个会话所有历史，你可以在开始命令行工作前简单地清除环境变量 HISTFILESIZE 的值即可。执行下面的命令来清除其值： + +``` +export HISTFILESIZE=0 +``` + +HISTFILESIZE 表示对于 bash 会话其历史文件中可以保存命令的个数（行数）。默认情况，它设置了一个非零值，例如在我的电脑上，它的值为 1000。 + +所以上面所提到的命令将其值设置为 0，结果就是直到你关闭终端，没有东西会存储在历史记录中。记住同样你也不能通过按向上的箭头按键或运行 history 命令来看到之前执行的命令。 + +#### 3. 工作结束后清除整个历史 + +这可以看作是前一部分所提方案的另外一种实现。唯一的区别是在你完成所有工作之后执行这个命令。下面是刚说到的命令： + +``` +history -cw +``` + +刚才已经提到，这个和 HISTFILESIZE 方法有相同效果。 + +#### 4. 只针对你的工作关闭历史记录 + +虽然前面描述的方法（2 和 3）可以实现目的，它们可以清除整个历史，在很多情况下，有些可能不是我们所期望的。有时候你可能想保存直到你开始命令行工作之间的历史记录。对于这样的需求，你开始在工作前执行下述命令： + +``` +[space]set +o history +``` + +备注：[space] 表示空格。并且由于空格的缘故，该命令本身也不会被记录。 + +上面的命令会临时禁用历史功能，这意味着在这命令之后你执行的所有操作都不会记录到历史中，然而这个命令之前的所有东西都会原样记录在历史列表中。 + +要重新开启历史功能，执行下面的命令： + +``` +[Space]set -o history +``` + +它将环境恢复原状，也就是你完成了你的工作，执行上述命令之后的命令都会出现在历史中。 + +#### 5. 从历史记录中删除指定的命令 + +现在假设历史记录中已经包含了一些你不希望记录的命令。这种情况下我们怎么办？很简单。直接动手删除它们。通过下面的命令来删除： + +``` +history | grep "part of command you want to remove" +``` + +上面的命令会输出历史记录中匹配的命令，每一条前面会有个数字。 + +一旦你找到你想删除的命令，执行下面的命令，从历史记录中删除那个指定的项： + +``` +history -d [num] +``` + +下面是这个例子的截图。 + +![](https://maketecheasier-2d0f.kxcdn.com/assets/uploads/2016/06/commandline-history-delete-specific-commands.png) + +第二个 ‘echo’命令被成功的删除了。 + +（LCTT 译注：如果你不希望上述命令本身也被记录进历史中，你可以在上述命令前加个空格） + +同样的，你可以使用向上的箭头一直往回翻看历史记录。当你发现你感兴趣的命令出现在终端上时，按下 “Ctrl + U”清除整行，也会从历史记录中删除它。 + +### 总结 + +有多种不同的方法可以操作 Linux 命令行历史来满足你的需求。然而请记住，从历史中隐藏或者删除命令通常不是一个好习惯，尽管本质上这并没有错。但是你必须知道你在做什么，以及可能产生的后果。 + +-------------------------------------------------------------------------------- + +via: https://www.maketecheasier.com/linux-command-line-history-incognito/ + +作者：[Himanshu Arora][a] +译者：[chunyang-wen](https://github.com/chunyang-wen) +校对：[wxy](https://github.com/wxy) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://www.maketecheasier.com/author/himanshu/ +[1]: https://www.maketecheasier.com/command-line-history-linux/ + + + + + diff --git a/published/201607/20160628 How To Setup Open Source Discussion Platform Discourse On Ubuntu Linux 16.04.md b/published/201607/20160628 How To Setup Open Source Discussion Platform Discourse On Ubuntu Linux 16.04.md new file mode 100644 index 0000000000..45c5d634dc --- /dev/null +++ b/published/201607/20160628 How To Setup Open Source Discussion Platform Discourse On Ubuntu Linux 16.04.md @@ -0,0 +1,101 @@ +如何在 Ubuntu Linux 16.04上安装开源的 Discourse 论坛 +=============================================================================== + +Discourse 是一个开源的论坛，它可以以邮件列表、聊天室或者论坛等多种形式工作。它是一个广受欢迎的现代的论坛工具。在服务端，它使用 Ruby on Rails 和 Postgres 搭建, 并且使用 Redis 缓存来减少读取时间 , 在客户端，它使用支持 Java Script 的浏览器。它非常容易定制，结构良好，并且它提供了转换插件，可以对你现存的论坛、公告板进行转换，例如： vBulletin、phpBB、Drupal、SMF 等等。在这篇文章中，我们将学习在 Ubuntu 操作系统下安装 Discourse。 + +它以安全作为设计思想，所以发垃圾信息的人和黑客们不能轻易的实现其企图。它能很好的支持各种现代设备，并可以相应的调整以手机和平板的显示。 + +### 在 Ubuntu 16.04 上安装 Discourse + +让我们开始吧 ! 最少需要 1G 的内存，并且官方支持的安装过程需要已经安装了 docker。 说到 docker，它还需要安装Git。要满足以上的两点要求我们只需要运行下面的命令： + +``` +wget -qO- https://get.docker.com/ | sh +``` + +![](http://linuxpitstop.com/wp-content/uploads/2016/06/124.png) + +用不了多久就安装好了 docker 和 Git，安装结束以后，在你的系统上的 /var 分区创建一个 Discourse 文件夹（当然你也可以选择其他的分区）。 + +``` +mkdir /var/discourse +``` + +现在我们来克隆 Discourse 的 Github 仓库到这个新建的文件夹。 + +``` +git clone https://github.com/discourse/discourse_docker.git /var/discourse +``` + +进入这个克隆的文件夹。 + +``` +cd /var/discourse +``` + +![](http://linuxpitstop.com/wp-content/uploads/2016/06/314.png) + +你将看到“discourse-setup” 脚本文件，运行这个脚本文件进行 Discourse 的初始化。 + +``` +./discourse-setup +``` + +**备注： 在安装 discourse 之前请确保你已经安装好了邮件服务器。** + +安装向导将会问你以下六个问题： + +``` +Hostname for your Discourse? +Email address for admin account? +SMTP server address? +SMTP user name? +SMTP port [587]: +SMTP password? []: +``` + +![](http://linuxpitstop.com/wp-content/uploads/2016/06/411.png) + +当你提交了以上信息以后, 它会让你提交确认, 如果一切都很正常，点击回车以后安装开始。 + +![](http://linuxpitstop.com/wp-content/uploads/2016/06/511.png) + +现在“坐等放宽”，需要花费一些时间来完成安装，倒杯咖啡，看看有什么错误信息没有。 + +![](http://linuxpitstop.com/wp-content/uploads/2016/06/610.png) + +安装成功以后看起来应该像这样。 + +![](http://linuxpitstop.com/wp-content/uploads/2016/06/710.png) + +现在打开浏览器，如果已经做了域名解析，你可以使用你的域名来连接 Discourse 页面 ，否则你只能使用IP地址了。你将看到如下信息： + +![](http://linuxpitstop.com/wp-content/uploads/2016/06/85.png) + +就是这个，点击 “Sign Up” 选项创建一个新的账户，然后进行你的 Discourse 设置。 + +![](http://linuxpitstop.com/wp-content/uploads/2016/06/106.png) + +### 结论 + +它安装简便，运行完美。 它拥有现代论坛所有必备功能。它以 GPL 发布，是完全开源的产品。简单、易用、以及特性丰富是它的最大特点。希望你喜欢这篇文章，如果有问题，你可以给我们留言。 + +-------------------------------------------------------------------------------- + +via: http://linuxpitstop.com/install-discourse-on-ubuntu-linux-16-04/ + +作者：[Aun][a] +译者：[kokialoves](https://github.com/kokialoves) +校对：[wxy](https://github.com/wxy) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: http://linuxpitstop.com/author/aun/ + + + + + + + + diff --git a/published/201607/20160629 USE TASK MANAGER EQUIVALENT IN LINUX.md b/published/201607/20160629 USE TASK MANAGER EQUIVALENT IN LINUX.md new file mode 100644 index 0000000000..444f37af43 --- /dev/null +++ b/published/201607/20160629 USE TASK MANAGER EQUIVALENT IN LINUX.md @@ -0,0 +1,51 @@ +在 Linux 下使用任务管理器 +==================================== + +![](https://itsfoss.com/wp-content/uploads/2016/06/Task-Manager-in-Linux.jpg) + +有很多 Linux 初学者经常问起的问题，“**Linux 有任务管理器吗？**”，“**怎样在 Linux 上打开任务管理器呢？**” + +来自 Windows 的用户都知道任务管理器非常有用。你可以在 Windows 中按下 `Ctrl+Alt+Del` 打开任务管理器。这个任务管理器向你展示了所有的正在运行的进程和它们消耗的内存，你可以从任务管理器程序中选择并杀死一个进程。 + +当你刚使用 Linux 的时候，你也会寻找一个**在 Linux 相当于任务管理器**的一个东西。一个 Linux 使用专家更喜欢使用命令行的方式查找进程和消耗的内存等等，但是你不用必须使用这种方式，至少在你初学 Linux 的时候。 + +所有主流的 Linux 发行版都有一个类似于任务管理器的东西。大部分情况下，它叫系统监视器（System Monitor），不过实际上它依赖于你的 Linux 的发行版及其使用的[桌面环境][1]。 + +在这篇文章中，我们将会看到如何在以 GNOME 为[桌面环境][2]的 Linux 上找到并使用任务管理器。 + +### 在使用 GNOME 桌面环境的 Linux 上的任务管理器等价物 + +使用 GNOME 时，按下 super 键（Windows 键）来查找任务管理器： + +![](https://itsfoss.com/wp-content/uploads/2016/06/system-monitor-gnome-fedora.png) + +当你启动系统监视器的时候，它会向你展示所有正在运行的进程及其消耗的内存。 + +![](https://itsfoss.com/wp-content/uploads/2016/06/fedora-system-monitor.jpeg) + +你可以选择一个进程并且点击“终止进程（End Process）”来杀掉它。 + +![](https://itsfoss.com/wp-content/uploads/2016/06/kill-process-fedora.png) + +你也可以在资源（Resources）标签里面看到关于一些统计数据，例如 CPU 的每个核心的占用，内存用量、网络用量等。 + +![](https://itsfoss.com/wp-content/uploads/2016/06/system-stats-fedora.png) + +这是图形化的方式。如果你想使用命令行，在终端里运行“top”命令然后你就可以看到所有运行的进程及其消耗的内存。你也可以很容易地使用命令行[杀死进程][3]。 + +这就是关于在 Fedora Linux 上任务管理器的知识。我希望这个教程帮你学到了知识，如果你有什么问题，请尽管问。 + +-------------------------------------------------------------------------------- + +via: https://itsfoss.com/task-manager-linux/ + +作者：[Abhishek Prakash][a] +译者：[xinglianfly](https://github.com/xinglianfly) +校对：[wxy](https://github.com/wxy) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject)原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://itsfoss.com/author/abhishek/ +[1]: https://wiki.archlinux.org/index.php/desktop_environment +[2]: https://itsfoss.com/best-linux-desktop-environments/ +[3]: https://itsfoss.com/how-to-find-the-process-id-of-a-program-and-kill-it-quick-tip/ diff --git a/published/201607/20160630 What makes up the Fedora kernel.md b/published/201607/20160630 What makes up the Fedora kernel.md new file mode 100644 index 0000000000..67c26ee93c --- /dev/null +++ b/published/201607/20160630 What makes up the Fedora kernel.md @@ -0,0 +1,31 @@ +Fedora 内核是由什么构成的？ +==================================== + +![](https://cdn.fedoramagazine.org/wp-content/uploads/2016/06/kernel-945x400.png) + +每个 Fedora 系统都运行着一个内核。许多代码片段组合在一起使之成为现实。 + +每个 Fedora 内核都起始于一个来自于[上游社区][1]的基线版本——通常称之为 vanilla 内核。上游内核就是标准。（Fedora 的）目标是包含尽可能多的上游代码，这样使得 bug 修复和 API 更新更加容易，同时也会有更多的人审查代码。理想情况下，Fedora 能够直接获取 kernel.org 的内核，然后发送给所有用户。 + +现实情况是，使用 vanilla 内核并不能完全满足 Fedora。Vanilla 内核可能并不支持一些 Fedora 用户希望拥有的功能。用户接收的 [Fedora 内核] 是在 vanilla 内核之上打了很多补丁的内核。这些补丁被认为“不在树上（out of tree）”。许多这些位于补丁树之外的补丁都不会存在太久。如果某补丁能够修复一个问题，那么该补丁可能会被合并到 Fedora 树，以便用户能够更快地收到修复。当内核变基到一个新版本时，在新版本中的补丁都将被清除。 + +一些补丁会在 Fedora 内核树上存在很长时间。一个很好的例子是，安全启动补丁就是这类补丁。这些补丁提供了 Fedora 希望支持的功能，即使上游社区还没有接受它们。保持这些补丁更新是需要付出很多努力的，所以 Fedora 尝试减少不被上游内核维护者接受的补丁数量。 + +通常来说，想要在 Fedora 内核中获得一个补丁的最佳方法是先给 [Linux 内核邮件列表（LKML）][3] 发送补丁，然后请求将该补丁包含到 Fedora 中。如果某个维护者接受了补丁，就意味着 Fedora 内核树中将来很有可能会包含该补丁。一些来自于 GitHub 等地方的还没有提交给 LKML 的补丁是不可能进入内核树的。首先向 LKML 发送补丁是非常重要的，它能确保 Fedora 内核树中携带的补丁是功能正常的。如果没有社区审查，Fedora 最终携带的补丁将会充满 bug 并会导致问题。 + +Fedora 内核中包含的代码来自许多地方。一切都需要提供最佳的体验。 + +-------------------------------------------------------------------------------- + +via: https://fedoramagazine.org/makes-fedora-kernel/ + +作者：[Laura Abbott][a] +译者：[ChrisLeeGit](https://github.com/chrisleegit) +校对：[wxy](https://github.com/wxy) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://fedoramagazine.org/makes-fedora-kernel/ +[1]: http://www.kernel.org/ +[2]: http://pkgs.fedoraproject.org/cgit/rpms/kernel.git/ +[3]: http://www.labbott.name/blog/2015/10/02/the-art-of-communicating-with-lkml/ diff --git a/published/201607/20160701 How To Setup Bridge (br0) Network on Ubuntu Linux 14.04 and 16.04 LTS.md b/published/201607/20160701 How To Setup Bridge (br0) Network on Ubuntu Linux 14.04 and 16.04 LTS.md new file mode 100644 index 0000000000..61fba7be98 --- /dev/null +++ b/published/201607/20160701 How To Setup Bridge (br0) Network on Ubuntu Linux 14.04 and 16.04 LTS.md @@ -0,0 +1,144 @@ +如何在 Ubuntu 上建立网桥 +======================================================================= + +> 作为一个 Ubuntu 16.04 LTS 的初学者。如何在 Ubuntu 14.04 和 16.04 的主机上建立网桥呢？ + +顾名思义，网桥的作用是通过物理接口连接内部和外部网络。对于虚拟端口或者 LXC/KVM/Xen/容器来说，这非常有用。网桥虚拟端口看起来是网络上的一个常规设备。在这个教程中，我将会介绍如何在 Ubuntu 服务器上通过 bridge-utils (brctl) 命令行来配置 Linux 网桥。 + +### 网桥化的网络示例 + +![](http://s0.cyberciti.org/uploads/faq/2016/07/my-br0-br1-setup.jpg) + +*图 01: Kvm/Xen/LXC 容器网桥示例 (br0)* + +在这个例子中，eth0 和 eth1 是物理网络接口。eth0 连接着局域网，eth1 连接着上游路由器和互联网。 + +### 安装 bridge-utils + +使用 [apt-get 命令][1] 安装 bridge-utils： + +``` +$ sudo apt-get install bridge-utils +``` + +或者 + +```` +$ sudo apt install bridge-utils +``` + +样例输出: + +![](http://s0.cyberciti.org/uploads/faq/2016/07/ubuntu-install-bridge-utils.jpg) + +*图 02: Ubuntu 安装 bridge-utils 包* + +### 在 Ubuntu 服务器上创建网桥 + +使用你熟悉的文本编辑器修改 `/etc/network/interfaces` ，例如 vi 或者 nano ： + +``` +$ sudo cp /etc/network/interfaces /etc/network/interfaces.bakup-1-july-2016 +$ sudo vi /etc/network/interfaces +``` + +接下来设置 eth1 并且将它映射到 br1 ，输入如下（删除或者注释所有 eth1 相关配置）： + +``` +# br1 使用静态公网 IP 地址，并以 ISP 的路由器作为网关 +auto br1 +iface br1 inet static + address 208.43.222.51 + network 255.255.255.248 + netmask 255.255.255.0 + broadcast 208.43.222.55 + gateway 208.43.222.49 + bridge_ports eth1 + bridge_stp off + bridge_fd 0 + bridge_maxwait 0 +``` + +接下来设置 eth0 并将它映射到 br0，输入如下（删除或者注释所有 eth0 相关配置）： + +``` +auto br0 +iface br0 inet static + address 10.18.44.26 + netmask 255.255.255.192 + broadcast 10.18.44.63 + dns-nameservers 10.0.80.11 10.0.80.12 + # set static route for LAN + post-up route add -net 10.0.0.0 netmask 255.0.0.0 gw 10.18.44.1 + post-up route add -net 161.26.0.0 netmask 255.255.0.0 gw 10.18.44.1 + bridge_ports eth0 + bridge_stp off + bridge_fd 0 + bridge_maxwait 0 +``` + +### 关于 br0 和 DHCP 的一点说明 + +如果使用 DHCP ，配置选项是这样的： + +``` +auto br0 +iface br0 inet dhcp + bridge_ports eth0 + bridge_stp off + bridge_fd 0 + bridge_maxwait 0 +``` + +保存并且关闭文件。 + +### 重启服务器或者网络服务 + +你需要重启服务器或者输入下列命令来重启网络服务（在 SSH 登录的会话中这可能不管用）： + +``` +$ sudo systemctl restart networking +``` + +如果你证使用 Ubuntu 14.04 LTS 或者更老的没有 systemd 的系统，输入： + +``` +$ sudo /etc/init.d/restart networking +``` + +### 验证网络配置成功 + +使用 ping/ip 命令来验证 LAN 和 WAN 网络接口运行正常： +``` +# 查看 br0 和 br1 +ip a show +# 查看路由信息 +ip r +# ping 外部站点 +ping -c 2 cyberciti.biz +# ping 局域网服务器 +ping -c 2 10.0.80.12 +``` + +样例输出： + +![](http://s0.cyberciti.org/uploads/faq/2016/07/br0-br1-eth0-eth1-configured-on-ubuntu.jpg) + +*图 03: 验证网桥的以太网连接* + +现在，你就可以配置 br0 和 br1 来让 XEN/KVM/LXC 容器访问因特网或者私有局域网了。再也没有必要去设置特定路由或者 iptables 的 SNAT 规则了。 + + +-------------------------------------------------------------------------------- + +via: http://www.cyberciti.biz/faq/how-to-create-bridge-interface-ubuntu-linux/ + +作者：[VIVEK GITE][a] +译者：[MikeCoder](https://github.com/MikeCoder) +校对：[wxy](https://github.com/wxy) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://twitter.com/nixcraft +[1]:　http://www.cyberciti.biz/tips/linux-debian-package-management-cheat-sheet.html + diff --git a/published/201607/20160705 Create Your Own Shell in Python - Part I.md b/published/201607/20160705 Create Your Own Shell in Python - Part I.md new file mode 100644 index 0000000000..3aee650db0 --- /dev/null +++ b/published/201607/20160705 Create Your Own Shell in Python - Part I.md @@ -0,0 +1,228 @@ +使用 Python 创建你自己的 Shell （一） +========================================== + +我很想知道一个 shell （像 bash，csh 等）内部是如何工作的。于是为了满足自己的好奇心，我使用 Python 实现了一个名为 **yosh** （Your Own Shell）的 Shell。本文章所介绍的概念也可以应用于其他编程语言。 + +（提示：你可以在[这里](https://github.com/supasate/yosh)查找本博文使用的源代码，代码以 MIT 许可证发布。在 Mac OS X 10.11.5 上，我使用 Python 2.7.10 和 3.4.3 进行了测试。它应该可以运行在其他类 Unix 环境，比如 Linux 和 Windows 上的 Cygwin。） + +让我们开始吧。 + +### 步骤 0：项目结构 + +对于此项目，我使用了以下的项目结构。 + +``` +yosh_project +|-- yosh + |-- __init__.py + |-- shell.py +``` + +`yosh_project` 为项目根目录（你也可以把它简单命名为 `yosh`）。 + +`yosh` 为包目录，且 `__init__.py` 可以使它成为与包的目录名字相同的包（如果你不用 Python 编写的话，可以忽略它。） + +`shell.py` 是我们主要的脚本文件。 + +### 步骤 1：Shell 循环 + +当启动一个 shell，它会显示一个命令提示符并等待你的命令输入。在接收了输入的命令并执行它之后（稍后文章会进行详细解释），你的 shell 会重新回到这里，并循环等待下一条指令。 + +在 `shell.py` 中，我们会以一个简单的 main 函数开始，该函数调用了 shell_loop() 函数，如下： + +``` +def shell_loop(): + # Start the loop here + + +def main(): + shell_loop() + + +if __name__ == "__main__": + main() +``` + +接着，在 `shell_loop()` 中，为了指示循环是否继续或停止，我们使用了一个状态标志。在循环的开始，我们的 shell 将显示一个命令提示符，并等待读取命令输入。 + +``` +import sys + +SHELL_STATUS_RUN = 1 +SHELL_STATUS_STOP = 0 + + +def shell_loop(): + status = SHELL_STATUS_RUN + + while status == SHELL_STATUS_RUN: + ### 显示命令提示符 + sys.stdout.write('> ') + sys.stdout.flush() + + ### 读取命令输入 + cmd = sys.stdin.readline() +``` + +之后，我们切分命令（tokenize）输入并进行执行（execute）（我们即将实现 `tokenize` 和 `execute` 函数）。 + +因此，我们的 shell_loop() 会是如下这样： + +``` +import sys + +SHELL_STATUS_RUN = 1 +SHELL_STATUS_STOP = 0 + + +def shell_loop(): + status = SHELL_STATUS_RUN + + while status == SHELL_STATUS_RUN: + ### 显示命令提示符 + sys.stdout.write('> ') + sys.stdout.flush() + + ### 读取命令输入 + cmd = sys.stdin.readline() + + ### 切分命令输入 + cmd_tokens = tokenize(cmd) + + ### 执行该命令并获取新的状态 + status = execute(cmd_tokens) +``` + +这就是我们整个 shell 循环。如果我们使用 `python shell.py` 启动我们的 shell，它会显示命令提示符。然而如果我们输入命令并按回车，它会抛出错误，因为我们还没定义 `tokenize` 函数。 + +为了退出 shell，可以尝试输入 ctrl-c。稍后我将解释如何以优雅的形式退出 shell。 + +### 步骤 2：命令切分（tokenize） + +当用户在我们的 shell 中输入命令并按下回车键，该命令将会是一个包含命令名称及其参数的长字符串。因此，我们必须切分该字符串（分割一个字符串为多个元组）。 + +咋一看似乎很简单。我们或许可以使用 `cmd.split()`，以空格分割输入。它对类似 `ls -a my_folder` 的命令起作用，因为它能够将命令分割为一个列表 `['ls', '-a', 'my_folder']`，这样我们便能轻易处理它们了。 + +然而，也有一些类似 `echo "Hello World"` 或 `echo 'Hello World'` 以单引号或双引号引用参数的情况。如果我们使用 cmd.spilt，我们将会得到一个存有 3 个标记的列表 `['echo', '"Hello', 'World"']` 而不是 2 个标记的列表 `['echo', 'Hello World']`。 + +幸运的是，Python 提供了一个名为 `shlex` 的库，它能够帮助我们如魔法般地分割命令。（提示：我们也可以使用正则表达式，但它不是本文的重点。） + + +``` +import sys +import shlex + +... + +def tokenize(string): + return shlex.split(string) + +... +``` + +然后我们将这些元组发送到执行进程。 + +### 步骤 3：执行 + +这是 shell 中核心而有趣的一部分。当 shell 执行 `mkdir test_dir` 时，到底发生了什么？（提示： `mkdir` 是一个带有 `test_dir` 参数的执行程序，用于创建一个名为 `test_dir` 的目录。） + +`execvp` 是这一步的首先需要的函数。在我们解释 `execvp` 所做的事之前，让我们看看它的实际效果。 + +``` +import os +... + +def execute(cmd_tokens): + ### 执行命令 + os.execvp(cmd_tokens[0], cmd_tokens) + + ### 返回状态以告知在 shell_loop 中等待下一个命令 + return SHELL_STATUS_RUN + +... +``` + +再次尝试运行我们的 shell，并输入 `mkdir test_dir` 命令，接着按下回车键。 + +在我们敲下回车键之后，问题是我们的 shell 会直接退出而不是等待下一个命令。然而，目录正确地创建了。 + +因此，`execvp` 实际上做了什么？ + +`execvp` 是系统调用 `exec` 的一个变体。第一个参数是程序名字。`v` 表示第二个参数是一个程序参数列表（参数数量可变）。`p` 表示将会使用环境变量 `PATH` 搜索给定的程序名字。在我们上一次的尝试中，它将会基于我们的 `PATH` 环境变量查找`mkdir` 程序。 + +（还有其他 `exec` 变体，比如 execv、execvpe、execl、execlp、execlpe；你可以 google 它们获取更多的信息。） + +`exec` 会用即将运行的新进程替换调用进程的当前内存。在我们的例子中，我们的 shell 进程内存会被替换为 `mkdir` 程序。接着，`mkdir` 成为主进程并创建 `test_dir` 目录。最后该进程退出。 + +这里的重点在于**我们的 shell 进程已经被 `mkdir` 进程所替换**。这就是我们的 shell 消失且不会等待下一条命令的原因。 + +因此，我们需要其他的系统调用来解决问题：`fork`。 + +`fork` 会分配新的内存并拷贝当前进程到一个新的进程。我们称这个新的进程为**子进程**，调用者进程为**父进程**。然后，子进程内存会被替换为被执行的程序。因此，我们的 shell，也就是父进程，可以免受内存替换的危险。 + +让我们看看修改的代码。 + +``` +... + +def execute(cmd_tokens): + ### 分叉一个子 shell 进程 + ### 如果当前进程是子进程，其 `pid` 被设置为 `0` + ### 否则当前进程是父进程的话，`pid` 的值 + ### 是其子进程的进程 ID。 + pid = os.fork() + + if pid == 0: + ### 子进程 + ### 用被 exec 调用的程序替换该子进程 + os.execvp(cmd_tokens[0], cmd_tokens) + elif pid > 0: + ### 父进程 + while True: + ### 等待其子进程的响应状态（以进程 ID 来查找） + wpid, status = os.waitpid(pid, 0) + + ### 当其子进程正常退出时 + ### 或者其被信号中断时，结束等待状态 + if os.WIFEXITED(status) or os.WIFSIGNALED(status): + break + + ### 返回状态以告知在 shell_loop 中等待下一个命令 + return SHELL_STATUS_RUN + +... +``` + +当我们的父进程调用 `os.fork()` 时，你可以想象所有的源代码被拷贝到了新的子进程。此时此刻，父进程和子进程看到的是相同的代码，且并行运行着。 + +如果运行的代码属于子进程，`pid` 将为 `0`。否则，如果运行的代码属于父进程，`pid` 将会是子进程的进程 id。 + +当 `os.execvp` 在子进程中被调用时，你可以想象子进程的所有源代码被替换为正被调用程序的代码。然而父进程的代码不会被改变。 + +当父进程完成等待子进程退出或终止时，它会返回一个状态，指示继续 shell 循环。 + +### 运行 + +现在，你可以尝试运行我们的 shell 并输入 `mkdir test_dir2`。它应该可以正确执行。我们的主 shell 进程仍然存在并等待下一条命令。尝试执行 `ls`，你可以看到已创建的目录。 + +但是，这里仍有一些问题。 + +第一，尝试执行 `cd test_dir2`，接着执行 `ls`。它应该会进入到一个空的 `test_dir2` 目录。然而，你将会看到目录并没有变为 `test_dir2`。 + +第二，我们仍然没有办法优雅地退出我们的 shell。 + +我们将会在 [第二部分][1] 解决诸如此类的问题。 + + +-------------------------------------------------------------------------------- + +via: https://hackercollider.com/articles/2016/07/05/create-your-own-shell-in-python-part-1/ + +作者：[Supasate Choochaisri][a] +译者：[cposture](https://github.com/cposture) +校对：[wxy](https://github.com/wxy) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://disqus.com/by/supasate_choochaisri/ +[1]: https://hackercollider.com/articles/2016/07/06/create-your-own-shell-in-python-part-2/ diff --git a/published/201607/20160706 Create Your Own Shell in Python - Part II.md b/published/201607/20160706 Create Your Own Shell in Python - Part II.md new file mode 100644 index 0000000000..9e66d5643c --- /dev/null +++ b/published/201607/20160706 Create Your Own Shell in Python - Part II.md @@ -0,0 +1,211 @@ +使用 Python 创建你自己的 Shell（下） +=========================================== + +在[上篇][1]中，我们已经创建了一个 shell 主循环、切分了命令输入，以及通过 `fork` 和 `exec` 执行命令。在这部分，我们将会解决剩下的问题。首先，`cd test_dir2` 命令无法修改我们的当前目录。其次，我们仍无法优雅地从 shell 中退出。 + +### 步骤 4：内置命令 + +“`cd test_dir2` 无法修改我们的当前目录” 这句话是对的，但在某种意义上也是错的。在执行完该命令之后，我们仍然处在同一目录，从这个意义上讲，它是对的。然而，目录实际上已经被修改，只不过它是在子进程中被修改。 + +还记得我们分叉（fork）了一个子进程，然后执行命令，执行命令的过程没有发生在父进程上。结果是我们只是改变了子进程的当前目录，而不是父进程的目录。 + +然后子进程退出，而父进程在原封不动的目录下继续运行。 + +因此，这类与 shell 自己相关的命令必须是内置命令。它必须在 shell 进程中执行而不是在分叉中（forking）。 + +#### cd + +让我们从 `cd` 命令开始。 + +我们首先创建一个 `builtins` 目录。每一个内置命令都会被放进这个目录中。 + +```shell +yosh_project +|-- yosh + |-- builtins + | |-- __init__.py + | |-- cd.py + |-- __init__.py + |-- shell.py +``` + +在 `cd.py` 中，我们通过使用系统调用 `os.chdir` 实现自己的 `cd` 命令。 + +```python +import os +from yosh.constants import * + +def cd(args): + os.chdir(args[0]) + + return SHELL_STATUS_RUN +``` + +注意，我们会从内置函数返回 shell 的运行状态。所以，为了能够在项目中继续使用常量，我们将它们移至 `yosh/constants.py`。 + +```shell +yosh_project +|-- yosh + |-- builtins + | |-- __init__.py + | |-- cd.py + |-- __init__.py + |-- constants.py + |-- shell.py +``` + +在 `constants.py` 中，我们将状态常量都放在这里。 + +```python +SHELL_STATUS_STOP = 0 +SHELL_STATUS_RUN = 1 +``` + +现在，我们的内置 `cd` 已经准备好了。让我们修改 `shell.py` 来处理这些内置函数。 + +```python +... +### 导入常量 +from yosh.constants import * + +### 使用哈希映射来存储内建的函数名及其引用 +built_in_cmds = {} + +def tokenize(string): + return shlex.split(string) + +def execute(cmd_tokens): + ### 从元组中分拆命令名称与参数 + cmd_name = cmd_tokens[0] + cmd_args = cmd_tokens[1:] + + ### 如果该命令是一个内建命令，使用参数调用该函数 + if cmd_name in built_in_cmds: + return built_in_cmds[cmd_name](cmd_args) + + ... +``` + +我们使用一个 python 字典变量 `built_in_cmds` 作为哈希映射（hash map），以存储我们的内置函数。我们在 `execute` 函数中提取命令的名字和参数。如果该命令在我们的哈希映射中，则调用对应的内置函数。 + +（提示：`built_in_cmds[cmd_name]` 返回能直接使用参数调用的函数引用。) + +我们差不多准备好使用内置的 `cd` 函数了。最后一步是将 `cd` 函数添加到 `built_in_cmds` 映射中。 + +``` +... +### 导入所有内建函数引用 +from yosh.builtins import * + +... + +### 注册内建函数到内建命令的哈希映射中 +def register_command(name, func): + built_in_cmds[name] = func + + +### 在此注册所有的内建命令 +def init(): + register_command("cd", cd) + + +def main(): + ###在开始主循环之前初始化 shell + init() + shell_loop() +``` + +我们定义了 `register_command` 函数，以添加一个内置函数到我们内置的命令哈希映射。接着，我们定义 `init` 函数并且在这里注册内置的 `cd` 函数。 + +注意这行 `register_command("cd", cd)` 。第一个参数为命令的名字。第二个参数为一个函数引用。为了能够让第二个参数 `cd` 引用到 `yosh/builtins/cd.py` 中的 `cd` 函数引用，我们必须将以下这行代码放在 `yosh/builtins/__init__.py` 文件中。 + +``` +from yosh.builtins.cd import * +``` + +因此，在 `yosh/shell.py` 中，当我们从 `yosh.builtins` 导入 `*` 时，我们可以得到已经通过 `yosh.builtins` 导入的 `cd` 函数引用。 + +我们已经准备好了代码。让我们尝试在 `yosh` 同级目录下以模块形式运行我们的 shell，`python -m yosh.shell`。 + +现在，`cd` 命令可以正确修改我们的 shell 目录了，同时非内置命令仍然可以工作。非常好！ + +#### exit + +最后一块终于来了：优雅地退出。 + +我们需要一个可以修改 shell 状态为 `SHELL_STATUS_STOP` 的函数。这样，shell 循环可以自然地结束，shell 将到达终点而退出。 + +和 `cd` 一样，如果我们在子进程中分叉并执行 `exit` 函数，其对父进程是不起作用的。因此，`exit` 函数需要成为一个 shell 内置函数。 + +让我们从这开始：在 `builtins` 目录下创建一个名为 `exit.py` 的新文件。 + +``` +yosh_project +|-- yosh + |-- builtins + | |-- __init__.py + | |-- cd.py + | |-- exit.py + |-- __init__.py + |-- constants.py + |-- shell.py +``` + +`exit.py` 定义了一个 `exit` 函数，该函数仅仅返回一个可以退出主循环的状态。 + +``` +from yosh.constants import * + +def exit(args): + return SHELL_STATUS_STOP +``` + +然后，我们导入位于 `yosh/builtins/__init__.py` 文件的 `exit` 函数引用。 + +``` +from yosh.builtins.cd import * +from yosh.builtins.exit import * +``` + +最后，我们在 `shell.py` 中的 `init()` 函数注册 `exit` 命令。 + +``` +... + +### 在此注册所有的内建命令 +def init(): + register_command("cd", cd) + register_command("exit", exit) + +... +``` + +到此为止！ + +尝试执行 `python -m yosh.shell`。现在你可以输入 `exit` 优雅地退出程序了。 + +### 最后的想法 + +我希望你能像我一样享受创建 `yosh` （**y**our **o**wn **sh**ell）的过程。但我的 `yosh` 版本仍处于早期阶段。我没有处理一些会使 shell 崩溃的极端状况。还有很多我没有覆盖的内置命令。为了提高性能，一些非内置命令也可以实现为内置命令（避免新进程创建时间）。同时，大量的功能还没有实现（请看 [公共特性](http://tldp.org/LDP/Bash-Beginners-Guide/html/x7243.html) 和 [不同特性](http://www.tldp.org/LDP/intro-linux/html/x12249.html)） + +我已经在 https://github.com/supasate/yosh 中提供了源代码。请随意 fork 和尝试。 + +现在该是创建你真正自己拥有的 Shell 的时候了。 + +Happy Coding! + +-------------------------------------------------------------------------------- + +via: https://hackercollider.com/articles/2016/07/06/create-your-own-shell-in-python-part-2/ + +作者：[Supasate Choochaisri][a] +译者：[cposture](https://github.com/cposture) +校对：[wxy](https://github.com/wxy) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://disqus.com/by/supasate_choochaisri/ +[1]: https://linux.cn/article-7624-1.html +[2]: http://tldp.org/LDP/Bash-Beginners-Guide/html/x7243.html +[3]: http://www.tldp.org/LDP/intro-linux/html/x12249.html +[4]: https://github.com/supasate/yosh diff --git a/published/201607/20160708 Using Vagrant to control your DigitalOcean cloud instances.md b/published/201607/20160708 Using Vagrant to control your DigitalOcean cloud instances.md new file mode 100644 index 0000000000..541bcda865 --- /dev/null +++ b/published/201607/20160708 Using Vagrant to control your DigitalOcean cloud instances.md @@ -0,0 +1,67 @@ +使用 Vagrant 控制你的 DigitalOcean 云主机 +========================================================= + +![](https://cdn.fedoramagazine.org/wp-content/uploads/2016/06/fedora-vagrant-do-945x400.jpg) + +[Vagrant][1] 是一个使用虚拟机创建和支持虚拟开发环境的应用。Fedora 官方已经在本地系统上通过库 `libvirt` [支持 Vagrant][2]。[DigitalOcean][3] 是一个提供一键部署 Fedora 云服务实例到全 SSD 服务器的云计算服务提供商。在[最近的 Raleigh 举办的 FAD 大会][4]中，Fedora 云计算队伍为 Vagrant 打包了一个新的插件，它能够帮助 Fedora 用户通过使用本地的 Vagrantfile 文件来管理 DigitalOcean 上的云服务实例。 + +### 如何使用这个插件 + +第一步在命令行下是安装软件。 + +``` +$ sudo dnf install -y vagrant-digitalocean +``` + +安装 结束之后，下一步是创建本地的 Vagrantfile 文件。下面是一个例子。 + +``` +$ mkdir digitalocean +$ cd digitalocean +$ cat Vagrantfile +Vagrant.configure('2') do |config| + config.vm.hostname = 'dropletname.kushaldas.in' + # Alternatively, use provider.name below to set the Droplet name. config.vm.hostname takes precedence. + + config.vm.provider :digital_ocean do |provider, override| + override.ssh.private_key_path = '/home/kdas/.ssh/id_rsa' + override.vm.box = 'digital_ocean' + override.vm.box_url = "https://github.com/devopsgroup-io/vagrant- digitalocean/raw/master/box/digital_ocean.box" + + provider.token = 'Your AUTH Token' + provider.image = 'fedora-23-x64' + provider.region = 'nyc2' + provider.size = '512mb' + provider.ssh_key_name = 'Kushal' + end +end +``` + +### Vagrant DigitalOcean 插件的注意事项 + +一定要记住的几个关于 SSH 的关键命名规范 : 如果你已经在 DigitalOcean 上传了秘钥，请确保 `provider.ssh_key_name` 和已经在服务器中的名字吻合。 `provider.image` 具体的文档可以在[DigitalOcean documentation][5]找到。在控制面板上的 `App & API` 部分可以创建 AUTH 令牌。 + +你可以使用下面的命令启动一个实例。 + +``` +$ vagrant up --provider=digital_ocean +``` + +这个命令会在 DigitalOcean 的启动一个服务器实例。然后你就可以使用 `vagrant ssh` 命令来 `ssh` 登录进入这个实例。可以执行 `vagrant destroy` 来删除这个实例。 + +-------------------------------------------------------------------------------- + +via: https://fedoramagazine.org/using-vagrant-digitalocean-cloud/ + +作者：[Kushal Das][a] +译者：[MikeCoder](https://github.com/MikeCoder) +校对：[Ezio](https://github.com/oska874) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: http://kushal.id.fedoraproject.org/ +[1]: https://www.vagrantup.com/ +[2]: https://fedoramagazine.org/running-vagrant-fedora-22/ +[3]: https://www.digitalocean.com/ +[4]: https://communityblog.fedoraproject.org/fedora-cloud-fad-2016/ +[5]: https://developers.digitalocean.com/documentation/v2/#create-a-new-droplet diff --git a/published/201607/20160718 OPEN SOURCE ACCOUNTING SOFTWARE.md b/published/201607/20160718 OPEN SOURCE ACCOUNTING SOFTWARE.md new file mode 100644 index 0000000000..7598de6bf1 --- /dev/null +++ b/published/201607/20160718 OPEN SOURCE ACCOUNTING SOFTWARE.md @@ -0,0 +1,80 @@ +GNU KHATA：开源的会计管理软件 +============================================ + +作为一个活跃的 Linux 爱好者，我经常向我的朋友们介绍 Linux，帮助他们选择最适合他们的发行版本，同时也会帮助他们安装一些适用于他们工作的开源软件。 + +但是在这一次，我就变得很无奈。我的叔叔，他是一个自由职业的会计师。他会有一系列的为了会计工作的漂亮而成熟的付费软件。我不那么确定我能在在开源软件中找到这么一款可以替代的软件——直到昨天。 + +Abhishek 给我推荐了一些[很酷的软件][1]，而其中 GNU Khata 脱颖而出。 + +[GNU Khata][2] 是一个会计工具。 或者，我应该说成是一系列的会计工具集合？它就像经济管理方面的 [Evernote][3] 一样。它的应用是如此之广，以至于它不但可以用于个人的财务管理，也可以用于大型公司的管理，从店铺存货管理到税率计算，都可以有效处理。 + +有个有趣的地方，Khata 这个词在印度或者是其他的印度语国家中意味着账户，所以这个会计软件叫做 GNU Khata。 + +### 安装 + +互联网上有很多关于旧的 Web 版本的 Khata 安装介绍。现在，GNU Khata 只能用在 Debian/Ubuntu 和它们的衍生版本中。我建议你按照 GNU Khata 官网给出的如下步骤来安装。我们来快速过一下。 + +- 从[这里][4]下载安装器。 +- 在下载目录打开终端。 +- 粘贴复制以下的代码到终端，并且执行。 + +``` +sudo chmod 755 GNUKhatasetup.run +sudo ./GNUKhatasetup.run +``` + +这就结束了，从你的 Dash 或者是应用菜单中启动 GNU Khata 吧。 + +### 第一次启动 + +GNU Khata 在浏览器中打开，并且展现以下的画面。 + +![](https://itsfoss.com/wp-content/uploads/2016/07/GNU-khata-1.jpg) + +填写组织的名字、组织形式，财务年度并且点击 proceed 按钮进入管理设置页面。 + +![](https://itsfoss.com/wp-content/uploads/2016/07/GNU-khata-2.jpg) + +仔细填写你的用户名、密码、安全问题及其答案，并且点击“create and login”。 + +![](https://itsfoss.com/wp-content/uploads/2016/07/GNU-khata-3.jpg) + +你已经全部设置完成了。使用菜单栏来开始使用 GNU Khata 来管理你的财务吧。这很容易。 + +### 移除 GNU KHATA + +如果你不想使用 GNU Khata 了，你可以执行如下命令移除： + +``` +sudo apt-get remove --auto-remove gnukhata-core-engine +``` + +你也可以通过新立得软件管理来删除它。 + +### GNU KHATA 真的是市面上付费会计应用的竞争对手吗？ + +首先，GNU Khata 以简化为设计原则。顶部的菜单栏组织的很方便，可以帮助你有效的进行工作。你可以选择管理不同的账户和项目，并且切换非常容易。[它们的官网][5]表明，GNU Khata 可以“像说印度语一样方便”（LCTT 译注：原谅我，这个软件作者和本文作者是印度人……）。同时，你知道 GNU Khata 也可以在云端使用吗？ + +所有的主流的账户管理工具，比如分类账簿、项目报表、财务报表等等都用专业的方式整理，并且支持自定义格式和即时展示。这让会计和仓储管理看起来如此的简单。 + +这个项目正在积极的发展，正在寻求实操中的反馈以帮助这个软件更加进步。考虑到软件的成熟性、使用的便利性还有免费的情况，GNU Khata 可能会成为你最好的账簿助手。 + +请在评论框里留言吧，让我们知道你是如何看待 GNU Khata 的。 + +-------------------------------------------------------------------------------- + +via: https://itsfoss.com/using-gnu-khata/ + +作者：[Aquil Roshan][a] +译者：[MikeCoder](https://github.com/MikeCoder) +校对：[wxy](https://github.com/wxy) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://itsfoss.com/author/aquil/ +[1]: https://itsfoss.com/category/apps/ +[2]: http://www.gnukhata.in/ +[3]: https://evernote.com/ +[4]: https://cloud.openmailbox.org/index.php/s/L8ppsxtsFq1345E/download +[5]: http://www.gnukhata.in/ diff --git a/published/201607/20160721 YOU CAN TRY A DEMO UBUNTU VERSION IN A WEB BROWSER.md b/published/201607/20160721 YOU CAN TRY A DEMO UBUNTU VERSION IN A WEB BROWSER.md new file mode 100644 index 0000000000..0fd776c078 --- /dev/null +++ b/published/201607/20160721 YOU CAN TRY A DEMO UBUNTU VERSION IN A WEB BROWSER.md @@ -0,0 +1,36 @@ +在浏览器中体验 Ubuntu +===================================================== + +[Ubuntu][2] 的背后的公司 [Canonical][1] 为 Linux 推广做了很多努力。无论你有多么不喜欢 Ubuntu，你必须承认它对 “Linux 易用性”的影响。Ubuntu 以及其衍生是使用最多的 Linux 版本。 + +为了进一步推广 Ubuntu Linux，Canonical 把它放到了浏览器里，你可以在任何地方使用这个 [Ubuntu 演示版][0]。 它将帮你更好的体验 Ubuntu，以便让新人更容易决定是否使用它。 + +你可能争辩说 USB 版的 Linux 更好。我同意，但是你要知道你要下载 ISO，创建 USB 启动盘，修改配置文件，然后才能使用这个 USB 启动盘来体验。这么乏味并不是每个人都乐意这么干的。 在线体验是一个更好的选择。 + +那么，你能在 Ubuntu 在线看到什么。实际上并不多。 + +你可以浏览文件，你可以使用 Unity Dash，浏览 Ubuntu 软件中心，甚至装几个应用（当然它们不会真的安装），看一看文件浏览器和其它一些东西。以上就是全部了。但是在我看来，这已经做的很好了，让你知道它是个什么，对这个流行的操作系统有个直接感受。 + +![](https://itsfoss.com/wp-content/uploads/2016/07/Ubuntu-online-demo.jpeg) + +![](https://itsfoss.com/wp-content/uploads/2016/07/Ubuntu-online-demo-1.jpeg) + +![](https://itsfoss.com/wp-content/uploads/2016/07/Ubuntu-online-demo-2.jpeg) + +如果你的朋友或者家人对试试 Linux 抱有兴趣，但是想在安装前想体验一下 Linux 。你可以给他们以下链接：[Ubuntu 在线导览][0] 。 + + +-------------------------------------------------------------------------------- + +via: https://itsfoss.com/ubuntu-online-demo/ + +作者：[Abhishek Prakash][a] +译者：[kokialoves](https://github.com/kokialoves) +校对：[wxy](https://github.com/wxy) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://itsfoss.com/author/abhishek/ +[0]: http://tour.ubuntu.com/en/ +[1]: http://www.canonical.com/ +[2]: http://www.ubuntu.com/ diff --git a/published/201607/20160722 7 Best Markdown Editors for Linux.md b/published/201607/20160722 7 Best Markdown Editors for Linux.md new file mode 100644 index 0000000000..7d1ffe0c86 --- /dev/null +++ b/published/201607/20160722 7 Best Markdown Editors for Linux.md @@ -0,0 +1,200 @@ +Linux 上 10 个最好的 Markdown 编辑器 +====================================== + +在这篇文章中，我们会点评一些可以在 Linux 上安装使用的最好的 Markdown 编辑器。 你可以找到非常多的 Linux 平台上的 Markdown 编辑器，但是在这里我们将尽可能地为您推荐那些最好的。 + +![](http://www.tecmint.com/wp-content/uploads/2016/07/Best-Linux-Markdown-Editors.png) + +*Best Linux Markdown Editors* + +对于不了解 Markdown 的人做个简单介绍，Markdown 是由著名的 Aaron Swartz 和 John Gruber 发明的标记语言，其最初的解析器是一个用 Perl 写的简单、轻量的[同名工具][1]。它可以将用户写的纯文本转为可用的 HTML（或 XHTML）。它实际上是一门易读，易写的纯文本语言，以及一个用于将文本转为 HTML 的转换工具。 + +希望你先对 Markdown 有一个稍微的了解，接下来让我们逐一列出这些编辑器。 + +### 1. Atom + +Atom 是一个现代的、跨平台、开源且强大的文本编辑器，它可以运行在 Linux、Windows 和 MAC OS X 等操作系统上。用户可以在它的基础上进行定制，删减修改任何配置文件。 + +它包含了一些非常杰出的特性： + +- 内置软件包管理器 +- 智能自动补全功能 +- 提供多窗口操作 +- 支持查找替换功能 +- 包含一个文件系统浏览器 +- 轻松自定义主题 +- 开源、高度扩展性的软件包等 + +![](http://www.tecmint.com/wp-content/uploads/2016/07/Atom-Markdown-Editor-for-Linux.png) + +*Atom Markdown Editor for Linux* + +访问主页: + +### 2. GNU Emacs + +Emacs 是 Linux 平台上一款的流行文本编辑器。它是一个非常棒的、具备高扩展性和定制性的 Markdown 语言编辑器。 + +它综合了以下这些神奇的特性： + +- 带有丰富的内置文档，包括适合初学者的教程 +- 有完整的 Unicode 支持，可显示所有的人类符号 +- 支持内容识别的文本编辑模式 +- 包括多种文件类型的语法高亮 +- 可用 Emacs Lisp 或 GUI 对其进行高度定制 +- 提供了一个包系统可用来下载安装各种扩展等 + +![](http://www.tecmint.com/wp-content/uploads/2016/07/Emacs-Markdown-Editor-for-Linux.png) + +*Emacs Markdown Editor for Linux* + +访问主页: + +### 3. Remarkable + +Remarkable 可能是 Linux 上最好的 Markdown 编辑器了，它也适用于 Windows 操作系统。它的确是是一个卓越且功能齐全的 Markdown 编辑器，为用户提供了一些令人激动的特性。 + +一些卓越的特性： + +- 支持实时预览 +- 支持导出 PDF 和 HTML +- 支持 Github Markdown 语法 +- 支持定制 CSS +- 支持语法高亮 +- 提供键盘快捷键 +- 高可定制性和其他 + +![](http://www.tecmint.com/wp-content/uploads/2016/07/Remarkable-Markdown-Editor-for-Linux.png) + +*Remarkable Markdown Editor for Linux* + +访问主页: + +### 4. Haroopad + +Haroopad 是为 Linux，Windows 和 Mac OS X 构建的跨平台 Markdown 文档处理程序。用户可以用它来书写许多专家级格式的文档，包括电子邮件、报告、博客、演示文稿和博客文章等等。 + +功能齐全且具备以下的亮点： + +- 轻松导入内容 +- 支持导出多种格式 +- 广泛支持博客和邮件 +- 支持许多数学表达式 +- 支持 Github Markdown 扩展 +- 为用户提供了一些令人兴奋的主题、皮肤和 UI 组件等等 + +![](http://www.tecmint.com/wp-content/uploads/2016/07/Haroopad-Markdown-Editor-for-Linux.png) + +*Haroopad Markdown Editor for Linux* + +访问主页: + +### 5. ReText + +ReText 是为 Linux 和其它几个 POSIX 兼容操作系统提供的简单、轻量、强大的 Markdown 编辑器。它还可以作为一个 reStructuredText 编辑器，并且具有以下的特性： + +- 简单直观的 GUI +- 具备高定制性，用户可以自定义语法文件和配置选项 +- 支持多种配色方案 +- 支持使用多种数学公式 +- 启用导出扩展等等 + +![](http://www.tecmint.com/wp-content/uploads/2016/07/ReText-Markdown-Editor-for-Linux.png) + +*ReText Markdown Editor for Linux* + +访问主页: + +### 6. UberWriter + +UberWriter 是一个简单、易用的 Linux Markdown 编辑器。它的开发受 Mac OS X 上的 iA writer 影响很大，同样它也具备这些卓越的特性： + +- 使用 pandoc 进行所有的文本到 HTML 的转换 +- 提供了一个简洁的 UI 界面 +- 提供了一种专心（distraction free）模式，高亮用户最后的句子 +- 支持拼写检查 +- 支持全屏模式 +- 支持用 pandoc 导出 PDF、HTML 和 RTF +- 启用语法高亮和数学函数等等 + +![](http://www.tecmint.com/wp-content/uploads/2016/07/UberWriter-Markdown-Editor-for-Linux.png) + +*UberWriter Markdown Editor for Linux* + +访问主页: + +### 7. Mark My Words + +Mark My Words 同样也是一个轻量、强大的 Markdown 编辑器。它是一个相对比较新的编辑器，因此提供了包含语法高亮在内的大量的功能，简单和直观的 UI。 + +下面是一些棒极了，但还未捆绑到应用中的功能： + +- 实时预览 +- Markdown 解析和文件 IO +- 状态管理 +- 支持导出 PDF 和 HTML +- 监测文件的修改 +- 支持首选项设置 + +![](http://www.tecmint.com/wp-content/uploads/2016/07/MarkMyWords-Markdown-Editor-for-Linux.png) + +*MarkMyWords Markdown Editor for-Linux* + +访问主页: + +### 8. Vim-Instant-Markdown 插件 + +Vim 是 Linux 上的一个久经考验的强大、流行而开源的文本编辑器。它用于编程极棒。它也高度支持插件功能，可以让用户为其增加一些其它功能，包括 Markdown 预览。 + +有好几种 Vim 的 Markdown 预览插件，但是 [Vim-Instant-Markdown][2] 的表现最佳。 + +###9. Bracket-MarkdownPreview 插件 + +Brackets 是一个现代、轻量、开源且跨平台的文本编辑器。它特别为 Web 设计和开发而构建。它的一些重要功能包括：支持内联编辑器、实时预览、预处理支持及更多。 + +它也是通过插件高度可扩展的，你可以使用 [Bracket-MarkdownPreview][3] 插件来编写和预览 Markdown 文档。 + +![](http://www.tecmint.com/wp-content/uploads/2016/07/Brackets-Markdown-Plugin.png) + +*Brackets Markdown Plugin Preview* + +### 10. SublimeText-Markdown 插件 + +Sublime Text 是一个精心打造的、流行的、跨平台文本编辑器，用于代码、markdown 和普通文本。它的表现极佳，包括如下令人兴奋的功能： + +- 简洁而美观的 GUI +- 支持多重选择 +- 提供专心模式 +- 支持窗体分割编辑 +- 通过 Python 插件 API 支持高度插件化 +- 完全可定制化，提供命令查找模式 + +[SublimeText-Markdown][4] 插件是一个支持格式高亮的软件包，带有一些漂亮的颜色方案。 + +![](http://www.tecmint.com/wp-content/uploads/2016/07/SublimeText-Markdown-Plugin-Preview.png) + +*SublimeText Markdown Plugin Preview* + +### 结论 + +通过上面的列表，你大概已经知道要为你的 Linux 桌面下载、安装什么样的 Markdown 编辑器和文档处理程序了。 + +请注意，这里提到的最好的 Markdown 编辑器可能对你来说并不是最好的选择。因此你可以通过下面的反馈部分，为我们展示你认为列表中未提及的，并且具备足够的资格的，令人兴奋的 Markdown 编辑器。 + + +-------------------------------------------------------------------------------- + +via: http://www.tecmint.com/best-markdown-editors-for-linux/ + +作者：[Aaron Kili][a] +译者：[Locez](https://github.com/locez) +校对：[wxy](https://github.com/wxy) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: http://www.tecmint.com/author/aaronkili/ +[1]: https://daringfireball.net/projects/markdown/ +[2]: https://github.com/suan/vim-instant-markdown +[3]: https://github.com/gruehle/MarkdownPreview +[4]: https://github.com/SublimeText-Markdown/MarkdownEditing + diff --git a/published/201607/20160722 HOW TO CHANGE DEFAULT APPLICATIONS IN UBUNTU.md b/published/201607/20160722 HOW TO CHANGE DEFAULT APPLICATIONS IN UBUNTU.md new file mode 100644 index 0000000000..b485632d6c --- /dev/null +++ b/published/201607/20160722 HOW TO CHANGE DEFAULT APPLICATIONS IN UBUNTU.md @@ -0,0 +1,69 @@ +怎样在 Ubuntu 中修改默认程序 +============================================== + +![](https://itsfoss.com/wp-content/uploads/2016/07/change-default-applications-ubuntu.jpg) + +> 简介: 这个新手指南会向你展示如何在 Ubuntu Linux 中修改默认程序 + +对于我来说，安装 [VLC 多媒体播放器][1]是[安装完 Ubuntu 16.04 该做的事][2]中最先做的几件事之一。为了能够使我双击一个视频就用 VLC 打开，在我安装完 VLC 之后我会设置它为默认程序。 + +作为一个新手，你需要知道如何在 Ubuntu 中修改任何默认程序，这也是我今天在这篇指南中所要讲的。 + +### 在 UBUNTU 中修改默认程序 + +这里提及的方法适用于所有的 Ubuntu 12.04，Ubuntu 14.04 和Ubuntu 16.04。在 Ubuntu 中，这里有两种基本的方法可以修改默认程序： + +- 通过系统设置 +- 通过右键菜单 + +#### 1.通过系统设置修改 Ubuntu 的默认程序 + +进入 Unity 面板并且搜索系统设置（System Settings）： + +![](https://itsfoss.com/wp-content/uploads/2013/11/System_Settings_Ubuntu.jpeg) + +在系统设置（System Settings）中，选择详细选项（Details）： + +![](https://itsfoss.com/wp-content/uploads/2016/07/System-settings-detail-ubuntu.jpeg) + +在左边的面板中选择默认程序（Default Applications），你会发现在右边的面板中可以修改默认程序。 + +![](https://itsfoss.com/wp-content/uploads/2016/07/System-settings-default-applications.jpeg) + +正如看到的那样，这里只有少数几类的默认程序可以被改变。你可以在这里改变浏览器、邮箱客户端、日历、音乐、视频和相册的默认程序。那其他类型的默认程序怎么修改？ + +不要担心，为了修改其他类型的默认程序，我们会用到右键菜单。 + +#### 2.通过右键菜单修改默认程序 + +如果你使用过 Windows 系统，你应该看见过右键菜单的“打开方式”，可以通过这个来修改默认程序。我们在 Ubuntu 中也有相似的方法。 + +右键一个还没有设置默认打开程序的文件，选择“属性（properties）” + +![](https://itsfoss.com/wp-content/uploads/2016/05/WebP-images-Ubuntu-Linux-3.png) + +*从右键菜单中选择属性* + +在这里，你可以选择使用什么程序打开，并且设置为默认程序。 + +![](https://itsfoss.com/wp-content/uploads/2016/05/WebP-images-Ubuntu-Linux-4.png) + +*在 Ubuntu 中设置打开 WebP 图片的默认程序为 gThumb* + +小菜一碟不是么？一旦你做完这些，所有同样类型的文件都会用你选择的默认程序打开。 + +我很希望这个新手指南对你在修改 Ubuntu 的默认程序时有帮助。如果你有任何的疑问或者建议，可以随时在下面评论。 + +-------------------------------------------------------------------------------- + +via: https://itsfoss.com/change-default-applications-ubuntu/ + +作者：[Abhishek Prakash][a] +译者：[Locez](https://github.com/locez) +校对：[wxy](https://github.com/wxy) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://itsfoss.com/author/abhishek/ +[1]: http://www.videolan.org/vlc/index.html +[2]: https://linux.cn/article-7453-1.html diff --git a/published/201607/20160722 Terminix – A New GTK 3 Tiling Terminal Emulator for Linux.md b/published/201607/20160722 Terminix – A New GTK 3 Tiling Terminal Emulator for Linux.md new file mode 100644 index 0000000000..e9ec640549 --- /dev/null +++ b/published/201607/20160722 Terminix – A New GTK 3 Tiling Terminal Emulator for Linux.md @@ -0,0 +1,136 @@ +Terminix：一个很赞的基于 GTK3 的平铺式 Linux 终端模拟器 +============================================================ + +现在，你可以很容易的找到[大量的 Linux 终端模拟器][1]，每一个都可以给用户留下深刻的印象。 + +但是，很多时候，我们会很难根据我们的喜好来找到一款心仪的日常使用的终端模拟器。这篇文章中，我们将会推荐一款叫做 Terminix 的令人激动的终端模拟机。 + +![](http://www.tecmint.com/wp-content/uploads/2016/07/Terminix-Terminal-Emulator-for-Linux.png) + +*Terminix Linux 终端模拟器* + +Terminix 是一个使用 VTE GTK+ 3 组件的平铺式终端模拟器。使用 GTK 3 开发的原因主要是为了符合 GNOME HIG（人机接口 Human Interface Guidelines) 标准。另外，Terminix 已经在 GNOME 和 Unity 桌面环境下测试过了，也有用户在其他的 Linux 桌面环境下测试成功。 + +和其他的终端模拟器一样，Terminix 有着很多知名的特征，列表如下： + +- 允许用户进行任意的垂直或者水平分屏 +- 支持拖拽功能来进行重新排布终端 +- 支持使用拖拽的方式终端从窗口中将脱离出来 +- 支持终端之间的输入同步，因此，可以在一个终端输入命令，而在另一个终端同步复现 +- 终端的分组配置可以保存在硬盘，并再次加载 +- 支持透明背景 +- 允许使用背景图片 +- 基于主机和目录来自动切换配置 +- 支持进程完成的通知信息 +- 配色方案采用文件存储，同时支持自定义配色方案 + +### 如何在 Linux 系统上安装 Terminix + +现在来详细说明一下在不同的 Linux 发行版本上安装 Terminix 的步骤。首先，在此列出 Terminix 在 Linux 所需要的环境需求。 + +#### 依赖组件 + +为了正常运行，该应用需要使用如下库： + +- GTK 3.14 或者以上版本 +- GTK VTE 0.42 或者以上版本 +- Dconf +- GSettings +- Nautilus 的 iNautilus-Python 插件 + +如果你已经满足了如上的系统要求，接下来就是安装 Terminix 的步骤。 + +#### 在 RHEL/CentOS 7 或者 Fedora 22-24 上 + +首先，你需要通过新建文件 `/etc/yum.repos.d/terminix.repo` 来增加软件仓库，使用你最喜欢的文本编辑器来进行编辑： + +``` +# vi /etc/yum.repos.d/terminix.repo +``` + +然后拷贝如下的文字到我们刚新建的文件中： + +``` +[heikoada-terminix] +name=Copr repo for terminix owned by heikoada +baseurl=https://copr-be.cloud.fedoraproject.org/results/heikoada/terminix/fedora-$releasever-$basearch/ +skip_if_unavailable=True +gpgcheck=1 +gpgkey=https://copr-be.cloud.fedoraproject.org/results/heikoada/terminix/pubkey.gpg +enabled=1 +enabled_metadata=1 +``` + +保存文件并退出。 + +然后更新你的系统，并且安装 Terminix，步骤如下： + +``` +---------------- On RHEL/CentOS 7 ---------------- +# yum update +# yum install terminix + +---------------- On Fedora 22-24 ---------------- +# dnf update +# dnf install terminix +``` + +#### 在 Ubuntu 16.04-14.04 和 Linux Mint 18-17 + +虽然没有基于 Debian/Ubuntu 发行版本的官方的软件包，但是你依旧可以通过如下的命令手动安装。 + +``` +$ wget -c https://github.com/gnunn1/terminix/releases/download/1.1.1/terminix.zip +$ sudo unzip terminix.zip -d / +$ sudo glib-compile-schemas /usr/share/glib-2.0/schemas/ +``` + +#### 其它 Linux 发行版 + +OpenSUSE 用户可以从默认仓库中安装 Terminix，Arch Linux 用户也可以安装 [AUR Terminix 软件包][2]。 + +### Terminix 截图教程 + +![](http://www.tecmint.com/wp-content/uploads/2016/07/Terminix-Terminal.png) + +*Terminix 终端* + +![](http://www.tecmint.com/wp-content/uploads/2016/07/Terminix-Terminal-Settings.png) + +*Terminix 终端设置* + +![](http://www.tecmint.com/wp-content/uploads/2016/07/Terminix-Terminal-Tabs.png) + +*Terminix 多终端界面* + +### 如何卸载删除 Terminix + + +如果你是手动安装的 Terminix 并且想要删除它，那么你可以参照如下的步骤来卸载它。从 [Github 仓库][3]上下载 uninstall.sh，并且给它可执行权限并且执行它： + +``` +$ wget -c https://github.com/gnunn1/terminix/blob/master/uninstall.sh +$ chmod +x uninstall.sh +$ sudo sh uninstall.sh +``` + +但是如果你是通过包管理器安装的 Terminix，你可以使用包管理器来卸载它。 + +在这篇介绍中，我们在众多优秀的终端模拟器中发现了一个重要的 Linux 终端模拟器。你可以尝试着去体验下它的新特性，并且可以将它和你现在使用的终端进行比较。 + +重要的一点，如果你想得到更多信息或者有疑问，请使用评论区，而且不要忘了，给我一个关于你使用体验的反馈。 + +-------------------------------------------------------------------------------- + +via: http://www.tecmint.com/terminix-tiling-terminal-emulator-for-linux/ + +作者：[Aaron Kili][a] +译者：[MikeCoder](https://github.com/MikeCoder) +校对：[wxy](https://github.com/wxy) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: http://www.tecmint.com/author/aaronkili/ +[1]: http://www.tecmint.com/linux-terminal-emulators/ +[2]: https://aur.archlinux.org/packages/terminix +[3]: https://github.com/gnunn1/terminix diff --git a/published/201607/20160726 Set a Real Time Photo of Earth as Your Linux Desktop Wallpaper.md b/published/201607/20160726 Set a Real Time Photo of Earth as Your Linux Desktop Wallpaper.md new file mode 100644 index 0000000000..40ba237020 --- /dev/null +++ b/published/201607/20160726 Set a Real Time Photo of Earth as Your Linux Desktop Wallpaper.md @@ -0,0 +1,90 @@ +为你的 Linux 桌面设置一张实时的地球照片 +================================================================= + +![](http://www.omgubuntu.co.uk/wp-content/uploads/2016/07/Screen-Shot-2016-07-26-at-16.36.47-1.jpg) + +厌倦了看同样的桌面背景了么？这里有一个（可能是）世界上最棒的东西。 + +‘[Himawaripy][1]’ 是一个 Python 3 小脚本，它会抓取由[日本 Himawari 8 气象卫星][2]拍摄的接近实时的地球照片，并将它设置成你的桌面背景。 + +安装完成后，你可以将它设置成每 10 分钟运行的定时任务（自然，它要在后台运行），这样它就可以实时地取回地球的照片并设置成背景了。 + +因为 Himawari-8 是一颗同步轨道卫星，你只能看到澳大利亚上空的地球的图片——但是它实时的天气形态、云团和光线仍使它很壮丽，对我而言要是看到英国上方的就更好了！ + +高级设置允许你配置从卫星取回的图片质量，但是要记住增加图片质量会增加文件大小及更长的下载等待！ + +最后，虽然这个脚本与其他我们提到过的其他脚本类似，它还仍保持更新及可用。 + +###获取 Himawaripy + +Himawaripy 已经在一系列的桌面环境中都测试过了，包括 Unity、LXDE、i3、MATE 和其他桌面环境。它是自由开源软件，但是整体来说安装及配置不太简单。 + +在该项目的 [Github 主页][0]上可以找到安装和设置该应用程序的所有指导（提示：没有一键安装功能）。 + +- [实时地球壁纸脚本的 GitHub 主页][0] + +### 安装及使用 + +![](http://www.omgubuntu.co.uk/wp-content/uploads/2016/07/Screen-Shot-2016-07-26-at-16.46.13-750x143.png) + +一些读者请我在本文中补充一下一步步安装该应用的步骤。以下所有步骤都在其 GitHub 主页上，这里再贴一遍。 + +1、下载及解压 Himawaripy + +这是最容易的步骤。点击下面的下载链接，然后下载最新版本，并解压到你的下载目录里面。 + + - [下载 Himawaripy 主干文件（.zip 格式）][3] + +2、安装 python3-setuptools + +你需要手工来安装主干软件包，Ubuntu 里面默认没有安装它： + +``` +sudo apt install python3-setuptools +``` + +3、安装 Himawaripy + +在终端中，你需要切换到之前解压的目录中，并运行如下安装命令： + +``` +cd ~/Downloads/himawaripy-master +sudo python3 setup.py install +``` + +4、 看看它是否可以运行并下载最新的实时图片： +``` +himawaripy +``` +5、 设置定时任务 + +如果你希望该脚本可以在后台自动运行并更新（如果你需要手动更新，只需要运行 ‘himarwaripy’ 即可） + +在终端中运行： +``` +crontab -e +``` +在其中新加一行（默认每10分钟运行一次） +``` +*/10 * * * * /usr/local/bin/himawaripy +``` +关于[配置定时任务][4]可以在 Ubuntu Wiki 上找到更多信息。 + +该脚本安装后你不需要不断运行它，它会自动的每十分钟在后台运行一次。 + +-------------------------------------------------------------------------------- + +via: http://www.omgubuntu.co.uk/2016/07/set-real-time-earth-wallpaper-ubuntu-desktop + +作者：[JOEY-ELIJAH SNEDDON][a] +译者：[geekpi](https://github.com/geekpi) +校对：[wxy](https://github.com/wxy) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://plus.google.com/117485690627814051450/?rel=author +[1]: https://github.com/boramalper/himawaripy +[2]: https://en.wikipedia.org/wiki/Himawari_8 +[0]: https://github.com/boramalper/himawaripy +[3]: https://github.com/boramalper/himawaripy/archive/master.zip +[4]: https://help.ubuntu.com/community/CronHowto \ No newline at end of file diff --git a/published/20160705 How to Encrypt a Flash Drive Using VeraCrypt.md b/published/20160705 How to Encrypt a Flash Drive Using VeraCrypt.md new file mode 100644 index 0000000000..71a2e01a24 --- /dev/null +++ b/published/20160705 How to Encrypt a Flash Drive Using VeraCrypt.md @@ -0,0 +1,100 @@ +用 VeraCrypt 加密闪存盘 +============================================ + +很多安全专家偏好像 VeraCrypt 这类能够用来加密闪存盘的开源软件，是因为可以获取到它的源代码。 + +保护 USB 闪存盘里的数据，加密是一个聪明的方法，正如我们在使用 Microsoft 的 BitLocker [加密闪存盘][1] 一文中提到的。 + +但是如果你不想用 BitLocker 呢？ + +你可能有顾虑，因为你不能够查看 Microsoft 的程序源码，那么它容易被植入用于政府或其它用途的“后门”。而由于开源软件的源码是公开的，很多安全专家认为开源软件很少藏有后门。 + +还好，有几个开源加密软件能作为 BitLocker 的替代。 + +要是你需要在 Windows 系统，苹果的 OS X 系统或者 Linux 系统上加密以及访问文件，开源软件 [VeraCrypt][2] 提供绝佳的选择。 + +VeraCrypt 源于 TrueCrypt。TrueCrypt 是一个备受好评的开源加密软件，尽管它现在已经停止维护了。但是 TrueCrypt 的代码通过了审核，没有发现什么重要的安全漏洞。另外，在 VeraCrypt 中对它进行了改善。 + +Windows，OS X 和 Linux 系统的版本都有。 + +用 VeraCrypt 加密 USB 闪存盘不像用 BitLocker 那么简单，但是它也只要几分钟就好了。 + +### 用 VeraCrypt 加密闪存盘的 8 个步骤 + +对应你的操作系统 [下载 VeraCrypt][3] 之后： + +打开 VeraCrypt，点击 Create Volume，进入 VeraCrypt 的创建卷的向导程序（VeraCrypt Volume Creation Wizard）。 + +![](http://www.esecurityplanet.com/imagesvr_ce/6246/Vera0.jpg) + +VeraCrypt 创建卷向导（VeraCrypt Volume Creation Wizard）允许你在闪存盘里新建一个加密文件容器，这与其它未加密文件是独立的。或者你也可以选择加密整个闪存盘。这个时候你就选加密整个闪存盘就行。 + +![](http://www.esecurityplanet.com/imagesvr_ce/6703/Vera1.jpg) + +然后选择标准模式（Standard VeraCrypt Volume）。 + +![](http://www.esecurityplanet.com/imagesvr_ce/835/Vera2.jpg) + +选择你想加密的闪存盘的驱动器卷标（这里是 O：）。 + +![](http://www.esecurityplanet.com/imagesvr_ce/9427/Vera3.jpg) + +选择创建卷模式（Volume Creation Mode）。如果你的闪存盘是空的，或者你想要删除它里面的所有东西，选第一个。要么你想保持所有现存的文件，选第二个就好了。 + +![](http://www.esecurityplanet.com/imagesvr_ce/7828/Vera4.jpg) + +这一步允许你选择加密选项。要是你不确定选哪个，就用默认的 AES 和 SHA-512 设置。 + +![](http://www.esecurityplanet.com/imagesvr_ce/5918/Vera5.jpg) + +确定了卷容量后，输入并确认你想要用来加密数据密码。 + +![](http://www.esecurityplanet.com/imagesvr_ce/3850/Vera6.jpg) + +要有效工作，VeraCrypt 要从一个熵或者“随机数”池中取出一个随机数。要初始化这个池，你将被要求随机地移动鼠标一分钟。一旦进度条变绿了，或者更方便的是等到进度条到了屏幕右边足够远的时候，点击 “Format” 来结束创建加密盘。 + +![](http://www.esecurityplanet.com/imagesvr_ce/7468/Vera8.jpg) + +### 用 VeraCrypt 使用加密过的闪存盘 + +当你想要使用一个加密了的闪存盘，先插入闪存盘到电脑上，启动 VeraCrypt。 + +然后选择一个没有用过的卷标（比如 z:），点击自动挂载设备（Auto-Mount Devices）。 + +![](http://www.esecurityplanet.com/imagesvr_ce/2016/Vera10.jpg) + +输入密码，点击确定。 + +![](http://www.esecurityplanet.com/imagesvr_ce/8222/Vera11.jpg) + +挂载过程需要几分钟，这之后你的解密盘就能通过你先前选择的盘符进行访问了。 + +### VeraCrypt 移动硬盘安装步骤 + +如果你设置闪存盘的时候，选择的是加密过的容器而不是加密整个盘，你可以选择创建 VeraCrypt 称为移动盘（Traveler Disk）的设备。这会复制安装一个 VeraCrypt 到 USB 闪存盘。当你在别的 Windows 电脑上插入 U 盘时，就能从 U 盘自动运行 VeraCrypt；也就是说没必要在新电脑上安装 VeraCrypt。 + +你可以设置闪存盘作为一个移动硬盘（Traveler Disk），在 VeraCrypt 的工具栏（Tools）菜单里选择 Traveler Disk SetUp 就行了。 + +![](http://www.esecurityplanet.com/imagesvr_ce/5812/Vera12.jpg) + +要从移动盘（Traveler Disk）上运行 VeraCrypt，你必须要有那台电脑的管理员权限，这不足为奇。尽管这看起来是个限制，机密文件无法在不受控制的电脑上安全打开，比如在一个商务中心的电脑上。 + +> 本文作者 Paul Rubens 从事技术行业已经超过 20 年。这期间他为英国和国际主要的出版社，包括 《The Economist》《The Times》《Financial Times》《The BBC》《Computing》和《ServerWatch》等出版社写过文章， + +-------------------------------------------------------------------------------- + +via: http://www.esecurityplanet.com/open-source-security/how-to-encrypt-flash-drive-using-veracrypt.html + +作者：[Paul Rubens][a] +译者：[GitFuture](https://github.com/GitFuture) +校对：[wxy](https://github.com/wxy) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: http://www.esecurityplanet.com/author/3700/Paul-Rubens +[1]: http://www.esecurityplanet.com/views/article.php/3880616/How-to-Encrypt-a-USB-Flash-Drive.htm +[2]: http://www.esecurityplanet.com/open-source-security/veracrypt-a-worthy-truecrypt-alternative.html +[3]: https://veracrypt.codeplex.com/releases/view/619351 + + + diff --git a/published/20160706 What is Git.md b/published/20160706 What is Git.md new file mode 100644 index 0000000000..f0fa7dded8 --- /dev/null +++ b/published/20160706 What is Git.md @@ -0,0 +1,118 @@ +Git 系列（一）：什么是 Git +=========== + +欢迎阅读本系列关于如何使用 Git 版本控制系统的教程！通过本文的介绍，你将会了解到 Git 的用途及谁该使用 Git。 + +如果你刚步入开源的世界，你很有可能会遇到一些在 Git 上托管代码或者发布使用版本的开源软件。事实上，不管你知道与否，你都在使用基于 Git 进行版本管理的软件：Linux 内核（就算你没有在手机或者电脑上使用 Linux，你正在访问的网站也是运行在 Linux 系统上的），Firefox、Chrome 等其他很多项目都通过 Git 代码库和世界各地开发者共享他们的代码。 + +换个角度来说，你是否仅仅通过 Git 就可以和其他人共享你的代码？你是否可以在家里或者企业里私有化的使用 Git？你必须要通过一个 GitHub 账号来使用 Git 吗？为什么要使用 Git 呢？Git 的优势又是什么？Git 是我唯一的选择吗？这对 Git 所有的疑问都会把我们搞的一脑浆糊。 + +因此，忘记你以前所知的 Git，让我们重新走进 Git 世界的大门。 + +### 什么是版本控制系统？ + +Git 首先是一个版本控制系统。现在市面上有很多不同的版本控制系统：CVS、SVN、Mercurial、Fossil 当然还有 Git。 + +很多像 GitHub 和 GitLab 这样的服务是以 Git 为基础的，但是你也可以只使用 Git 而无需使用其他额外的服务。这意味着你可以以私有或者公有的方式来使用 Git。 + +如果你曾经和其他人有过任何电子文件方面的合作，你就会知道传统版本管理的工作流程。开始是很简单的：你有一个原始的版本，你把这个版本发送给你的同事，他们在接收到的版本上做了些修改，现在你们有两个版本了，然后他们把他们手上修改过的版本发回来给你。你把他们的修改合并到你手上的版本中，现在两个版本又合并成一个最新的版本了。 + +然后，你修改了你手上最新的版本，同时，你的同事也修改了他们手上合并前的版本。现在你们有 3 个不同的版本了，分别是合并后最新的版本，你修改后的版本，你同事手上继续修改过的版本。至此，你们的版本管理工作开始变得越来越混乱了。 + +正如 Jason van Gumster 在他的文章中指出 [即使是艺术家也需要版本控制][1]，而且已经在个别人那里发现了这种趋势变化。无论是艺术家还是科学家，开发一个某种实验版本是并不鲜见的；在你的项目中，可能有某个版本大获成功，把项目推向一个新的高度，也可能有某个版本惨遭失败。因此，最终你不可避免的会创建出一堆名为project\_justTesting.kdenlive、project\_betterVersion.kdenlive、project\_best\_FINAL.kdenlive、project\_FINAL-alternateVersion.kdenlive 等类似名称的文件。 + +不管你是修改一个 for 循环，还是一些简单的文本编辑，一个好的版本控制系统都会让我们的生活更加的轻松。 + +### Git 快照 + +Git 可以为项目创建快照，并且存储这些快照为唯一的版本。 + +如果你将项目带领到了一个错误的方向上，你可以回退到上一个正确的版本，并且开始尝试另一个可行的方向。 + +如果你是和别人合作开发，当有人向你发送他们的修改时，你可以将这些修改合并到你的工作分支中，然后你的同事就可以获取到合并后的最新版本，并在此基础上继续工作。 + +Git 并不是魔法，因此冲突还是会发生的（“你修改了某文件的最后一行，但是我把这行整行都删除了；我们怎样处理这些冲突呢？”），但是总体而言，Git 会为你保留了所有更改的历史版本，甚至允许并行版本。这为你保留了以任何方式处理冲突的能力。 + +### 分布式 Git + +在不同的机器上为同一个项目工作是一件复杂的事情。因为在你开始工作时，你想要获得项目的最新版本，然后此基础上进行修改，最后向你的同事共享这些改动。传统的方法是通过笨重的在线文件共享服务或者老旧的电邮附件，但是这两种方式都是效率低下且容易出错。 + +Git 天生是为分布式工作设计的。如果你要参与到某个项目中，你可以克隆（clone）该项目的 Git 仓库，然后就像这个项目只有你本地一个版本一样对项目进行修改。最后使用一些简单的命令你就可以拉取（pull）其他开发者的修改，或者你可以把你的修改推送（push）给别人。现在不用担心谁手上的是最新的版本，或者谁的版本又存放在哪里等这些问题了。全部人都是在本地进行开发，然后向共同的目标推送或者拉取更新。（或者不是共同的目标，这取决于项目的开发方式）。 + +### Git 界面 + +最原始的 Git 是运行在 Linux 终端上的应用软件。然而，得益于 Git 是开源的，并且拥有良好的设计，世界各地的开发者都可以为 Git 设计不同的访问界面。 + +Git 完全是免费的，并且已经打包在 Linux，BSD，Illumos 和其他类 Unix 系统中，Git 命令看起来像这样： + +``` +$ git --version +git version 2.5.3 +``` + +可能最著名的 Git 访问界面是基于网页的，像 GitHub、开源的 GitLab、Savannah、BitBucket 和 SourceForge 这些网站都是基于网页端的 Git 界面。这些站点为面向公众和面向社会的开源软件提供了最大限度的代码托管服务。在一定程度上，基于浏览器的图形界面（GUI）可以尽量的减缓 Git 的学习曲线。下面的 GitLab 界面的截图： + +![](https://opensource.com/sites/default/files/0_gitlab.png) + +再者，第三方 Git 服务提供商或者独立开发者甚至可以在 Git 的基础上开发出不是基于 HTML 的定制化前端界面。此类界面让你可以不用打开浏览器就可以方便的使用 Git 进行版本管理。其中对用户最透明的方式是直接集成到文件管理器中。KDE 文件管理器 Dolphin 可以直接在目录中显示 Git 状态，甚至支持提交，推送和拉取更新操作。 + +![](https://opensource.com/sites/default/files/0_dolphin.jpg) + +[Sparkleshare][2] 使用 Git 作为其 Dropbox 式的文件共享界面的基础。 + +![](https://opensource.com/sites/default/files/0_sparkleshare_1.jpg) + +想了解更多的内容，可以查看 [Git wiki][3]，这个（长长的）页面中展示了很多 Git 的图形界面项目。 + +### 谁应该使用 Git？ + +就是你！我们更应该关心的问题是什么时候使用 Git？和用 Git 来干嘛？ + +### 我应该在什么时候使用 Git 呢？我要用 Git 来干嘛呢？ + +想更深入的学习 Git，我们必须比平常考虑更多关于文件格式的问题。 + +Git 是为了管理源代码而设计的，在大多数编程语言中，源代码就意味者一行行的文本。当然，Git 并不知道你把这些文本当成是源代码还是下一部伟大的美式小说。因此，只要文件内容是以文本构成的，使用 Git 来跟踪和管理其版本就是一个很好的选择了。 + +但是什么是文本呢？如果你在像 Libre Office 这类办公软件中编辑一些内容，通常并不会产生纯文本内容。因为通常复杂的应用软件都会对原始的文本内容进行一层封装，就如把原始文本内容用 XML 标记语言包装起来，然后封装在 Zip 包中。这种对原始文本内容进行一层封装的做法可以保证当你把文件发送给其他人时，他们可以看到你在办公软件中编辑的内容及特定的文本效果。奇怪的是，虽然，通常你的需求可能会很复杂，就像保存 [Kdenlive][4] 项目文件，或者保存从 [Inkscape][5] 导出的SVG文件，但是，事实上使用 Git 管理像 XML 文本这样的纯文本类容是最简单的。 + +如果你在使用 Unix 系统，你可以使用 `file` 命令来查看文件内容构成： + +``` +$ file ~/path/to/my-file.blah +my-file.blah: ASCII text +$ file ~/path/to/different-file.kra: Zip data (MIME type "application/x-krita") +``` + +如果还是不确定，你可以使用 `head` 命令来查看文件内容： + +``` +$ head ~/path/to/my-file.blah +``` + +如果输出的文本你基本能看懂，这个文件就很有可能是文本文件。如果你仅仅在一堆乱码中偶尔看到几个熟悉的字符，那么这个文件就可能不是文本文件了。 + +准确的说：Git 可以管理其他格式的文件，但是它会把这些文件当成二进制大对象（blob）。两者的区别是，在文本文件中，Git 可以明确的告诉你在这两个快照（或者说提交）间有 3 行是修改过的。但是如果你在两个提交（commit）之间对一张图片进行的编辑操作，Git 会怎么指出这种修改呢？实际上，因为图片并不是以某种可以增加或删除的有意义的文本构成，因此 Git 并不能明确的描述这种变化。当然我个人是非常希望图片的编辑可以像把文本“\丑陋的蓝绿色\”修改成“\漂浮着蓬松白云的天蓝色\”一样的简单，但是事实上图片的编辑并没有这么简单。 + +经常有人在 Git 上放入 png 图标、电子表格或者流程图这类二进制大型对象（blob）。尽管，我们知道在 Git 上管理此类大型文件并不直观，但是，如果你需要使用 Git 来管理此类文件，你也并不需要过多的担心。如果你参与的项目同时生成文本文件和二进制大文件对象（如视频游戏中常见的场景，这些和源代码同样重要的图像和音频材料），那么你有两条路可以走：要么开发出你自己的解决方案，就如使用指向共享网络驱动器的引用；要么使用 Git 插件，如 Joey Hess 开发的 [git annex][6]，以及 [Git-Media][7] 项目。 + +你看，Git 真的是一个任何人都可以使用的工具。它是你进行文件版本管理的一个强大而且好用工具，同时它并没有你开始认为的那么可怕。 + +-------------------------------------------------------------------------------- + +via: https://opensource.com/resources/what-is-git + +作者：[Seth Kenlon][a] +译者：[cvsher](https://github.com/cvsher) +校对：[wxy](https://github.com/wxy) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://opensource.com/users/seth +[1]: https://opensource.com/life/16/2/version-control-isnt-just-programmers +[2]: http://sparkleshare.org/ +[3]: https://git.wiki.kernel.org/index.php/InterfacesFrontendsAndTools#Graphical_Interfaces +[4]: https://opensource.com/life/11/11/introduction-kdenlive +[5]: http://inkscape.org/ +[6]: https://git-annex.branchable.com/ +[7]: https://github.com/alebedev/git-media diff --git a/published/20160711 Getting started with Git.md b/published/20160711 Getting started with Git.md new file mode 100644 index 0000000000..a490e59e2d --- /dev/null +++ b/published/20160711 Getting started with Git.md @@ -0,0 +1,141 @@ +初步了解 Git +========================= + +![](https://opensource.com/sites/default/files/styles/image-full-size/public/images/life/get_started_lead.jpeg?itok=r22AKc6P) + +*图片来源：opensource.com* + +在这个系列的[介绍篇][4]中，我们学习到了谁应该使用 Git，以及 Git 是用来做什么的。今天，我们将学习如何克隆公共 Git 仓库，以及如何提取出独立的文件而不用克隆整个仓库。 + +由于 Git 如此流行，因而如果你能够至少熟悉一些基础的 Git 知识也能为你的生活带来很多便捷。如果你可以掌握 Git 基础（你可以的，我发誓！），那么你将能够下载任何你需要的东西，甚至还可能做一些贡献作为回馈。毕竟，那就是开源的精髓所在：你拥有获取你使用的软件代码的权利，拥有和他人分享的自由，以及只要你愿意就可以修改它的权利。只要你熟悉了 Git，它就可以让这一切都变得很容易。 + +那么，让我们一起来熟悉 Git 吧。 + +### 读和写 + +一般来说，有两种方法可以和 Git 仓库交互：你可以从仓库中读取，或者你也能够向仓库中写入。它就像一个文件：有时候你打开一个文档只是为了阅读它，而其它时候你打开文档是因为你需要做些改动。 + +本文仅讲解如何从 Git 仓库读取。我们将会在后面的一篇文章中讲解如何向 Git 仓库写回的主题。 + +### Git 还是 GitHub？ + +一句话澄清：Git 不同于 GitHub（或 GitLab，或 Bitbucket）。Git 是一个命令行程序，所以它就像下面这样： + +``` +$ git +usage: Git [--version] [--help] [-C ] + [-p | --paginate | --no-pager] [--bare] + [--Git-dir=] [] + +``` + +由于 Git 是开源的，所以就有许多聪明人围绕它构建了基础软件；这些基础软件，包括在他们自己身边，都已经变得非常流行了。 + +我的文章系列将首先教你纯粹的 Git 知识，因为一旦你理解了 Git 在做什么，那么你就无需关心正在使用的前端工具是什么了。然而，我的文章系列也将涵盖通过流行的 Git 服务完成每项任务的常用方法，因为那些将可能是你首先会遇到的。 + +### 安装 Git + +在 Linux 系统上，你可以从所使用的发行版软件仓库中获取并安装 Git。BSD 用户应当在 Ports 树的 devel 部分查找 Git。 + +对于闭源的操作系统，请前往其[项目官网][1]，并根据说明安装。一旦安装后，在 Linux、BSD 和 Mac OS X 上的命令应当没有任何差别。Windows 用户需要调整 Git 命令，从而和 Windows 文件系统相匹配，或者安装 Cygwin 以原生的方式运行 Git，而不受 Windows 文件系统转换问题的羁绊。 + +### Git 下午茶 + +并非每个人都需要立刻将 Git 加入到我们的日常生活中。有些时候，你和 Git 最多的交互就是访问一个代码库，下载一两个文件，然后就不用它了。以这样的方式看待 Git，它更像是下午茶而非一次正式的宴会。你进行一些礼节性的交谈，获得了需要的信息，然后你就会离开，至少接下来的三个月你不再想这样说话。 + +当然，那是可以的。 + +一般来说，有两种方法访问 Git：使用命令行，或者使用一种神奇的因特网技术通过 web 浏览器快速轻松地访问。 + +假设你想要给终端安装一个回收站，因为你已经被 rm 命令毁掉太多次了。你可能听说过 Trashy ，它称自己为「理智的 rm 命令中间人」，也许你想在安装它之前阅读它的文档。幸运的是，[Trashy 公开地托管在 GitLab.com][2]。 + +### Landgrab + +我们工作的第一步是对这个 Git 仓库使用 landgrab 排序方法：我们会克隆这个完整的仓库，然后会根据内容排序。由于该仓库是托管在公共的 Git 服务平台上，所以有两种方式来完成工作：使用命令行，或者使用 web 界面。 + +要想使用 Git 获取整个仓库，就要使用 git clone 命令和 Git 仓库的 URL 作为参数。如果你不清楚正确的 URL 是什么，仓库应该会告诉你的。GitLab 为你提供了 [Trashy][3] 仓库的用于拷贝粘贴的 URL。 + +![](https://opensource.com/sites/default/files/1_gitlab-url.jpg) + +你也许注意到了，在某些服务平台上，会同时提供 SSH 和 HTTPS 链接。只有当你拥有仓库的写权限时，你才可以使用 SSH。否则的话，你必须使用 HTTPS URL。 + +一旦你获得了正确的 URL，克隆仓库是非常容易的。就是 git clone 该 URL 即可，以及一个可选的指定要克隆到的目录。默认情况下会将 git 目录克隆到你当前所在的目录；例如，'trashy.git' 将会克隆到你当前位置的 'trashy' 目录。我使用 .clone 扩展名标记那些只读的仓库，而使用 .git 扩展名标记那些我可以读写的仓库，不过这并不是官方要求的。 + +``` +$ git clone https://gitlab.com/trashy/trashy.git trashy.clone +Cloning into 'trashy.clone'... +remote: Counting objects: 142, done. +remote: Compressing objects: 100% (91/91), done. +remote: Total 142 (delta 70), reused 103 (delta 47) +Receiving objects: 100% (142/142), 25.99 KiB | 0 bytes/s, done. +Resolving deltas: 100% (70/70), done. +Checking connectivity... done. +``` + +一旦成功地克隆了仓库，你就可以像对待你电脑上任何其它目录那样浏览仓库中的文件。 + +另外一种获得仓库拷贝的方式是使用 web 界面。GitLab 和 GitHub 都会提供一个 .zip 格式的仓库快照文件。GitHub 有一个大大的绿色下载按钮，但是在 GitLab 中，可以在浏览器的右侧找到并不显眼的下载按钮。 + +![](https://opensource.com/sites/default/files/1_gitlab-zip.jpg) + +### 仔细挑选 + +另外一种从 Git 仓库中获取文件的方法是找到你想要的文件，然后把它从仓库中拽出来。只有 web 界面才提供这种方法，本质上来说，你看到的是别人的仓库克隆；你可以把它想象成一个 HTTP 共享目录。 + +使用这种方法的问题是，你也许会发现某些文件并不存在于原始仓库中，因为完整形式的文件可能只有在执行 make 命令后才能构建，那只有你下载了完整的仓库，阅读了 README 或者 INSTALL 文件，然后运行相关命令之后才会产生。不过，假如你确信文件存在，而你只想进入仓库，获取那个文件，然后离开的话，你就可以那样做。 + +在 GitLab 和 GitHub 中，单击文件链接，并在 Raw 模式下查看，然后使用你的 web 浏览器的保存功能，例如：在 Firefox 中，“文件” \> “保存页面为”。在一个 GitWeb 仓库中（这是一个某些更喜欢自己托管 git 的人使用的私有 git 仓库 web 查看器），Raw 查看链接在文件列表视图中。 + +![](https://opensource.com/sites/default/files/1_webgit-file.jpg) + +### 最佳实践 + +通常认为，和 Git 交互的正确方式是克隆完整的 Git 仓库。这样认为是有几个原因的。首先，可以使用 git pull 命令轻松地使克隆仓库保持更新，这样你就不必在每次文件改变时就重回 web 站点获得一份全新的拷贝。第二，你碰巧需要做些改进，只要保持仓库整洁，那么你可以非常轻松地向原来的作者提交所做的变更。 + +现在，可能是时候练习查找感兴趣的 Git 仓库，然后将它们克隆到你的硬盘中了。只要你了解使用终端的基础知识，那就不会太难做到。还不知道基本的终端使用方式吗？那再给多我 5 分钟时间吧。 + +### 终端使用基础 + +首先要知道的是，所有的文件都有一个路径。这是有道理的；如果我让你在常规的非终端环境下为我打开一个文件，你就要导航到文件在你硬盘的位置，并且直到你找到那个文件，你要浏览一大堆窗口。例如，你也许要点击你的家目录 > 图片 > InktoberSketches > monkey.kra。 + +在那样的场景下，文件 monkeysketch.kra 的路径是：$HOME/图片/InktoberSketches/monkey.kra。 + +在终端中，除非你正在处理一些特殊的系统管理员任务，你的文件路径通常是以 $HOME 开头的（或者，如果你很懒，就使用 ~ 字符），后面紧跟着一些列的文件夹直到文件名自身。 + +这就和你在 GUI 中点击各种图标直到找到相关的文件或文件夹类似。 + +如果你想把 Git 仓库克隆到你的文档目录，那么你可以打开一个终端然后运行下面的命令： + +``` +$ git clone https://gitlab.com/foo/bar.git +$HOME/文档/bar.clone +``` + +一旦克隆完成，你可以打开一个文件管理器窗口，导航到你的文档文件夹，然后你就会发现 bar.clone 目录正在等待着你访问。 + +如果你想要更高级点，你或许会在以后再次访问那个仓库，可以尝试使用 git pull 命令来查看项目有没有更新： + +``` +$ cd $HOME/文档/bar.clone +$ pwd +bar.clone +$ git pull +``` + +到目前为止，你需要初步了解的所有终端命令就是那些了，那就去探索吧。你实践得越多，Git 掌握得就越好（熟能生巧），这是重点，也是事情的本质。 + +-------------------------------------------------------------------------------- + +via: https://opensource.com/life/16/7/stumbling-git + +作者：[Seth Kenlon][a] +译者：[ChrisLeeGit](https://github.com/chrisleegit) +校对：[wxy](https://github.com/wxy) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创翻译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://opensource.com/users/seth +[1]: https://git-scm.com/download +[2]: https://gitlab.com/trashy/trashy +[3]: https://gitlab.com/trashy/trashy.git +[4]: https://linux.cn/article-7639-1.html diff --git a/published/20160718 Creating your first Git repository.md b/published/20160718 Creating your first Git repository.md new file mode 100644 index 0000000000..d1a8ca2840 --- /dev/null +++ b/published/20160718 Creating your first Git repository.md @@ -0,0 +1,176 @@ +Git 系列（三）：建立你的第一个 Git 仓库 +====================================== + +![](https://opensource.com/sites/default/files/styles/image-full-size/public/images/life/open_abstract_pieces.jpg?itok=ZRt0Db00) + +现在是时候学习怎样创建你自己的 Git 仓库了，还有怎样增加文件和完成提交。 + +在本系列[前面的文章][4]中，你已经学习了怎样作为一个最终用户与 Git 进行交互；你就像一个漫无目的的流浪者一样偶然发现了一个开源项目网站，克隆了仓库，然后你就可以继续钻研它了。你知道了和 Git 进行交互并不像你想的那样困难，或许你只是需要被说服现在去使用 Git 完成你的工作罢了。 + +虽然 Git 确实是被许多重要软件选作版本控制工具，但是并不是仅能用于这些重要软件；它也能管理你购物清单（如果它们对你来说很重要的话，当然可以了！）、你的配置文件、周报或日记、项目进展日志、甚至源代码！ + +使用 Git 是很有必要的，毕竟，你肯定有过因为一个备份文件不能够辨认出版本信息而抓狂的时候。 + +Git 无法帮助你，除非你开始使用它，而现在就是开始学习和使用它的最好时机。或者，用 Git 的话来说，“没有其他的 `push` 能像 `origin HEAD` 一样有帮助了”（千里之行始于足下的意思）。我保证，你很快就会理解这一点的。 + +### 类比于录音 + +我们经常用名词“快照”来指代计算机上的镜像，因为很多人都能够对插满了不同时光的照片的相册充满了感受。这很有用，不过，我认为 Git 更像是进行一场录音。 + +也许你不太熟悉传统的录音棚卡座式录音机，它包括几个部件：一个可以正转或反转的转轴、保存声音波形的磁带，可以通过拾音头在磁带上记录声音波形，或者检测到磁带上的声音波形并播放给听众。 + +除了往前播放磁带，你也可以把磁带倒回到之前的部分，或快进跳过后面的部分。 + +想象一下上世纪 70 年代乐队录制磁带的情形。你可以想象到他们一遍遍地练习歌曲，直到所有部分都非常完美，然后记录到音轨上。起初，你会录下鼓声，然后是低音，再然后是吉他声，最后是主唱。每次你录音时，录音棚工作人员都会把磁带倒带，然后进入循环模式，这样它就会播放你之前录制的部分。比如说如果你正在录制低音，你就会在背景音乐里听到鼓声，就像你自己在击鼓一样，然后吉他手在录制时会听到鼓声、低音（和牛铃声）等等。在每个循环中，你都会录制一部分，在接下来的循环中，工作人员就会按下录音按钮将其合并记录到磁带中。 + +你也可以拷贝或换下整个磁带，如果你要对你的作品重新混音的话。 + +现在我希望对于上述的上世纪 70 年代的录音工作的描述足够生动，这样我们就可以把 Git 的工作想象成一个录音工作了。 + +### 新建一个 Git 仓库 + +首先得为我们的虚拟的录音机买一些磁带。用 Git 的话说，这些磁带就是*仓库*；它是完成所有工作的基础，也就是说这里是存放 Git 文件的地方（即 Git 工作区）。 + +任何目录都可以成为一个 Git 仓库，但是让我们从一个新目录开始。这需要下面三个命令： + +- 创建目录（如果你喜欢的话，你可以在你的图形化的文件管理器里面完成。） +- 在终端里切换到目录。 +- 将其初始化成一个 Git 管理的目录。 + +也就是运行如下代码： + +``` +$ mkdir ~/jupiter # 创建目录 +$ cd ~/jupiter # 进入目录 +$ git init . # 初始化你的新 Git 工作区 +``` + +在这个例子中，文件夹 jupiter 是一个空的但是合法的 Git 仓库。 + +有了仓库接下来的事情就可以按部就班进行了。你可以克隆该仓库，你可以在一个历史点前后来回穿梭（前提是你有一个历史点），创建交替的时间线，以及做 Git 能做的其它任何事情。 + +在 Git 仓库里面工作和在任何目录里面工作都是一样的，可以在仓库中新建文件、复制文件、保存文件。你可以像平常一样做各种事情；Git 并不复杂，除非你把它想复杂了。 + +在本地的 Git 仓库中，一个文件可以有以下这三种状态： + +- 未跟踪文件（Untracked）：你在仓库里新建了一个文件，但是你没有把文件加入到 Git 的管理之中。 +- 已跟踪文件（Tracked）：已经加入到 Git 管理的文件。 +- 暂存区文件（Staged）：被修改了的已跟踪文件，并加入到 Git 的提交队列中。 + +任何你新加入到 Git 仓库中的文件都是未跟踪文件。这些文件保存在你的电脑硬盘上，但是你没有告诉 Git 这是需要管理的文件，用我们的录音机来类比，就是录音机还没打开；乐队就开始在录音棚里忙碌了，但是录音机并没有准备录音。 + +不用担心，Git 会在出现这种情况时告诉你： + +``` +$ echo "hello world" > foo +$ git status +On branch master +Untracked files: +(use "git add ..." to include in what will be committed) + foo +nothing added but untracked files present (use "git add" to track) +``` + +你看到了，Git 会提醒你怎样把文件加入到提交任务中。 + +### 不使用 Git 命令进行 Git 操作 + +在 GitHub 或 GitLab 上创建一个仓库只需要用鼠标点几下即可。这并不难，你单击“New Repository”这个按钮然后跟着提示做就可以了。 + +在仓库中包括一个“README”文件是一个好习惯，这样人们在浏览你的仓库的时候就可以知道你的仓库是干什么的，更有用的是可以让你在克隆一个有东西的仓库前知道它有些什么。 + +克隆仓库通常很简单，但是在 GitHub 上获取仓库改动权限就稍微复杂一些，为了通过 GitHub 验证你必须有一个 SSH 密钥。如果你使用 Linux 系统，可以通过下面的命令生成： + +``` +$ ssh-keygen +``` + +然后复制你的新密钥的内容，它是纯文本文件，你可以使用一个文本编辑器打开它，也可以使用如下 cat 命令查看： + +``` +$ cat ~/.ssh/id_rsa.pub +``` + +现在把你的密钥粘贴到 [GitHub SSH 配置文件][1] 中，或者 [GitLab 配置文件][2]。 + +如果你通过使用 SSH 模式克隆了你的项目，你就可以将修改写回到你的仓库了。 + +另外，如果你的系统上没有安装 Git 的话也可以使用 GitHub 的文件上传接口来添加文件。 + +![](https://opensource.com/sites/default/files/2_githubupload.jpg) + +### 跟踪文件 + +正如命令 `git status` 的输出告诉你的那样，如果你想让 git 跟踪一个文件，你必须使用命令 `git add` 把它加入到提交任务中。这个命令把文件存在了暂存区，这里存放的都是等待提交的文件，或者也可以用在快照中。在将文件包括到快照中，和添加要 Git 管理的新的或临时文件时，`git add` 命令的目的是不同的，不过至少现在，你不用为它们之间的不同之处而费神。 + +类比录音机，这个动作就像打开录音机开始准备录音一样。你可以想象为对已经在录音的录音机按下暂停按钮，或者倒回开头等着记录下个音轨。 + +当你把文件添加到 Git 管理中，它会标识其为已跟踪文件： + +``` +$ git add foo +$ git status +On branch master +Changes to be committed: +(use "git reset HEAD ..." to unstage) +new file: foo +``` + +加入文件到提交任务中并不是“准备录音”。这仅仅是将该文件置于准备录音的状态。在你添加文件后，你仍然可以修改该文件；它只是被标记为**已跟踪**和**处于暂存区**，所以在它被写到“磁带”前你可以将它撤出或修改它（当然你也可以再次将它加入来做些修改）。但是请注意：你还没有在磁带中记录该文件，所以如果弄坏了一个之前还是好的文件，你是没有办法恢复的，因为你没有在“磁带”中记下那个文件还是好着的时刻。 + +如果你最后决定不把文件记录到 Git 历史列表中，那么你可以撤销提交任务，在 Git 中是这样做的： + +``` +$ git reset HEAD foo +``` + +这实际上就是解除了录音机的准备录音状态，你只是在录音棚中转了一圈而已。 + +### 大型提交 + +有时候，你想要提交一些内容到仓库；我们以录音机类比，这就好比按下录音键然后记录到磁带中一样。 + +在一个项目所经历的不同阶段中，你会按下这个“记录键”无数次。比如，如果你尝试了一个新的 Python 工具包并且最终实现了窗口呈现功能，然后你肯定要进行提交，以便你在实验新的显示选项时搞砸了可以回退到这个阶段。但是如果你在 Inkscape 中画了一些图形草样，在提交前你可能需要等到已经有了一些要开发的内容。尽管你可能提交了很多次，但是 Git 并不会浪费很多，也不会占用太多磁盘空间，所以在我看来，提交的越多越好。 + +`commit` 命令会“记录”仓库中所有的暂存区文件。Git 只“记录”已跟踪的文件，即，在过去某个时间点你使用 `git add` 命令加入到暂存区的所有文件，以及从上次提交后被改动的文件。如果之前没有过提交，那么所有跟踪的文件都包含在这次提交中，以 Git 的角度来看，这是一次非常重要的修改，因为它们从没放到仓库中变成了放进去。 + +完成一次提交需要运行下面的命令： + +``` +$ git commit -m 'My great project, first commit.' +``` + +这就保存了所有提交的文件，之后可以用于其它操作（或者，用英国电视剧《神秘博士》中时间领主所讲的 Gallifreyan 语说，它们成为了“固定的时间点” ）。这不仅是一个提交事件，也是一个你在 Git 日志中找到该提交的引用指针： + +``` +$ git log --oneline +55df4c2 My great project, first commit. +``` + +如果想浏览更多信息，只需要使用不带 `--oneline` 选项的 `git log` 命令。 + +在这个例子中提交时的引用号码是 55df4c2。它被叫做“提交哈希（commit hash）”（LCTT 译注：这是一个 SHA-1 算法生成的哈希码，用于表示一个 git 提交对象），它代表着刚才你的提交所包含的所有新改动，覆盖到了先前的记录上。如果你想要“倒回”到你的提交历史点上，就可以用这个哈希作为依据。 + +你可以把这个哈希想象成一个声音磁带上的 [SMPTE 时间码][3]，或者再形象一点，这就是好比一个黑胶唱片上两首不同的歌之间的空隙，或是一个 CD 上的音轨编号。 + +当你改动了文件之后并且把它们加入到提交任务中，最终完成提交，这就会生成新的提交哈希，它们每一个所标示的历史点都代表着你的产品不同的版本。 + +这就是 Charlie Brown 这样的音乐家们为什么用 Git 作为版本控制系统的原因。 + +在接下来的文章中，我们将会讨论关于 Git HEAD 的各个方面，我们会真正地向你揭示时间旅行的秘密。不用担心，你只需要继续读下去就行了（或许你已经在读了？）。 + +-------------------------------------------------------------------------------- + +via: https://opensource.com/life/16/7/creating-your-first-git-repository + +作者：[Seth Kenlon][a] +译者：[vim-kakali](https://github.com/vim-kakali) +校对：[wxy](https://github.com/wxy) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://opensource.com/users/seth +[1]: https://github.com/settings/keys +[2]: https://gitlab.com/profile/keys +[3]: http://slackermedia.ml/handbook/doku.php?id=timecode +[4]: https://linux.cn/article-7641-1.html diff --git a/published/20160721 5 tricks for getting started with Vim.md b/published/20160721 5 tricks for getting started with Vim.md new file mode 100644 index 0000000000..684a1d6295 --- /dev/null +++ b/published/20160721 5 tricks for getting started with Vim.md @@ -0,0 +1,60 @@ +Vim 起步的五个技巧 +===================================== + +![](https://opensource.com/sites/default/files/styles/image-full-size/public/images/education/BUSINESS_peloton.png?itok=nuMbW9d3) + +多年来，我一直想学 Vim。如今 Vim 是我最喜欢的 Linux 文本编辑器，也是开发者和系统管理者最喜爱的开源工具。我说的学习，指的是真正意义上的学习。想要精通确实很难，所以我只想要达到熟练的水平。我使用了这么多年的 Linux ，我会的也仅仅只是打开一个文件，使用上下左右箭头按键来移动光标，切换到插入模式，更改一些文本，保存，然后退出。 + +但那只是 Vim 的最最基本的操作。我的技能水平只能让我在终端使用 Vim 修改文本，但是它并没有任何一个我想象中强大的文本处理功能。这样我完全无法用 Vim 发挥出胜出 Pico 和 Nano 的能力。 + +所以到底为什么要学习 Vim？因为我花费了相当多的时间用于编辑文本，而且我知道还有很大的效率提升空间。为什么不选择 Emacs，或者是更为现代化的编辑器例如 Atom？因为 Vim 适合我，至少我有一丁点的使用经验。而且，很重要的一点就是，在我需要处理的系统上很少碰见没有装 Vim 或者它的弱化版（Vi）。如果你有强烈的欲望想学习对你来说更给力的 Emacs，我希望这些对于 Emacs 同类编辑器的建议能对你有所帮助。 + +花了几周的时间专注提高我的 Vim 使用技巧之后，我想分享的第一个建议就是必须使用它。虽然这看起来就是明知故问的回答，但事实上它比我所预想的计划要困难一些。我的大多数工作是在网页浏览器上进行的，而且每次我需要在浏览器之外打开并编辑一段文本时，就需要避免下意识地打开 Gedit。Gedit 已经放在了我的快速启动栏中，所以第一步就是移除这个快捷方式，然后替换成 Vim 的。 + +为了更好的学习 Vim，我尝试了很多。如果你也正想学习，以下列举了一些作为推荐。 + +### Vimtutor + +通常如何开始学习最好就是使用应用本身。我找到一个小的应用叫 Vimtutor，当你在学习编辑一个文本时它能辅导你一些基础知识，它向我展示了很多我这些年都忽视的基础命令。Vimtutor 一般在有 Vim 的地方都能找到它，如果你的系统上没有 Vimtutor，Vimtutor 可以很容易从你的包管理器上安装。 + +### GVim + +我知道并不是每个人都认同这个，但就是它让我从使用终端中的 Vim 转战到使用 GVim 来满足我基本编辑需求。反对者表示 GVim 鼓励使用鼠标，而 Vim 主要是为键盘党设计的。但是我能通过 GVim 的下拉菜单快速找到想找的指令，并且 GVim 可以提醒我正确的指令然后通过敲键盘执行它。努力学习一个新的编辑器然后陷入无法解决的困境，这种感觉并不好受。每隔几分钟读一下 man 出来的文字或者使用搜索引擎来提醒你该用的按键序列也并不是最好的学习新事物的方法。 + +### 键盘表 + +当我转战 GVim，我发现有一个键盘的“速查表”来提醒我最基础的按键很是便利。网上有很多这种可用的表，你可以下载、打印，然后贴在你身边的某一处地方。但是为了我的笔记本键盘，我选择买一沓便签纸。这些便签纸在美国不到 10 美元，当我使用键盘编辑文本，尝试新的命令的时候，可以随时提醒我。 + +### Vimium + +上文提到，我工作都在浏览器上进行。其中一条我觉得很有帮助的建议就是，使用 [Vimium][1] 来用增强使用 Vim 的体验。Vimium 是 Chrome 浏览器上的一个开源插件，能用 Vim 的指令快捷操作 Chrome。我发现我只用了几次使用快捷键切换上下文，就好像比之前更熟悉这些快捷键了。同样的扩展 Firefox 上也有，例如 [Vimerator][2]。 + +### 其它人 + +毫无疑问，最好的学习方法就是求助于在你之前探索过的人，让他给你建议、反馈和解决方法。 + +如果你住在一个大城市，那么附近可能会有一个 Vim meetup 小组，或者还有 Freenode IRC 上的 #vim 频道。#vim 频道是 Freenode 上最活跃的频道之一，那上面可以针对你个人的问题来提供帮助。听上面的人发发牢骚或者看看别人尝试解决自己没有遇到过的问题，仅仅是这样我都觉得很有趣。 + +------ + +那么，现在怎么样了？到现在为止还不错。为它所花的时间是否值得就在于之后它为你节省了多少时间。但是当我发现一个新的按键序列可以来跳过词，或者一些相似的小技巧，我经常会收获意外的惊喜与快乐。每天我至少可以看见，一点点的回报，正在逐渐配得上当初的付出。 + +学习 Vim 并不仅仅只有这些建议，还有很多。我很喜欢指引别人去 [Vim Advantures][3]，它是一种使用 Vim 按键方式进行移动的在线游戏。而在另外一天我在 [Vimgifts.com][4] 发现了一个非常神奇的虚拟学习工具，那可能就是你真正想要的：用一个小小的 gif 动图来描述 Vim 操作。 + +你有花时间学习 Vim 吗？或者是任何需要大量键盘操作的程序？那些经过你努力后掌握的工具，你认为这些努力值得吗？效率的提高有没有达到你的预期？分享你们的故事在下面的评论区吧。 + +-------------------------------------------------------------------------------- + +via: https://opensource.com/life/16/7/tips-getting-started-vim + +作者：[Jason Baker][a] +译者：[maywanting](https://github.com/maywanting) +校对：[wxy](https://github.com/wxy) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://opensource.com/users/jason-baker +[1]: https://github.com/philc/vimium +[2]: http://www.vimperator.org/ +[3]: http://vim-adventures.com/ +[4]: http://vimgifs.com/ diff --git a/translated/tech/LFCS/Part 10 - LFCS--Understanding and Learning Basic Shell Scripting and Linux Filesystem Troubleshooting.md b/published/LFCS/Part 10 - LFCS--Understanding and Learning Basic Shell Scripting and Linux Filesystem Troubleshooting.md similarity index 67% rename from translated/tech/LFCS/Part 10 - LFCS--Understanding and Learning Basic Shell Scripting and Linux Filesystem Troubleshooting.md rename to published/LFCS/Part 10 - LFCS--Understanding and Learning Basic Shell Scripting and Linux Filesystem Troubleshooting.md index 884ad9055f..c58e73d197 100644 --- a/translated/tech/LFCS/Part 10 - LFCS--Understanding and Learning Basic Shell Scripting and Linux Filesystem Troubleshooting.md +++ b/published/LFCS/Part 10 - LFCS--Understanding and Learning Basic Shell Scripting and Linux Filesystem Troubleshooting.md @@ -1,10 +1,10 @@ -LFCS 第十讲：学习简单的 Shell 脚本编程和文件系统故障排除 +LFCS 系列第十讲：学习简单的 Shell 脚本编程和文件系统故障排除 ================================================================================ -Linux 基金会发起了 LFCS 认证 (Linux Foundation Certified Sysadmin, Linux 基金会认证系统管理员)，这是一个全新的认证体系，主要目标是让全世界任何人都有机会考取认证。认证内容为 Linux 中间系统的管理，主要包括：系统运行和服务的维护、全面监控和分析的能力以及问题来临时何时想上游团队请求帮助的决策能力 +Linux 基金会发起了 LFCS 认证 (Linux Foundation Certified Sysadmin，Linux 基金会认证系统管理员)，这是一个全新的认证体系，旨在让世界各地的人能够参与到中等水平的 Linux 系统的基本管理操作的认证考试中去，这项认证包括：维护正在运行的系统和服务的能力、全面监控和分析的能力以及何时向上游团队请求支持的决策能力。 ![Basic Shell Scripting and Filesystem Troubleshooting](http://www.tecmint.com/wp-content/uploads/2014/11/lfcs-Part-10.png) -LFCS 系列第十讲 +*LFCS 系列第十讲* 请看以下视频，这里边介绍了 Linux 基金会认证程序。 @@ -18,54 +18,53 @@ LFCS 系列第十讲 首先要声明一些概念。 - Shell 是一个程序，它将命令传递给操作系统来执行。 -- Terminal 也是一个程序，作为最终用户，我们需要使用它与 Shell 来交互。比如，下边的图片是 GNOME Terminal。 +- Terminal 也是一个程序，允许最终用户使用它与 Shell 来交互。比如，下边的图片是 GNOME Terminal。 ![Gnome Terminal](http://www.tecmint.com/wp-content/uploads/2014/11/Gnome-Terminal.png) -Gnome Terminal +*Gnome Terminal* 启动 Shell 之后，会呈现一个命令提示符 (也称为命令行) 提示我们 Shell 已经做好了准备，接受标准输入设备输入的命令，这个标准输入设备通常是键盘。 -你可以参考该系列文章的 [第一讲 使用命令创建、编辑和操作文件][1] 来温习一些常用的命令。 +你可以参考该系列文章的 [第一讲 如何在 Linux 上使用 GNU sed 等命令来创建、编辑和操作文件][1] 来温习一些常用的命令。 Linux 为提供了许多可以选用的 Shell，下面列出一些常用的： **bash Shell** -Bash 代表 Bourne Again Shell，它是 GNU 项目默认的 Shell。它借鉴了 Korn shell (ksh) 和 C shell (csh) 中有用的特性，并同时对性能进行了提升。它同时也是 LFCS 认证中所涵盖的风发行版中默认 Shell，也是本系列教程将使用的 Shell。 +Bash 代表 Bourne Again Shell，它是 GNU 项目默认的 Shell。它借鉴了 Korn shell (ksh) 和 C shell (csh) 中有用的特性，并同时对性能进行了提升。它同时也是 LFCS 认证中所涵盖的各发行版中默认 Shell，也是本系列教程将使用的 Shell。 **sh Shell** -Bash Shell 是一个比较古老的 shell，一次多年来都是多数类 Unix 系统的默认 shell。 +Bourne SHell 是一个比较古老的 shell，多年来一直都是很多类 Unix 系统的默认 shell。 **ksh Shell** Korn SHell (ksh shell) 也是一个 Unix shell，是贝尔实验室 (Bell Labs) 的 David Korn 在 19 世纪 80 年代初的时候开发的。它兼容 Bourne shell ，并同时包含了 C shell 中的多数特性。 - 一个 shell 脚本仅仅只是一个可执行的文本文件，里边包含一条条可执行命令。 ### 简单的 Shell 脚本编程 ### -如前所述，一个 shell 脚本就是一个纯文本文件，因此，可以使用自己喜欢的文本编辑器来创建和编辑。你可以考虑使用 vi/vim (参考本系列 [第二部分 - vi/vim 编辑器的使用][2])，它的语法高亮让我的编辑工作非常方便。 +如前所述，一个 shell 脚本就是一个纯文本文件，因此，可以使用自己喜欢的文本编辑器来创建和编辑。你可以考虑使用 vi/vim (参考本系列 [第二讲 如何安装和使用纯文本编辑器 vi/vim][2])，它的语法高亮让我的编辑工作非常方便。 输入如下命令来创建一个名为 myscript.sh 的脚本文件： # vim myscript.sh -shell 脚本的第一行 (著名的 [shebang 符](http://smilejay.com/2012/03/linux_shebang/)) 必须如下： +shell 脚本的第一行 (著名的 [释伴（shebang）行](https://linux.cn/article-3664-1.html)) 必须如下： #!/bin/bash -这条语句“告诉”操作系统需要用那个解释器来运行这个脚本文件之后命令。 +这条语句“告诉”操作系统需要用哪个解释器来运行这个脚本文件之后命令。 -现在可以添加需要执行的命令了。通过注释，我们可以声明每一条命令或者整个脚本的具体含义。注意，shell 会忽略掉以井号 (#) 开始的语句。 +现在可以添加需要执行的命令了。通过注释，我们可以声明每一条命令或者整个脚本的具体含义。注意，shell 会忽略掉以井号 (#) 开始的注释语句。 #!/bin/bash echo 这是关于 LFCS 认证系列的第十部分 echo 今天是 $(date +%Y-%m-%d) -编写并保存脚本之后，通过以下命令来是脚本文件称为可执行文件： +编写并保存脚本之后，通过以下命令来使脚本文件成为可执行文件： # chmod 755 myscript.sh @@ -73,17 +72,17 @@ shell 脚本的第一行 (著名的 [shebang 符](http://smilejay.com/2012/03/li echo $PATH -我们就会看到环境变量 ($PATH) 的具体内容：当输入命令是系统搜索可执行程序的目录，每一项之间使用冒号 (:) 隔开。称它为环境变量，是因为他本是就是 shell 环境的一部分 —— 当 shell 第每次启动时 shell 及其子进程可以获取的一系列信息。 +我们就会看到环境变量 ($PATH) 的具体内容：这是当输入命令时系统所搜索可执行程序的目录，每一项之间使用冒号 (:) 隔开。称它为环境变量，是因为它本是就是 shell 环境的一部分 —— 这是当 shell 每次启动时 shell 及其子进程可以获取的一系列信息。 当我们输入一个命令并按下回车时，shell 会搜索 $PATH 变量中列出的目录并执行第一个知道的实例。请看如下例子： ![Linux Environment Variables](http://www.tecmint.com/wp-content/uploads/2014/11/Environment-Variable.png) -环境变量 +*环境变量* 假如存在两个同名的可执行程序，一个在 /usr/local/bin，另一个在 /usr/bin，则会执行环境变量中最先列出的那个，并忽略另外一个。 -如果我们自己编写的脚本没有在 $PATH 变量列出目录的其中一个，则需要输入 ./filename 来执行它。而如果存储在 $PATH 变量中的任意一个目录，我们就可以像运行其他命令一样来运行之前编写的脚本了。 +如果我们自己编写的脚本没有放在 $PATH 变量列出目录中的任何一个，则需要输入 ./filename 来执行它。而如果存储在 $PATH 变量中的任意一个目录，我们就可以像运行其他命令一样来运行之前编写的脚本了。 # pwd # ./myscript.sh @@ -94,7 +93,7 @@ shell 脚本的第一行 (著名的 [shebang 符](http://smilejay.com/2012/03/li ![Execute Script in Linux](http://www.tecmint.com/wp-content/uploads/2014/11/Execute-Script.png) -执行脚本 +*执行脚本* #### if 条件语句 #### @@ -106,22 +105,22 @@ shell 脚本的第一行 (著名的 [shebang 符](http://smilejay.com/2012/03/li OTHER-COMMANDS fi -其中，CONDITION 为如下情形的任意一项 (仅列出常用的)，并且达到以下条件时返回 true： +其中，CONDITION 可以是如下情形的任意一项 (仅列出常用的)，并且达到以下条件时返回 true： - [ -a file ] → 指定文件存在。 - [ -d file ] → 指定文件存在，并且是一个目录。 - [ -f file ] → 指定文件存在，并且是一个普通文件。 -- [ -u file ] → 指定文件存在，并设置了 SUID。 -- [ -g file ] → 指定文件存在，并设置了 SGID。 +- [ -u file ] → 指定文件存在，并设置了 SUID 权限位。 +- [ -g file ] → 指定文件存在，并设置了 SGID 权限位。 - [ -k file ] → 指定文件存在，并设置了“黏连 (Sticky)”位。 - [ -r file ] → 指定文件存在，并且文件可读。 -- [ -s file ] → 指定文件存在，并且文件为空。 -- [ -w file ] → 指定文件存在，并且文件可写入· +- [ -s file ] → 指定文件存在，并且文件不为空。 +- [ -w file ] → 指定文件存在，并且文件可写入。 - [ -x file ] → 指定文件存在，并且可执行。 - [ string1 = string2 ] → 字符串相同。 - [ string1 != string2 ] → 字符串不相同。 -[ int1 op int2 ] 为前述列表中的一部分，紧跟着的项 (例如： -eq –> int1 与 int2 相同时返回 true) 则是 [ int1 op int2 ] 的一个子项， 其中 op 为以下比较操作符。 +[ int1 op int2 ] 为前述列表中的一部分 (例如： -eq –> int1 与 int2 相同时返回 true) ，其中比较项也可以是一个列表子项， 其中 op 为以下比较操作符。 - -eq –> int1 等于 int2 时返回 true。 - -ne –> int1 不等于 int2 时返回 true。 @@ -142,13 +141,13 @@ shell 脚本的第一行 (著名的 [shebang 符](http://smilejay.com/2012/03/li #### While 循环语句 #### -该循环结构会一直执行重复的命令，直到控制命令执行的退出状态值等于 0 时 (即执行成功) 停止。基本语法如下： +该循环结构会一直执行重复的命令，直到控制命令（EVALUATION_COMMAND）执行的退出状态值等于 0 时 (即执行成功) 停止。基本语法如下： while EVALUATION_COMMAND; do EXECUTE_COMMANDS; done -其中，EVALUATION_COMMAND 可以是任何能够返回成功 (0) 或失败 (0 以外的值) 的退出状态值的命令，EXECUTE_COMMANDS 则可以是任何的程序、脚本或者 shell 结构体，包括其他的嵌套循环。 +其中，EVALUATION\_COMMAND 可以是任何能够返回成功 (0) 或失败 (0 以外的值) 的退出状态值的命令，EXECUTE\_COMMANDS 则可以是任何的程序、脚本或者 shell 结构体，包括其他的嵌套循环。 #### 综合使用 #### @@ -168,7 +167,7 @@ shell 脚本的第一行 (著名的 [shebang 符](http://smilejay.com/2012/03/li ![Script to Monitor Linux Services](http://www.tecmint.com/wp-content/uploads/2014/11/Monitor-Services.png) -使用脚本监控 Linux 服务 +*使用脚本监控 Linux 服务* 我们编写的脚本看起来应该是这样的： @@ -188,7 +187,7 @@ shell 脚本的第一行 (著名的 [shebang 符](http://smilejay.com/2012/03/li ![Linux Service Monitoring Script](http://www.tecmint.com/wp-content/uploads/2014/11/Monitor-Script.png) -Linux 服务监控脚本 +*Linux 服务监控脚本* **我们来解释一下这个脚本的工作流程** @@ -196,21 +195,21 @@ Linux 服务监控脚本 # cat myservices.txt -2). 以上命令由圆括号括着，并在前面添加美元符，表示它需要从 myservices.txt 的记录列表中取值作为变量传递给 for 循环。 +2). 以上命令由圆括号括着，并在前面添加美元符，表示它需要从 myservices.txt 的记录列表中取值并作为变量传递给 for 循环。 -3). 对于记录列表中的每一项纪录 (即每一项纪录的服务变量)，都会这行以下动作： +3). 对于记录列表中的每一项纪录 (即每一项纪录的服务变量)，都会执行以下动作： # systemctl status $service | grep --quiet "running" 此时，需要在每个通用变量名 (即每一项纪录的服务变量) 的前面添加美元符，以表明它是作为变量来传递的。其输出则通过管道符传给 grep。 -其中，-quiet 选项用于阻止 grep 命令将出现 "running" 的行回显到屏幕。当 grep 捕获到 "running" 时，则会返回一个退出状态码 "0" (在 if 结构体表示为 $?)，由此确认某个服务正在运行中。 +其中，-quiet 选项用于阻止 grep 命令将发现的 “running” 的行回显到屏幕。当 grep 捕获到 “running” 时，则会返回一个退出状态码 “0” (在 if 结构体表示为 $?)，由此确认某个服务正在运行中。 -如果退出状态码是非零值 (即 systemctl status $service 命令中的回显中没有出现 "running")，则表明某个服务为运行。 +如果退出状态码是非零值 (即 systemctl status $service 命令中的回显中没有出现 “running”)，则表明某个服务为运行。 ![Services Monitoring Script](http://www.tecmint.com/wp-content/uploads/2014/11/Services-Monitoring-Script.png) -服务监控脚本 +*服务监控脚本* 我们可以增加一步，在开始循环之前，先确认 myservices.txt 是否存在。 @@ -236,7 +235,7 @@ Linux 服务监控脚本 你可能想把自己维护的主机写入一个文本文件，并使用脚本探测它们是否能够 ping 得通 (脚本中的 myhosts 可以随意替换为你想要的名称)。 -内置的 read shell 命令将告诉 while 循环一行行的读取 myhosts，并将读取的每行内容传给 host 变量，随后 host 变量传递给 ping 命令。 +shell 的内置 read 命令将告诉 while 循环一行行的读取 myhosts，并将读取的每行内容传给 host 变量，随后 host 变量传递给 ping 命令。 #!/bin/bash @@ -248,18 +247,18 @@ Linux 服务监控脚本 ![Script to Ping Servers](http://www.tecmint.com/wp-content/uploads/2014/11/Script-to-Ping-Servers.png) -使用脚本 Ping 服务器 +*使用脚本 Ping 服务器* 扩展阅读: - [Learn Shell Scripting: A Guide from Newbies to System Administrator][3] - [5 Shell Scripts to Learn Shell Programming][4] -### 文件系统排除 ### +### 文件系统排错 ### -尽管 Linux 是一个很稳定的操作系统，但仍然会因为某些原因出现崩溃 (比如以外断电等)，正好你有一个 (或者更多个) 文件系统未能正确卸载，Linux 重启的时候就会自动检测其中可能发生的错误。 +尽管 Linux 是一个很稳定的操作系统，但仍然会因为某些原因出现崩溃时 (比如因为断电等)，正好你有一个 (或者更多个) 文件系统未能正确卸载，Linux 重启的时候就会自动检测其中可能发生的错误。 -此外，每次系统正常启动的时候，都会在文件系统挂载之前校验它们的完整度。而这些全部都依赖于 fsck 工具 ("文件系统校验")。 +此外，每次系统正常启动的时候，都会在文件系统挂载之前校验它们的完整度。而这些全部都依赖于 fsck 工具 (“file system check，文件系统校验”)。 如果对 fsck 进行设定，它除了校验文件系统的完整性之外，还可以尝试修复错误。fsck 能否成功修复错误，取决于文件系统的损伤程度；如果可以修复，被损坏部分的文件会恢复到位于每个文件系统根目录的 lost+found。 @@ -279,13 +278,13 @@ fsck 的基本用如下： ![Scan Linux Filesystem for Errors](http://www.tecmint.com/wp-content/uploads/2014/11/Check-Filesystem-Errors.png) -检查文件系统错误 +*检查文件系统错误* -除了 -y 选项，我们也可以使用 -a 选项来自动修复文件系统错误，而不必做出交互式应答，并在文件系统看起来 "干净" 的情况下强制校验。 +除了 -y 选项，我们也可以使用 -a 选项来自动修复文件系统错误，而不必做出交互式应答，并在文件系统看起来 “干净” 卸载的情况下强制校验。 # fsck -af /dev/sdg1 -如果只是要找出什么地方发生了错误 (不用再检测到错误的时候修复)，我们开使用 -n 选项，这样只会讲文集系统错误输出到标准输出设备。 +如果只是要找出什么地方发生了错误 (不用在检测到错误的时候修复)，我们可以使用 -n 选项，这样只会将文件系统错误输出到标准输出设备上。 # fsck -n /dev/sdg1 @@ -293,11 +292,11 @@ fsck 的基本用如下： ### 总结 ### -至此，系列教程的十讲就全部结束了，全系列教程涵盖了通过 LFCS 测试所需的基础内容。 +至此，系列教程的第十讲就全部结束了，全系列教程涵盖了通过 LFCS 测试所需的基础内容。 -但显而易见的，本系列的十讲并不足以在单个主题方面做到全面描述，我们希望这一系列教程可以成为你学习的基础素材，并一直保持学习的热情。 +但显而易见的，本系列的十讲并不足以在单个主题方面做到全面描述，我们希望这一系列教程可以成为你学习的基础素材，并一直保持学习的热情（LCTT 译注：还有后继补充的几篇）。 -我们欢迎你提出任何问题或者建议，所以你可以毫不犹豫的通过以下链接联系我们。 +我们欢迎你提出任何问题或者建议，所以你可以毫不犹豫的通过以下链接联系到我们： 成为一个 [Linux 认证系统工程师][5] -------------------------------------------------------------------------------- @@ -305,12 +304,13 @@ via: http://www.tecmint.com/linux-basic-shell-scripting-and-linux-filesystem-tro 作者：[Gabriel Cánepa][a] 译者：[GHLandy](https://github.com/GHLandy) -校对：[校对者ID](https://github.com/校对者ID) +校对：[wxy](https://github.com/wxy) 本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创翻译，[Linux中国](https://linux.cn/) 荣誉推出 [a]:http://www.tecmint.com/author/gacanepa/ -[1]:http://www.tecmint.com/sed-command-to-create-edit-and-manipulate-files-in-linux/ -[2]:http://www.tecmint.com/vi-editor-usage/ +[1]:https://linux.cn/article-7161-1.html +[2]:https://linux.cn/article-7165-1.html [3]:http://www.tecmint.com/learning-shell-scripting-language-a-guide-from-newbies-to-system-administrator/ [4]:http://www.tecmint.com/basic-shell-programming-part-ii/ +[5]:http://www.shareasale.com/r.cfm?b=768106&u=1260899&m=59485&urllink=&afftrack= diff --git a/published/LFCS/Part 11 - How to Manage and Create LVM Using vgcreate, lvcreate and lvextend Commands.md b/published/LFCS/Part 11 - How to Manage and Create LVM Using vgcreate, lvcreate and lvextend Commands.md new file mode 100644 index 0000000000..49ac0e34f4 --- /dev/null +++ b/published/LFCS/Part 11 - How to Manage and Create LVM Using vgcreate, lvcreate and lvextend Commands.md @@ -0,0 +1,213 @@ +LFCS 系列第十一讲：如何使用命令 vgcreate、lvcreate 和 lvextend 管理和创建 LVM +======================================================================================== + +由于 LFCS 考试中的一些改变已在 2016 年 2 月 2 日生效，我们添加了一些必要的专题到 [LFCS 系列][1]。我们也非常推荐备考的同学，同时阅读 [LFCE 系列][2]。 + +![](http://www.tecmint.com/wp-content/uploads/2016/03/Manage-LVM-and-Create-LVM-Partition-in-Linux.png) + +*LFCS：管理 LVM 和创建 LVM 分区* + +在安装 Linux 系统的时候要做的最重要的决定之一便是给系统文件、home 目录等分配空间。在这个地方犯了错，再要扩大空间不足的分区，那样既麻烦又有风险。 + +**逻辑卷管理** （**LVM**）相较于传统的分区管理有许多优点，已经成为大多数（如果不能说全部的话） Linux 发行版安装时的默认选择。LVM 最大的优点应该是能方便的按照你的意愿调整（减小或增大）逻辑分区的大小。 + +LVM 的组成结构： + +* 把一块或多块硬盘或者一个或多个分区配置成物理卷（PV）。 +* 一个用一个或多个物理卷创建出的卷组（**VG**）。可以把一个卷组想象成一个单独的存储单元。 +* 在一个卷组上可以创建多个逻辑卷。每个逻辑卷相当于一个传统意义上的分区 —— 优点是它的大小可以根据需求重新调整大小，正如之前提到的那样。 + +本文，我们将使用三块 **8 GB** 的磁盘（**/dev/sdb**、**/dev/sdc** 和 **/dev/sdd**）分别创建三个物理卷。你既可以直接在整个设备上创建 PV，也可以先分区在创建。 + +在这里我们选择第一种方式，如果你决定使用第二种（可以参考本系列[第四讲：创建分区和文件系统][3]）确保每个分区的类型都是 `8e`。 + +### 创建物理卷，卷组和逻辑卷 + +要在 **/dev/sdb**、**/dev/sdc** 和 **/dev/sdd**上创建物理卷，运行： + +``` +# pvcreate /dev/sdb /dev/sdc /dev/sdd +``` + +你可以列出新创建的 PV ，通过： + +``` +# pvs +``` + +并得到每个 PV 的详细信息，通过： + +``` +# pvdisplay /dev/sdX +``` + +（**X** 即 b、c 或 d） + +如果没有输入 `/dev/sdX` ，那么你将得到所有 PV 的信息。 + +使用 /dev/sdb` 和 `/dev/sdc` 创建卷组 ，命名为 `vg00` (在需要时是可以通过添加其他设备来扩展空间的，我们等到说明这点的时候再用，所以暂时先保留 `/dev/sdd`）： + +``` +# vgcreate vg00 /dev/sdb /dev/sdc +``` + +就像物理卷那样，你也可以查看卷组的信息，通过： + +``` +# vgdisplay vg00 +``` + +由于 `vg00` 是由两个 **8 GB** 的磁盘组成的，所以它将会显示成一个 **16 GB** 的硬盘： + +![](http://www.tecmint.com/wp-content/uploads/2016/03/List-LVM-Volume-Groups.png) + +*LVM 卷组列表* + +当谈到创建逻辑卷，空间的分配必须考虑到当下和以后的需求。根据每个逻辑卷的用途来命名是一个好的做法。 + +举个例子，让我们创建两个 LV，命名为 `vol_projects` （**10 GB**） 和 `vol_backups` （剩下的空间）， 在日后分别用于部署项目文件和系统备份。 + +参数 `-n` 用于为 LV 指定名称，而 `-L` 用于设定固定的大小，还有 `-l` （小写的 L）在 VG 的预留空间中用于指定百分比大小的空间。 + +``` +# lvcreate -n vol_projects -L 10G vg00 +# lvcreate -n vol_backups -l 100%FREE vg00 +``` + +和之前一样，你可以查看 LV 的列表和基础信息，通过： + +``` +# lvs +``` + +或是查看详细信息，通过： + +``` +# lvdisplay +``` + +若要查看单个 **LV** 的信息，使用 **lvdisplay** 加上 **VG** 和 **LV** 作为参数，如下： + +``` +# lvdisplay vg00/vol_projects +``` + +![](http://www.tecmint.com/wp-content/uploads/2016/03/List-Logical-Volume.png) + +*逻辑卷列表* + +如上图，我们看到 LV 已经被创建成存储设备了（参考 LV Path 那一行）。在使用每个逻辑卷之前，需要先在上面创建文件系统。 + +这里我们拿 ext4 来做举例，因为对于每个 LV 的大小， ext4 既可以增大又可以减小（相对的 xfs 就只允许增大）： + +``` +# mkfs.ext4 /dev/vg00/vol_projects +# mkfs.ext4 /dev/vg00/vol_backups +``` + +我们将在下一节向大家说明，如何调整逻辑卷的大小并在需要的时候添加额外的外部存储空间。 + +### 调整逻辑卷大小和扩充卷组 + +现在设想以下场景。`vol_backups` 中的空间即将用完，而 `vol_projects` 中还有富余的空间。由于 LVM 的特性，我们可以轻易的减小后者的大小（比方说 **2.5 GB**），并将其分配给前者，与此同时调整每个文件系统的大小。 + +幸运的是这很简单，只需： + +``` +# lvreduce -L -2.5G -r /dev/vg00/vol_projects +# lvextend -l +100%FREE -r /dev/vg00/vol_backups +``` + +![](http://www.tecmint.com/wp-content/uploads/2016/03/Resize-Reduce-Logical-Volume-and-Volume-Group.png) + +*减小逻辑卷和卷组* + +在调整逻辑卷的时候，其中包含的减号 `(-)` 或加号 `(+)` 是十分重要的。否则 LV 将会被设置成指定的大小，而非调整指定大小。 + +有些时候，你可能会遭遇那种无法仅靠调整逻辑卷的大小就可以解决的问题，那时你就需要购置额外的存储设备了，你可能需要再加一块硬盘。这里我们将通过添加之前配置时预留的 PV （`/dev/sdd`），用以模拟这种情况。 + +想把 `/dev/sdd` 加到 `vg00`，执行： + +``` +# vgextend vg00 /dev/sdd +``` + +如果你在运行上条命令的前后执行 vgdisplay `vg00` ，你就会看出 VG 的大小增加了。 + +``` +# vgdisplay vg00 +``` + +![](http://www.tecmint.com/wp-content/uploads/2016/03/List-Volume-Group-Size.png) + +*查看卷组磁盘大小* + +现在，你可以使用新加的空间，按照你的需求调整现有 LV 的大小，或者创建一个新的 LV。 + +### 在启动和需求时挂载逻辑卷 + +当然，如果我们不打算实际的使用逻辑卷，那么创建它们就变得毫无意义了。为了更好的识别逻辑卷，我们需要找出它的 `UUID` （用于识别一个格式化存储设备的唯一且不变的属性）。 + +要做到这点，可使用 blkid 加每个设备的路径来实现： + +``` +# blkid /dev/vg00/vol_projects +# blkid /dev/vg00/vol_backups +``` + +![](http://www.tecmint.com/wp-content/uploads/2016/03/Find-Logical-Volume-UUID.png) + +*寻找逻辑卷的 UUID* + +为每个 LV 创建挂载点： + +``` +# mkdir /home/projects +# mkdir /home/backups +``` + +并在 `/etc/fstab` 插入相应的条目（确保使用之前获得的UUID）： + +``` +UUID=b85df913-580f-461c-844f-546d8cde4646 /home/projects ext4 defaults 0 0 +UUID=e1929239-5087-44b1-9396-53e09db6eb9e /home/backups ext4 defaults 0 0 +``` + +保存并挂载 LV： + +``` +# mount -a +# mount | grep home +``` + +![](http://www.tecmint.com/wp-content/uploads/2016/03/Mount-Logical-Volumes-on-Linux-1.png) + +*挂载逻辑卷* + +在涉及到 LV 的实际使用时，你还需要按照曾在本系列[第八讲：管理用户和用户组][4]中讲解的那样，为其设置合适的 `ugo+rwx`。 + +### 总结 + +本文介绍了 [逻辑卷管理][5]，一个用于管理可扩展存储设备的多功能工具。与 RAID（曾在本系列讲解过的 [第六讲：组装分区为RAID设备——创建和管理系统备份][6]）结合使用，你将同时体验到（LVM 带来的）可扩展性和（RAID 提供的）冗余。 + +在这类的部署中，你通常会在 `RAID` 上发现 `LVM`，这就是说，要先配置好 RAID 然后它在上面配置 LVM。 + +如果你对本问有任何的疑问和建议，可以直接在下方的评论区告诉我们。 + +-------------------------------------------------------------------------------- + +via: http://www.tecmint.com/manage-and-create-lvm-parition-using-vgcreate-lvcreate-and-lvextend/ + +作者：[Gabriel Cánepa][a] +译者：[martin2011qi](https://github.com/martin2011qi) +校对：[wxy](https://github.com/wxy) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创翻译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: http://www.tecmint.com/author/gacanepa/ +[1]: https://linux.cn/article-7161-1.html +[2]: http://www.tecmint.com/installing-network-services-and-configuring-services-at-system-boot/ +[3]: https://linux.cn/article-7187-1.html +[4]: https://linux.cn/article-7418-1.html +[5]: https://linux.cn/article-3965-1.html +[6]: https://linux.cn/article-7229-1.html diff --git a/published/LFCS/Part 12 - How to Explore Linux with Installed Help Documentations and Tools.md b/published/LFCS/Part 12 - How to Explore Linux with Installed Help Documentations and Tools.md new file mode 100644 index 0000000000..bc5e764637 --- /dev/null +++ b/published/LFCS/Part 12 - How to Explore Linux with Installed Help Documentations and Tools.md @@ -0,0 +1,184 @@ +LFCS 系列第十二讲：如何使用 Linux 的帮助文档和工具 +================================================================================== + +由于 2016 年 2 月 2 号开始启用了新的 LFCS 考试要求, 我们在 [LFCS 系列][1]系列添加了一些必要的内容。为了考试的需要，我们强烈建议你看一下[LFCE 系列][2]。 + +![](http://www.tecmint.com/wp-content/uploads/2016/03/Explore-Linux-with-Documentation-and-Tools.png) + +*LFCS: 了解 Linux 的帮助文档和工具* + +当你习惯了在命令行下进行工作，你会发现 Linux 已经有了许多使用和配置 Linux 系统所需要的文档。 + +另一个你必须熟悉命令行帮助工具的理由是，在[LFCS][3] 和 [LFCE][4] 考试中，它们是你唯一能够使用的信息来源，没有互联网也没有百度。你只能依靠你自己和命令行。 + +基于上面的理由，在这一章里我们将给你一些建议来可以让你有效的使用这些安装的文档和工具，以帮助你通过**Linux 基金会认证**考试。 + +### Linux 帮助手册（man） + +man 手册是 manual 手册的缩写，就是其名字所揭示的那样：一个给定工具的帮助手册。它包含了命令所支持的选项列表（以及解释），有些工具甚至还提供一些使用范例。 + +我们用 **man 命令** 跟上你想要了解的工具名称来打开一个帮助手册。例如： + +``` +# man diff +``` + +这将打开`diff`的手册页，这个工具将逐行对比文本文件（如你想退出只需要轻轻的点一下 q 键）。 + +下面我来比较两个文本文件 `file1` 和 `file2`。这两个文本文件包含了使用同一个 Linux 发行版相同版本安装的两台机器上的的安装包列表。 + +输入`diff` 命令它将告诉我们 `file1` 和`file2` 有什么不同: + +``` +# diff file1 file2 +``` + +![](http://www.tecmint.com/wp-content/uploads/2016/03/Compare-Two-Text-Files-in-Linux.png) + +*在Linux中比较两个文本文件* + +`<` 这个符号是说`file2`缺失的行。如果是 `file1`缺失，我们将用 `>` 符号来替代指示。 + +另外，**7d6** 意思是说`file1`的第**7**行要删除了才能和`file2`一致（**24d22** 和 **41d38** 也是同样的意思） **65,67d61** 告诉需要删除从第 **65** 行到 **67** 行。我们完成了以上步骤，那么这两个文件将完全一致。 + +此外，根据 man 手册说明，你还可以通过 `-y` 选项来以两路的方式显示文件。你可以发现这对于你找到两个文件间的不同根据方便容易。 + +``` +# diff -y file1 file2 +``` + +![](http://www.tecmint.com/wp-content/uploads/2016/03/Compare-and-List-Difference-of-Two-Files.png) + +*比较并列出两个文件的不同* + +此外，你也可以用`diff`来比较两个二进制文件。如果它们完全一样，`diff` 将什么也不会输出。否则，它将会返回如下信息：“**Binary files X and Y differ**”。 + +### –help 选项 + +`--help`选项，大多数命令都支持它（并不是所有）， 它可以理解为一个命令的简短帮助手册。尽管它没有提供工具的详细介绍，但是确实是一个能够快速列出程序的所支持的选项的不错的方法。 + +例如， + +``` +# sed --help +``` + +将显示 sed （流编辑器）的每个支持的选项。 + +`sed`命令的一个典型用法是替换文件中的字符。用 `-i` 选项（意思是 “**原地编辑编辑文件**”），你可以编辑一个文件而且并不需要打开它。 如果你想要同时备份一个原始文件，用 `-i` 选项加后缀来创建一个原始文件的副本。 + +例如，替换 `lorem.txt` 中的`Lorem` 为 `Tecmint`（忽略大小写），并且创建一个原文件的备份副本，命令如下： + +``` +# less lorem.txt | grep -i lorem +# sed -i.orig 's/Lorem/Tecmint/gI' lorem.txt +# less lorem.txt | grep -i lorem +# less lorem.txt.orig | grep -i lorem +``` + +请注意`lorem.txt`文件中`Lorem` 都已经替换为 `Tecmint`，并且原文件 `lorem.txt` 被保存为`lorem.txt.orig`。 + +![](http://www.tecmint.com/wp-content/uploads/2016/03/Replace-A-String-in-File.png) + +*替换文件中的文本* + +### /usr/share/doc 内的文档 + +这可能是我最喜欢的方法。如果你进入 `/usr/share/doc` 目录，并列出该目录，你可以看到许多以安装在你的 Linux 上的工具为名称的文件夹。 + +根据 [文件系统层级标准][5]，这些文件夹包含了许多帮助手册没有的信息，还有一些可以使配置更方便的模板和配置文件。 + +例如，让我们来看一下 `squid-3.3.8` （不同发行版的版本可能会不同），这还是一个非常受欢迎的 HTTP 代理和 [squid 缓存服务器][6]。 + +让我们用`cd`命令进入目录： + +``` +# cd /usr/share/doc/squid-3.3.8 +``` + +列出当前文件夹列表： + +``` +# ls +``` + +![](http://www.tecmint.com/wp-content/uploads/2016/03/List-Files-in-Linux.png) + +*使用 ls 列出目录* + +你应该特别注意 `QUICKSTART` 和 `squid.conf.documented`。这些文件分别包含了 Squid 详细文档及其经过详细备注的配置文件。对于别的安装包来说，具体的名字可能不同（有可能是 **QuickRef** 或者**00QUICKSTART**），但意思是一样的。 + +对于另外一些安装包，比如 Apache web 服务器，在`/usr/share/doc`目录提供了配置模板，当你配置独立服务器或者虚拟主机的时候会非常有用。 + +### GNU 信息文档 + +你可以把它看做帮助手册的“开挂版”。它不仅仅提供工具的帮助信息，而且还是超级链接的形式（没错，在命令行中的超级链接），你可以通过箭头按钮从一个章节导航到另外章节，并按下回车按钮来确认。 + +一个典型的例子是： + +``` +# info coreutils +``` + +因为 coreutils 包含了每个系统中都有的基本文件、shell 和文本处理工具，你自然可以从 coreutils 的 info 文档中得到它们的详细介绍。 + +![](http://www.tecmint.com/wp-content/uploads/2016/03/Info-Coreutils.png) + +*Info Coreutils* + +和帮助手册一样，你可以按 q 键退出。 + +此外，GNU info 还可以显示标准的帮助手册。 例如： + +``` +# info tune2fs +``` + +它将显示 **tune2fs**的帮助手册, 这是一个 ext2/3/4 文件系统管理工具。 + +我们现在看到了，让我们来试试怎么用**tune2fs**： + +显示 **/dev/mapper/vg00-vol_backups** 文件系统信息： + +``` +# tune2fs -l /dev/mapper/vg00-vol_backups +``` + +修改文件系统标签（修改为 Backups）： + +``` +# tune2fs -L Backups /dev/mapper/vg00-vol_backups +``` + +设置文件系统的自检间隔及挂载计数（用`-c` 选项设置挂载计数间隔， 用 `-i` 选项设置自检时间间隔，这里 **d 表示天，w 表示周，m 表示月**)。 + +``` +# tune2fs -c 150 /dev/mapper/vg00-vol_backups # 每 150 次挂载检查一次 +# tune2fs -i 6w /dev/mapper/vg00-vol_backups # 每 6 周检查一次 +``` + +以上这些内容也可以通过 `--help` 选项找到，或者查看帮助手册。 + +### 摘要 + +不管你选择哪种方法，知道并且会使用它们在考试中对你是非常有用的。你知道其它的一些方法吗? 欢迎给我们留言。 + +-------------------------------------------------------------------------------- + +via: http://www.tecmint.com/explore-linux-installed-help-documentation-and-tools/ + +作者：[Gabriel Cánepa][a] +译者：[kokialoves](https://github.com/kokialoves) +校对：[wxy](https://github.com/wxy) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创翻译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]:http://www.tecmint.com/author/gacanepa/ +[1]: https://linux.cn/article-7161-1.html +[2]: http://www.tecmint.com/installing-network-services-and-configuring-services-at-system-boot/ +[3]: https://linux.cn/article-7161-1.html +[4]: http://www.tecmint.com/installing-network-services-and-configuring-services-at-system-boot/ +[5]: https://linux.cn/article-6132-1.html +[6]: http://www.tecmint.com/configure-squid-server-in-linux/ +[7]: http://www.tecmint.com/sed-command-to-create-edit-and-manipulate-files-in-linux/ + diff --git a/translated/tech/LXD/Part 1 - LXD 2.0--Introduction to LXD.md b/published/LXD/Part 1 - LXD 2.0--Introduction to LXD.md similarity index 61% rename from translated/tech/LXD/Part 1 - LXD 2.0--Introduction to LXD.md rename to published/LXD/Part 1 - LXD 2.0--Introduction to LXD.md index 011f385881..11c7220964 100644 --- a/translated/tech/LXD/Part 1 - LXD 2.0--Introduction to LXD.md +++ b/published/LXD/Part 1 - LXD 2.0--Introduction to LXD.md @@ -1,4 +1,4 @@ -Part 1 - LXD 2.0: LXD 入门 +LXD 2.0 系列（一）：LXD 入门 ====================================== 这是 [LXD 2.0 系列介绍文章][1]的第一篇。 @@ -20,12 +20,11 @@ LXD 最主要的目标就是使用 Linux 容器而不是硬件虚拟化向用户 LXD 聚焦于系统容器，通常也被称为架构容器。这就是说 LXD 容器实际上如在裸机或虚拟机上运行一般运行了一个完整的 Linux 操作系统。 -这些容器一般基于一个干净的发布镜像并会长时间运行。传统的配置管理工具和部署工具可以如在虚拟机、云和物理机器上一样与 LXD 一起使用。 +这些容器一般基于一个干净的发布镜像并会长时间运行。传统的配置管理工具和部署工具可以如在虚拟机、云实例和物理机器上一样与 LXD 一起使用。 -相对的， Docker 关注于短期的、无状态的最小容器，这些容器通常并不会升级或者重新配置，而是作为一个整体被替换掉。这就使得 Docker 及类似项目更像是一种软件发布机制，而不是一个机器管理工具。 - -这两种模型并不是完全互斥的。你完全可以使用 LXD 为你的用户提供一个完整的 Linux 系统，而他们可以在 LXD 内安装 Docker 来运行他们想要的软件。 +相对的， Docker 关注于短期的、无状态的、最小化的容器，这些容器通常并不会升级或者重新配置，而是作为一个整体被替换掉。这就使得 Docker 及类似项目更像是一种软件发布机制，而不是一个机器管理工具。 +这两种模型并不是完全互斥的。你完全可以使用 LXD 为你的用户提供一个完整的 Linux 系统，然后他们可以在 LXD 内安装 Docker 来运行他们想要的软件。 #### 为什么要用 LXD? @@ -35,56 +34,55 @@ LXD 聚焦于系统容器，通常也被称为架构容器。这就是说 LXD 我们把 LXD 作为解决这些缺陷的一个很好的机会。作为一个长时间运行的守护进程， LXD 可以绕开 LXC 的许多限制，比如动态资源限制、无法进行容器迁移和高效的在线迁移；同时，它也为创造新的默认体验提供了机会：默认开启安全特性，对用户更加友好。 - ### LXD 的主要组件 -LXD 是由几个主要组件构成的，这些组件都是 LXD 目录结构、命令行客户端和 API 结构体里下可见的。 +LXD 是由几个主要组件构成的，这些组件都出现在 LXD 目录结构、命令行客户端和 API 结构体里。 #### 容器 LXD 中的容器包括以下及部分： -- 根文件系统 +- 根文件系统（rootfs） +- 配置选项列表，包括资源限制、环境、安全选项等等 - 设备：包括磁盘、unix 字符/块设备、网络接口 - 一组继承而来的容器配置文件 -- 属性（容器架构，暂时的或持久的，容器名） -- 运行时状态（当时为了记录检查点、恢复时用到了 CRIU时） +- 属性（容器架构、暂时的还是持久的、容器名） +- 运行时状态（当用 CRIU 来中断/恢复时） #### 快照 容器快照和容器是一回事，只不过快照是不可修改的，只能被重命名，销毁或者用来恢复系统，但是无论如何都不能被修改。 -值得注意的是，因为我们允许用户保存容器的运行时状态，这就有效的为我们提供了“有状态”的快照的功能。这就是说我们可以使用快照回滚容器的 CPU 和内存。 +值得注意的是，因为我们允许用户保存容器的运行时状态，这就有效的为我们提供了“有状态”的快照的功能。这就是说我们可以使用快照回滚容器的状态，包括快照当时的 CPU 和内存状态。 #### 镜像 LXD 是基于镜像实现的，所有的 LXD 容器都是来自于镜像。容器镜像通常是一些纯净的 Linux 发行版的镜像，类似于你们在虚拟机和云实例上使用的镜像。 -所以就可以「发布」容器：使用容器制作一个镜像并在本地或者远程 LXD 主机上使用。 +所以可以「发布」一个容器：使用容器制作一个镜像并在本地或者远程 LXD 主机上使用。 -镜像通常使用全部或部分 sha256 哈希码来区分。因为输入长长的哈希码对用户来说不好，所以镜像可以使用几个自身的属性来区分，这就使得用户在镜像商店里方便搜索镜像。别名也可以用来 1 对 1 地把对用户友好的名字映射到某个镜像的哈希码。 +镜像通常使用全部或部分 sha256 哈希码来区分。因为输入长长的哈希码对用户来说不方便，所以镜像可以使用几个自身的属性来区分，这就使得用户在镜像商店里方便搜索镜像。也可以使用别名来一对一地将一个用户好记的名字映射到某个镜像的哈希码上。 LXD 安装时已经配置好了三个远程镜像服务器（参见下面的远程一节）： -- “ubuntu：” 提供稳定版的 Ubuntu 镜像 -- “ubuntu-daily：” 提供每天构建出来的 Ubuntu -- “images：” 社区维护的镜像服务器，提供一系列的 Linux 发布版，使用的是上游 LXC 的模板 +- “ubuntu”：提供稳定版的 Ubuntu 镜像 +- “ubuntu-daily”：提供 Ubuntu 的每日构建镜像 +- “images”： 社区维护的镜像服务器，提供一系列的其它 Linux 发布版，使用的是上游 LXC 的模板 LXD 守护进程会从镜像上次被使用开始自动缓存远程镜像一段时间（默认是 10 天），超过时限后这些镜像才会失效。 此外， LXD 还会自动更新远程镜像（除非指明不更新），所以本地的镜像会一直是最新版的。 - #### 配置 -配置文件是一种在一处定义容器配置和容器设备，然后应用到一系列容器的方法。 +配置文件是一种在一个地方定义容器配置和容器设备，然后将其应用到一系列容器的方法。 -一个容器可以被应用多个配置文件。当构建最终容器配置时（即通常的扩展配置），这些配置文件都会按照他们定义顺序被应用到容器上，当有重名的配置时，新的会覆盖掉旧的。然后本地容器设置会在这些基础上应用，覆盖所有来自配置文件的选项。 +一个容器可以被应用多个配置文件。当构建最终容器配置时（即通常的扩展配置），这些配置文件都会按照他们定义顺序被应用到容器上，当有重名的配置键或设备时，新的会覆盖掉旧的。然后本地容器设置会在这些基础上应用，覆盖所有来自配置文件的选项。 LXD 自带两种预配置的配置文件： -- 「 default 」配置是自动应用在所有容器之上，除非用户提供了一系列替代的配置文件。目前这个配置文件只做一件事，为容器定义 eth0 网络设备。 -- 「 docker” 」配置是一个允许你在容器里运行 Docker 容器的配置文件。它会要求 LXD 加载一些需要的内核模块以支持容器嵌套并创建一些设备入口。 +- “default”配置是自动应用在所有容器之上，除非用户提供了一系列替代的配置文件。目前这个配置文件只做一件事，为容器定义 eth0 网络设备。 +- “docker”配置是一个允许你在容器里运行 Docker 容器的配置文件。它会要求 LXD 加载一些需要的内核模块以支持容器嵌套并创建一些设备。 #### 远程 @@ -92,14 +90,14 @@ LXD 自带两种预配置的配置文件： 默认情况下，我们的命令行客户端会与下面几个预定义的远程服务器通信： -- local：（默认的远程服务器，使用 UNIX socket 和本地的 LXD 守护进程通信） -- ubuntu：（ Ubuntu 镜像服务器，提供稳定版的 Ubuntu 镜像） -- ubuntu-daily：（ Ubuntu 镜像服务器，提供每天构建出来的 Ubuntu ） -- images：（ images.linuxcontainers.org 镜像服务器） +- local：默认的远程服务器，使用 UNIX socket 和本地的 LXD 守护进程通信 +- ubuntu：Ubuntu 镜像服务器，提供稳定版的 Ubuntu 镜像 +- ubuntu-daily：Ubuntu 镜像服务器，提供 Ubuntu 的每日构建版 +- images：images.linuxcontainers.org 的镜像服务器 所有这些远程服务器的组合都可以在命令行客户端里使用。 -你也可以添加任意数量的远程 LXD 主机来监听网络。匿名的开放镜像服务器，或者通过认证可以管理远程容器的镜像服务器，都可以添加进来。 +你也可以添加任意数量的远程 LXD 主机，并配置它们监听网络。匿名的开放镜像服务器，或者通过认证可以管理远程容器的镜像服务器，都可以添加进来。 正是这种远程机制使得与远程镜像服务器交互及在主机间复制、移动容器成为可能。 @@ -107,30 +105,29 @@ LXD 自带两种预配置的配置文件： 我们设计 LXD 时的一个核心要求，就是在不修改现代 Linux 发行版的前提下，使容器尽可能的安全。 -LXD 使用的、通过使用 LXC 库实现的主要安全特性有： +LXD 通过使用 LXC 库实现的主要安全特性有： -- 内核名字空间。尤其是用户名字空间，它让容器和系统剩余部分完全分离。LXD 默认使用用户名字空间（和 LXC 相反），并允许用户在需要的时候以容器为单位打开或关闭。 +- 内核名字空间。尤其是用户名字空间，它让容器和系统剩余部分完全分离。LXD 默认使用用户名字空间（和 LXC 相反），并允许用户在需要的时候以容器为单位关闭（将容器标为“特权的”）。 - Seccomp 系统调用。用来隔离潜在危险的系统调用。 -- AppArmor：对 mount、socket、ptrace 和文件访问提供额外的限制。特别是限制跨容器通信。 +- AppArmor。对 mount、socket、ptrace 和文件访问提供额外的限制。特别是限制跨容器通信。 - Capabilities。阻止容器加载内核模块，修改主机系统时间，等等。 -- CGroups。限制资源使用，防止对主机的 DoS 攻击。 +- CGroups。限制资源使用，防止针对主机的 DoS 攻击。 +为了对用户友好，LXD 构建了一个新的配置语言把大部分的这些特性都抽象封装起来，而不是如 LXC 一般直接将这些特性暴露出来。举了例子，一个用户可以告诉 LXD 把主机设备放进容器而不需要手动检查他们的主/次设备号来手动更新 CGroup 策略。 -为了对用户友好 ， LXD 构建了一个新的配置语言把大部分的这些特性都抽象封装起来，而不是如 LXC 一般直接将这些特性暴露出来。举了例子，一个用户可以告诉 LXD 把主机设备放进容器而不需要手动检查他们的主/次设备号来更新 CGroup 策略。 - -和 LXD 本身通信是基于使用 TLS 1.2 保护的链路，这些链路只允许使用有限的几个被允许的密钥。当和那些经过系统证书认证之外的主机通信时， LXD 会提示用户验证主机的远程足迹（SSH 方式），然后把足迹缓存起来以供以后使用。 +和 LXD 本身通信是基于使用 TLS 1.2 保护的链路，只允许使用有限的几个被允许的密钥算法。当和那些经过系统证书认证之外的主机通信时， LXD 会提示用户验证主机的远程指纹（SSH 方式），然后把指纹缓存起来以供以后使用。 ### REST 接口 -LXD 的工作都是通过 REST 接口实现的。在客户端和守护进程之间并没有其他的通讯手段。 +LXD 的工作都是通过 REST 接口实现的。在客户端和守护进程之间并没有其他的通讯渠道。 -REST 接口可以通过本地的 unix socket 访问，这只需要经过组认证，或者经过 HTTP 套接字使用客户端认证进行通信。 +REST 接口可以通过本地的 unix socket 访问，这只需要经过用户组认证，或者经过 HTTP 套接字使用客户端认证进行通信。 REST 接口的结构能够和上文所说的不同的组件匹配，是一种简单、直观的使用方法。 当需要一种复杂的通信机制时， LXD 将会进行 websocket 协商完成剩余的通信工作。这主要用于交互式终端会话、容器迁移和事件通知。 -LXD 2.0 附带了 1.0 版的稳定 API。虽然我们在 1.0 版 API 添加了额外的特性，但是这不会在 1.0 版 API 的端点里破坏向后兼容性，因为我们会声明额外的 API 扩展使得客户端可以找到新的接口。 +LXD 2.0 附带了 1.0 版的稳定 API。虽然我们在 1.0 版 API 添加了额外的特性，但是这不会在 1.0 版 API 端点里破坏向后兼容性，因为我们会声明额外的 API 扩展使得客户端可以找到新的接口。 ### 容器规模化 diff --git a/published/awk/Part 1 - How to Use Awk and Regular Expressions to Filter Text or String in Files.md b/published/awk/Part 1 - How to Use Awk and Regular Expressions to Filter Text or String in Files.md new file mode 100644 index 0000000000..1c1b5577c9 --- /dev/null +++ b/published/awk/Part 1 - How to Use Awk and Regular Expressions to Filter Text or String in Files.md @@ -0,0 +1,222 @@ +awk 系列：如何使用 awk 和正则表达式过滤文本或文件中的字符串 +============================================================================= + +![](http://www.tecmint.com/wp-content/uploads/2016/04/Linux-Awk-Command-Examples.png) + +当我们在 Unix/Linux 下使用特定的命令从字符串或文件中读取或编辑文本时，我们经常需要过滤输出以得到感兴趣的部分。这时正则表达式就派上用场了。 + +### 什么是正则表达式? + +正则表达式可以定义为代表若干个字符序列的字符串。它最重要的功能之一就是它允许你过滤一条命令或一个文件的输出、编辑文本或配置文件的一部分等等。 + +### 正则表达式的特点 + +正则表达式由以下内容组合而成： + +- **普通字符**，例如空格、下划线、A-Z、a-z、0-9。 +- 可以扩展为普通字符的**元字符**，它们包括： + - `(.)` 它匹配除了换行符外的任何单个字符。 + - `(*)` 它匹配零个或多个在其之前紧挨着的字符。 + - `[ character(s) ]` 它匹配任何由其中的字符/字符集指定的字符，你可以使用连字符(-)代表字符区间，例如 [a-f]、[1-5]等。 + - `^` 它匹配文件中一行的开头。 + - `$` 它匹配文件中一行的结尾。 + - `\` 这是一个转义字符。 + +你必须使用类似 awk 这样的文本过滤工具来过滤文本。你还可以把 awk 自身当作一个编程语言。但由于这个指南的适用范围是关于使用 awk 的，我会按照一个简单的命令行过滤工具来介绍它。 + +awk 的一般语法如下： + +``` +# awk 'script' filename +``` + +此处 `'script'` 是一个由 awk 可以理解并应用于 filename 的命令集合。 + +它通过读取文件中的给定行，复制该行的内容并在该行上执行脚本的方式工作。这个过程会在该文件中的所有行上重复。 + +该脚本 `'script'` 中内容的格式是 `'/pattern/ action'`，其中 `pattern` 是一个正则表达式，而 `action` 是当 awk 在该行中找到此模式时应当执行的动作。 + +### 如何在 Linux 中使用 awk 过滤工具 + +在下面的例子中，我们将聚焦于之前讨论过的元字符。 + +#### 一个使用 awk 的简单示例： + +下面的例子打印文件 /etc/hosts 中的所有行，因为没有指定任何的模式。 + +``` +# awk '//{print}' /etc/hosts +``` + +![](http://www.tecmint.com/wp-content/uploads/2016/04/Awk-Command-Example.gif) + +*awk 打印文件中的所有行* + +#### 结合模式使用 awk + +在下面的示例中，指定了模式 `localhost`，因此 awk 将匹配文件 `/etc/hosts` 中有 `localhost` 的那些行。 + +``` +# awk '/localhost/{print}' /etc/hosts +``` + +![](http://www.tecmint.com/wp-content/uploads/2016/04/Use-Awk-Command-with-Pattern.gif) + +*awk 打印文件中匹配模式的行* + +#### 在 awk 模式中使用通配符 (.) + +在下面的例子中，符号 `(.)` 将匹配包含 loc、localhost、localnet 的字符串。 + +这里的正则表达式的意思是匹配 **l一个字符c**。 + +``` +# awk '/l.c/{print}' /etc/hosts +``` + +![](http://www.tecmint.com/wp-content/uploads/2016/04/Use-Awk-with-Wild-Cards.gif) + +*使用 awk 打印文件中匹配模式的字符串* + +#### 在 awk 模式中使用字符 (*) + +在下面的例子中，将匹配包含 localhost、localnet、lines, capable 的字符串。 + +``` +# awk '/l*c/{print}' /etc/localhost +``` + +![](http://www.tecmint.com/wp-content/uploads/2016/04/Use-Awk-to-Match-Strings-in-File.gif) + +*使用 awk 匹配文件中的字符串* + +你可能也意识到 `(*)` 将会尝试匹配它可能检测到的最长的匹配。 + +让我们看一看可以证明这一点的例子，正则表达式 `t*t` 的意思是在下面的行中匹配以 `t` 开始和 `t` 结束的字符串： + +``` +this is tecmint, where you get the best good tutorials, how to's, guides, tecmint. +``` + +当你使用模式 `/t*t/` 时，会得到如下可能的结果： + +``` +this is t +this is tecmint +this is tecmint, where you get t +this is tecmint, where you get the best good t +this is tecmint, where you get the best good tutorials, how t +this is tecmint, where you get the best good tutorials, how tos, guides, t +this is tecmint, where you get the best good tutorials, how tos, guides, tecmint +``` + +在 `/t*t/` 中的通配符 `(*)` 将使得 awk 选择匹配的最后一项： + +``` +this is tecmint, where you get the best good tutorials, how to's, guides, tecmint +``` + +#### 结合集合 [ character(s) ] 使用 awk + +以集合 [al1] 为例，awk 将匹配文件 /etc/hosts 中所有包含字符 a 或 l 或 1 的字符串。 + +``` +# awk '/[al1]/{print}' /etc/hosts +``` + +![](http://www.tecmint.com/wp-content/uploads/2016/04/Use-Awk-to-Print-Matching-Character.gif) + +*使用 awk 打印文件中匹配的字符* + +下一个例子匹配以 `K` 或 `k` 开始头，后面跟着一个 `T` 的字符串： + +``` +# awk '/[Kk]T/{print}' /etc/hosts +``` + +![](http://www.tecmint.com/wp-content/uploads/2016/04/Use-Awk-to-Print-Matched-String-in-File.gif) + +*使用 awk 打印文件中匹配的字符* + +#### 以范围的方式指定字符 + +awk 所能理解的字符： + +- `[0-9]` 代表一个单独的数字 +- `[a-z]` 代表一个单独的小写字母 +- `[A-Z]` 代表一个单独的大写字母 +- `[a-zA-Z]` 代表一个单独的字母 +- `[a-zA-Z 0-9]` 代表一个单独的字母或数字 + +让我们看看下面的例子： + +``` +# awk '/[0-9]/{print}' /etc/hosts +``` + +![](http://www.tecmint.com/wp-content/uploads/2016/04/Use-Awk-To-Print-Matching-Numbers-in-File.gif) + +*使用 awk 打印文件中匹配的数字* + +在上面的例子中，文件 /etc/hosts 中的所有行都至少包含一个单独的数字 [0-9]。 + +#### 结合元字符 (\^) 使用 awk + +在下面的例子中，它匹配所有以给定模式开头的行： + +``` +# awk '/^fe/{print}' /etc/hosts +# awk '/^ff/{print}' /etc/hosts +``` + +![](http://www.tecmint.com/wp-content/uploads/2016/04/Use-Awk-to-Print-All-Matching-Lines-with-Pattern.gif) + +*使用 awk 打印与模式匹配的行* + +#### 结合元字符 ($) 使用 awk + +它将匹配所有以给定模式结尾的行： + +``` +# awk '/ab$/{print}' /etc/hosts +# awk '/ost$/{print}' /etc/hosts +# awk '/rs$/{print}' /etc/hosts +``` + +![](http://www.tecmint.com/wp-content/uploads/2016/04/Use-Awk-to-Print-Given-Pattern-String.gif) + +*使用 awk 打印与模式匹配的字符串* + +#### 结合转义字符 (\\) 使用 awk + +它允许你将该转义字符后面的字符作为文字，即理解为其字面的意思。 + +在下面的例子中，第一个命令打印出文件中的所有行，第二个命令中我想匹配具有 $25.00 的一行，但我并未使用转义字符，因而没有打印出任何内容。 + +第三个命令是正确的，因为一个这里使用了一个转义字符以转义 $，以将其识别为 '$'（而非元字符）。 + +``` +# awk '//{print}' deals.txt +# awk '/$25.00/{print}' deals.txt +# awk '/\$25.00/{print}' deals.txt +``` + +![](http://www.tecmint.com/wp-content/uploads/2016/04/Use-Awk-with-Escape-Character.gif) + +*结合转义字符使用 awk* + +### 总结 + +以上内容并不是 awk 命令用做过滤工具的全部，上述的示例均是 awk 的基础操作。在下面的章节中，我将进一步介绍如何使用 awk 的高级功能。感谢您的阅读，请在评论区贴出您的评论。 + +-------------------------------------------------------------------------------- + +via: http://www.tecmint.com/use-linux-awk-command-to-filter-text-string-in-files/ + +作者：[Aaron Kili][a] +译者：[wwy-hust](https://github.com/wwy-hust) +校对：[wxy](https://github.com/wxy) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: http://www.tecmint.com/author/aaronkili/ diff --git a/published/awk/Part 2 - How to Use Awk to Print Fields and Columns in File.md b/published/awk/Part 2 - How to Use Awk to Print Fields and Columns in File.md new file mode 100644 index 0000000000..69f372d099 --- /dev/null +++ b/published/awk/Part 2 - How to Use Awk to Print Fields and Columns in File.md @@ -0,0 +1,109 @@ +awk 系列：如何使用 awk 输出文本中的字段和列 +====================================================== + +在 Awk 系列的这一节中，我们将看到 awk 最重要的特性之一，字段编辑。 + +首先我们要知道，Awk 能够自动将输入的行，分隔为若干字段。每一个字段就是一组字符，它们和其他的字段由一个内部字段分隔符分隔开来。 + +![](http://www.tecmint.com/wp-content/uploads/2016/04/Awk-Print-Fields-and-Columns.png) + +*Awk 输出字段和列* + +如果你熟悉 Unix/Linux 或者懂得 [bash shell 编程][1]，那么你应该知道什么是内部字段分隔符（IFS）变量。awk 中默认的 IFS 是制表符和空格。 + +awk 中的字段分隔符的工作原理如下：当读到一行输入时，将它按照指定的 IFS 分割为不同字段，第一组字符就是字段一，可以通过 $1 来访问，第二组字符就是字段二，可以通过 $2 来访问，第三组字符就是字段三，可以通过 $3 来访问，以此类推，直到最后一组字符。 + +为了更好地理解 awk 的字段编辑，让我们看一个下面的例子： + +**例 1**：我创建了一个名为 tecmintinfo.txt 的文本文件。 + +``` +# vi tecmintinfo.txt +# cat tecmintinfo.txt +``` + +![](http://www.tecmint.com/wp-content/uploads/2016/04/Create-File-in-Linux.png) + +*在 Linux 上创建一个文件* + +然后在命令行中，我试着使用下面的命令从文本 tecmintinfo.txt 中输出第一个，第二个，以及第三个字段。 + +``` +$ awk '//{print $1 $2 $3 }' tecmintinfo.txt +TecMint.comisthe +``` + +从上面的输出中你可以看到，前三个字段的字符是以空格为分隔符输出的： + +- 字段一是 “TecMint.com”，可以通过 `$1` 来访问。 +- 字段二是 “is”，可以通过 `$2` 来访问。 +- 字段三是 “the”，可以通过 `$3` 来访问。 + +如果你注意观察输出的话可以发现，输出的字段值并没有被分隔开，这是 print 函数默认的行为。 + +为了使输出看得更清楚，输出的字段值之间使用空格分开，你需要添加 (,) 操作符。 + +``` +$ awk '//{print $1, $2, $3; }' tecmintinfo.txt + +TecMint.com is the +``` + +需要记住而且非常重要的是，`($)` 在 awk 和在 shell 脚本中的使用是截然不同的！ + +在 shell 脚本中，`($)` 被用来获取变量的值。而在 awk 中，`($)` 只有在获取字段的值时才会用到，不能用于获取变量的值。 + +**例 2**：让我们再看一个例子，用到了一个名为 my_shoping.list 的包含多行的文件。 + +``` +No Item_Name Unit_Price Quantity Price +1 Mouse #20,000 1 #20,000 +2 Monitor #500,000 1 #500,000 +3 RAM_Chips #150,000 2 #300,000 +4 Ethernet_Cables #30,000 4 #120,000 +``` + +如果你只想输出购物清单上每一个物品的`单价`，你只需运行下面的命令： + +``` +$ awk '//{print $2, $3 }' my_shopping.txt + +Item_Name Unit_Price +Mouse #20,000 +Monitor #500,000 +RAM_Chips #150,000 +Ethernet_Cables #30,000 +``` + +可以看到上面的输出不够清晰，awk 还有一个 `printf` 的命令，可以帮助你将输出格式化。 + +使用 `printf` 来格式化 Item_Name 和 Unit_Price 的输出： + +``` +$ awk '//{printf "%-10s %s\n",$2, $3 }' my_shopping.txt + +Item_Name Unit_Price +Mouse #20,000 +Monitor #500,000 +RAM_Chips #150,000 +Ethernet_Cables #30,000 +``` + +### 总结 + +使用 awk 过滤文本或字符串时，字段编辑的功能是非常重要的。它能够帮助你从一个表的数据中得到特定的列。一定要记住的是，awk 中 `($)` 操作符的用法与其在 shell 脚本中的用法是不同的！ + +希望这篇文章对您有所帮助。如有任何疑问，可以在评论区域发表评论。 + +-------------------------------------------------------------------------------- + +via: http://www.tecmint.com/awk-print-fields-columns-with-space-separator/ + +作者：[Aaron Kili][a] +译者：[Cathon](https://github.com/Cathon)，[ictlyh](https://github.com/ictlyh) +校对：[wxy](https://github.com/wxy) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: http://www.tecmint.com/author/aaronkili/ +[1]: http://www.tecmint.com/category/bash-shell/ diff --git a/published/awk/Part 3 - How to Use Awk to Filter Text or Strings Using Pattern Specific Actions.md b/published/awk/Part 3 - How to Use Awk to Filter Text or Strings Using Pattern Specific Actions.md new file mode 100644 index 0000000000..53e9aabd68 --- /dev/null +++ b/published/awk/Part 3 - How to Use Awk to Filter Text or Strings Using Pattern Specific Actions.md @@ -0,0 +1,85 @@ +awk 系列：如何使用 awk 按模式筛选文本或字符串 +========================================================================= + +![](http://www.tecmint.com/wp-content/uploads/2016/04/Use-Awk-to-Filter-Text-or-Strings-Using-Pattern.png) + +作为 awk 命令系列的第三部分，这次我们将看一看如何基于用户定义的特定模式来筛选文本或字符串。 + +在筛选文本时，有时你可能想根据某个给定的条件或使用一个可被匹配的特定模式，去标记某个文件或数行字符串中的某几行。使用 awk 来完成这个任务是非常容易的，这也正是 awk 中可能对你有所帮助的几个功能之一。 + +让我们看一看下面这个例子，比方说你有一个写有你想要购买的食物的购物清单，其名称为 food_prices.list，它所含有的食物名称及相应的价格如下所示： + +``` +$ cat food_prices.list +No Item_Name Quantity Price +1 Mangoes 10 $2.45 +2 Apples 20 $1.50 +3 Bananas 5 $0.90 +4 Pineapples 10 $3.46 +5 Oranges 10 $0.78 +6 Tomatoes 5 $0.55 +7 Onions 5 $0.45 +``` + +然后，你想使用一个 `(*)` 符号去标记那些单价大于 $2 的食物，那么你可以通过运行下面的命令来达到此目的： + +``` +$ awk '/ *\$[2-9]\.[0-9][0-9] */ { print $1, $2, $3, $4, "*" ; } / *\$[0-1]\.[0-9][0-9] */ { print ; }' food_prices.list +``` + +![](http://www.tecmint.com/wp-content/uploads/2016/04/Filter-and-Print-Text-Using-Awk.gif) + +*打印出单价大于 $2 的项目* + +从上面的输出你可以看到在含有 芒果（mangoes） 和菠萝（pineapples）的那行末尾都已经有了一个 `(*)` 标记。假如你检查它们的单价，你可以看到它们的单价的确超过了 $2 。 + +在这个例子中，我们已经使用了两个模式： + +- 第一个模式: `/ *\$[2-9]\.[0-9][0-9] */` 将会得到那些含有食物单价大于 $2 的行， +- 第二个模式: `/*\$[0-1]\.[0-9][0-9] */` 将查找那些食物单价小于 $2 的那些行。 + +上面的命令具体做了什么呢？这个文件有四个字段，当模式一匹配到含有食物单价大于 $2 的行时，它便会输出所有的四个字段并在该行末尾加上一个 `(*)` 符号来作为标记。 + +第二个模式只是简单地输出其他含有食物单价小于 $2 的行，按照它们出现在输入文件 food_prices.list 中的样子。 + +这样你就可以使用模式来筛选出那些价格超过 $2 的食物项目，尽管上面的输出还有些问题，带有 `(*)` 符号的那些行并没有像其他行那样被格式化输出，这使得输出显得不够清晰。 + +我们在 awk 系列的第二部分中也看到了同样的问题，但我们可以使用下面的两种方式来解决： + +1、可以像下面这样使用 printf 命令，但这样使用又长又无聊： + +``` +$ awk '/ *\$[2-9]\.[0-9][0-9] */ { printf "%-10s %-10s %-10s %-10s\n", $1, $2, $3, $4 "*" ; } / *\$[0-1]\.[0-9][0-9] */ { printf "%-10s %-10s %-10s %-10s\n", $1, $2, $3, $4; }' food_prices.list +``` + +![](http://www.tecmint.com/wp-content/uploads/2016/04/Filter-and-Print-Items-Using-Awk-and-Printf.gif) + +*使用 Awk 和 Printf 来筛选和输出项目* + +2、 使用 `$0` 字段。Awk 使用变量 **0** 来存储整个输入行。对于上面的问题，这种方式非常方便，并且它还简单、快速： + +``` +$ awk '/ *\$[2-9]\.[0-9][0-9] */ { print $0 "*" ; } / *\$[0-1]\.[0-9][0-9] */ { print ; }' food_prices.list +``` + +![](http://www.tecmint.com/wp-content/uploads/2016/04/Filter-and-Print-Items-Using-Awk-and-Variable.gif) + +*使用 Awk 和变量来筛选和输出项目* + +### 结论 + +这就是全部内容了，使用 awk 命令你便可以通过几种简单的方法去利用模式匹配来筛选文本，帮助你在一个文件中对文本或字符串的某些行做标记。 + +希望这篇文章对你有所帮助。记得阅读这个系列的下一部分，我们将关注在 awk 工具中使用比较运算符。 + +-------------------------------------------------------------------------------- + +via: http://www.tecmint.com/awk-filter-text-or-string-using-patterns/ + +作者：[Aaron Kili][a] +译者：[FSSlc](https://github.com/FSSlc) +校对：[wxy](https://github.com/wxy) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: http://www.tecmint.com/author/aaronkili/ \ No newline at end of file diff --git a/published/awk/Part 4 - How to Use Comparison Operators with Awk in Linux.md b/published/awk/Part 4 - How to Use Comparison Operators with Awk in Linux.md new file mode 100644 index 0000000000..4ed7d8ed02 --- /dev/null +++ b/published/awk/Part 4 - How to Use Comparison Operators with Awk in Linux.md @@ -0,0 +1,95 @@ +awk 系列：如何使用 awk 比较操作符 +=================================================== + +![](http://www.tecmint.com/wp-content/uploads/2016/05/Use-Comparison-Operators-with-AWK.png) + +对于 使用 awk 命令的用户来说，处理一行文本中的数字或者字符串时，使用比较运算符来过滤文本和字符串是十分方便的。 + +在 awk 系列的此部分中，我们将探讨一下如何使用比较运算符来过滤文本或者字符串。如果你是程序员，那么你应该已经熟悉了比较运算符；对于其它人，下面的部分将介绍比较运算符。 + +### awk 中的比较运算符是什么？ + +awk 中的比较运算符用于比较字符串和或者数值，包括以下类型： + +- `>` – 大于 +- `<` – 小于 +- `>=` – 大于等于 +- `<=` – 小于等于 +- `==` – 等于 +- `!=` – 不等于 +- `some_value ~ / pattern/` – 如果 some_value 匹配模式 pattern，则返回 true +- `some_value !~ / pattern/` – 如果 some_value 不匹配模式 pattern，则返回 true + +现在我们通过例子来熟悉 awk 中各种不同的比较运算符。 + +在这个例子中，我们有一个文件名为 food_list.txt 的文件，里面包括不同食物的购买列表。我想给食物数量小于或等于 30 的物品所在行的后面加上`(**)` + +``` +File – food_list.txt +No Item_Name Quantity Price +1 Mangoes 45 $3.45 +2 Apples 25 $2.45 +3 Pineapples 5 $4.45 +4 Tomatoes 25 $3.45 +5 Onions 15 $1.45 +6 Bananas 30 $3.45 +``` + +Awk 中使用比较运算符的通用语法如下： + +``` +# 表达式 { 动作; } +``` + +为了实现刚才的目的，执行下面的命令： + +``` +# awk '$3 <= 30 { printf "%s\t%s\n", $0,"**" ; } $3 > 30 { print $0 ;}' food_list.txt + +No Item_Name` Quantity Price +1 Mangoes 45 $3.45 +2 Apples 25 $2.45 ** +3 Pineapples 5 $4.45 ** +4 Tomatoes 25 $3.45 ** +5 Onions 15 $1.45 ** +6 Bananas 30 $3.45 ** +``` + +在刚才的例子中，发生如下两件重要的事情： + +- 第一个“表达式 {动作;}”组合中， `$3 <= 30 { printf “%s\t%s\n”, $0,”**” ; }` 打印出数量小于等于30的行，并且在后面增加`(**)`。物品的数量是通过 `$3` 这个域变量获得的。 +- 第二个“表达式 {动作;}”组合中， `$3 > 30 { print $0 ;}` 原样输出数量小于等于 `30` 的行。 + +再举一个例子： + +``` +# awk '$3 <= 20 { printf "%s\t%s\n", $0,"TRUE" ; } $3 > 20 { print $0 ;} ' food_list.txt + +No Item_Name Quantity Price +1 Mangoes 45 $3.45 +2 Apples 25 $2.45 +3 Pineapples 5 $4.45 TRUE +4 Tomatoes 25 $3.45 +5 Onions 15 $1.45 TRUE +6 Bananas 30 $3.45 +``` + +在这个例子中，我们想通过在行的末尾增加 (TRUE) 来标记数量小于等于20的行。 + +### 总结 + +这是一篇对 awk 中的比较运算符介绍性的指引，因此你需要尝试其他选项，发现更多使用方法。 + +如果你遇到或者想到任何问题，请在下面评论区留下评论。请记得阅读 awk 系列下一部分的文章，那里我将介绍组合表达式。 + +-------------------------------------------------------------------------------- + +via: http://www.tecmint.com/comparison-operators-in-awk/ + +作者：[Aaron Kili][a] +译者：[chunyang-wen](https://github.com/chunyang-wen) +校对：[wxy](https://github.com/wxy) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: http://www.tecmint.com/author/aaronkili/ diff --git a/published/awk/Part 5 - How to Use Compound Expressions with Awk in Linux.md b/published/awk/Part 5 - How to Use Compound Expressions with Awk in Linux.md new file mode 100644 index 0000000000..ebe288b020 --- /dev/null +++ b/published/awk/Part 5 - How to Use Compound Expressions with Awk in Linux.md @@ -0,0 +1,80 @@ +awk 系列：如何使用 awk 复合表达式 +==================================================== + +![](http://www.tecmint.com/wp-content/uploads/2016/05/Use-Compound-Expressions-with-Awk.png) + +一直以来在查对条件是否匹配时，我们使用的都是简单的表达式。那如果你想用超过一个表达式来查对特定的条件呢？ + +本文，我们将看看如何在过滤文本和字符串时，结合多个表达式，即复合表达式，用以查对条件。 + +awk 的复合表达式可由表示“与”的组合操作符 `&&` 和表示“或”的 `||` 构成。 + +复合表达式的常规写法如下： + +``` +( 第一个表达式 ) && ( 第二个表达式 ) +``` + +这里只有当“第一个表达式” 和“第二个表达式”都是真值时整个表达式才为真。 + +``` +( 第一个表达式 ) || ( 第二个表达式) +``` + +这里只要“第一个表达式” 为真或“第二个表达式”为真，整个表达式就为真。 + +**注意**：切记要加括号。 + +表达式可以由比较操作符构成，具体可查看[ awk 系列的第四节][1]。 + +现在让我们通过一个例子来加深理解： + +此例中，有一个文本文件 `tecmint_deals.txt`，文本中包含着一张随机的 Tecmint 交易清单，其中包含了名称、价格和种类。 + +``` +TecMint Deal List +No Name Price Type +1 Mac_OS_X_Cleanup_Suite $9.99 Software +2 Basics_Notebook $14.99 Lifestyle +3 Tactical_Pen $25.99 Lifestyle +4 Scapple $19.00 Unknown +5 Nano_Tool_Pack $11.99 Unknown +6 Ditto_Bluetooth_Altering_Device $33.00 Tech +7 Nano_Prowler_Mini_Drone $36.99 Tech +``` + +我们只想打印出价格超过 $20 且其种类为 “Tech” 的物品，在其行末用 (*) 打上标记。 + +我们将要执行以下命令。 + +``` +# awk '($3 ~ /^\$[2-9][0-9]*\.[0-9][0-9]$/) && ($4=="Tech") { printf "%s\t%s\n",$0,"*"; } ' tecmint_deals.txt + +6 Ditto_Bluetooth_Altering_Device $33.00 Tech * +7 Nano_Prowler_Mini_Drone $36.99 Tech * +``` + +此例，在复合表达式中我们使用了两个表达式： + +- 表达式 1：`($3 ~ /^\$[2-9][0-9]*\.[0-9][0-9]$/)` ；查找交易价格超过 `$20` 的行，即只有当 `$3` 也就是价格满足 `/^\$[2-9][0-9]*\.[0-9][0-9]$/` 时值才为真值。 +- 表达式 2：`($4 == “Tech”)` ；查找是否有种类为 “`Tech`”的交易，即只有当 `$4` 等于 “`Tech`” 时值才为真值。 +切记，只有当 `&&` 操作符的两端状态，也就是两个表达式都是真值的情况下，这一行才会被打上 `(*)` 标志。 + +### 总结 + +有些时候为了真正符合你的需求，就不得不用到复合表达式。当你掌握了比较和复合表达式操作符的用法之后，复杂的文本或字符串过滤条件也能轻松解决。 + +希望本向导对你有所帮助，如果你有任何问题或者补充，可以在下方发表评论，你的问题将会得到相应的解释。 + +-------------------------------------------------------------------------------- + +via: http://www.tecmint.com/combine-multiple-expressions-in-awk/ + +作者：[Aaron Kili][a] +译者：[martin2011qi](https://github.com/martin2011qi) +校对：[wxy](https://github.com/wxy) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: http://www.tecmint.com/author/aaronkili/ +[1]: https://linux.cn/article-7602-1.html \ No newline at end of file diff --git a/published/awk/Part 6 - How to Use ‘next’ Command with Awk in Linux.md b/published/awk/Part 6 - How to Use ‘next’ Command with Awk in Linux.md new file mode 100644 index 0000000000..c2d277fc17 --- /dev/null +++ b/published/awk/Part 6 - How to Use ‘next’ Command with Awk in Linux.md @@ -0,0 +1,76 @@ +awk 系列：如何使用 awk 的 ‘next’ 命令 +============================================= + +![](http://www.tecmint.com/wp-content/uploads/2016/06/Use-next-Command-with-Awk-in-Linux.png) + +在 awk 系列的第六节，我们来看一下`next`命令 ，它告诉 awk 跳过你所提供的所有剩下的模式和表达式，直接处理下一个输入行。 + +`next` 命令帮助你阻止运行命令执行过程中多余的步骤。 + +要明白它是如何工作的, 让我们来分析一下 food_list.txt 它看起来像这样： + +``` +Food List Items +No Item_Name Price Quantity +1 Mangoes $3.45 5 +2 Apples $2.45 25 +3 Pineapples $4.45 55 +4 Tomatoes $3.45 25 +5 Onions $1.45 15 +6 Bananas $3.45 30 +``` + +运行下面的命令，它将在每个食物数量小于或者等于 20 的行后面标一个星号: + +``` +# awk '$4 <= 20 { printf "%s\t%s\n", $0,"*" ; } $4 > 20 { print $0 ;} ' food_list.txt + +No Item_Name Price Quantity +1 Mangoes $3.45 5 * +2 Apples $2.45 25 +3 Pineapples $4.45 55 +4 Tomatoes $3.45 25 +5 Onions $1.45 15 * +6 Bananas $3.45 30 +``` + +上面的命令实际运行如下: + +- 首先，它用`$4 <= 20`表达式检查每个输入行的第四列（数量（Quantity））是否小于或者等于 20，如果满足条件，它将在末尾打一个星号 `(*)`。 +- 接着，它用`$4 > 20`表达式检查每个输入行的第四列是否大于20，如果满足条件，显示出来。 + +但是这里有一个问题, 当第一个表达式用`{ printf "%s\t%s\n", $0,"**" ; }`命令进行标注的时候在同样的步骤第二个表达式也进行了判断这样就浪费了时间. + +因此当我们已经用第一个表达式打印标志行的时候就不再需要用第二个表达式`$4 > 20`再次打印。 + +要处理这个问题, 我们需要用到`next` 命令： + +``` +# awk '$4 <= 20 { printf "%s\t%s\n", $0,"*" ; next; } $4 > 20 { print $0 ;} ' food_list.txt + +No Item_Name Price Quantity +1 Mangoes $3.45 5 * +2 Apples $2.45 25 +3 Pineapples $4.45 55 +4 Tomatoes $3.45 25 +5 Onions $1.45 15 * +6 Bananas $3.45 30 +``` + +当输入行用`$4 <= 20` `{ printf "%s\t%s\n", $0,"*" ; next ; }`命令打印以后，`next`命令将跳过第二个`$4 > 20` `{ print $0 ;}`表达式，继续判断下一个输入行，而不是浪费时间继续判断一下是不是当前输入行还大于 20。 + +`next`命令在编写高效的命令脚本时候是非常重要的，它可以提高脚本速度。本系列的下一部分我们将来学习如何使用 awk 来处理标准输入（STDIN）。 + +希望这篇文章对你有帮助，你可以给我们留言。 + +-------------------------------------------------------------------------------- + +via: http://www.tecmint.com/use-next-command-with-awk-in-linux/ + +作者：[Aaron Kili][a] +译者：[kokialoves](https://github.com/kokialoves) +校对：[wxy](https://github.com/wxy) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: http://www.tecmint.com/author/aaronkili/ diff --git a/published/awk/Part 7 - How to Read Awk Input from STDIN in Linux.md b/published/awk/Part 7 - How to Read Awk Input from STDIN in Linux.md new file mode 100644 index 0000000000..2730691459 --- /dev/null +++ b/published/awk/Part 7 - How to Read Awk Input from STDIN in Linux.md @@ -0,0 +1,75 @@ +awk 系列：awk 怎么从标准输入（STDIN）读取输入 +============================================ + +![](http://www.tecmint.com/wp-content/uploads/2016/06/Read-Awk-Input-from-STDIN.png) + +在 awk 系列的前几节，我们看到大多数操作都是从一个文件或多个文件读取输入，或者你想要把标准输入作为 awk 的输入。 + +在 awk 系列的第七节中，我们将会看到几个例子，你可以筛选其他命令的输出代替从一个文件读取输入作为 awk 的输入。 + +我们首先从使用 [dir 命令][1]开始，它类似于 [ls 命令][2]，在第一个例子下面，我们使用 `dir -l` 命令的输出作为 awk 命令的输入，这样就可以打印出文件拥有者的用户名，所属组组名以及在当前路径下他／她拥有的文件。 + +``` +# dir -l | awk '{print $3, $4, $9;}' +``` + +![](http://www.tecmint.com/wp-content/uploads/2016/06/List-Files-Owned-By-User-in-Directory.png) + +*列出当前路径下的用户文件* + + +再来看另一个例子，我们[使用 awk 表达式][3] ，在这里，我们想要在 awk 命令里使用一个表达式筛选出字符串来打印出属于 root 用户的文件。命令如下： + +``` +# dir -l | awk '$3=="root" {print $1,$3,$4, $9;} ' +``` + +![](http://www.tecmint.com/wp-content/uploads/2016/06/List-Files-Owned-by-Root-User.png) + +*列出 root 用户的文件* + +上面的命令包含了 `(==)` 来进行比较操作，这帮助我们在当前路径下筛选出 root 用户的文件。这是通过使用 `$3=="root"` 表达式实现的。 + +让我们再看另一个例子，我们使用一个 [awk 比较运算符][4] 来匹配一个确定的字符串。 + +这里，我们使用了 [cat 命令][5] 来浏览文件名为 tecmint_deals.txt 的文件内容，并且我们想要仅仅查看有字符串 Tech 的部分，所以我们会运行下列命令： + +``` +# cat tecmint_deals.txt +# cat tecmint_deals.txt | awk '$4 ~ /tech/{print}' +# cat tecmint_deals.txt | awk '$4 ~ /Tech/{print}' +``` + +![](http://www.tecmint.com/wp-content/uploads/2016/06/Use-Comparison-Operator-to-Match-String.png) + +*用 Awk 比较运算符匹配字符串* + +在上面的例子中，我们已经用了参数为 `~ /匹配字符/` 的比较操作，但是上面的两个命令给我们展示了一些很重要的问题。 + +当你运行带有 tech 字符串的命令时终端没有输出，因为在文件中没有 tech 这种字符串，但是运行带有 Tech 字符串的命令，你却会得到包含 Tech 的输出。 + +所以你应该在进行这种比较操作的时候时刻注意这种问题，正如我们在上面看到的那样，awk 对大小写很敏感。 + +你总是可以使用另一个命令的输出作为 awk 命令的输入来代替从一个文件中读取输入，这就像我们在上面看到的那样简单。 + +希望这些例子足够简单到可以使你理解 awk 的用法，如果你有任何问题，你可以在下面的评论区提问，记得查看 awk 系列接下来的章节内容，我们将关注 awk 的一些功能，比如变量，数字表达式以及赋值运算符。 + +-------------------------------------------------------------------------------- + +via: http://www.tecmint.com/read-awk-input-from-stdin-in-linux/ + +作者：[Aaron Kili][a] +译者：[vim-kakali](https://github.com/vim-kakali) +校对：[wxy](https://github.com/wxy) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: http://www.tecmint.com/author/aaronkili/ +[1]: http://www.tecmint.com/linux-dir-command-usage-with-examples/ +[2]: http://www.tecmint.com/15-basic-ls-command-examples-in-linux/ +[3]: https://linux.cn/article-7599-1.html +[4]: https://linux.cn/article-7602-1.html +[5]: http://www.tecmint.com/13-basic-cat-command-examples-in-linux/ + + + diff --git a/sources/news/README.md b/sources/news/README.md deleted file mode 100644 index 98d53847b1..0000000000 --- a/sources/news/README.md +++ /dev/null @@ -1 +0,0 @@ -这里放新闻类文章，要求时效性 diff --git a/sources/share/README.md b/sources/share/README.md deleted file mode 100644 index e5e225858e..0000000000 --- a/sources/share/README.md +++ /dev/null @@ -1 +0,0 @@ -这里放分享类文章，包括各种软件的简单介绍、有用的书籍和网站等。 diff --git a/sources/talk/20150806 Torvalds 2.0--Patricia Torvalds on computing college feminism and increasing diversity in tech.md b/sources/talk/20150806 Torvalds 2.0--Patricia Torvalds on computing college feminism and increasing diversity in tech.md index 10a30119e1..57faa7998f 100644 --- a/sources/talk/20150806 Torvalds 2.0--Patricia Torvalds on computing college feminism and increasing diversity in tech.md +++ b/sources/talk/20150806 Torvalds 2.0--Patricia Torvalds on computing college feminism and increasing diversity in tech.md @@ -1,5 +1,6 @@ Torvalds 2.0: Patricia Torvalds on computing, college, feminism, and increasing diversity in tech ================================================================================ + ![Image by : Photo by Becky Svartström. Modified by Opensource.com. CC BY-SA 4.0](http://opensource.com/sites/default/files/styles/image-full-size/public/images/life/osdc-lead-patriciatorvalds.png) Image by : Photo by Becky Svartström. Modified by Opensource.com. [CC BY-SA 4.0][1] diff --git a/sources/talk/20151117 How bad a boss is Linus Torvalds.md b/sources/talk/20151117 How bad a boss is Linus Torvalds.md deleted file mode 100644 index 7ebba90483..0000000000 --- a/sources/talk/20151117 How bad a boss is Linus Torvalds.md +++ /dev/null @@ -1,78 +0,0 @@ -sonofelice translating -How bad a boss is Linus Torvalds? -================================================================================ -![linus torvalds](http://images.techhive.com/images/article/2015/08/linus_torvalds-100600260-primary.idge.jpg) - -*Linus Torvalds addressed a packed auditorium of Linux enthusiasts during his speech at the LinuxWorld show in San Jose, California, on August 10, 1999. Credit: James Niccolai* - -**It depends on context. In the world of software development, he’s what passes for normal. The question is whether that situation should be allowed to continue.** - -I've known Linus Torvalds, Linux's inventor, for over 20 years. We're not chums, but we like each other. - -Lately, Torvalds has been getting a lot of flack for his management style. Linus doesn't suffer fools gladly. He has one way of judging people in his business of developing the Linux kernel: How good is your code? - -Nothing else matters. As Torvalds said earlier this year at the Linux.conf.au Conference, "I'm not a nice person, and I don't care about you. [I care about the technology and the kernel][1] -- that's what's important to me." - -Now, I can deal with that kind of person. If you can't, you should avoid the Linux kernel community, where you'll find a lot of this kind of meritocratic thinking. Which is not to say that I think everything in Linuxland is hunky-dory and should be impervious to calls for change. A meritocracy I can live with; a bastion of male dominance where women are subjected to scorn and disrespect is a problem. - -That's why I see the recent brouhaha about Torvalds' management style -- or more accurately, his total indifference to the personal side of management -- as nothing more than standard operating procedure in the world of software development. And at the same time, I see another instance that has come to light as evidence of a need for things to really change. - -The first situation arose with the [release of Linux 4.3][2], when Torvalds used the Linux Kernel Mailing List to tear into a developer who had inserted some networking code that Torvalds thought was -- well, let's say "crappy." "[[A]nd it generates [crappy] code.][3] It looks bad, and there's no reason for it." He goes on in this vein for quite a while. Besides the word "crap" and its earthier synonym, he uses the word "idiotic" pretty often. - -Here's the thing, though. He's right. I read the code. It's badly written and it does indeed seem to have been designed to use the new "overflow_usub()" function just for the sake of using it. - -Now, some people see this diatribe as evidence that Torvalds is a bad-tempered bully. I see a perfectionist who, within his field, doesn't put up with crap. - -Many people have told me that this is not how professional programmers should act. People, have you ever worked with top developers? That's exactly how they act, at Apple, Microsoft, Oracle and everywhere else I've known them. - -I've heard Steve Jobs rip a developer to pieces. I've cringed while a senior Oracle developer lead tore into a room of new programmers like a piranha through goldfish. - -In Accidental Empires, his classic book on the rise of PCs, Robert X. Cringely described Microsoft's software management style when Bill Gates was in charge as a system where "Each level, from Gates on down, screams at the next, goading and humiliating them." Ah, yes, that's the Microsoft I knew and hated. - -The difference between the leaders at big proprietary software companies and Torvalds is that he says everything in the open for the whole world to see. The others do it in private conference rooms. I've heard people claim that Torvalds would be fired in their company. Nope. He'd be right where he is now: on top of his programming world. - -Oh, and there's another difference. If you get, say, Larry Ellison mad at you, you can kiss your job goodbye. When you get Torvalds angry at your work, you'll get yelled at in an email. That's it. - -You see, Torvalds isn't anyone's boss. He's the guy in charge of a project with about 10,000 contributors, but he has zero hiring and firing authority. He can hurt your feelings, but that's about it. - -That said, there is a serious problem within both open-source and proprietary software development circles. No matter how good a programmer you are, if you're a woman, the cards are stacked against you. - -No case shows this better than that of Sarah Sharp, an Intel developer and formerly a top Linux programmer. [In a post on her blog in October][4], she explained why she had stopped contributing to the Linux kernel more than a year earlier: "I finally realized that I could no longer contribute to a community where I was technically respected, but I could not ask for personal respect.... I did not want to work professionally with people who were allowed to get away with subtle sexist or homophobic jokes." - -Who can blame her? I can't. Torvalds, like almost every software manager I've ever known, I'm sorry to say, has permitted a hostile work environment. - -He would probably say that it's not his job to ensure that Linux contributors behave with professionalism and mutual respect. He's concerned with the code and nothing but the code. - -As Sharp wrote: - -> I have the utmost respect for the technical efforts of the Linux kernel community. They have scaled and grown a project that is focused on maintaining some of the highest coding standards out there. The focus on technical excellence, in combination with overloaded maintainers, and people with different cultural and social norms, means that Linux kernel maintainers are often blunt, rude, or brutal to get their job done. Top Linux kernel developers often yell at each other in order to correct each other's behavior. -> -> That's not a communication style that works for me. … -> -> Many senior Linux kernel developers stand by the right of maintainers to be technically and personally brutal. Even if they are very nice people in person, they do not want to see the Linux kernel communication style change. - -She's right. - -Where I differ from other observers is that I don't think that this problem is in any way unique to Linux or open-source communities. With five years of work in the technology business and 25 years as a technology journalist, I've seen this kind of immature boy behavior everywhere. - -It's not Torvalds' fault. He's a technical leader with a vision, not a manager. The real problem is that there seems to be no one in the software development universe who can set a supportive tone for teams and communities. - -Looking ahead, I hope that companies and organizations, such as the Linux Foundation, can find a way to empower community managers or other managers to encourage and enforce civil behavior. - -We won't, unfortunately, find that kind of managerial finesse in our pure technical or business leaders. It's not in their DNA. - --------------------------------------------------------------------------------- - -via: http://www.computerworld.com/article/3004387/it-management/how-bad-a-boss-is-linus-torvalds.html - -作者：[Steven J. Vaughan-Nichols][a] -译者：[译者ID](https://github.com/译者ID) -校对：[校对者ID](https://github.com/校对者ID) - -本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 - -[a]:http://www.computerworld.com/author/Steven-J.-Vaughan_Nichols/ -[1]:http://www.computerworld.com/article/2874475/linus-torvalds-diversity-gaffe-brings-out-the-best-and-worst-of-the-open-source-world.html -[2]:http://www.zdnet.com/article/linux-4-3-released-after-linus-torvalds-scraps-brain-damage-code/ -[3]:http://lkml.iu.edu/hypermail/linux/kernel/1510.3/02866.html -[4]:http://sarah.thesharps.us/2015/10/05/closing-a-door/ diff --git a/sources/talk/20160506 Linus Torvalds Talks IoT Smart Devices Security Concerns and More.md b/sources/talk/20160506 Linus Torvalds Talks IoT Smart Devices Security Concerns and More.md deleted file mode 100644 index e17c33bd81..0000000000 --- a/sources/talk/20160506 Linus Torvalds Talks IoT Smart Devices Security Concerns and More.md +++ /dev/null @@ -1,46 +0,0 @@ -Linus Torvalds Talks IoT, Smart Devices, Security Concerns, and More[video] -=========================================================================== - -![](https://www.linux.com/sites/lcom/files/styles/rendered_file/public/elc-linus-b.jpg?itok=6WwnCSjL) ->Dirk Hohndel interviews Linus Torvalds at ELC. - -For the first time in the 11-year history of the [Embedded Linux Conference (ELC)][0], held in San Diego, April 4-6, the keynotes included a discussion with Linus Torvalds. The creator and lead overseer of the Linux kernel, and “the reason we are all here,” in the words of his interviewer, Intel Chief Linux and Open Source Technologist Dirk Hohndel, seemed upbeat about the state of Linux in embedded and Internet of Things applications. Torvalds very presence signaled that embedded Linux, which has often been overshadowed by Linux desktop, server, and cloud technologies, had come of age. - -![](https://www.linux.com/sites/lcom/files/styles/floated_images/public/elc-linus_0.jpg?itok=FNPIDe8k) ->Linus Torvalds speaking at Embedded Linux Conference. - -IoT was the main topic at ELC, which included an OpenIoT Summit track, and the chief topic in the Torvalds interview. - -“Maybe you won’t see Linux at the IoT leaf nodes, but anytime you have a hub, you will need it,” Torvalds told Hohndel. “You need smart devices especially if you have 23 [IoT standards]. If you have all these stupid devices that don’t necessarily run Linux, and they all talk with slightly different standards, you will need a lot of smart devices. We will never have one completely open standard, one ring to rule them all, but you will have three of four major protocols, and then all these smart hubs that translate.” - -Torvalds remained customarily philosophical when Hohndel asked about the gaping security holes in IoT. “I don’t worry about security because there’s not a lot we can do,” he said. “IoT is unpatchable -- it’s a fact of life.” - -The Linux creator seemed more concerned about the lack of timely upstream contributions from one-off embedded projects, although he noted there have been significant improvements in recent years, partially due to consolidation on hardware. - -“The embedded world has traditionally been hard to interact with as an open source developer, but I think that’s improving,” Torvalds said. “The ARM community has become so much better. Kernel people can now actually keep up with some of the hardware improvements. It’s improving, but we’re not nearly there yet.” - -Torvalds admitted to being more at home on the desktop than in embedded and to having “two left hands” when it comes to hardware. - -“I’ve destroyed things with a soldering iron many times,” he said. “I’m not really set up to do hardware.” On the other hand, Torvalds guessed that if he were a teenager today, he would be fiddling around with a Raspberry Pi or BeagleBone. “The great part is if you’re not great at soldering, you can just buy a new one.” - -Meanwhile, Torvalds vowed to continue fighting for desktop Linux for another 25 years. “I’ll wear them down,” he said with a smile. - -Watch the full video, below. - -Get the Latest on Embedded Linux and IoT. Access 150+ recorded sessions from Embedded Linux Conference 2016. [Watch Now][1]. - -[video](https://youtu.be/tQKUWkR-wtM) - --------------------------------------------------------------------------------- - -via: https://www.linux.com/news/linus-torvalds-talks-iot-smart-devices-security-concerns-and-more-video - -作者：[ERIC BROWN][a] -译者：[译者ID](https://github.com/译者ID) -校对：[校对者ID](https://github.com/校对者ID) - -本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 - -[a]: https://www.linux.com/users/ericstephenbrown -[0]: http://events.linuxfoundation.org/events/embedded-linux-conference -[1]: http://go.linuxfoundation.org/elc-openiot-summit-2016-videos?utm_source=lf&utm_medium=blog&utm_campaign=linuxcom diff --git a/sources/talk/20160509 Android vs. iPhone Pros and Cons.md b/sources/talk/20160509 Android vs. iPhone Pros and Cons.md new file mode 100644 index 0000000000..9977d46d35 --- /dev/null +++ b/sources/talk/20160509 Android vs. iPhone Pros and Cons.md @@ -0,0 +1,87 @@ +Android vs. iPhone: Pros and Cons +=================================== + +正在翻译 by jovov +>When comparing Android vs. iPhone, clearly Android has certain advantages even as the iPhone is superior in some key ways. But ultimately, which is better? + +The question of Android vs. iPhone is a personal one. + +Take myself, for example. I'm someone who has used both Android and the iPhone iOS. I'm well aware of the strengths of both platforms along with their weaknesses. Because of this, I decided to share my perspective regarding these two mobile platforms. Additionally, we'll take a look at my impressions of the new Ubuntu mobile platform and where it stacks up. + +### What iPhone gets right + +Even though I'm a full time Android user these days, I do recognize the areas where the iPhone got it right. First, Apple has a better record in updating their devices. This is especially true for older devices running iOS. With Android, if it's not a “Google blessed” Nexus...it better be a higher end carrier supported phone. Otherwise, you're going to find updates are either sparse or non-existent. + +Another area where the iPhone does well is apps availability. Expanding on that: iPhone apps almost always have a cleaner look to them. This isn't to say that Android apps are ugly, rather, they may not have an expected flow and consistency found with iOS. Two examples of exclusivity and great iOS-only layout would have to be [Dark Sky][1] (weather) and [Facebook Paper][2]. + +Then there is the backup process. Android can, by default, back stuff up to Google. But that doesn't help much with application data! By contrast, iCloud can essentially make a full backup of your iOS device. + +### Where iPhone loses me + +The biggest indisputable issue I have with the iPhone is more of a hardware limitation than a software one. That issue is storage. + +Look, with most Android phones, I can buy a smaller capacity phone and then add an SD card later. This does two things: First, I can use the SD card to store a lot of media files. Second, I can even use the SD card to store "some" of my apps. Apple has nothing that will touch this. + +Another area where the iPhone loses me is in the lack of choice it provides. Backing up your device? Hope you like iTunes or iCloud. For someone like myself who uses Linux, this means my ONLY option would be to use iCloud. + +To be ultimately fair, there are additional solutions for your iPhone if you're willing to jailbreak it. But that's not what this article is about. Same goes for rooting Android. This article is addressing a vanilla setup for both platforms. + +Finally, let us not forget this little treat – [iTunes decides to delete a user's music][3] because it was seen as a duplication of Apple Music contents...or something along those lines. Not iPhone specific? I disagree, as that music would have very well ended up onto the iPhone at some point. I can say with great certainty that in no universe would I ever put up with this kind of nonsense! + +![](http://www.datamation.com/imagesvr_ce/5552/mobile-abstract-icon-200x150.jpg) +>The Android vs. iPhone debate depends on what features matter the most to you. + +### What Android gets right + +The biggest thing Android gives me that the iPhone doesn't: choice. Choices in applications, devices and overall layout of how my phone works. + +I love desktop widgets! To iPhone users, they may seem really silly. But I can tell you that they save me from opening up applications as I can see the desired data without the extra hassle. Another similar feature I love is being able to install custom launchers instead of my phone's default! + +Finally, I can utilize tools like [Airdroid][4] and [Tasker][5] to add full computer-like functionality to my smart phone. Airdroid allows me treat my Android phone like a computer with file management and SMS with anyone – this becomes a breeze to use with my mouse and keyboard. Tasker is awesome in that I can setup "recipes" to connect/disconnect, put my phone into meeting mode or even put itself into power saving mode when I set the parameters to do so. I can even set it to launch applications when I arrive at specific destinations. + +### Where Android loses me + +Backup options are limited to specific user data, not a full clone of your phone. Without rooting, you're either left out in the wind or you must look to the Android SDK for solutions. Expecting casual users to either root their phone or run the SDK for a complete (I mean everything) Android backup is a joke. + +Yes, Google's backup service will backup Google app data, along with other related customizations. But it's nowhere near as complete as what we see with the iPhone. To accomplish something similar to what the iPhone enjoys, I've found you're going to either be rooting your Android phone or connecting it to a Windows PC to utilize some random program. + +To be fair, however, I believe Nexus owners benefit from a [full backup service][6] that is device specific. Sorry, but Google's default backup is not cutting it. Same applies for adb backups via your PC – they don't always restore things as expected. + +Wait, it gets better. Now after a lot of failed let downs and frustration, I found that there was one app that looked like it "might" offer a glimmer of hope, it's called Helium. Unlike other applications I found to be misleading and frustrating with their limitations, [Helium][7] initially looked like it was the backup application Google should have been offering all along -- emphasis on "looked like." Sadly, it was a huge let down. Not only did I need to connect it to my computer for a first run, it didn't even work using their provided Linux script. After removing their script, I settling for a good old fashioned adb backup...to my Linux PC. Fun facts: You will need to turn on a laundry list of stuff in developer tools, plus if you run the Twilight app, that needs to be turned off. It took me a bit to put this together when the backup option for adb on my phone wasn't responding. + +At the end of the day, Android has ample options for non-rooted users to backup superficial stuff like contacts, SMS and other data easily. But a deep down phone backup is best left to a wired connection and adb from my experience. + +### Ubuntu will save us? + +With the good and the bad examined between the two major players in the mobile space, there's a lot of hope that we're going to see good things from Ubuntu on the mobile front. Well, thus far, it's been pretty lackluster. + +I like what the developers are doing with the OS and I certainly love the idea of a third option for mobile besides iPhone and Android. Unfortunately, though, it's not that popular on the phone and the tablet received a lot of bad press due to subpar hardware and a lousy demonstration that made its way onto YouTube. + +To be fair, I've had subpar experiences with iPhone and Android, too, in the past. So this isn't a dig on Ubuntu. But until it starts showing up with a ready to go ecosystem of functionality that matches what Android and iOS offer, it's not something I'm terribly interested in yet. At a later date, perhaps, I'll feel like the Ubuntu phones are ready to meet my needs. + +### Android vs. iPhone bottom line: Why Android wins long term + +Despite its painful shortcomings, Android treats me like an adult. It doesn't lock me into only two methods for backing up my data. Yes, some of Android's limitations are due to the fact that it's focused on letting me choose how to handle my data. But, I also get to choose my own device, add storage on a whim. Android enables me to do a lot of cool stuff that the iPhone simply isn't capable of doing. + +At its core, Android gives non-root users greater access to the phone's functionality. For better or worse, it's a level of freedom that I think people are gravitating towards. Now there are going to be many of you who swear by the iPhone thanks to efforts like the [libimobiledevice][8] project. But take a long hard look at all the stuff Apple blocks Linux users from doing...then ask yourself – is it really worth it as a Linux user? Hit the Comments, share your thoughts on Android, iPhone or Ubuntu. + +------------------------------------------------------------------------------ + +via: http://www.datamation.com/mobile-wireless/android-vs.-iphone-pros-and-cons.html + +作者：[Matt Hartley][a] +译者：[译者ID](https://github.com/译者ID) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创翻译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: http://www.datamation.com/author/Matt-Hartley-3080.html +[1]: http://darkskyapp.com/ +[2]: https://www.facebook.com/paper/ +[3]: https://blog.vellumatlanta.com/2016/05/04/apple-stole-my-music-no-seriously/ +[4]: https://www.airdroid.com/ +[5]: http://tasker.dinglisch.net/ +[6]: https://support.google.com/nexus/answer/2819582?hl=en +[7]: https://play.google.com/store/apps/details?id=com.koushikdutta.backup&hl=en +[8]: http://www.libimobiledevice.org/ + diff --git a/sources/talk/20160516 Linux will be the major operating system of 21st century cars.md b/sources/talk/20160516 Linux will be the major operating system of 21st century cars.md index ec7a33aaa6..dbde68bda8 100644 --- a/sources/talk/20160516 Linux will be the major operating system of 21st century cars.md +++ b/sources/talk/20160516 Linux will be the major operating system of 21st century cars.md @@ -1,3 +1,4 @@ +KevinSJ Translating Linux will be the major operating system of 21st century cars =============================================================== diff --git a/sources/talk/20160523 Driving cars into the future with Linux.md b/sources/talk/20160523 Driving cars into the future with Linux.md deleted file mode 100644 index 9b9d69d68c..0000000000 --- a/sources/talk/20160523 Driving cars into the future with Linux.md +++ /dev/null @@ -1,108 +0,0 @@ - -驾车通往未来Linux -=========================================== - -![](https://opensource.com/sites/default/files/styles/image-full-size/public/images/life/open-snow-car-osdc-lead.png?itok=IgYZ6mNY) - - -当我开车的时候不认为和 Linux 有多大联系，但是我肯定我是喜欢一个配备有系统的车子，让我按几个按钮语音就可以传给我的妻子母亲以及孩子。同样，这样的系统可以让我选择是否从云端流媒体收听音乐，卫星广播，以及传统的 AM/FM 收音机。我也会得到天气更新以及可以给我的车载信息娱乐 GPS 找到最快的下一个目的地[In-vehicle infotainment][1]，以及 IVI 作为行业知名产业，已经普及到最新的汽车生产商。 - -前段时间，我不得坐飞机飞跃数百英里，租一辆车。令人愉快的是，我发现我的租凭车配置了 IVI 技术。任何时候，我只要通过蓝牙连接，上传联系人到系统中，打电话回家给我的家人，让他们知道我已经安全到家了。然后“主人“会知道我再途中还是已经到他们家了。 - -在最近的 [news roundup][2]，Scott Nesbitt 引用一篇文章，说福特汽车公司是由它的开源 [Smart Device Link][3]（SDL）中间设备框架，对手汽车制造商，支持那个移动手机获得大量的支持。 SDL 是 [GENIVI Alliance][4] 的项目，一个非营利性的致力于建设中间件支持开源的车载信息娱乐系统。根据文献 [[Steven Crumb][5]，GENIVI 执行董事，他们 [membership][6] 很广，包括 Daimler 集团，现代，沃尔沃，日产，本田等等 170 个。 - -为了在同行业中保持竞争力，汽车企业需要一个中间设备系统，可以支持当今消费者提供的各种人机界面技术。无论您拥有 Android，iOS 或其他设备，汽车 OEM 厂商希望自己的系统单位能够支持这些。此外，这些的 IVI 系统必须有足够适应能力以支持移动技术的不断下降，半衰期。 OEM 厂商要提供价值服务，并在他们的 IVI 堆栈支持各种为他们的客户添加选择。进入 Linux 和开源软件。 - -除了 GENIVI 的努力下，[Linux Foundation][7] 赞助 [Automotive Grade Linux][8]（AGL）工作组，一个软件基金会，致力于寻找针对汽车应用的开源解决方案。虽然 AGL 初期将侧重于 IVI 系统，他们展望不同的分歧，包括 [telematics][9]，小心显示器和其他控制系统。 AGL 有超过 50 名成员在这个时候，包括捷豹，丰田，日产，并在 [recent press release][10] 宣布福特、马自达、三菱、和斯巴鲁加入。 - - -为了了解更多信息，我们在这一新鲜兴领域采访了两位领导人。明确地来说，我们想知道是如何被使用的 Linux 和开源软件，如果它们实际上是改变汽车行业的面貌。首先，我们谈谈 [Alison Chaiken][11]，在大集团技术的软件工程师和汽车 Linux 专家，网络安全和透明度。她曾任职于 [Alison Chaiken][11] 公司，诺基亚和斯坦福直线性加速器。然后我们用 [Steven Crumb][12]，GENIVI 执行董事，谁得到了在开源环境高性能计算（超级计算机和早期的云计算）开始聊天。他说，虽然他再不是一个程序员了，但是他喜欢帮助企业解决开源软件的实际业务问题。 - -### 采访 Alison Chaiken (by [Deb Nicholson][13]) - -#### 你是如何开始对汽车软件空间感兴趣的？ - -我是在诺基亚手机产品时， 2009 年该项目被取消。我想，下一步是什么？一位同事正在对 [MeeGo-IVI][15]，早期的汽车 Linux 发行版。 “Linux 在汽车是大了，” 我想，所以我在朝着这个方向努力。 - -#### 你能告诉我们你这些日子工作在哪些方面？ - -我目前正在启动为使用 Linux 系统增加大货车钻机的安全性和燃油经济性的先进巡航控制。我喜欢在这方面的工作，因为没有人会反对卡车得以提升。 - -#### 目前关于汽车已在近年来砍死几个人故事。开源代码方案可以帮助解决这个问题吗？ - -I presented a talk on precisely this topic, on how Linux can (and cannot) contribute to security solutions in automotive at Southern California Linux Expo 2016 ([Slides][16]). Notably, GENIVI and Automotive Grade Linux have published their code and both projects take patches via Git. Please send your fixes upstream! Many eyes make all bugs shallow. -我提出的谈话正是这一主题，就如何 Linux 可以（或不可以）在南加州 2016 年世博会作出贡献的安全解决方案的 Linux汽车([Slides][16])。值得注意的是，GENIVI 和汽车级 Linux 已经公布了他们的代码，这两个项目的 Git 通过采取补丁。请上游发送您的修复！许多眼睛都盯着肤浅的bugs。 - -#### 执法机构和保险公司可以找到很多有关数据用途的驱动程序。它将如何容易成为他们获取这些信息？ - -好问题。该专用短程通信标准（IEEE-1609），以保持匿名的 Wi-Fi 安全消息驱动程序。不过，如果你从你的车张贴到 Twitter，有人能够跟踪你。 - -#### 有什么可以开发人员和公民个人一起完成，以确保公民自由受到保护作为汽车技术发展的？ - -电子前沿基金会（EFF）一样对汽车保持的问题上，通过什么样的数据可以存储在汽车 “黑盒子”，并在 DMCA 的规定 1201 如何应用于汽车官方渠道评论已经出色的工作了。 - -#### 在未来几年令人兴奋的事情上，那些是你看到的驱动因素？ - -自适应巡航控制和防撞系统有足够的预付款来挽救生命。当他们通过运输车队的推出，我真的相信死亡人数会下降。如果这还不是令人兴奋的，我不知道是什么。此外，像自动化停车辅助功能，将会使汽车更容易驾驶，减少汽车相撞事故。 - -#### 有什么是需要人参与以及如何建造？ - -汽车 Linux 级开发是开放源代码的，运行在廉价硬件（如树莓派 Pi 2 和中等价位的 Renesas Porter board），任何人都可以购买。 GENIVI 汽车 Linux 的中间设备联盟有很多软件通过 Git 的公开。此外，还有很酷的 [OSVehicle open hardware][17] 汽车平台。 - -#### 这里是 Linux 软件和开放硬件，许多方面具有中等人数预算的参与。如果您有任何疑问，加入我们在 Freenode 上 IRC#automotive。 - -### 采访 Steven Crumb (by Don Watkins) - -#### 关于GENIVI's 对 IVI 为什么那么大 ? - -GENIVI 率先通过使用自由和开源软件，包括 Linux，像车载信息娱乐（IVI）系统的非安全关键汽车软件填补了汽车行业的巨大差距。作为消费者来到期望在他们的车辆相同的功能在智能手机上的软件，以支持 IVI 功能所需的量成倍增长。软件增加量也增加了建设 IVI 系统的成本，从而延缓了上市时间。 - -GENIVI 的使用开源软件和社区发展模式节省了汽车制造商和他们的软件提供商显著大量的资金，而显著减少了产品上市时间。我很兴奋，因为 GENIVI 我们很幸运慢慢从高度结构化和专有的方法来社区为基础的方法不断发展的组织​​领导排序在汽车行业的一场革命。我们还没有完成，但它一直是一个荣幸参加正在产生实实在在的好处的转换。 - -#### 你的庞大会员怎么才可以驱动 GENIVI 方向？ - -GENIVI 有很多会员和非会员促进我们的工作。与许多开源项目，任何公司都可以通过简单地贡献代码，修补程序和时间来检验影响的技术输出。随着中说，宝马，奔驰，现代汽车，捷豹路虎，标致雪铁龙，雷诺 / 日产和沃尔沃是所有积极采用者和贡献者 GENIVI 和其他许多 OEM 厂商已经在他们的汽车 IVI 解决方案，广泛使用 GENIVI 的软件。 - -#### 贡献的代码使用了什么许可证？ - -GENIVI 采用数量的许可证从（L）GPLv2 许可，以 MPLv2 到 Apache2.0。我们的一些工具使用 Eclipse 许可证。我们有一个[public licensing policy][18]，详细说明我们的许可偏好。 - -#### 一个人或一群人如何参与其中？重要的是如何对项目的持续成功的社区贡献？ - -GENIVI 完全做它开放发展的在([projects.genivi.org][19])，因此，有兴趣的人在汽车使用开源软件，欢迎参加。这就是说，该联盟能够通过公司 [joining GENIVI][20] 作为成员不断发展的开放基金。 GENIVI 会员享受各种各样的福利，而不是其中最重要的是在已经发展了近六年来 140 家公司全球社区参与。 - -社区是 GENIVI 非常重要的，我们不可能生产和维护我们发展了很多年没有贡献者一个活跃的社区有价值的软件。我们努力做出贡献 GENIVI 简单，只要加入一个 [邮件列表] [21] 并连接到人们在不同的软件项目。我们使用许多开源项目采用的标准做法，并提供高质量的工具和基础设施，以帮助开发人员有宾至如归的感觉，并富有成效。 - -无论在汽车软件某人的熟悉，欢迎他们加入我们的社区。人们已经改装车多年，所以对于许多人来说，是一种天然的抽奖，任何汽车。软件是汽车的新域，GENIVI 希望成为敞开的门有兴趣的人与汽车，开源软件的工作。 - -------------------------------- -via: https://opensource.com/business/16/5/interview-alison-chaiken-steven-crumb - -作者：[Don Watkins][a] -译者：[erlinux](https://github.com/erlinux) -校对：[校对者ID](https://github.com/校对者ID) - -本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创翻译，[Linux中国](https://linux.cn/) 荣誉推出 - -[a]: https://opensource.com/users/don-watkins -[1]: https://en.wikipedia.org/wiki/In_car_entertainment -[2]: https://opensource.com/life/16/1/weekly-news-jan-9 -[3]: http://projects.genivi.org/smartdevicelink/home -[4]: http://www.genivi.org/ -[5]: https://www.linkedin.com/in/stevecrumb -[6]: http://www.genivi.org/genivi-members -[7]: http://www.linuxfoundation.org/ -[8]: https://www.automotivelinux.org/ -[9]: https://en.wikipedia.org/wiki/Telematics -[10]: https://www.automotivelinux.org/news/announcement/2016/01/ford-mazda-mitsubishi-motors-and-subaru-join-linux-foundation-and -[11]: https://www.linkedin.com/in/alison-chaiken-3ba456b3 -[12]: https://www.linkedin.com/in/stevecrumb -[13]: https://opensource.com/users/eximious -[14]: https://en.wikipedia.org/wiki/MeeGo -[15]: http://webinos.org/deliverable-d026-target-platform-requirements-and-ipr/automotive/ -[16]: http://she-devel.com/Chaiken_automotive_cybersecurity.pdf -[17]: https://www.osvehicle.com/ -[18]: http://projects.genivi.org/how -[19]: http://projects.genivi.org/ -[20]: http://genivi.org/join -[21]: http://lists.genivi.org/mailman/listinfo/genivi-projects diff --git a/sources/talk/20160525 What containers and unikernels can learn from Arduino and Raspberry Pi.md b/sources/talk/20160525 What containers and unikernels can learn from Arduino and Raspberry Pi.md index a1d6257d4d..ff81871630 100644 --- a/sources/talk/20160525 What containers and unikernels can learn from Arduino and Raspberry Pi.md +++ b/sources/talk/20160525 What containers and unikernels can learn from Arduino and Raspberry Pi.md @@ -1,3 +1,5 @@ +MikeCoder Translating... + What containers and unikernels can learn from Arduino and Raspberry Pi ========================================================================== diff --git a/sources/talk/20160531 The Anatomy of a Linux User.md b/sources/talk/20160531 The Anatomy of a Linux User.md deleted file mode 100644 index b403758f2a..0000000000 --- a/sources/talk/20160531 The Anatomy of a Linux User.md +++ /dev/null @@ -1,57 +0,0 @@ -vim-kakali translating - -The Anatomy of a Linux User -================================ - - -**Some new GNU/Linux users understand right away that Linux isn’t Windows. Others never quite get it. The best distro designers strive to keep both in mind.** - -### The Heart of Linux - -Nicky isn’t outwardly remarkable in any way. She’s a thirtysomething who decided to go back to school later in life than most. She spent six years in the Navy until she decided a job offer from an old friend would be a better bet than a career in the armed forces. That happens a lot in any of the post-war military service branches. It was at that job where I met her. She was the regional manager for an eight state trucking broker and I was driving for a meat packing outfit in Dallas. - -![](http://i2.wp.com/fossforce.com/wp-content/uploads/2016/05/anatomy.jpg?w=525) - -We became good friends in 2006, Nicky and me. She’s an outgoing spirit, curious about almost anyone whose path she crosses. We had an ongoing Friday night date to go fight in an indoor laser combat arena. It wasn’t rare for us to burn through three 30 minute sessions in a row. Maybe it wasn’t as cheap as a paint ball arena, but it was climate controlled and had a horror game feel to it. It was during one of those outings that she asked me if I could fix her computer. - -She knew about my efforts to get computers into the homes of disadvantaged kids and I kidded her about paying into Bill Gates’ 401K plan when she complained about her computer becoming too slow. Nicky figured this was as good a time as any to see what Linux was all about. - -Her computer was a decent machine, a mid 2005 Asus desktop with a Dell 19″ monitor. Unfortunately, it had all the obligatory toolbars and popups that a Windows computer can collect when not properly tended. After getting all of the files from the computer, we began the process of installing Linux. We sat together during the install process and I made sure she understood the partitioning process. Inside of an hour, she had a bright new and shiny PCLinuxOS desktop. - -She remarked often, as she navigated her way through her new system, at how beautiful the system looked. She wasn’t mentioning this as an aside; she was almost hypnotized by the sleek beauty in front of her. She remarked that her screen “shimmered” with beauty. That’s something I took away from our install session and have made sure to deploy on every Linux computer I’ve installed since. I want the screen to shimmer for everyone. - -The first week or so, she called or emailed me with the usual questions, but the one that was probably the most important was wanting to know how to save her OpenOffice documents so colleagues could read them. This is key when teaching anyone Linux or Open/LibreOffice. Most people just obey the first popup, allow the document to be saved in Open Document Format and get their fingers bit in the process. - -There was a story going around a year or so ago about a high school kid who claimed he flunked an exam when his professor couldn’t open the file containing his paper. It made for some blustery comments from readers who couldn’t decide who was more of a moron, the kid for not having a clue or his professor for not having a ummm… clue of his own. - -I know some college professors and each and every one of them could figure out how to open an ODF file. Heck, even as much as Microsoft can be grade A, blue-ribbon proprietary jerks, I think Microsoft Office has been able to open an ODT or ODF file for a while now. I can’t say for sure since I haven’t used Microsoft Office much since 2005. - -Even in the bad ol’ days, when Microsoft was openly and flagrantly shoving their way onto enterprise desktops via their vendor lock-in, I never had a problem when conducting business or collaborating with users of Microsoft Office, because I became pro-active and never assumed. I would email the person or people I was to work with and ask what version of Office they were using. From that information, I could make sure to save my documents in a format they could readily open and read. - -But back to Nicky, who put a lot of time into learning about her Linux computer. I was surprised by her enthusiasm. - -Learning how to use Linux on the desktop is made much simpler when the person doing the learning realizes that all habits and tools for using Windows are to be left at the door. Even after telling our Reglue kids this, more often than not when I come back to do a check-up with them there is some_dodgy_file.exe on the desktop or in the download folder. - -While we are in the general vicinity of discussing files, let’s talk about doing updates. For a long time I was dead set against having multiple program installers or updaters on the same computer. In the case of Mint, it was decided to disable the update ability completely within Synaptic and that frosted my flakes. But while for us older folks dpkg and apt are our friends, wise heads have prevailed and have come to understand that the command line doesn’t often seem warm and welcoming to new users. - -I frothed at the mouth and raged against the machine over the crippling of Synaptic until it was ‘splained to me. Do you remember when you were just starting out and had full admin rights to your brand new Linux install? Remember when you combed through the massive amounts of software listed in Synaptic? Remember how you began check marking every cool program you found? Do you remember how many of those cool programs started with the letters “lib”? - -Yeah, me too. I installed and broke a few brand new installations until I found out that those LIB files were the nuts and bolts of the application and not the application itself. That’s why the genius’ behind Linux Mint and Ubuntu have created smart, pretty-to-look-at and easy-to-use application installers. Synaptic is still there for us old heads, but for the people coming up behind us, there are just too many ways to leave a system open to major borks by installing lib files and the like. In the new installers, those files are tucked away and not even shown to the user. And really, that’s the way it should be. - -Unless you are charging for support calls that is. - -There are a lot of smarts built into today’s Linux distros and I applaud those folks because they make my job easier. Not every new user is a Nicky. She was pretty much an install and forget project for me, and she is in the minority. The majority of new Linux users can be needy at times. - -That’s okay. They are the ones who will be teaching their kids how to use Linux. - --------------------------------------------------------------------------------- - -via: http://fossforce.com/2016/05/anatomy-linux-user/ - -作者：[Ken Starks][a] -译者：[译者ID](https://github.com/译者ID) -校对：[校对者ID](https://github.com/校对者ID) - -本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 - -[a]: http://linuxlock.blogspot.com/ diff --git a/sources/talk/20160606 Who needs a GUI - How to live in a Linux terminal.md b/sources/talk/20160606 Who needs a GUI - How to live in a Linux terminal.md new file mode 100644 index 0000000000..148d758216 --- /dev/null +++ b/sources/talk/20160606 Who needs a GUI - How to live in a Linux terminal.md @@ -0,0 +1,109 @@ +chenxinlong translating +Who needs a GUI? How to live in a Linux terminal +================================================= + +![](http://core0.staticworld.net/images/article/2016/07/linux-terminal-1-100669790-orig.jpg) + +### The best Linux shell apps for handling common functions + +Ever consider the idea of living entirely in a Linux terminal? No graphical desktop. No modern GUI software. Just text—and nothing but text—inside a Linux shell. It may not be easy, but it’s absolutely doable. [I recently tried living completely in a Linux shell for 30 days][1]. What follows are my favorite shell applications for handling some of the most common bits of computer functionality (web browsing, word processing, etc.). With a few obvious holes. Because being text-only is hard. + +![](http://core0.staticworld.net/images/article/2016/07/linux-terminal-2-100669791-orig.png) + +### Emailing within a Linux terminal + +For emailing in a terminal, we are spoiled for choice. Many people recommend mutt and notmuch. Both of those are powerful and excellent, but I prefer alpine. Why? Not only does it work well, but it’s also much more of a familiar interface if you are used to GUI email software like Thunderbird. + +![](http://core0.staticworld.net/images/article/2016/07/linux-terminal-3-100669837-orig.jpg) + +### Web browsing within a Linux terminal + +I have one word for you: [w3m][5]. Well, I suppose that’s not even really a word. But w3m is definitely my terminal web browser of choice. It tenders things fairly well and is powerful enough to even let you post to sites such as Google Plus (albeit, not in a terribly fun way). Lynx may be the de facto text-based web browser, but w3m is my favorite. + +![](http://core0.staticworld.net/images/article/2016/07/linux-terminal-4-100669838-orig.jpg) + +### Text editing within a Linux terminal + +For editing simple text files, I have one application that I straight-up love. No, not emacs. Also, definitely not vim. For editing of a text file or jotting down some notes, I like nano. Yes, nano. It’s simple, easy to learn and pleasant to use. Are there pieces of software with more features? Sure. But nano is just delightful. + +![](http://core0.staticworld.net/images/article/2016/07/linux-terminal-5-100669839-orig.jpg) + +### Word processing within a Linux terminal + +In a shell—with nothing but text—there really isn’t a huge difference between a “text editor” and a “word processor.” But being as I do a lot of writing, having a piece of software built specifically for long-form writing is a definite must. My favorite is wordgrinder. It has just enough tools to make me happy, a nice menu-driven interface (with hot-keys), and it supports multiple file types, including OpenDocument, HTML and a bunch of other ones. + +![](http://core0.staticworld.net/images/article/2016/07/linux-terminal-6-100669795-orig.jpg) + +### Music playing within a Linux terminal + +When it comes to playing music (mp3, Ogg, etc.) from a shell, one piece of software is king: [cmus][7]. It supports every conceivable file format. It’s super easy to use and incredibly fast and light on system resource usage. So clean. So streamlined. This is what a good music player should be like. + +![](http://core0.staticworld.net/images/article/2016/07/linux-terminal-7-100669796-orig.jpg) + +### Instant messaging within a Linux terminal + +When I realized how will I could instant message from the terminal, my head exploded. You know Pidgin, the multi-protocol IM client? Well, it has a version for the terminal, called “[finch][8],” that allows you to connect to multiple networks and chat with multiple people at once. The interface is even similar to Pidgin. Just amazing. Use Google Hangouts? Try [hangups][9]. It has a nice tabbed interface and works amazingly well. Seriously. Other than needing perhaps some emoji and inline pictures, instant messaging from the shell is a great experience. + +![](http://core0.staticworld.net/images/article/2016/07/linux-terminal-8-100669797-orig.jpg) + +### Tweeting within a Linux terminal + +No joke. Twitter, in your terminal, thanks to [rainbowstream][10]. I hit a few bugs here and there, but overall, it works rather well. Not as well as the website itself—and not as well as the official mobile clients—but, come on, this is Twitter in a shell. Even if it has one or two rough edges, this is pretty stinkin’ cool. + +![](http://core0.staticworld.net/images/article/2016/07/linux-terminal-9-100669798-orig.jpg) + +### Reddit-ing within a Linux terminal + +Spending time on Reddit from the comforts of the command line feels right somehow. And with rtv, it’s a rather pleasant experience. Reading. Commenting. Voting. It all works. The experience isn’t actually all that different than the website itself. + +![](http://core0.staticworld.net/images/article/2016/07/linux-terminal-10-100669799-orig.jpg) + +### Process managing within a Linux terminal + +Use [htop][12]. It’s like top—only better and prettier. Sometimes I just leave htop up and running all the time. Just because. In that regard, it’s like a music visualizer—only for RAM and CPU usage. + +![](http://core0.staticworld.net/images/article/2016/07/linux-terminal-11-100669800-orig.png) + +### File managing within a Linux terminal + +Just because you’re in a text-based shell doesn’t mean you don’t enjoy the finer things in life. Like having a nice file browser and manager. In that regard, [Midnight Commander][13] is a pretty doggone great one. + +![](http://core0.staticworld.net/images/article/2016/07/linux-terminal-12-100669801-orig.png) + +### Terminal managing within a Linux terminal + +If you spend much time in the shell, you’re going to need a terminal multiplexer. Basically it’s a piece of software that lets you split up your terminal session into a customizable grid, allowing you to use and see multiple terminal applications at the same time. It’s a tiled window manager for your shell. My favorite is [tmux][14]. But [GNU Screen][15] is also quite nice. It might take a few minutes to learn how to use it, but once you do, you’ll be glad you did. + +![](http://core0.staticworld.net/images/article/2016/07/linux-terminal-13-100669802-orig.jpg) + +### Presentation-ing within a Linux terminal + +LibreOffice, Google Slides or, gasp, PowerPoint. I spend a lot of time in presentation software. The fact that one exists for the shell pleases me greatly. It’s called, appropriately, “[text presentation program][16].” There are no images (obviously), just a simple program for displaying slides put together in a simple markup language. It may not let you embed pictures of cats, but you’ll earn some serious nerd-cred for doing an entire presentation from the terminal. + +-------------------------------------------------------------------------------- + +via: http://www.networkworld.com/article/3091139/linux/who-needs-a-gui-how-to-live-in-a-linux-terminal.html#slide1 + +作者：[Bryan Lunduke][a] +译者：[译者ID](https://github.com/chenxinlong) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创翻译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: http://www.networkworld.com/author/Bryan-Lunduke/ +[1]: http://www.networkworld.com/article/3083268/linux/30-days-in-a-terminal-day-0-the-adventure-begins.html +[2]: https://en.wikipedia.org/wiki/Mutt_(email_client) +[3]: https://notmuchmail.org/ +[4]: https://en.wikipedia.org/wiki/Alpine_(email_client) +[5]: https://en.wikipedia.org/wiki/W3m +[6]: http://cowlark.com/wordgrinder/index.html +[7]: https://en.wikipedia.org/wiki/Cmus +[8]: https://developer.pidgin.im/wiki/Using%20Finch +[9]: https://github.com/tdryer/hangups +[10]: http://www.rainbowstream.org/ +[11]: https://github.com/michael-lazar/rtv +[12]: http://hisham.hm/htop/ +[13]: https://en.wikipedia.org/wiki/Midnight_Commander +[14]: https://tmux.github.io/ +[15]: https://en.wikipedia.org/wiki/GNU_Screen +[16]: http://www.ngolde.de/tpp.html diff --git a/sources/talk/20160614 ​Ubuntu Snap takes charge of Linux desktop and IoT software distribution.md b/sources/talk/20160614 ​Ubuntu Snap takes charge of Linux desktop and IoT software distribution.md deleted file mode 100644 index 6992f76156..0000000000 --- a/sources/talk/20160614 ​Ubuntu Snap takes charge of Linux desktop and IoT software distribution.md +++ /dev/null @@ -1,110 +0,0 @@ -Ubuntu Snap takes charge of Linux desktop and IoT software distribution -=========================================================================== - -[Canonical][28] and [Ubuntu][29] founder Mark Shuttleworth said in an interview that he hadn't planned on an announcement about Ubuntu's new [Snap app package format][30]. But then in a matter of a few months, developers from multiple Linux distributions and companies announced they would use Snap as a universal Linux package format. - -![](http://zdnet2.cbsistatic.com/hub/i/r/2016/06/14/a9b2a139-3cd4-41bf-8e10-180cb9450134/resize/770xauto/adc7d16a46167565399ecdb027dd1416/ubuntu-snap.jpg) ->Linux distributors, ISVs, and companies are all adopting Ubuntu Snap to distribute and update programs across all Linux varieties. - -Why? Because Snap enables a single binary package to work perfectly and securely on any Linux desktop, server, cloud or device. According to Olli Ries, head of Canonical's Ubuntu client platform products and releases: - ->The [security mechanisms in Snap packages][1] allow us to open up the platform for much faster iteration across all our flavors as Snap applications are isolated from the rest of the system. Users can install a Snap without having to worry whether it will have an impact on their other apps or their system. - -Of course, as Matthew Garrett, a former Linux kernel developer and CoreOS security developer, has pointed out: If you [use Snap with an insecure program, such as the X11][2] window system, you don't actually gain any security. - -Shuttleworth agrees with Garrett but points out that you can control how Snap applications interact with the rest of this system. So, for example, a web browser can be contained within a secure Snap, which uses the Ubuntu packaged [openssl][3] Transport Layer Security (TLS) and Secure Sockets Layer (SSL) library. In addition, even if something does break into the browser instance, it still can't get to the underlying operating system. - -Many companies agree. [Dell][4], [Samsung][5], [Mozilla][6], [Krita][7], [Mycroft][8], and [Horizon Computing][9] are adopting Snap. [Arch Linux][10], [Debian][11], [Gentoo][12], and [OpenWrt][13] developers have also embraced Snaps and are adding it to their Linux distributions - -Snap packages, aka "Snaps", now work natively on Arch, Debian, Fedora, Kubuntu, Lubuntu, Ubuntu GNOME, Ubuntu Kylin, Ubuntu MATE, Ubuntu Unity, and Xubuntu. Snap is being validated on CentOS, Elementary, Gentoo, Mint, OpenSUSE, and Red Hat Enterprise Linux (RHEL), and are easy to enable on other Linux distributions. - -These distributions are adopting Snaps, Shuttleworth explained, because "Snaps bring those apps to every Linux desktop, server, device or cloud machine, giving users freedom to choose any Linux distribution while retaining access to the best apps." - -Taken together these distributions represent the vast majority of common Linux desktop, server and cloud distributions. Why would they switch from their existing package management systems? "One nice feature of Snaps is support for edge and beta channels, which allow users to opt-in to the pre-release developer versions of software or stick with the latest stable versions." explained Tim Jester-Pfadt, an Arch Linux contributor. - -In addition to the Linux distributors, independent software vendors (ISVs) are embracing Snap since it greatly simplifies third-party Linux app distribution and security maintenance. For example, [The Document Foundation][14] will be making the popular open-source office suite [LibreOffice][15] available as a Snap. - -Thorsten Behrens, co-founder of The Document Foundation explained: - ->Our objective is to make LibreOffice easily available to as many users as possible. Snaps enable our users to get the freshest LibreOffice releases across different desktops and distributions quickly, easily and consistently. As a bonus, it should help our release engineers to eventually move away from bespoke, home-grown and ancient Linux build solutions, towards something that is collectively maintained. - -In a statement, Nick Nguyen, Mozilla's [Firefox][16] VP, added: - ->We strive to offer users a great experience and make Firefox available across many platforms, devices and operating systems. With the introduction of Snaps, continually optimizing Firefox will become possible, providing Linux users the most up-to-date features. - -Boudewijn Rempt, project lead at the [Krita Foundation][17], a KDE-based graphics program, said: - ->Maintaining DEB packages in a private repository was complex and time consuming, snaps are much easier to maintain, package and distribute. Putting the snap in the store was particularly simple, this is the most streamlined app store I have published software in. [Krita 3.0][18] has just been released as a snap which will be updated automatically as newer versions become available. - -It's not just Linux desktop programmers who are excited by Snap. Internet of Things (IoT) and embedded developers are also grabbing on to Snap with both hands. - -Because Snaps are isolated from one another to help with data security, and can be updated or rolled back automatically, they are ideal for devices. Multiple vendors have launched snappy IoT devices, enabling a new class of "smart edge" device with IoT app store. Snappy devices receive automatic updates for the base OS, together with updates to the apps installed on the device. - -Dell, which according to Shuttleworth was one of the first IoT vendors to see the power of Snap, will be using Snap in its devices. - -"We believe Snaps address the security risks and manageability challenges associated with deploying and running multiple third party applications on a single IoT Gateway," said Jason Shepherd, Dell's Director of IoT Strategy and Partnerships. "This trusted and universal app format is essential for Dell, our IoT Solutions Partners and commercial customers to build a scalable, IT-ready, and vibrant ecosystem of IoT applications." - -It's simple, explained OpenWrt developer Matteo Croce. "Snaps deliver new applications to OpenWrt while leaving the core OS unchanged.... Snaps are a faster way to deliver a wider range of software to supported OpenWrt access points and routers." - -Shuttleworth doesn't see Snaps replacing existing Linux package systems such as [RPM][19] and [DEB][20]. Instead he sees it as being complementary to them. Snaps will sit alongside the native package. Each distribution has its own mechanisms to provide and update the core operating system and its updates. What Snap brings to the table is universal apps that cannot interfere with the base operating system - -Each Snap is confined using a range of kernel isolation and security mechanisms, tailored to the Snap application's needs. A careful review process ensures that snaps only receive the permissions they require to operate. Users will not have to make complex security decisions when installing the snap. - -Since Snaps are essentially self-contained zip files that can be quickly executed in place, "Snaps are much easier to create than traditional Linux packages, and allow us to evolve dependencies independent of the base operating system, so we can easily provide the very best and latest Chinese Linux apps to users across all distributions," explained Jack Yu, leader of the popular [Chinese Ubuntu Kylin][21] team. - -The snap format, designed by Canonical, is handled by [snapd][22]. Its development work is done on [GitHub][23]. Porting snapd to a wide range of Linux distributions has proven straightforward, and the community has grown to include contributors from a wide range of Linux backgrounds. - -Snap packages are created with the snapcrafttool. The home of the project is [snapcraft.io][24], which includes a tour and step-by-step guides to Snap creation, along with documentation for users and contributors to the project. Snaps can be built from existing distribution packages, but are more commonly built from source for optimization and size efficiency. - -Unless you're an Ubuntu power-user or serious Linux developer you may not have heard of Snap. In the future, anyone who does work with Linux on any platform will know the program. It's well on its way to becoming a major -- perhaps the most important of all -- Linux application installation and upgrade mechanism. - -#### Related Stories: - -- [Linux expert Matthew Garrett: Ubuntu 16.04's new Snap format is a security risk][25] -- [Ubuntu Linux 16.04 is here][26] -- [Microsoft and Canonical partner to bring Ubuntu to Windows 10][27] - - --------------------------------------------------------------------------------- - -via: http://www.zdnet.com/article/ubuntu-snap-takes-charge-of-linux-desktop-and-iot-software-distribution/ - -作者：[Steven J. Vaughan-Nichols][a] -译者：[译者ID](https://github.com/译者ID) -校对：[校对者ID](https://github.com/校对者ID) - -本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 - -[a]: http://www.zdnet.com/meet-the-team/us/steven-j-vaughan-nichols/ -[28]: http://www.canonical.com/ -[29]: http://www.ubuntu.com/ -[30]: https://insights.ubuntu.com/2016/04/13/snaps-for-classic-ubuntu/ -[1]: https://insights.ubuntu.com/2016/04/13/snaps-for-classic-ubuntu/ -[2]: http://www.zdnet.com/article/linux-expert-matthew-garrett-ubuntu-16-04s-new-snap-format-is-a-security-risk/ -[3]: https://www.openssl.org/ -[4]: http://www.dell.com/en-us/ -[5]: http://www.samsung.com/us/ -[6]: http://www.mozilla.com/ -[7]: https://krita.org/en/ -[8]: https://mycroft.ai/ -[9]: http://www.horizon-computing.com/ -[10]: https://www.archlinux.org/ -[11]: https://www.debian.org/ -[12]: https://www.gentoo.org/ -[13]: https://openwrt.org/ -[14]: https://www.documentfoundation.org/ -[15]: https://www.libreoffice.org/download/libreoffice-fresh/ -[16]: https://www.mozilla.org/en-US/firefox/new/ -[17]: https://krita.org/en/about/krita-foundation/ -[18]: https://krita.org/en/item/krita-3-0-released/ -[19]: http://rpm5.org/ -[20]: https://www.debian.org/doc/manuals/debian-faq/ch-pkg_basics.en.html -[21]: http://www.ubuntu.com/desktop/ubuntu-kylin -[22]: https://launchpad.net/ubuntu/+source/snapd -[23]: https://github.com/snapcore/snapd -[24]: http://snapcraft.io/ -[25]: http://www.zdnet.com/article/linux-expert-matthew-garrett-ubuntu-16-04s-new-snap-format-is-a-security-risk/ -[26]: http://www.zdnet.com/article/ubuntu-linux-16-04-is-here/ -[27]: http://www.zdnet.com/article/microsoft-and-canonical-partner-to-bring-ubuntu-to-windows-10/ - - diff --git a/sources/talk/20160620 5 SSH Hardening Tips.md b/sources/talk/20160620 5 SSH Hardening Tips.md new file mode 100644 index 0000000000..e1a7353807 --- /dev/null +++ b/sources/talk/20160620 5 SSH Hardening Tips.md @@ -0,0 +1,127 @@ +translating by maywanting + +5 SSH Hardening Tips +====================== + +![](https://www.linux.com/sites/lcom/files/styles/rendered_file/public/binary-1188510_1920_0.jpg?itok=ocPCL_9G) +>Make your OpenSSH sessions more secure with these simple tips. +> Creative Commons Zero + +When you look at your SSH server logs, chances are they are full of attempted logins from entities of ill intent. Here are 5 general ways (along with several specific tactics) to make your OpenSSH sessions more secure. + +### 1. Make Password Auth Stronger + +Password logins are convenient, because you can log in from any machine anywhere. But they are vulnerable to brute-force attacks. Try these tactics for strengthening your password logins. + +- Use a password generator, such as pwgen. pwgen takes several options; the most useful is password length (e.g., pwgen 12 generates a 12-character password). + +- Never reuse a password. Ignore all the bad advice about not writing down your passwords, and keep a notebook with your logins written in it. If you don't believe me that this is a good idea, then believe security guru [Bruce Schneier][1]. If you're reasonably careful, nobody will ever find your notebook, and it is immune from online attacks. + +- You can add extra protection to your login notebook by obscuring the logins recorded in your notebook with character substitution or padding. Use a simple, easily-memorable convention such as padding your passwords with two extra random characters, or use a single simple character substitution such as # for *. + +- Use a non-standard listening port on your SSH server. Yes, this is old advice, and it's still good. Examine your logs; chances are that port 22 is the standard attack point, with few attacks on other ports. + +- Use [Fail2ban][2] to dynamically protect your server from brute force attacks. + +- Create non-standard usernames. Never ever enable a remote root login, and avoid "admin". + +### 2. Fix Too Many Authentication Failures + +When my ssh logins fail with "Too many authentication failures for carla" error messages, it makes me feel bad. I know I shouldn't take it personally, but it still stings. But, as my wise granny used to say, hurt feelings don't fix the problem. The cure for this is to force a password-based login in your ~/.ssh/config file. If this file does not exist, first create the ~/.ssh/ directory: + +``` +$ mkdir ~/.ssh +$ chmod 700 ~/.ssh +``` + +Then create the `~/.ssh/config` file in a text editor and enter these lines, using your own remote HostName address: + +``` +HostName remote.site.com +PubkeyAuthentication=no +``` + +### 3. Use Public Key Authentication + +Public Key authentication is much stronger than password authentication, because it is immune to brute-force password attacks, but it’s less convenient because it relies on RSA key pairs. To begin, you create a public/private key pair. Next, the private key goes on your client computer, and you copy the public key to the remote server that you want to log into. You can log in to the remote server only from computers that have your private key. Your private key is just as sensitive as your house key; anyone who has possession of it can access your accounts. You can add a strong layer of protection by putting a passphrase on your private key. + +Using RSA key pairs is a great tool for managing multiple users. When a user leaves, disable their login by deleting their public key from the server. + +This example creates a new key pair of 3072 bits strength, which is stronger than the default 2048 bits, and gives it a unique name so you know what server it belongs to: + +``` +$ ssh-keygen -t rsa -b 3072 -f id_mailserver +``` + +This creates two new keys, id_mailserver and id_mailserver.pub. id_mailserver is your private key -- do not share this! Now securely copy your public key to your remote server with the ssh-copy-id command. You must already have a working SSH login on the remote server: + +``` +$ ssh-copy-id -i id_rsa.pub user@remoteserver + +/usr/bin/ssh-copy-id: INFO: attempting to log in with the new key(s), to filter out any that are already installed +user@remoteserver's password: + +Number of key(s) added: 1 + +Now try logging into the machine, with: "ssh 'user@remoteserver'" +and check to make sure that only the key(s) you wanted were added. +``` + +ssh-copy-id ensures that you will not accidentally copy your private key. Test your new key login by copying the example from your command output, with single quotes: + +``` +$ ssh 'user@remoteserver' +``` + +It should log you in using your new key, and if you set a password on your private key, it will prompt you for it. + +### 4. Disable Password Logins + +Once you have tested and verified your public key login, disable password logins so that your remote server is not vulnerable to brute force password attacks. Do this in the /etc/sshd_config file on your remote server with this line: + +``` +PasswordAuthentication no +``` + +Then restart your SSH daemon. + +### 5. Set Up Aliases -- They’re Fast and Cool + +You can set up aliases for remote logins that you use a lot, so instead of logging in with something like "ssh -u username -p 2222 remote.site.with.long-name", you can use "ssh remote1". Set it up like this in your ~/.ssh/config file: + +``` +Host remote1 +HostName remote.site.with.long-name +Port 2222 +User username +PubkeyAuthentication no +``` + +If you are using public key authentication, it looks like this: + +``` +Host remote1 +HostName remote.site.with.long-name +Port 2222 +User username +IdentityFile ~/.ssh/id_remoteserver +``` + +The [OpenSSH documentation][3] is long and detailed, but after you have mastered basic SSH use, you'll find it's very useful and contains a trove of cool things you can do with OpenSSH. + + + +-------------------------------------------------------------------------------- + +via: https://www.linux.com/learn/5-ssh-hardening-tips + +作者：[CARLA SCHRODER][a] +译者：[译者ID](https://github.com/译者ID) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创翻译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://www.linux.com/users/cschroder +[1]: https://www.schneier.com/blog/archives/2005/06/write_down_your.html +[2]: http://www.fail2ban.org/wiki/index.php/Main_Page +[3]: http://www.openssh.com/ diff --git a/sources/talk/20160620 Training vs. hiring to meet the IT needs of today and tomorrow.md b/sources/talk/20160620 Training vs. hiring to meet the IT needs of today and tomorrow.md deleted file mode 100644 index e4d511c5bd..0000000000 --- a/sources/talk/20160620 Training vs. hiring to meet the IT needs of today and tomorrow.md +++ /dev/null @@ -1,62 +0,0 @@ -Training vs. hiring to meet the IT needs of today and tomorrow -================================================================ - -![](https://enterprisersproject.com/sites/default/files/styles/620x350/public/images/cio_talent_4.png?itok=QLhyS_Xf) - -In the digital era, IT skills requirements are in a constant state of flux thanks to the constant change of the tools and technologies companies need to keep pace. It’s not easy for companies to find and hire talent with coveted skills that will enable them to innovate. Meanwhile, training internal staff to take on new skills and challenges takes time that is often in short supply. - -[Sandy Hill][1] is quite familiar with the various skills required across a variety of IT disciplines. As the director of IT for [Pegasystems][2], she is responsible for IT teams involved in areas ranging from application development to data center operations. What’s more, Pegasystems develops applications to help sales, marketing, service and operations teams streamline operations and connect with customers, which means she has to grasp the best way to use IT resources internally, and the IT challenges the company’s customers face. - -![](https://enterprisersproject.com/sites/default/files/CIO_Q%20and%20A_0.png) - -**The Enterprisers Project (TEP): How has the emphasis you put on training changed in recent years?** - -**Hill**: We’ve been growing exponentially over the past couple of years so now we’re implementing more global processes and procedures. With that comes the training aspect of making sure everybody is on the same page. - -Most of our focus has shifted to training staff on new products and tools that get implemented to drive innovation and enhance end user productivity. For example, we’ve implemented an asset management system; we didn’t have one before. So we had to do training globally instead of hiring someone who already knew the product. As we’re growing, we’re also trying to maintain a tight budget and flat headcount. So we’d rather internally train than try to hire new people. - -**TEP: Describe your approach to training. What are some of the ways you help employees evolve their skills?** - -**Hill**: I require each staff member to have a technical and non-technical training goal, which are tracked and reported on as part of their performance review. Their technical goal needs to align within their job function, and the non-technical goal can be anything from focusing on sharpening one of their soft skills to learning something outside of their area of expertise. I perform yearly staff evaluations to see where the gaps and shortages are so that teams remain well-rounded. - -**TEP: To what extent have your training initiatives helped quell recruitment and retention issues?** - -**Hill**: Keeping our staff excited about learning new technologies keeps their skill sets sharp. Having the staff know that we value them, and we are vested in their professional growth and development motivates them. - -**TEP: What sorts of training have you found to be most effective?** - -**Hill**: We use several different training methods that we’ve found to be effective. With new or special projects, we try to incorporate a training curriculum led by the vendor as part of the project rollout. If that’s not an option, we use off-site training. We also purchase on-line training packages, and I encourage my staff to attend at least one conference per year to keep up with what’s new in the industry. - -**TEP**: For what sorts of skills have you found it’s better to hire new people than train existing staff? - -**Hill**: It depends on the project. In one recent initiative, trying to implement OpenStack, we didn’t have internal expertise at all. So we aligned with a consulting firm that specialized in that area. We utilized their expertise on-site to help run the project and train internal team members. It was a massive undertaking to get internal people to learn the skills they needed while also doing their day-to-day jobs. - -The consultant helped us determine the headcount we needed to be proficient. This allowed us to assess our staff to see if gaps remained, which would require additional training or hiring. And we did end up hiring some of the contractors. But the alternative was to send some number of FTEs (full-time employees) for 6 to 8 weeks of training, and our pipeline of projects wouldn’t allow that. - -**TEP: In thinking about some of your most recent hires, what skills did they have that are especially attractive to you?** - -**Hill**: In recent hires, I’ve focused on soft skills. In addition to having solid technical skills, they need to be able to communicate effectively, work in teams and have the ability to persuade, negotiate and resolve conflicts. - -IT people in general kind of keep to themselves; they’re often not the most social people. Now, where IT is more integrated throughout the organization, the ability to give useful updates and status reports to other business units is critical to show that IT is an active presence and to be successful. - - - --------------------------------------------------------------------------------- - -via: http://linoxide.com/firewall/pfsense-setup-basic-configuration/ - -作者：[ Paul Desmond][a] -译者：[译者ID](https://github.com/译者ID) -校对：[校对者ID](https://github.com/校对者ID) - -本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 - -[a]: https://enterprisersproject.com/user/paul-desmond -[1]: https://enterprisersproject.com/user/sandy-hill -[2]: https://www.pega.com/pega-can?&utm_source=google&utm_medium=cpc&utm_campaign=900.US.Evaluate&utm_term=pegasystems&gloc=9009726&utm_content=smAXuLA4U|pcrid|102822102849|pkw|pegasystems|pmt|e|pdv|c| - - - - - - diff --git a/sources/talk/20160625 Ubuntu’s Snap, Red Hat’s Flatpak And Is ‘One Fits All’ Linux Packages Useful.md b/sources/talk/20160625 Ubuntu’s Snap, Red Hat’s Flatpak And Is ‘One Fits All’ Linux Packages Useful.md new file mode 100644 index 0000000000..35088e4be1 --- /dev/null +++ b/sources/talk/20160625 Ubuntu’s Snap, Red Hat’s Flatpak And Is ‘One Fits All’ Linux Packages Useful.md @@ -0,0 +1,110 @@ +Ubuntu’s Snap, Red Hat’s Flatpak And Is ‘One Fits All’ Linux Packages Useful? +================================================================================= + +![](http://www.iwillfolo.com/wordpress/wp-content/uploads/2016/06/Flatpak-and-Snap-Packages.jpg) + +An in-depth look into the new generation of packages starting to permeate the Linux ecosystem. + + +Lately we’ve been hearing more and more about Ubuntu’s Snap packages and Flatpak (formerly referred to as xdg-app) created by Red Hat’s employee Alexander Larsson. + +These 2 types of next generation packages are in essence having the same goal and characteristics which are: being standalone packages that doesn’t rely on 3rd-party system libraries in order to function. + +This new technology direction which Linux seems to be headed is automatically giving rise to questions such as, what are the advantages / disadvantages of standalone packages? does this lead us to a better Linux overall? what are the motives behind it? + +To answer these questions and more, let us explore the things we know about Snap and Flatpak so far. + +### The Motive + +According to both [Flatpak][1] and [Snap][2] statements, the main motive behind them is to be able to bring one and the same version of application to run across multiple Linux distributions. + +>“From the very start its primary goal has been to allow the same application to run across a myriad of Linux distributions and operating systems.” Flatpak + +>“… ‘snap’ universal Linux package format, enabling a single binary package to work perfectly and securely on any Linux desktop, server, cloud or device.” Snap + +To be more specific, the guys behind Snap and Flatpak (S&F) believe that there’s a barrier of fragmentation on the Linux platform. + +A barrier which holds back the platform advancement by burdening developers with more, perhaps unnecessary, work to get their software run on the many distributions out there. + +Therefore, as leading Linux distributions (Ubuntu & Red Hat), they wish to eliminate the barrier and strengthen the platform in general. + +But what are the more personal gains which motivate the development of S&F? + +#### Personal Gains? + +Although not officially stated anywhere, it may be assumed that by leading the efforts of creating a unified package that could potentially be adopted by the vast majority of Linux distros (if not all of them), the captains of these projects could assume a key position in determining where the Linux ship sails. + +### The Advantages + +The benefits of standalone packages are diverse and can depend on different factors. + +Basically however, these factors can be categorized under 2 distinct criteria: + +#### User Perspective + ++ From a Linux user point of view, Snap and Flatpak both bring the possibility of installing any package (software / app) on any distribution the user is using. + +That is, for instance, if you’re using a not so popular distribution which has only a scarce supply of packages available in their repo, due to workforce limitations probably, you’ll now be able to easily and significantly increase the amount of packages available to you – which is a great thing. + ++ Also, users of popular distributions that do have many packages available in their repos, will enjoy the ability of installing packages that might not have behaved with their current set of installed libraries. + +For example, a Debian user who wants to install a package from ‘testing branch’ will not have to convert his entire system into ‘testing’ (in order for the package to run against newer libraries), rather, that user will simply be able to install only the package he wants from whichever branch he likes and on whatever branch he’s on. + +The latter point, was already basically possible for users who were compiling their packages straight from source, however, unless using a source based distribution such as Gentoo, most users will see this as just an unworthily hassle. + ++ The advanced user, or perhaps better put, the security aware user might feel more comfortable with this type of packages as long as they come from a reliable source as they tend to provide another layer of isolation since they are generally isolated from system packages. + +* Both S&F are being developed with enhanced security in mind, which generally makes use of “sandboxing” i.e isolation in order to prevent cases where they carry a virus which can infect the entire system, similar to the way .exe files on MS Windows may. (More on MS and S&F later) + +#### Developer Perspective + +For developers, the advantages of developing S&F packages will probably be a lot clearer than they are to the average user, some of these were already hinted in a previous section of this post. + +Nonetheless, here they are: + ++ S&F will make it easier on devs who want to develop for more than one Linux distribution by unifying the process of development, therefore minimizing the amount of work a developer needs to do in order to get his app running on multiple distributions. + +++ Developers could therefore gain easier access to a wider range of distributions. + ++ S&F allow devs to privately distribute their packages without being dependent on distribution maintainers to stabilize their package for each and every distro. + +++ Through the above, devs may gain access to direct statistics of user adoption / engagement for their software. + +++ Also through the above, devs could get more directly involved with users, rather than having to do so through a middleman, in this case, the distribution. + +### The Downsides + +– Bloat. Simple as that. Flatpak and Snap aren’t just magic making dependencies evaporate into thin air. Rather, instead of relying on the target system to provide the required dependencies, S&F comes with the dependencies prebuilt into them. + +As the saying goes “if the mountain won’t come to Muhammad, Muhammad must go to the mountain…” + +– Just as the security-aware user might enjoy S&F packages extra layer of isolation, as long they come from a trusted source. The less knowledgeable user on the hand, might be prone to the other side of the coin hazard which is using a package from an unknown source which may contain malicious software. + +The above point can be said to be valid even with today’s popular methods, as PPAs, overlays, etc might also be maintained by untrusted sources. + +However, with S&F packages the risk increases since malicious software developers need to create only one version of their program in order to infect a large number of distributions, whereas, without it they’d needed to create multiple versions in order to adjust their malware to other distributions. + +Was Microsoft Right All Along? + +With all that’s mentioned above in mind, it’s pretty clear that for the most part, the advantages of using S&F packages outweighs the drawbacks. + +At the least for users of binary-based distributions, or, non lightweight focused distros. + +Which eventually lead me to asking the above question – could it be that Microsoft was right all along? if so and S&F becomes the Linux standard, would you still consider Linux a Unix-like variant? + +Well apparently, the best one to answer those questions is probably time. + +Nevertheless, I’d argue that even if not entirely right, MS certainly has a good point to their credit, and having all these methods available here on Linux out of the box is certainly a plus in my book. + + +-------------------------------------------------------------------------------- + +via: http://www.iwillfolo.com/ubuntus-snap-red-hats-flatpack-and-is-one-fits-all-linux-packages-useful/ + +作者：[Editorials][a] +译者：[译者ID](https://github.com/译者ID) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创翻译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: http://www.iwillfolo.com/category/editorials/ diff --git a/sources/talk/20160627 Linux Applications That Works On All Distributions – Are They Any Good.md b/sources/talk/20160627 Linux Applications That Works On All Distributions – Are They Any Good.md new file mode 100644 index 0000000000..98967d866b --- /dev/null +++ b/sources/talk/20160627 Linux Applications That Works On All Distributions – Are They Any Good.md @@ -0,0 +1,90 @@ +Linux Applications That Works On All Distributions – Are They Any Good? +============================================================================ + +![](http://www.iwillfolo.com/wordpress/wp-content/uploads/2016/06/Bundled-applications.jpg) + + +A revisit of Linux community’s latest ambitions – promoting decentralized applications in order to tackle distribution fragmentation. + +Following last week’s article: [Ubuntu’s Snap, Red Hat’s Flatpak And Is ‘One Fits All’ Linux Packages Useful][1]?, a couple of new opinions rose to the surface which may contain crucial information about the usefulness of such apps. + +### The Con Side + +Commenting on the subject [here][2], a [Gentoo][3] user who goes by the name Till, gave rise to a few points which hasn’t been addressed to the fullest the last time we covered the issue. + +While previously we settled on merely calling it bloat, Till here on the other hand, is dissecting that bloat further so to help us better understand both its components and its consequences. + +Referring to such apps as “bundled applications” – for the way they work on all distributions is by containing dependencies together with the apps themselves, Till says: + +>“bundles ship a lot of software that now needs to be maintained by the application developer. If library X has a security problem and needs an update, you rely on every single applications to ship correct updates in order to make your system save.” + +Essentially, Till raises an important security point. However, it isn’t necessarily has to be tied to security alone, but can also be linked to other aspects such as system maintenance, atomic updates, etc… + +Furthermore, if we take that notion one step further and assume that dependencies developers may cooperate, therefore releasing their software in correlation with the apps who use them (an utopic situation), we shall then get an overall slowdown of the entire platform development. + +Another problem that arises from the same point made above is dependencies-transparency becomes obscure, that is, if you’d want to know which libraries are bundled with a certain app, you’ll have to rely on the developer to publish such data. + +Or, as Till puts it: “Questions like, did package XY already include the updated library Z, will be your daily bread”. + +For comparison, with the standard methods available on Linux nowadays (both binary and source distributions), you can easily notice which libraries are being updated upon a system update. + +And you can also rest assure that all other apps on the system will use it, freeing you from the need to check each app individually. + +Other cons that may be deduced from the term bloat include: bigger package size (each app is bundled with dependencies), higher memory usage (no more library sharing) and also – + +One less filter mechanism to prevent malicious software – distributions package maintainers also serve as a filter between developers and users, helping to assure users get quality software. + +With bundled apps this may no longer be the case. + +As a finalizing general point, Till asserts that although useful in some cases, for the most part, bundled apps weakens the free software position in distributions (as proprietary vendors will now be able to deliver software without sharing it on public repositories). + +And apart from that, it introduces many other issues. Many problems are simply moved towards the developers. + +### The Pro Side + +In contrast, another comment by a person named Sven tries to contradict common claims that basically go against the use of bundled applications, hence justifying and promoting the use of it. + +“waste of space” – Sven claims that in today’s world we have many other things that wastes disk space, such as movies stored on hard drive, installed locals, etc… + +Ultimately, these things are infinitely more wasteful than a mere “100 MB to run a program you use all day … Don’t be ridiculous.” + +“waste of RAM” – the major points in favor are: + +- Shared libraries waste significantly less RAM compared to application runtime data. +- RAM is cheap today. + +“security nightmare” – not every application you run is actually security-critical. + +Also, many applications never even see any security updates, unless on a ‘rolling distro’. + +In addition to Sven’s opinions, who try to stick to the pragmatic side, a few advantages were also pointed by Till who admits that bundled apps has their merits in certain cases: + +- Proprietary vendors who want to keep their code out of the public repositories will be able to do so more easily. +- Niche applications, which are not packaged by your distribution, will now be more readily available. +- Testing on binary distributions which do not have beta packages will become easier. +- Freeing users from solving dependencies problems. + +### Final Thoughts + +Although shedding new light onto the matter, it seems that one conclusion still stands and accepted by all parties – bundled apps has their niche to fill in the Linux ecosystem. + +Nevertheless, the role that niche should take, whether main or marginal one, appears to be a lot clearer now, at least from a theoretical point of view. + +Users who are looking to make their system optimized as possible, should, in the majority of cases, avoid using bundled apps. + +Whereas, users that are after ease-of-use, meaning – doing the least of work in order to maintain their systems, should and probably would feel very comfortable adopting the new method. + +-------------------------------------------------------------------------------- + +via: http://www.iwillfolo.com/linux-applications-that-works-on-all-distributions-are-they-any-good/ + +作者：[Editorials][a] +译者：[译者ID](https://github.com/译者ID) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创翻译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: http://www.iwillfolo.com/category/editorials/ +[1]: http://www.iwillfolo.com/ubuntus-snap-red-hats-flatpack-and-is-one-fits-all-linux-packages-useful/ +[2]: http://www.proli.net/2016/06/25/gnulinux-bundled-application-ramblings/ +[3]: http://www.iwillfolo.com/5-reasons-use-gentoo-linux/ diff --git a/sources/talk/20160718 Tips for managing your project's issue tracker.md b/sources/talk/20160718 Tips for managing your project's issue tracker.md new file mode 100644 index 0000000000..1b89fe5851 --- /dev/null +++ b/sources/talk/20160718 Tips for managing your project's issue tracker.md @@ -0,0 +1,101 @@ +Tips for managing your project's issue tracker +============================================== + +![](https://opensource.com/sites/default/files/styles/image-full-size/public/images/business/BUSINESS_opennature_3.png?itok=30fRGfpv) + +Issue-tracking systems are important for many open source projects, and there are many open source tools that provide this functionality but many projects opt to use GitHub's built-in issue tracker. + +Its simple structure makes it easy for others to weigh in, but issues are really only as good as you make them. + +Without a process, your repository can become unwieldy, overflowing with duplicate issues, vague feature requests, or confusing bug reports. Project maintainers can become burdened by the organizational load, and it can become difficult for new contributors to understand where priorities lie. + +In this article, I'll discuss how to take your GitHub issues from good to great. + +### The issue as user story + +My team spoke with open source expert [Jono Bacon][1]—author of [The Art of Community][2], a strategy consultant, and former Director of Community at GitHub—who said that high-quality issues are at the core of helping a projects succeed. He says that while some see issues as merely a big list of problems you have to tend to, well-managed, triaged, and labeled issues can provide incredible insight into your code, your community, and where the problem spots are. + +"At the point of submission of an issue, the user likely has little patience or interest in providing expansive detail. As such, you should make it as easy as possible to get the most useful information from them in the shortest time possible," Jono Bacon said. + +A consistent structure can take a lot of burden off project maintainers, particularly for open source projects. We've found that encouraging a user story approach helps make clarity a constant. The common structure for a user story addresses the "who, what, and why" of a feature: As a [user type], I want to [task] so that [goal]. + +Here's what that looks like in practice: + +>As a customer, I want to create an account so that I can make purchases. + +We suggest sticking that user story in the issue's title. You can also set up [issue templates][3] to keep things consistent. + +![](https://opensource.com/sites/default/files/resize/issuetemplate-new-520x293.png) +> Issue templates bring consistency to feature requests. + +The point is to make the issue well-defined for everyone involved: it identifies the audience (or user), the action (or task), and the outcome (or goal) as simply as possible. There's no need to obsess over this structure, though; as long as the what and why of a story are easy to spot, you're good. + +### Qualities of a good issue + +Not all issues are created equal—as any OSS contributor or maintainer can attest. A well-formed issue meets these qualities outlined in [The Agile Samurai][4]. + +Ask yourself if it is... + +- something of value to customers +- avoids jargon or mumbo jumbo; a non-expert should be able to understand it +- "slices the cake," which means it goes end-to-end to deliver something of value +- independent from other issues if possible; dependent issues reduce flexibility of scope +- negotiable, meaning there are usually several ways to get to the stated goal +- small and easily estimable in terms of time and resources required +- measurable; you can test for results + +### What about everything else? Working with constraints + +If an issue is difficult to measure or doesn't seem feasible to complete within a short time period, you can still work with it. Some people call these "constraints." + +For example, "the product needs to be fast" doesn't fit the story template, but it is non-negotiable. But how fast is fast? Vague requirements don't meet the criteria of a "good issue", but if you further define these concepts—for example, "the product needs to be fast" can be "each page needs to load within 0.5 seconds"—you can work with it more easily. Constraints can be seen as internal metrics of success, or a landmark to shoot for. Your team should test for them periodically. + +### What's inside your issue? + +In agile, user stories typically include acceptance criteria or requirements. In GitHub, I suggest using markdown checklists to outline any tasks that make up an issue. Issues should get more detail as they move up in priority. + +Say you're creating an issue around a new homepage for a website. The sub-tasks for that task might look something like this. + +![](https://opensource.com/sites/default/files/resize/markdownchecklist-520x255.png) +>Use markdown checklists to split a complicated issue into several parts. + +If necessary, link to other issues to further define a task. (GitHub makes this really easy.) + +Defining features as granularly as possible makes it easier to track progress, test for success, and ultimately ship valuable code more frequently. + +Once you've gathered some data points in the form of issues, you can use APIs to glean deeper insight into the health of your project. + +"The GitHub API can be hugely helpful here in identifying patterns and trends in your issues," Bacon said. "With some creative data science, you can identify problem spots in your code, active members of your community, and other useful insights." + +Some issue management tools provide APIs that add additional context, like time estimates or historical progress. + +### Getting others on board + +Once your team decides on an issue structure, how do you get others to buy in? Think of your repo's ReadMe.md file as your project's "how-to." It should clearly define what your project does (ideally using searchable language) and explain how others can contribute (by submitting requests, bug reports, suggestions, or by contributing code itself.) + +![](https://opensource.com/sites/default/files/resize/readme-520x184.png) +>Edit your ReadMe file with clear instructions for new collaborators. + +This is the perfect spot to share your GitHub issue guidelines. If you want feature requests to follow the user story format, share that here. If you use a tracking tool to organize your product backlog, share the badge so others can gain visibility. + +"Issue templates, sensible labels, documentation for how to file issues, and ensuring your issues get triaged and responded to quickly are all important" for your open source project, Bacon said. + +Remember: It's not about adding process for the process' sake. It's about setting up a structure that makes it easy for others to discover, understand, and feel confident contributing to your community. + +"Focus your community growth efforts not just on growing the number of programmers, but also [on] people interested in helping issues be accurate, up to date, and a source of active conversation and productive problem solving," Bacon said. + +-------------------------------------------------------------------------------- + +via: https://opensource.com/life/16/7/how-take-your-projects-github-issues-good-great + +作者：[Matt Butler][a] +译者：[译者ID](https://github.com/译者ID) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创翻译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://opensource.com/users/mattzenhub +[1]: http://www.jonobacon.org/ +[2]: http://www.artofcommunityonline.org/ +[3]: https://help.github.com/articles/creating-an-issue-template-for-your-repository/ +[4]: https://www.amazon.ca/Agile-Samurai-Masters-Deliver-Software/dp/1934356581 diff --git a/sources/talk/my-open-source-story/20160316 Growing a career alongside Linux.md b/sources/talk/my-open-source-story/20160316 Growing a career alongside Linux.md deleted file mode 100644 index 24799508c3..0000000000 --- a/sources/talk/my-open-source-story/20160316 Growing a career alongside Linux.md +++ /dev/null @@ -1,49 +0,0 @@ -Growing a career alongside Linux -================================== - -![](https://opensource.com/sites/default/files/styles/image-full-size/public/images/business/OPENHERE_blue.png?itok=3eqp-7gT) - -My Linux story started in 1998 and continues today. Back then, I worked for The Gap managing thousands of desktops running [OS/2][1] (and a few years later, [Warp 3.0][2]). As an OS/2 guy, I was really happy then. The desktops hummed along and it was quite easy to support thousands of users with the tools the GAP had built. Changes were coming, though. - -In November of 1998, I received an invitation to join a brand new startup which would focus on Linux in the enterprise. This startup became quite famous as [Linuxcare][2]. - -### My time at Linuxcare - -I had played with Linux a bit, but had never considered delivering it to enterprise customers. Mere months later (which is a turn of the corner in startup time and space), I was managing a line of business that let enterprises get their hardware, software, and even books certified on a few flavors of Linux that were popular back then. - -I supported customers like IBM, Dell, and HP in ensuring their hardware ran Linux successfully. You hear a lot now about preloading Linux on hardware today, but way back then I was invited to Dell to discuss getting a laptop certified to run Linux for an upcoming trade show. Very exciting times! We also supported IBM and HP on a number of certification efforts that spanned a few years. - -Linux was changing fast, much like it always has. It gained hardware support for more key devices like sound, network, graphics. At around that time, I shifted from RPM-based systems to [Debian][3] for my personal use. - -### Using Linux through the years - -Fast forward some years and I worked at a number of companies that did Linux as hardened appliances, Linux as custom software, and Linux in the data center. By the mid 2000s, I was busy doing consulting for that rather large software company in Redmond around some analysis and verification of Linux compared to their own solutions. My personal use had not changed though—I would still run Debian testing systems on anything I could. - -I really appreciated the flexibility of a distribution that floated and was forever updated. Debian is one of the most fun and well supported distributions and has the best community I've ever been a part of. - -When I look back at my own adoption of Linux, I remember with fondness the numerous Linux Expo trade shows in San Jose, San Francisco, Boston, and New York in the early and mid 2000's. At Linuxcare we always did fun and funky booths, and walking the show floor always resulted in getting re-acquainted with old friends. Rumors of work were always traded, and the entire thing underscored the fun of using Linux in real endeavors. - -The rise of virtualization and cloud has really made the use of Linux even more interesting. When I was with Linuxcare, we partnered with a small 30-person company in Palo Alto. We would drive to their offices and get things ready for a trade show that they would attend with us. Who would have ever known that little startup would become VMware? - -I have so many stories, and there were so many people I was so fortunate to meet and work with. Linux has evolved in so many ways and has become so important. And even with its increasing importance, Linux is still fun to use. I think its openness and the ability to modify it has contributed to a legion of new users, which always astounds me. - -### Today - -I've moved away from doing mainstream Linux things over the past five years. I manage large scale infrastructure projects that include a variety of OSs (both proprietary and open), but my heart has always been with Linux. - -The constant evolution and fun of using Linux has been a driving force for me for over the past 18 years. I started with the 2.0 Linux kernel and have watched it become what it is now. It's a remarkable thing. An organic thing. A cool thing. - --------------------------------------------------------------------------------- - -via: https://opensource.com/life/16/3/my-linux-story-michael-perry - -作者：[Michael Perry][a] -译者：[译者ID](https://github.com/译者ID) -校对：[校对者ID](https://github.com/校对者ID) - -[a]: https://opensource.com/users/mpmilestogo -[1]: https://en.wikipedia.org/wiki/OS/2 -[2]: https://archive.org/details/IBMOS2Warp3Collection -[3]: https://en.wikipedia.org/wiki/Linuxcare -[4]: https://www.debian.org/ -[5]: diff --git a/sources/team_test/README.md b/sources/team_test/README.md new file mode 100644 index 0000000000..0798a592ef --- /dev/null +++ b/sources/team_test/README.md @@ -0,0 +1,7 @@ +组队翻译 ： 《Building a data science portfolio: Machine learning project》 + +本次组织者 ： @选题-oska874 + +参加译者 ： @译者-vim-kakali @译者-Noobfish @译者-zky001 @译者-kokialoves @译者-ideas4u @译者-cposture + +分配方式 ： 原文按大致长度分成 6 部分，参与者自由选择，先到先选，如有疑问联系 @选题-oska874 diff --git a/sources/team_test/part 1 - Building a data science portfolio - Machine learning project.md b/sources/team_test/part 1 - Building a data science portfolio - Machine learning project.md new file mode 100644 index 0000000000..439be578ce --- /dev/null +++ b/sources/team_test/part 1 - Building a data science portfolio - Machine learning project.md @@ -0,0 +1,84 @@ ++@noobfish translating since Aug 2nd,2016. ++ ++ + + +>This is the third in a series of posts on how to build a Data Science Portfolio. If you like this and want to know when the next post in the series is released, you can [subscribe at the bottom of the page][1]. + +Data science companies are increasingly looking at portfolios when making hiring decisions. One of the reasons for this is that a portfolio is the best way to judge someone’s real-world skills. The good news for you is that a portfolio is entirely within your control. If you put some work in, you can make a great portfolio that companies are impressed by. + +The first step in making a high-quality portfolio is to know what skills to demonstrate. The primary skills that companies want in data scientists, and thus the primary skills they want a portfolio to demonstrate, are: + +- Ability to communicate +- Ability to collaborate with others +- Technical competence +- Ability to reason about data +- Motivation and ability to take initiative + +Any good portfolio will be composed of multiple projects, each of which may demonstrate 1-2 of the above points. This is the third post in a series that will cover how to make a well-rounded data science portfolio. In this post, we’ll cover how to make the second project in your portfolio, and how to build an end to end machine learning project. At the end, you’ll have a project that shows your ability to reason about data, and your technical competence. [Here’s][2] the completed project if you want to take a look. + +### An end to end project + +As a data scientist, there are times when you’ll be asked to take a dataset and figure out how to [tell a story with it][3]. In times like this, it’s important to communicate very well, and walk through your process. Tools like Jupyter notebook, which we used in a previous post, are very good at helping you do this. The expectation here is that the deliverable is a presentation or document summarizing your findings. + +However, there are other times when you’ll be asked to create a project that has operational value. A project with operational value directly impacts the day-to-day operations of a company, and will be used more than once, and often by multiple people. A task like this might be “create an algorithm to forecast our churn rate”, or “create a model that can automatically tag our articles”. In cases like this, storytelling is less important than technical competence. You need to be able to take a dataset, understand it, then create a set of scripts that can process that data. It’s often important that these scripts run quickly, and use minimal system resources like memory. It’s very common that these scripts will be run several times, so the deliverable becomes the scripts themselves, not a presentation. The deliverable is often integrated into operational flows, and may even be user-facing. + +The main components of building an end to end project are: + +- Understanding the context +- Exploring the data and figuring out the nuances +- Creating a well-structured project, so its easy to integrate into operational flows +- Writing high-performance code that runs quickly and uses minimal system resources +- Documenting the installation and usage of your code well, so others can use it + +In order to effectively create a project of this kind, we’ll need to work with multiple files. Using a text editor like [Atom][4], or an IDE like [PyCharm][5] is highly recommended. These tools will allow you to jump between files, and edit files of different types, like markdown files, Python files, and csv files. Structuring your project so it’s easy to version control and upload to collaborative coding tools like [Github][6] is also useful. + +![](https://www.dataquest.io/blog/images/end_to_end/github.png) +>This project on Github. + +We’ll use our editing tools along with libraries like [Pandas][7] and [scikit-learn][8] in this post. We’ll make extensive use of Pandas [DataFrames][9], which make it easy to read in and work with tabular data in Python. + +### Finding good datasets + +A good dataset for an end to end portfolio project can be hard to find. [The dataset][10] needs to be sufficiently large that memory and performance constraints come into play. It also needs to potentially be operationally useful. For instance, this dataset, which contains data on the admission criteria, graduation rates, and graduate future earnings for US colleges would be a great dataset to use to tell a story. However, as you think about the dataset, it becomes clear that there isn’t enough nuance to build a good end to end project with it. For example, you could tell someone their potential future earnings if they went to a specific college, but that would be a quick lookup without enough nuance to demonstrate technical competence. You could also figure out if colleges with higher admissions standards tend to have graduates who earn more, but that would be more storytelling than operational. + +These memory and performance constraints tend to come into play when you have more than a gigabyte of data, and when you have some nuance to what you want to predict, which involves running algorithms over the dataset. + +A good operational dataset enables you to build a set of scripts that transform the data, and answer dynamic questions. A good example would be a dataset of stock prices. You would be able to predict the prices for the next day, and keep feeding new data to the algorithm as the markets closed. This would enable you to make trades, and potentially even profit. This wouldn’t be telling a story – it would be adding direct value. + +Some good places to find datasets like this are: + +- [/r/datasets][11] – a subreddit that has hundreds of interesting datasets. +- [Google Public Datasets][12] – public datasets available through Google BigQuery. +- [Awesome datasets][13] – a list of datasets, hosted on Github. + +As you look through these datasets, think about what questions someone might want answered with the dataset, and think if those questions are one-time (“how did housing prices correlate with the S&P 500?”), or ongoing (“can you predict the stock market?”). The key here is to find questions that are ongoing, and require the same code to be run multiple times with different inputs (different data). + +For the purposes of this post, we’ll look at [Fannie Mae Loan Data][14]. Fannie Mae is a government sponsored enterprise in the US that buys mortgage loans from other lenders. It then bundles these loans up into mortgage-backed securities and resells them. This enables lenders to make more mortgage loans, and creates more liquidity in the market. This theoretically leads to more homeownership, and better loan terms. From a borrowers perspective, things stay largely the same, though. + +Fannie Mae releases two types of data – data on loans it acquires, and data on how those loans perform over time. In the ideal case, someone borrows money from a lender, then repays the loan until the balance is zero. However, some borrowers miss multiple payments, which can cause foreclosure. Foreclosure is when the house is seized by the bank because mortgage payments cannot be made. Fannie Mae tracks which loans have missed payments on them, and which loans needed to be foreclosed on. This data is published quarterly, and lags the current date by 1 year. As of this writing, the most recent dataset that’s available is from the first quarter of 2015. + +Acquisition data, which is published when the loan is acquired by Fannie Mae, contains information on the borrower, including credit score, and information on their loan and home. Performance data, which is published every quarter after the loan is acquired, contains information on the payments being made by the borrower, and the foreclosure status, if any. A loan that is acquired may have dozens of rows in the performance data. A good way to think of this is that the acquisition data tells you that Fannie Mae now controls the loan, and the performance data contains a series of status updates on the loan. One of the status updates may tell us that the loan was foreclosed on during a certain quarter. + +![](https://www.dataquest.io/blog/images/end_to_end/foreclosure.jpg) +>A foreclosed home being sold. + +### Picking an angle + +There are a few directions we could go in with the Fannie Mae dataset. We could: + +- Try to predict the sale price of a house after it’s foreclosed on. +- Predict the payment history of a borrower. +- Figure out a score for each loan at acquisition time. + +The important thing is to stick to a single angle. Trying to focus on too many things at once will make it hard to make an effective project. It’s also important to pick an angle that has sufficient nuance. Here are examples of angles without much nuance: + +- Figuring out which banks sold loans to Fannie Mae that were foreclosed on the most. +- Figuring out trends in borrower credit scores. +- Exploring which types of homes are foreclosed on most often. +- Exploring the relationship between loan amounts and foreclosure sale prices + +All of the above angles are interesting, and would be great if we were focused on storytelling, but aren’t great fits for an operational project. + +With the Fannie Mae dataset, we’ll try to predict whether a loan will be foreclosed on in the future by only using information that was available when the loan was acquired. In effect, we’ll create a “score” for any mortgage that will tell us if Fannie Mae should buy it or not. This will give us a nice foundation to build on, and will be a great portfolio piece. + diff --git a/sources/team_test/part 2 - Building a data science portfolio - Machine learning project.md b/sources/team_test/part 2 - Building a data science portfolio - Machine learning project.md new file mode 100644 index 0000000000..ff979de34f --- /dev/null +++ b/sources/team_test/part 2 - Building a data science portfolio - Machine learning project.md @@ -0,0 +1,98 @@ + +翻译中 by ideas4u +### 理解数据 +我们来简单看一下原始数据文件。下面是2012年1季度前几行的采集数据。 +``` +100000853384|R|OTHER|4.625|280000|360|02/2012|04/2012|31|31|1|23|801|N|C|SF|1|I|CA|945||FRM| +100003735682|R|SUNTRUST MORTGAGE INC.|3.99|466000|360|01/2012|03/2012|80|80|2|30|794|N|P|SF|1|P|MD|208||FRM|788 +100006367485|C|PHH MORTGAGE CORPORATION|4|229000|360|02/2012|04/2012|67|67|2|36|802|N|R|SF|1|P|CA|959||FRM|794 +``` + +下面是2012年1季度的前几行执行数据 +``` +100000853384|03/01/2012|OTHER|4.625||0|360|359|03/2042|41860|0|N|||||||||||||||| +100000853384|04/01/2012||4.625||1|359|358|03/2042|41860|0|N|||||||||||||||| +100000853384|05/01/2012||4.625||2|358|357|03/2042|41860|0|N|||||||||||||||| +``` +在开始编码之前，花些时间真正理解数据是值得的。这对于操作项目优为重要，因为我们没有交互式探索数据，将很难察觉到细微的差别除非我们在前期发现他们。在这种情况下，第一个步骤是阅读房利美站点的资料： +- [概述][15] +- [有用的术语表][16] +- [问答][17] +- [采集和执行文件中的列][18] +- [采集数据文件样本][19] +- [执行数据文件样本][20] + +在看完这些文件后后，我们了解到一些能帮助我们的关键点： +- 从2000年到现在，每季度都有一个采集和执行文件，因数据是滞后一年的，所以到目前为止最新数据是2015年的。 +- 这些文件是文本格式的，采用管道符号“|”进行分割。 +- 这些文件是没有表头的，但我们有文件列明各列的名称。 +- 所有一起，文件包含2200万个贷款的数据。 +由于执行文件包含过去几年获得的贷款的信息，在早些年获得的贷款将有更多的执行数据（即在2014获得的贷款没有多少历史执行数据）。 +这些小小的信息将会为我们节省很多时间，因为我们知道如何构造我们的项目和利用这些数据。 + +### 构造项目 +在我们开始下载和探索数据之前，先想一想将如何构造项目是很重要的。当建立端到端项目时，我们的主要目标是： +- 创建一个可行解决方案 +- 有一个快速运行且占用最小资源的解决方案 +- 容易可扩展 +- 写容易理解的代码 +- 写尽量少的代码 + +为了实现这些目标，需要对我们的项目进行良好的构造。一个结构良好的项目遵循几个原则： +- 分离数据文件和代码文件 +- 从原始数据中分离生成的数据。 +- 有一个README.md文件帮助人们安装和使用该项目。 +- 有一个requirements.txt文件列明项目运行所需的所有包。 +- 有一个单独的settings.py 文件列明其它文件中使用的所有的设置 + - 例如，如果从多个Python脚本读取相同的文件，把它们全部import设置和从一个集中的地方获得文件名是有用的。 +- 有一个.gitignore文件，防止大的或秘密文件被提交。 +- 分解任务中每一步可以单独执行的步骤到单独的文件中。 + - 例如，我们将有一个文件用于读取数据，一个用于创建特征，一个用于做出预测。 +- 保存中间结果，例如，一个脚本可输出下一个脚本可读取的文件。 + + - 这使我们无需重新计算就可以在数据处理流程中进行更改。 + + +我们的文件结构大体如下： + +``` +loan-prediction +├── data +├── processed +├── .gitignore +├── README.md +├── requirements.txt +├── settings.py +``` + +### 创建初始文件 +首先，我们需要创建一个loan-prediction文件夹，在此文件夹下面，再创建一个data文件夹和一个processed文件夹。data文件夹存放原始数据，processed文件夹存放所有的中间计算结果。 +其次，创建.gitignore文件，.gitignore文件将保证某些文件被git忽略而不会被推送至github。关于这个文件的一个好的例子是由OSX在每一个文件夹都会创建的.DS_Store文件，.gitignore文件一个很好的起点就是在这了。我们还想忽略数据文件因为他们实在是太大了，同时房利美的条文禁止我们重新分发该数据文件，所以我们应该在我们的文件后面添加以下2行： +``` +data +processed +``` + +这是该项目的一个关于.gitignore文件的例子。 +再次，我们需要创建README.md文件，它将帮助人们理解该项目。后缀.md表示这个文件采用markdown格式。Markdown使你能够写纯文本文件，同时还可以添加你想要的梦幻格式。这是关于markdown的导引。如果你上传一个叫README.md的文件至Github，Github会自动处理该markdown，同时展示给浏览该项目的人。 +至此，我们仅需在README.md文件中添加简单的描述： +``` +Loan Prediction +----------------------- + +Predict whether or not loans acquired by Fannie Mae will go into foreclosure. Fannie Mae acquires loans from other lenders as a way of inducing them to lend more. Fannie Mae releases data on the loans it has acquired and their performance afterwards [here](http://www.fanniemae.com/portal/funding-the-market/data/loan-performance-data.html). +``` + +现在，我们可以创建requirements.txt文件了。这会唯其它人可以很方便地安装我们的项目。我们还不知道我们将会具体用到哪些库，但是以下几个库是一个很好的开始： +``` +pandas +matplotlib +scikit-learn +numpy +ipython +scipy +``` + +以上几个是在python数据分析任务中最常用到的库。可以认为我们将会用到大部分这些库。这里是【24】该项目requirements文件的一个例子。 + 创建requirements.txt文件之后，你应该安装包了。我们将会使用python3.如果你没有安装python，你应该考虑使用 [Anaconda][25]，一个python安装程序，同时安装了上面列出的所有包。 +最后，我们可以建立一个空白的settings.py文件，因为我们的项目还没有任何设置。 diff --git a/sources/team_test/part 3 - Building a data science portfolio - Machine learning project.md b/sources/team_test/part 3 - Building a data science portfolio - Machine learning project.md new file mode 100644 index 0000000000..31fb6f0fc9 --- /dev/null +++ b/sources/team_test/part 3 - Building a data science portfolio - Machine learning project.md @@ -0,0 +1,194 @@ +### Acquiring the data + +Once we have the skeleton of our project, we can get the raw data. + +Fannie Mae has some restrictions around acquiring the data, so you’ll need to sign up for an account. You can find the download page [here][26]. After creating an account, you’ll be able to download as few or as many loan data files as you want. The files are in zip format, and are reasonably large after decompression. + +For the purposes of this blog post, we’ll download everything from Q1 2012 to Q1 2015, inclusive. We’ll then need to unzip all of the files. After unzipping the files, remove the original .zip files. At the end, the loan-prediction folder should look something like this: + +``` +loan-prediction +├── data +│ ├── Acquisition_2012Q1.txt +│ ├── Acquisition_2012Q2.txt +│ ├── Performance_2012Q1.txt +│ ├── Performance_2012Q2.txt +│ └── ... +├── processed +├── .gitignore +├── README.md +├── requirements.txt +├── settings.py +``` + +After downloading the data, you can use the head and tail shell commands to look at the lines in the files. Do you see any columns that aren’t needed? It might be useful to consult the [pdf of column names][27] while doing this. + +### Reading in the data + +There are two issues that make our data hard to work with right now: + +- The acquisition and performance datasets are segmented across multiple files. +- Each file is missing headers. + +Before we can get started on working with the data, we’ll need to get to the point where we have one file for the acquisition data, and one file for the performance data. Each of the files will need to contain only the columns we care about, and have the proper headers. One wrinkle here is that the performance data is quite large, so we should try to trim some of the columns if we can. + +The first step is to add some variables to settings.py, which will contain the paths to our raw data and our processed data. We’ll also add a few other settings that will be useful later on: + +``` +DATA_DIR = "data" +PROCESSED_DIR = "processed" +MINIMUM_TRACKING_QUARTERS = 4 +TARGET = "foreclosure_status" +NON_PREDICTORS = [TARGET, "id"] +CV_FOLDS = 3 +``` + +Putting the paths in settings.py will put them in a centralized place and make them easy to change down the line. When referring to the same variables in multiple files, it’s easier to put them in a central place than edit them in every file when you want to change them. [Here’s][28] an example settings.py file for this project. + +The second step is to create a file called assemble.py that will assemble all the pieces into 2 files. When we run python assemble.py, we’ll get 2 data files in the processed directory. + +We’ll then start writing code in assemble.py. We’ll first need to define the headers for each file, so we’ll need to look at [pdf of column names][29] and create lists of the columns in each Acquisition and Performance file: + +``` +HEADERS = { + "Acquisition": [ + "id", + "channel", + "seller", + "interest_rate", + "balance", + "loan_term", + "origination_date", + "first_payment_date", + "ltv", + "cltv", + "borrower_count", + "dti", + "borrower_credit_score", + "first_time_homebuyer", + "loan_purpose", + "property_type", + "unit_count", + "occupancy_status", + "property_state", + "zip", + "insurance_percentage", + "product_type", + "co_borrower_credit_score" + ], + "Performance": [ + "id", + "reporting_period", + "servicer_name", + "interest_rate", + "balance", + "loan_age", + "months_to_maturity", + "maturity_date", + "msa", + "delinquency_status", + "modification_flag", + "zero_balance_code", + "zero_balance_date", + "last_paid_installment_date", + "foreclosure_date", + "disposition_date", + "foreclosure_costs", + "property_repair_costs", + "recovery_costs", + "misc_costs", + "tax_costs", + "sale_proceeds", + "credit_enhancement_proceeds", + "repurchase_proceeds", + "other_foreclosure_proceeds", + "non_interest_bearing_balance", + "principal_forgiveness_balance" + ] +} +``` + +The next step is to define the columns we want to keep. Since all we’re measuring on an ongoing basis about the loan is whether or not it was ever foreclosed on, we can discard many of the columns in the performance data. We’ll need to keep all the columns in the acquisition data, though, because we want to maximize the information we have about when the loan was acquired (after all, we’re predicting if the loan will ever be foreclosed or not at the point it’s acquired). Discarding columns will enable us to save disk space and memory, while also speeding up our code. + +``` +SELECT = { + "Acquisition": HEADERS["Acquisition"], + "Performance": [ + "id", + "foreclosure_date" + ] +} +``` + +Next, we’ll write a function to concatenate the data sets. The below code will: + +- Import a few needed libraries, including settings. +- Define a function concatenate, that: + - Gets the names of all the files in the data directory. + - Loops through each file. + - If the file isn’t the right type (doesn’t start with the prefix we want), we ignore it. + - Reads the file into a [DataFrame][30] with the right settings using the Pandas [read_csv][31] function. + - Sets the separator to | so the fields are read in correctly. + - The data has no header row, so sets header to None to indicate this. + - Sets names to the right value from the HEADERS dictionary – these will be the column names of our DataFrame. + - Picks only the columns from the DataFrame that we added in SELECT. +- Concatenates all the DataFrames together. +- Writes the concatenated DataFrame back to a file. + +``` +import os +import settings +import pandas as pd + +def concatenate(prefix="Acquisition"): + files = os.listdir(settings.DATA_DIR) + full = [] + for f in files: + if not f.startswith(prefix): + continue + + data = pd.read_csv(os.path.join(settings.DATA_DIR, f), sep="|", header=None, names=HEADERS[prefix], index_col=False) + data = data[SELECT[prefix]] + full.append(data) + + full = pd.concat(full, axis=0) + + full.to_csv(os.path.join(settings.PROCESSED_DIR, "{}.txt".format(prefix)), sep="|", header=SELECT[prefix], index=False) +``` + +We can call the above function twice with the arguments Acquisition and Performance to concatenate all the acquisition and performance files together. The below code will: + +- Only execute if the script is called from the command line with python assemble.py. +- Concatenate all the files, and result in two files: + - `processed/Acquisition.txt` + - `processed/Performance.txt` + +``` +if __name__ == "__main__": + concatenate("Acquisition") + concatenate("Performance") +``` + +We now have a nice, compartmentalized assemble.py that’s easy to execute, and easy to build off of. By decomposing the problem into pieces like this, we make it easy to build our project. Instead of one messy script that does everything, we define the data that will pass between the scripts, and make them completely separate from each other. When you’re working on larger projects, it’s a good idea to do this, because it makes it much easier to change individual pieces without having unexpected consequences on unrelated pieces of the project. + +Once we finish the assemble.py script, we can run python assemble.py. You can find the complete assemble.py file [here][32]. + +This will result in two files in the processed directory: + +``` +loan-prediction +├── data +│ ├── Acquisition_2012Q1.txt +│ ├── Acquisition_2012Q2.txt +│ ├── Performance_2012Q1.txt +│ ├── Performance_2012Q2.txt +│ └── ... +├── processed +│ ├── Acquisition.txt +│ ├── Performance.txt +├── .gitignore +├── assemble.py +├── README.md +├── requirements.txt +├── settings.py +``` diff --git a/sources/team_test/part 4 - Building a data science portfolio - Machine learning project.md b/sources/team_test/part 4 - Building a data science portfolio - Machine learning project.md new file mode 100644 index 0000000000..a9af49b188 --- /dev/null +++ b/sources/team_test/part 4 - Building a data science portfolio - Machine learning project.md @@ -0,0 +1,84 @@ +vim-kakali translating + + + +### Computing values from the performance data + +The next step we’ll take is to calculate some values from processed/Performance.txt. All we want to do is to predict whether or not a property is foreclosed on. To figure this out, we just need to check if the performance data associated with a loan ever has a foreclosure_date. If foreclosure_date is None, then the property was never foreclosed on. In order to avoid including loans with little performance history in our sample, we’ll also want to count up how many rows exist in the performance file for each loan. This will let us filter loans without much performance history from our training data. + +One way to think of the loan data and the performance data is like this: + +![](https://github.com/LCTT/wiki-images/blob/master/TranslateProject/ref_img/001.png) + +As you can see above, each row in the Acquisition data can be related to multiple rows in the Performance data. In the Performance data, foreclosure_date will appear in the quarter when the foreclosure happened, so it should be blank prior to that. Some loans are never foreclosed on, so all the rows related to them in the Performance data have foreclosure_date blank. + +We need to compute foreclosure_status, which is a Boolean that indicates whether a particular loan id was ever foreclosed on, and performance_count, which is the number of rows in the performance data for each loan id. + +There are a few different ways to compute the counts we want: + +- We could read in all the performance data, then use the Pandas groupby method on the DataFrame to figure out the number of rows associated with each loan id, and also if the foreclosure_date is ever not None for the id. + - The upside of this method is that it’s easy to implement from a syntax perspective. + - The downside is that reading in all 129236094 lines in the data will take a lot of memory, and be extremely slow. +- We could read in all the performance data, then use apply on the acquisition DataFrame to find the counts for each id. + - The upside is that it’s easy to conceptualize. + - The downside is that reading in all 129236094 lines in the data will take a lot of memory, and be extremely slow. +- We could iterate over each row in the performance dataset, and keep a separate dictionary of counts. + - The upside is that the dataset doesn’t need to be loaded into memory, so it’s extremely fast and memory-efficient. + - The downside is that it will take slightly longer to conceptualize and implement, and we need to parse the rows manually. + +Loading in all the data will take quite a bit of memory, so let’s go with the third option above. All we need to do is to iterate through all the rows in the Performance data, while keeping a dictionary of counts per loan id. In the dictionary, we’ll keep track of how many times the id appears in the performance data, as well as if foreclosure_date is ever not None. This will give us foreclosure_status and performance_count. + +We’ll create a new file called annotate.py, and add in code that will enable us to compute these values. In the below code, we’ll: + +- Import needed libraries. +- Define a function called count_performance_rows. + - Open processed/Performance.txt. This doesn’t read the file into memory, but instead opens a file handler that can be used to read in the file line by line. + - Loop through each line in the file. + - Split the line on the delimiter (|) + - Check if the loan_id is not in the counts dictionary. + - If not, add it to counts. + - Increment performance_count for the given loan_id because we’re on a row that contains it. + - If date is not None, then we know that the loan was foreclosed on, so set foreclosure_status appropriately. + +``` +import os +import settings +import pandas as pd + +def count_performance_rows(): + counts = {} + with open(os.path.join(settings.PROCESSED_DIR, "Performance.txt"), 'r') as f: + for i, line in enumerate(f): + if i == 0: + # Skip header row + continue + loan_id, date = line.split("|") + loan_id = int(loan_id) + if loan_id not in counts: + counts[loan_id] = { + "foreclosure_status": False, + "performance_count": 0 + } + counts[loan_id]["performance_count"] += 1 + if len(date.strip()) > 0: + counts[loan_id]["foreclosure_status"] = True + return counts +``` + +### Getting the values + +Once we create our counts dictionary, we can make a function that will extract values from the dictionary if a loan_id and a key are passed in: + +``` +def get_performance_summary_value(loan_id, key, counts): + value = counts.get(loan_id, { + "foreclosure_status": False, + "performance_count": 0 + }) + return value[key] +``` + +The above function will return the appropriate value from the counts dictionary, and will enable us to assign a foreclosure_status value and a performance_count value to each row in the Acquisition data. The [get][33] method on dictionaries returns a default value if a key isn’t found, so this enables us to return sensible default values if a key isn’t found in the counts dictionary. + + + diff --git a/sources/team_test/part 5 - Building a data science portfolio - Machine learning project.md b/sources/team_test/part 5 - Building a data science portfolio - Machine learning project.md new file mode 100644 index 0000000000..a92bb01900 --- /dev/null +++ b/sources/team_test/part 5 - Building a data science portfolio - Machine learning project.md @@ -0,0 +1,163 @@ + +### 注解数据 + +我们已经在annotate.py中添加了一些功能, 现在我们来看一看数据文件. 我们需要将采集到的数据转换到训练数据表来进行机器学习的训练. 这涉及到以下几件事情: + +- 转换所以列数字. +- 填充缺失值. +- 分配 performance_count 和 foreclosure_status. +- 移除出现次数很少的行(performance_count 计数低). + +我们有几个列是文本类型的, 看起来对于机器学习算法来说并不是很有用. 然而, 他们实际上是分类变量, 其中有很多不同的类别代码, 例如R,S等等. 我们可以把这些类别标签转换为数值: + +![](https://github.com/LCTT/wiki-images/blob/master/TranslateProject/ref_img/002.png) + +通过这种方法转换的列我们可以应用到机器学习算法中. + +还有一些包含日期的列 (first_payment_date 和 origination_date). 我们可以将这些日期放到两个列中: + +![](https://github.com/LCTT/wiki-images/blob/master/TranslateProject/ref_img/003.png) +在下面的代码中, 我们将转换采集到的数据. 我们将定义一个函数如下: + +- 在采集到的数据中创建foreclosure_status列 . +- 在采集到的数据中创建performance_count列. +- 将下面的string列转换为integer列: + - channel + - seller + - first_time_homebuyer + - loan_purpose + - property_type + - occupancy_status + - property_state + - product_type +- 转换first_payment_date 和 origination_date 为两列: + - 通过斜杠分离列. + - 将第一部分分离成月清单. + - 将第二部分分离成年清单. + - 删除这一列. + - 最后, 我们得到 first_payment_month, first_payment_year, origination_month, and origination_year. +- 所有缺失值填充为-1. + +``` +def annotate(acquisition, counts): + acquisition["foreclosure_status"] = acquisition["id"].apply(lambda x: get_performance_summary_value(x, "foreclosure_status", counts)) + acquisition["performance_count"] = acquisition["id"].apply(lambda x: get_performance_summary_value(x, "performance_count", counts)) + for column in [ + "channel", + "seller", + "first_time_homebuyer", + "loan_purpose", + "property_type", + "occupancy_status", + "property_state", + "product_type" + ]: + acquisition[column] = acquisition[column].astype('category').cat.codes + + for start in ["first_payment", "origination"]: + column = "{}_date".format(start) + acquisition["{}_year".format(start)] = pd.to_numeric(acquisition[column].str.split('/').str.get(1)) + acquisition["{}_month".format(start)] = pd.to_numeric(acquisition[column].str.split('/').str.get(0)) + del acquisition[column] + + acquisition = acquisition.fillna(-1) + acquisition = acquisition[acquisition["performance_count"] > settings.MINIMUM_TRACKING_QUARTERS] + return acquisition +``` + +### 聚合到一起 + +我们差不多准备就绪了, 我们只需要再在annotate.py添加一点点代码. 在下面代码中, 我们将: + +- 定义一个函数来读取采集的数据. +- 定义一个函数来写入数据到/train.csv +- 如果我们在命令行运行annotate.py来读取更新过的数据文件，它将做如下事情: + - 读取采集到的数据. + - 计算数据性能. + - 注解数据. + - 将注解数据写入到train.csv. + +``` +def read(): + acquisition = pd.read_csv(os.path.join(settings.PROCESSED_DIR, "Acquisition.txt"), sep="|") + return acquisition + +def write(acquisition): + acquisition.to_csv(os.path.join(settings.PROCESSED_DIR, "train.csv"), index=False) + +if __name__ == "__main__": + acquisition = read() + counts = count_performance_rows() + acquisition = annotate(acquisition, counts) + write(acquisition) +``` + +修改完成以后为了确保annotate.py能够生成train.csv文件. 你可以在这里找到完整的 annotate.py file [here][34]. + +文件夹结果应该像这样: + +``` +loan-prediction +├── data +│ ├── Acquisition_2012Q1.txt +│ ├── Acquisition_2012Q2.txt +│ ├── Performance_2012Q1.txt +│ ├── Performance_2012Q2.txt +│ └── ... +├── processed +│ ├── Acquisition.txt +│ ├── Performance.txt +│ ├── train.csv +├── .gitignore +├── annotate.py +├── assemble.py +├── README.md +├── requirements.txt +├── settings.py +``` + +### 找到标准 + +我们已经完成了训练数据表的生成, 现在我们需要最后一步, 生成预测. 我们需要找到错误的标准, 以及该如何评估我们的数据. 在这种情况下, 因为有很多的贷款没有收回, 所以根本不可能做到精确的计算. + +我们需要读取数据, 并且计算foreclosure_status列, 我们将得到如下信息: + +``` +import pandas as pd +import settings + +train = pd.read_csv(os.path.join(settings.PROCESSED_DIR, "train.csv")) +train["foreclosure_status"].value_counts() +``` + +``` +False 4635982 +True 1585 +Name: foreclosure_status, dtype: int64 +``` + +因为只有一点点贷款收回, 通过百分比标签来建立的机器学习模型会把每行都设置为Fasle, 所以我们在这里要考虑每个样本的不平衡性,确保我们做出的预测是准确的. 我们不想要这么多假的false, 我们将预计贷款收回但是它并没有收回, 我们预计贷款不会回收但是却回收了. 通过以上两点, Fannie Mae的false太多了, 因此显示他们可能无法收回投资. + +所以我们将定义一个百分比，就是模型预测没有收回但是实际上收回了, 这个数除以总的负债回收总数. 这个负债回收百分比模型实际上是“没有的”. 下面看这个图表: + +![](https://github.com/LCTT/wiki-images/blob/master/TranslateProject/ref_img/004.png) + +通过上面的图表, 1个负债预计不会回收, 也确实没有回收. 如果我们将这个数除以总数, 2, 我们将得到false的概率为50%. 我们将使用这个标准, 因此我们可以评估一下模型的性能. + +### 设置机器学习分类器 + +我们使用交叉验证预测. 通过交叉验证法, 我们将数据分为3组. 按照下面的方法来做: + +- Train a model on groups 1 and 2, and use the model to make predictions for group 3. +- Train a model on groups 1 and 3, and use the model to make predictions for group 2. +- Train a model on groups 2 and 3, and use the model to make predictions for group 1. + +将它们分割到不同的组 ,这意味着我们永远不会用相同的数据来为预测训练模型. 这样就避免了overfitting(过拟合). 如果我们overfit(过拟合), 我们将得到很低的false概率, 这使得我们难以改进算法或者应用到现实生活中. + +[Scikit-learn][35] 有一个叫做 [cross_val_predict][36] 他可以帮助我们理解交叉算法. + +我们还需要一种算法来帮我们预测. 我们还需要一个分类器 [binary classification][37]（二元分类）. 目标变量foreclosure_status 只有两个值, True 和 False. + +我们用[logistic regression][38]（回归算法）, 因为它能很好的进行binary classification（二元分类）, 并且运行很快, 占用内存很小. 我们来说一下它是如何工作的 – 取代许多树状结构, 更像随机森林, 进行转换, 更像一个向量机, 逻辑回归涉及更少的步骤和更少的矩阵. + +我们可以使用[logistic regression classifier][39]（逻辑回归分类器）算法 来实现scikit-learn. 我们唯一需要注意的是每个类的标准. 如果我们使用同样标准的类, 算法将会预测每行都为false, 因为它总是试图最小化误差.不管怎样, 我们关注有多少贷款能够回收而不是有多少不能回收. 因此, 我们通过 [LogisticRegression][40]（逻辑回归）来平衡标准参数, 并计算回收贷款的标准. 这将使我们的算法不会认为每一行都为false. diff --git a/sources/team_test/part 6 - Building a data science portfolio - Machine learning project.md b/sources/team_test/part 6 - Building a data science portfolio - Machine learning project.md new file mode 100644 index 0000000000..3bec1d0a98 --- /dev/null +++ b/sources/team_test/part 6 - Building a data science portfolio - Machine learning project.md @@ -0,0 +1,156 @@ +Translating by cposture 2016-08-02 +### Making predictions + +Now that we have the preliminaries out of the way, we’re ready to make predictions. We’ll create a new file called predict.py that will use the train.csv file we created in the last step. The below code will: + +- Import needed libraries. +- Create a function called cross_validate that: + - Creates a logistic regression classifier with the right keyword arguments. + - Creates a list of columns that we want to use to train the model, removing id and foreclosure_status. + - Run cross validation across the train DataFrame. + - Return the predictions. + + +``` +import os +import settings +import pandas as pd +from sklearn import cross_validation +from sklearn.linear_model import LogisticRegression +from sklearn import metrics + +def cross_validate(train): + clf = LogisticRegression(random_state=1, class_weight="balanced") + + predictors = train.columns.tolist() + predictors = [p for p in predictors if p not in settings.NON_PREDICTORS] + + predictions = cross_validation.cross_val_predict(clf, train[predictors], train[settings.TARGET], cv=settings.CV_FOLDS) + return predictions +``` + +### Predicting error + +Now, we just need to write a few functions to compute error. The below code will: + +- Create a function called compute_error that: + - Uses scikit-learn to compute a simple accuracy score (the percentage of predictions that matched the actual foreclosure_status values). +- Create a function called compute_false_negatives that: + - Combines the target and the predictions into a DataFrame for convenience. + - Finds the false negative rate. +- Create a function called compute_false_positives that: + - Combines the target and the predictions into a DataFrame for convenience. + - Finds the false positive rate. + - Finds the number of loans that weren’t foreclosed on that the model predicted would be foreclosed on. + - Divide by the total number of loans that weren’t foreclosed on. + +``` +def compute_error(target, predictions): + return metrics.accuracy_score(target, predictions) + +def compute_false_negatives(target, predictions): + df = pd.DataFrame({"target": target, "predictions": predictions}) + return df[(df["target"] == 1) & (df["predictions"] == 0)].shape[0] / (df[(df["target"] == 1)].shape[0] + 1) + +def compute_false_positives(target, predictions): + df = pd.DataFrame({"target": target, "predictions": predictions}) + return df[(df["target"] == 0) & (df["predictions"] == 1)].shape[0] / (df[(df["target"] == 0)].shape[0] + 1) +``` + + +### Putting it all together + +Now, we just have to put the functions together in predict.py. The below code will: + +- Read in the dataset. +- Compute cross validated predictions. +- Compute the 3 error metrics above. +- Print the error metrics. + +``` +def read(): + train = pd.read_csv(os.path.join(settings.PROCESSED_DIR, "train.csv")) + return train + +if __name__ == "__main__": + train = read() + predictions = cross_validate(train) + error = compute_error(train[settings.TARGET], predictions) + fn = compute_false_negatives(train[settings.TARGET], predictions) + fp = compute_false_positives(train[settings.TARGET], predictions) + print("Accuracy Score: {}".format(error)) + print("False Negatives: {}".format(fn)) + print("False Positives: {}".format(fp)) +``` + +Once you’ve added the code, you can run python predict.py to generate predictions. Running everything shows that our false negative rate is .26, which means that of the foreclosed loans, we missed predicting 26% of them. This is a good start, but can use a lot of improvement! + +You can find the complete predict.py file [here][41]. + +Your file tree should now look like this: + +``` +loan-prediction +├── data +│ ├── Acquisition_2012Q1.txt +│ ├── Acquisition_2012Q2.txt +│ ├── Performance_2012Q1.txt +│ ├── Performance_2012Q2.txt +│ └── ... +├── processed +│ ├── Acquisition.txt +│ ├── Performance.txt +│ ├── train.csv +├── .gitignore +├── annotate.py +├── assemble.py +├── predict.py +├── README.md +├── requirements.txt +├── settings.py +``` + +### Writing up a README + +Now that we’ve finished our end to end project, we just have to write up a README.md file so that other people know what we did, and how to replicate it. A typical README.md for a project should include these sections: + +- A high level overview of the project, and what the goals are. +- Where to download any needed data or materials. +- Installation instructions. + - How to install the requirements. +- Usage instructions. + - How to run the project. + - What you should see after each step. +- How to contribute to the project. + - Good next steps for extending the project. + +[Here’s][42] a sample README.md for this project. + +### Next steps + +Congratulations, you’re done making an end to end machine learning project! You can find a complete example project [here][43]. It’s a good idea to upload your project to [Github][44] once you’ve finished it, so others can see it as part of your portfolio. + +There are still quite a few angles left to explore with this data. Broadly, we can split them up into 3 categories – extending this project and making it more accurate, finding other columns to predict, and exploring the data. Here are some ideas: + +- Generate more features in annotate.py. +- Switch algorithms in predict.py. +- Try using more data from Fannie Mae than we used in this post. +- Add in a way to make predictions on future data. The code we wrote will still work if we add more data, so we can add more past or future data. +- Try seeing if you can predict if a bank should have issued the loan originally (vs if Fannie Mae should have acquired the loan). + - Remove any columns from train that the bank wouldn’t have known at the time of issuing the loan. + - Some columns are known when Fannie Mae bought the loan, but not before. + - Make predictions. +- Explore seeing if you can predict columns other than foreclosure_status. + - Can you predict how much the property will be worth at sale time? +- Explore the nuances between performance updates. + - Can you predict how many times the borrower will be late on payments? + - Can you map out the typical loan lifecycle? +- Map out data on a state by state or zip code by zip code level. + - Do you see any interesting patterns? + +If you build anything interesting, please let us know in the comments! + +If you liked this, you might like to read the other posts in our ‘Build a Data Science Porfolio’ series: + +- [Storytelling with data][45]. +- [How to setup up a data science blog][46]. diff --git a/sources/tech/20160104 What is good stock portfolio management software on Linux.md b/sources/tech/20160104 What is good stock portfolio management software on Linux.md deleted file mode 100644 index 258cf104fc..0000000000 --- a/sources/tech/20160104 What is good stock portfolio management software on Linux.md +++ /dev/null @@ -1,109 +0,0 @@ -What is good stock portfolio management software on Linux -================================================================================ -If you are investing in the stock market, you probably understand the importance of a sound portfolio management plan. The goal of portfolio management is to come up with the best investment plan tailored for you, considering your risk tolerance, time horizon and financial goals. Given its importance, no wonder there are no shortage of commercial portfolio management apps and stock market monitoring software, each touting various sophisticated portfolio performance tracking and reporting capabilities. - -For those of you Linux aficionados who are looking for a **good open-source portfolio management tool** to manage and track your stock portfolio on Linux, I would highly recommend a Java-based portfolio manager called [JStock][1]. If you are not a big Java fan, you might be turned off by the fact that JStock runs on a heavyweight JVM. At the same time I am sure many people will appreciate the fact that JStock is instantly accessible on every Linux platform with JRE installed. No hoops to jump through to make it work on your Linux environment. - -The day is gone when "open-source" means "cheap" or "subpar". Considering that JStock is just a one-man job, JStock is impressively packed with many useful features as a portfolio management tool, and all that credit goes to Yan Cheng Cheok! For example, JStock supports price monitoring via watchlists, multiple portfolios, custom/built-in stock indicators and scanners, support for 27 different stock markets and cross-platform cloud backup/restore. JStock is available on multiple platforms (Linux, OS X, Android and Windows), and you can save and restore your JStock portfolios seamlessly across different platforms via cloud backup/restore. - -Sounds pretty neat, huh? Now I am going to show you how to install and use JStock in more detail. - -### Install JStock on Linux ### - -Since JStock is written in Java, you must [install JRE][2] to run it. Note that JStock requires JRE 1.7 or higher. If your JRE version does not meet this requirement, JStock will fail with the following error. - - Exception in thread "main" java.lang.UnsupportedClassVersionError: org/yccheok/jstock/gui/JStock : Unsupported major.minor version 51.0 - -Once you install JRE on your Linux, download the latest JStock release from the official website, and launch it as follows. - - $ wget https://github.com/yccheok/jstock/releases/download/release_1-0-7-13/jstock-1.0.7.13-bin.zip - $ unzip jstock-1.0.7.13-bin.zip - $ cd jstock - $ chmod +x jstock.sh - $ ./jstock.sh - -In the rest of the tutorial, let me demonstrate several useful features of JStock. - -### Monitor Stock Price Movements via Watchlist ### - -On JStock you can monitor stock price movement and automatically get notified by creating one or more watchlists. In each watchlist, you can add multiple stocks you are interested in. Then add your alert thresholds under "Fall Below" and "Rise Above" columns, which correspond to minimum and maximum stock prices you want to set, respectively. - -![](https://c2.staticflickr.com/2/1588/23795349969_37f4b0f23c_c.jpg) - -For example, if you set minimum/maximum prices of AAPL stock to $102 and $115.50, you will be alerted via desktop notifications if the stock price goes below $102 or moves higher than $115.50 at any time. - -You can also enable email alert option, so that you will instead receive email notifications for such price events. To enable email alerts, go to "Options" menu. Under "Alert" tab, turn on "Send message to email(s)" box, and enter your Gmail account. Once you go through Gmail authorization steps, JStock will start sending email alerts to that Gmail account (and optionally CC to any third-party email address). - -![](https://c2.staticflickr.com/2/1644/24080560491_3aef056e8d_b.jpg) - -### Manage Multiple Portfolios ### - -JStock allows you to manage multiple portfolios. This feature is useful if you are using multiple stock brokers. You can create a separate portfolio for each broker and manage your buy/sell/dividend transactions on a per-broker basis. You can switch different portfolios by choosing a particular portfolio under "Portfolio" menu. The following screenshot shows a hypothetical portfolio. - -![](https://c2.staticflickr.com/2/1646/23536385433_df6c036c9a_c.jpg) - -Optionally you can enable broker fee option, so that you can enter any broker fees, stamp duty and clearing fees for each buy/sell transaction. If you are lazy, you can enable fee auto-calculation and enter fee schedules for each brokering firm from the option menu beforehand. Then JStock will automatically calculate and enter fees when you add transactions to your portfolio. - -![](https://c2.staticflickr.com/2/1653/24055085262_0e315c3691_b.jpg) - -### Screen Stocks with Built-in/Custom Indicators ### - -If you are doing any technical analysis on stocks, you may want to screen stocks based on various criteria (so-called "stock indicators"). For stock screening, JStock offers several [pre-built technical indicators][3] that capture upward/downward/reversal trends of individual stocks. The following is a list of available indicators. - -- Moving Average Convergence Divergence (MACD) -- Relative Strength Index (RSI) -- Money Flow Index (MFI) -- Commodity Channel Index (CCI) -- Doji -- Golden Cross, Death Cross -- Top Gainers/Losers - -To install any pre-built indicator, go to "Stock Indicator Editor" tab on JStock. Then click on "Install" button in the right-side panel. Choose "Install from JStock server" option, and then install any indicator(s) you want. - -![](https://c2.staticflickr.com/2/1476/23867534660_b6a9c95a06_c.jpg) - -Once one or more indicators are installed, you can scan stocks using them. Go to "Stock Indicator Scanner" tab, click on "Scan" button at the bottom, and choose any indicator. - -![](https://c2.staticflickr.com/2/1653/24137054996_e8fcd10393_c.jpg) - -Once you select the stocks to scan (e.g., NYSE, NASDAQ), JStock will perform scan, and show a list of stocks captured by the indicator. - -![](https://c2.staticflickr.com/2/1446/23795349889_0f1aeef608_c.jpg) - -Besides pre-built indicators, you can also define custom indicator(s) on your own with a GUI-based indicator editor. The following example screens for stocks whose current price is less than or equal to its 60-day average price. - -![](https://c2.staticflickr.com/2/1605/24080560431_3d26eac6b5_c.jpg) - -### Cloud Backup and Restore between Linux and Android JStock ### - -Another nice feature of JStock is cloud backup and restore. JStock allows you to save and restore your portfolios/watchlists via Google Drive, and this features works seamlessly across different platforms (e.g., Linux and Android). For example, if you saved your JStock portfolios to Google Drive on Android, you can restore them on Linux version of JStock. - -![](https://c2.staticflickr.com/2/1537/24163165565_bb47e04d6c_c.jpg) - -![](https://c2.staticflickr.com/2/1556/23536385333_9ed1a75d72_c.jpg) - -If you don't see your portfolios/watchlists after restoring from Google Drive, make sure that your country is correctly set under "Country" menu. - -JStock Android free version is available from [Google Play store][4]. You will need to upgrade to premium version for one-time payment if you want to use its full features (e.g., cloud backup, alerts, charts). I think the premium version is definitely worth it. - -![](https://c2.staticflickr.com/2/1687/23867534720_18b917028c_c.jpg) - -As a final note, I should mention that its creator, Yan Cheng Cheok, is pretty active in JStock development, and quite responsive in addressing any bugs. Kudos to him! - -What do you think of JStock as portfolio tracking software? - --------------------------------------------------------------------------------- - -via: http://xmodulo.com/stock-portfolio-management-software-linux.html - -作者：[Dan Nanni][a] -译者：[译者ID](https://github.com/译者ID) -校对：[校对者ID](https://github.com/校对者ID) - -本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 - -[a]:http://xmodulo.com/author/nanni -[1]:http://jstock.org/ -[2]:http://ask.xmodulo.com/install-java-runtime-linux.html -[3]:http://jstock.org/ma_indicator.html -[4]:https://play.google.com/store/apps/details?id=org.yccheok.jstock.gui diff --git a/sources/tech/20160218 How to Set Nginx as Reverse Proxy on Centos7 CPanel.md b/sources/tech/20160218 How to Set Nginx as Reverse Proxy on Centos7 CPanel.md index dc21bc0b23..7e0c87cd80 100644 --- a/sources/tech/20160218 How to Set Nginx as Reverse Proxy on Centos7 CPanel.md +++ b/sources/tech/20160218 How to Set Nginx as Reverse Proxy on Centos7 CPanel.md @@ -1,4 +1,8 @@ -zky001开始翻译 + + +【flankershen翻译中】 + + How to Set Nginx as Reverse Proxy on Centos7 CPanel ================================================================================ @@ -24,9 +28,9 @@ First of all, we need to install the EPEL repo to start-up with the process. --> Running transaction check ---> Package epel-release.noarch 0:7-5 will be installed --> Finished Dependency Resolution - + Dependencies Resolved - + =============================================================================================================================================== Package Arch Version Repository Size =============================================================================================================================================== @@ -44,9 +48,9 @@ First of all, we need to install the EPEL repo to start-up with the process. --> Running transaction check ---> Package nDeploy-release-centos.noarch 0:1.0-1 will be installed --> Finished Dependency Resolution - + Dependencies Resolved - + =============================================================================================================================================== Package Arch Version Repository Size =============================================================================================================================================== @@ -63,9 +67,9 @@ First of all, we need to install the EPEL repo to start-up with the process. (1/4): ndeploy/7/x86_64/primary_db | 14 kB 00:00:00 (2/4): epel/x86_64/group_gz | 169 kB 00:00:00 (3/4): epel/x86_64/primary_db | 3.7 MB 00:00:02 - + Dependencies Resolved - + =============================================================================================================================================== Package Arch Version Repository Size =============================================================================================================================================== @@ -78,7 +82,7 @@ First of all, we need to install the EPEL repo to start-up with the process. memcached x86_64 1.4.15-9.el7 base 84 k python-inotify noarch 0.9.4-4.el7 base 49 k python-lxml x86_64 3.2.1-4.el7 base 758 k - + Transaction Summary =============================================================================================================================================== Install 2 Packages (+5 Dependent packages) @@ -89,7 +93,7 @@ With these steps, we've completed with the installation of Nginx plugin in our s root@server1 [/usr]# /opt/nDeploy/scripts/cpanel-nDeploy-setup.sh enable Modifying apache http and https port in cpanel - + httpd restarted successfully. Created symlink from /etc/systemd/system/multi-user.target.wants/nginx.service to /usr/lib/systemd/system/nginx.service. Created symlink from /etc/systemd/system/multi-user.target.wants/ndeploy_watcher.service to /usr/lib/systemd/system/ndeploy_watcher.service. @@ -109,7 +113,7 @@ As you can see these script will modify the Apache port from 80 to another port Main PID: 24760 (httpd) CGroup: /system.slice/httpd.service ‣ 24760 /usr/local/apache/bin/httpd -k start - + Jan 18 06:34:23 server1.centos7-test.com systemd[1]: Starting Apache Web Server... Jan 18 06:34:23 server1.centos7-test.com apachectl[25606]: httpd (pid 24760) already running Jan 18 06:34:23 server1.centos7-test.com systemd[1]: Started Apache Web Server. @@ -127,7 +131,7 @@ As you can see these script will modify the Apache port from 80 to another port ├─25473 nginx: worker process ├─25474 nginx: worker process └─25475 nginx: cache manager process - + Jan 17 17:18:29 server1.centos7-test.com systemd[1]: Starting nginx-nDeploy - high performance web server... Jan 17 17:18:29 server1.centos7-test.com nginx[3804]: nginx: the configuration file /etc/nginx/nginx.conf syntax is ok Jan 17 17:18:29 server1.centos7-test.com nginx[3804]: nginx: configuration file /etc/nginx/nginx.conf test is successful @@ -159,14 +163,14 @@ The virtualhost entries created for the existing users as located in the folder listen 45.79.183.73:80; #CPIPVSIX:80; - + # ServerNames server_name saheetha.com www.saheetha.com; access_log /usr/local/apache/domlogs/saheetha.com main; access_log /usr/local/apache/domlogs/saheetha.com-bytes_log bytes_log; - + include /etc/nginx/sites-enabled/saheetha.com.include; - + } We can confirm the working of the web server status by calling a website in the browser. Please see the web server information on my server after the installation. @@ -200,4 +204,4 @@ via: http://linoxide.com/linux-how-to/set-nginx-reverse-proxy-centos-7-cpanel/ 本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 -[a]:http://linoxide.com/author/saheethas/ +[a]: http://linoxide.com/author/saheethas/ diff --git a/sources/tech/20160218 What do Linux developers think of Git and GitHub.md b/sources/tech/20160218 What do Linux developers think of Git and GitHub.md deleted file mode 100644 index b444b0958c..0000000000 --- a/sources/tech/20160218 What do Linux developers think of Git and GitHub.md +++ /dev/null @@ -1,95 +0,0 @@ -@4357 翻译中 - -What do Linux developers think of Git and GitHub? -===================================================== - -**Also in today’s open source roundup: DistroWatch reviews XStream Desktop 153, and Street Fighter V is coming to Linux and SteamOS in the spring** - -## What do Linux developers think of Git and GitHub? - -The popularity of Git and GitHub among Linux developers is well established. But what do developers think of them? And should GitHub really be synonymous with Git itself? A Linux redditor recently asked about this and got some very interesting answers. - -Dontwakemeup46 asked his question: - ->I am learning Git and Github. What I am interested in is how these two are viewed by the community. That git and github are used extensively, is something I know. But are there serious issues with either Git or Github? Something that the community would love to change? - -[More at Reddit](http://api.viglink.com/api/click?format=go&jsonp=vglnk_145580413015211&key=0a7039c08493c7c51b759e3d13019dbe&libId=iksc5hc8010113at000DL3yrsuvp7&loc=http%3A%2F%2Fwww.infoworld.com%2Farticle%2F3033059%2Flinux%2Fwhat-do-linux-developers-think-of-git-and-github.html&v=1&out=https%3A%2F%2Fwww.reddit.com%2Fr%2Flinux%2Fcomments%2F45jy59%2Fthe_popularity_of_git_and_github%2F&ref=http%3A%2F%2Fwww.linux.com%2Fnews%2Fsoftware%2Fapplications%2F886008-what-do-linux-developers-think-of-git-and-github&title=What%20do%20Linux%20developers%20think%20of%20Git%20and%20GitHub%3F%20%7C%20InfoWorld&txt=More%20at%20Reddit) - -His fellow Linux redditors responded with their thoughts about Git and GitHub: - ->Derenir: ”Github is not affliated with Git. - ->Git is made by Linus Torvalds. - ->Github hardly supports Linux. - ->Github is a corporate bordelo that tries to make money from Git. - ->[https://desktop.github.com/](http://api.viglink.com/api/click?format=go&jsonp=vglnk_145580415025712&key=0a7039c08493c7c51b759e3d13019dbe&libId=iksc5hc8010113at000DL3yrsuvp7&loc=http%3A%2F%2Fwww.infoworld.com%2Farticle%2F3033059%2Flinux%2Fwhat-do-linux-developers-think-of-git-and-github.html&v=1&type=U&out=https%3A%2F%2Fdesktop.github.com%2F&ref=http%3A%2F%2Fwww.linux.com%2Fnews%2Fsoftware%2Fapplications%2F886008-what-do-linux-developers-think-of-git-and-github&title=What%20do%20Linux%20developers%20think%20of%20Git%20and%20GitHub%3F%20%7C%20InfoWorld&txt=https%3A%2F%2Fdesktop.github.com%2F) see here no Linux Support.” - ->**Bilog78**: ”A minor update: git hasn't been “made by Linus Torvalds” for a while. The maintainer is Junio C Hamano and the main contributors after him are Jeff King and Shawn O. Pearce.” - ->**Fearthefuture**: ”I like git but can't understand why people even use github anymore. From my point of view the only thing it does better than bitbucket are user statistics and the larger userbase. Bitbucket has unlimited free private repos, much better UI and very good integration with other services such as Jenkins.” - ->**Thunger**: ”Gitlab.com is also nice, especially since you can host your own instance on your own servers.” - ->**Takluyver**: ”Lots of people are familiar with the UI of Github and associated services like Travis, and lots of people already have Github accounts, so it's a good place for projects to be. People also use their Github profile as a kind of portfolio, so they're motivated to put more projects on there. Github is a de facto standard for hosting open source projects.” - ->**Tdammers**: ”Serious issue with git would be the UI, which is kind of counterintuitive, to the point that many users just stick with a handful of memorized incantations. - -Github: most serious issue here is that it's a proprietary hosted solution; you buy convenience, and the price is that your code is on someone else's server and not under your control anymore. Another common criticism of github is that its workflow isn't in line with the spirit of git itself, particularly the way pull requests work. And finally, github is monopolizing the code hosting landscape, and that's bad for diversity, which in turn is crucial for a thriving free software community.” - ->**Dies**: ”How is that the case? More importantly, if that is the case, then what's done is done and I guess we're stuck with Github since they control so many projects.” - ->**Tdammers**: ”The code is hosted on someone else's server, "someone else" in this case being github. Which, for an open-source project, is not typically a huge problem, but still, you don't control it. If you have a private project on github, then the only assurance you have that it will remain private is github's word for it. If you decide to delete things, then you can never be sure whether it's been deleted, or just hidden. - -Github doesn't control the projects themselves (you can always take your code and host it elsewhere, declaring the new location the "official" one), it just has deeper access to the code than the developers themselves.” - ->**Drelos**: ”I have read a lot of praises and bad stuff about Github ([here's an example](http://api.viglink.com/api/click?format=go&jsonp=vglnk_145580428524613&key=0a7039c08493c7c51b759e3d13019dbe&libId=iksc5hc8010113at000DL3yrsuvp7&loc=http%3A%2F%2Fwww.infoworld.com%2Farticle%2F3033059%2Flinux%2Fwhat-do-linux-developers-think-of-git-and-github.html&v=1&out=http%3A%2F%2Fwww.wired.com%2F2015%2F06%2Fproblem-putting-worlds-code-github%2F&ref=http%3A%2F%2Fwww.linux.com%2Fnews%2Fsoftware%2Fapplications%2F886008-what-do-linux-developers-think-of-git-and-github&title=What%20do%20Linux%20developers%20think%20of%20Git%20and%20GitHub%3F%20%7C%20InfoWorld&txt=here%27s%20an%20example)) but my simple noob question is why aren't efforts towards a free and open "version" ?” - ->**Twizmwazin**: ”GitLab is sorta pushing there.” - -[More at Reddit](http://api.viglink.com/api/click?format=go&jsonp=vglnk_145580429720714&key=0a7039c08493c7c51b759e3d13019dbe&libId=iksc5hc8010113at000DL3yrsuvp7&loc=http%3A%2F%2Fwww.infoworld.com%2Farticle%2F3033059%2Flinux%2Fwhat-do-linux-developers-think-of-git-and-github.html&v=1&out=https%3A%2F%2Fwww.reddit.com%2Fr%2Flinux%2Fcomments%2F45jy59%2Fthe_popularity_of_git_and_github%2F&ref=http%3A%2F%2Fwww.linux.com%2Fnews%2Fsoftware%2Fapplications%2F886008-what-do-linux-developers-think-of-git-and-github&title=What%20do%20Linux%20developers%20think%20of%20Git%20and%20GitHub%3F%20%7C%20InfoWorld&txt=More%20at%20Reddit) - -## DistroWatch reviews XStream Desktop 153 - -XStreamOS is a version of Solaris created by Sonicle. XStream Desktop brings the power of Solaris to desktop users, and distrohoppers might be interested in checking it out. DistroWatch did a full review of XStream Desktop 153 and found that it performed fairly well. - -Jesse Smith reports for DistroWatch: - ->I think XStream Desktop does a lot of things well. Admittedly, my trial got off to a rocky start when the operating system would not boot on my hardware and I could not get the desktop to use my display's full screen resolution when running in VirtualBox. However, after that, XStream performed fairly well. The installer works well, the operating system automatically sets up and uses boot environments, insuring we can recover the system if something goes wrong. The package management tools work well and XStream ships with a useful collection of software. - ->I did run into a few problems playing media, specifically getting audio to work. I am not sure if that is another hardware compatibility issue or a problem with the media software that ships with the operating system. On the other hand, tools such as the web browser, e-mail, productivity suite and configuration tools all worked well. - ->What I appreciate about XStream the most is that the operating system is a branch of the OpenSolaris family that is being kept up to date. Other derivatives of OpenSolaris tend to lag behind, at least with desktop software, but XStream is still shipping recent versions of Firefox and LibreOffice. - ->For me personally, XStream is missing a few components, like a printer manager, multimedia support and drivers for my specific hardware. Other aspects of the operating system are quite attractive. I like the way the developers have set up LXDE, I like the default collection of software and I especially like the way file system snapshots and boot environments are enabled out of the box. Most Linux distributions, openSUSE aside, have not caught on to the usefulness of boot environments yet and I hope it is a technology that is picked up by more projects. - -[More at DistroWatch](http://api.viglink.com/api/click?format=go&jsonp=vglnk_145580434172315&key=0a7039c08493c7c51b759e3d13019dbe&libId=iksc5hc8010113at000DL3yrsuvp7&loc=http%3A%2F%2Fwww.infoworld.com%2Farticle%2F3033059%2Flinux%2Fwhat-do-linux-developers-think-of-git-and-github.html&v=1&out=http%3A%2F%2Fdistrowatch.com%2Fweekly.php%3Fissue%3D20160215%23xstreamos&ref=http%3A%2F%2Fwww.linux.com%2Fnews%2Fsoftware%2Fapplications%2F886008-what-do-linux-developers-think-of-git-and-github&title=What%20do%20Linux%20developers%20think%20of%20Git%20and%20GitHub%3F%20%7C%20InfoWorld&txt=More%20at%20DistroWatch) - -## Street Fighter V and SteamOS - -Street Fighter is one of the most well known game franchises of all time, and now [Capcom has announced](http://api.viglink.com/api/click?format=go&jsonp=vglnk_145580435418216&key=0a7039c08493c7c51b759e3d13019dbe&libId=iksc5hc8010113at000DL3yrsuvp7&loc=http%3A%2F%2Fwww.infoworld.com%2Farticle%2F3033059%2Flinux%2Fwhat-do-linux-developers-think-of-git-and-github.html&v=1&out=http%3A%2F%2Fsteamcommunity.com%2Fgames%2F310950%2Fannouncements%2Fdetail%2F857177755595160250&ref=http%3A%2F%2Fwww.linux.com%2Fnews%2Fsoftware%2Fapplications%2F886008-what-do-linux-developers-think-of-git-and-github&title=What%20do%20Linux%20developers%20think%20of%20Git%20and%20GitHub%3F%20%7C%20InfoWorld&txt=Capcom%20has%20announced) that Street Fighter V will be coming to Linux and SteamOS in the spring. This is great news for Linux gamers. - -Joe Parlock reports for Destructoid: - ->Are you one of the less than one percent of Steam users who play on a Linux-based system? Are you part of the even smaller percentage of people who play on Linux and are excited for Street Fighter V? Well, I’ve got some good news for you. - ->Capcom has announced via Steam that Street Fighter V will be coming to SteamOS and other Linux operating systems sometime this spring. It’ll come at no extra cost, so those who already own the PC build of the game will just be able to install it on Linux and be good to go. - -[More at Destructoid](http://api.viglink.com/api/click?format=go&jsonp=vglnk_145580435418216&key=0a7039c08493c7c51b759e3d13019dbe&libId=iksc5hc8010113at000DL3yrsuvp7&loc=http%3A%2F%2Fwww.infoworld.com%2Farticle%2F3033059%2Flinux%2Fwhat-do-linux-developers-think-of-git-and-github.html&v=1&out=http%3A%2F%2Fsteamcommunity.com%2Fgames%2F310950%2Fannouncements%2Fdetail%2F857177755595160250&ref=http%3A%2F%2Fwww.linux.com%2Fnews%2Fsoftware%2Fapplications%2F886008-what-do-linux-developers-think-of-git-and-github&title=What%20do%20Linux%20developers%20think%20of%20Git%20and%20GitHub%3F%20%7C%20InfoWorld&txt=Capcom%20has%20announced) - -Did you miss a roundup? Check the [Eye On Open home page](http://www.infoworld.com/blog/eye-on-open/) to get caught up with the latest news about open source and Linux. - ------------------------------------------------------------------------------- - -via: http://www.infoworld.com/article/3033059/linux/what-do-linux-developers-think-of-git-and-github.html - -作者：[Jim Lynch][a] -译者：[译者ID](https://github.com/译者ID) -校对：[校对者ID](https://github.com/校对者ID) - -本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创翻译，[Linux中国](https://linux.cn/) 荣誉推出 - -[a]:http://www.infoworld.com/author/Jim-Lynch/ - diff --git a/sources/tech/20160222 Achieving Enterprise-Ready Container Tools With Wercker’s Open Source CLI.md b/sources/tech/20160222 Achieving Enterprise-Ready Container Tools With Wercker’s Open Source CLI.md deleted file mode 100644 index 81f7467719..0000000000 --- a/sources/tech/20160222 Achieving Enterprise-Ready Container Tools With Wercker’s Open Source CLI.md +++ /dev/null @@ -1,80 +0,0 @@ -Achieving Enterprise-Ready Container Tools With Wercker’s Open Source CLI -=========================================== - -For enterprises, containers offer more efficient build environments, cloud-native applications and migration from legacy systems to the cloud. But enterprise adoption of the technology -- Docker specifically -- has been hampered by, among other issues, [a lack of mature developer tools][1]. - -Amsterdam-based [Wercker][2] is one of many early-stage companies looking to meet the need for better tools with its cloud platform for automating microservices and application development, based on Docker. - -The company [announced a $4.5 million Series A][3] funding round this month, which will help it ramp up development on an upcoming on-premise enterprise product. Key to its success, however, will be building a community around its newly [open-sourced CLI][4] tool. Wercker must quickly integrate with myriad other container technologies -- open source Kubernetes and Mesos among them -- to remain competitive in the evolving container space. - -“By open sourcing our CLI technology, we hope to get to dev-prod parity faster and turn “build once, ship anywhere” into an automated reality,” said Wercker CEO and founder Micha Hernández van Leuffen. - -I reached out to van Leuffen to learn more about the company, its CLI tool, and how it’s planning to help grow the pool of enterprise customers actually using containers in production. Below is an edited version of the interview. - -### Linux.com: Can you briefly tell us about Wercker? - -van Leuffen: Wercker is a container-centric platform for automating the development of microservices and applications. - -With Wercker’s Docker-based infrastructure, teams can increase developer velocity with custom automation pipelines using steps that produce containers as artifacts. Once the build passes, users can continue to deploy the steps as specified in the wercker.yml. Continuously repeating these steps allows teams to work in small increments, making it easy to debug and ship faster. - -![](https://www.linux.com/images/stories/66866/wercker-cli.png) - -### Linux.com: How does it help developers? - -van Leuffen: The Wercker CLI helps developers attain greater dev-prod parity. They’re able to release faster and more often because they are developing, building and testing in an environment very similar to that in production. We’ve open sourced the exact same program that we execute in the Wercker cloud platform to run your pipelines. - -### Linux.com: Can you point out some of the features and advantages of your tool as compared to competitors? - -van Leuffen: Unlike some of our competitors, we’re not just offering Docker support. With Wercker, the Docker container is the unit of work. All jobs run inside containers, and each build artifact can be a Docker container. - -Wercker’s Docker container pipeline is completely customizable. A ‘pipeline’ refers to any automated workflow, for instance, a build or deploy pipeline. In those workflows, you want to execute tasks: install dependencies, test your code, push your container, or create a slack notification when something fails, for example. We call these tasks ‘steps,’ and there is no limit to the types of steps created. In fact, we have a marketplace of steps built by the Wercker community. So if you’ve built a step that fits my workflow, I can use that in my pipeline. - -Our Docker container pipelines adapt to any developer workflow. Users can use any Docker container out there — not just those made by or for Wercker. Whether the container is on Docker Hub or a private registry such as CoreOS’s Quay, it works with Wercker. - -Our competitors range from the classic CI/CD tools to larger-scale DevOps solutions like CloudBees. - -### Linux.com: How does it integrate with other cloud technologies? - -van Leuffen: Wercker is vendor-agnostic and can automate development with any cloud platform or service. We work closely with ecosystem partners like Mesosphere, Kubernetes and CoreOS to make integrations as seamless as possible. We also recently partnered with Atlassian to integrate the Wercker platform with Bitbucket. More than 3 million Bitbucket users can install the Wercker Pipeline Viewer and view build status directly from their dashboard. - -### Linux.com: Why did you open source the Wercker CLI tool? - -van Leuffen: Open sourcing the Wercker CLI will help us stay ahead of the curve and strengthen the developer community. The market landscape is changing fast; developers are expected to release more frequently, using infrastructure of increasing complexity. While Docker has solved a lot of infrastructure problems, developer teams are still looking for the perfect tools to test, build and deploy rapidly. - -The Wercker community is already experimenting with these new tools: Kubernetes, Mesosphere, CoreOS. It makes sense to tap that community to create integrations that work with our technology – and make that process as frictionless as possible. By open sourcing our CLI technology, we hope to get to dev-prod parity faster and turn “build once, ship anywhere” into an automated reality. - -### Linux.com: You recently raised over $4.5 million, so how is this fund being used for product development? - -van Leuffen: We’re focused on building out our commercial team and bringing an enterprise product to market. We’ve had a lot of inbound interest from the enterprise looking for VPC and on-premise solutions. While the enterprise is still largely in the discovery stage, we can see the market shifting toward containers. Enterprise software devs need to release often, just like the small, agile teams with whom they are increasingly competing. We need to prove containers can scale, and that Wercker has the organizational permissions and the automation suite to make that process as efficient as possible. - -In addition to continuing to invest in our product, we’ll be focusing our resources on market education and developer evangelism. Developer teams are still looking for the right mix of tools to test, build and deploy rapidly (including Kubernetes, Mesosphere, CoreOS, etc.). As an ecosystem, we need to do more to educate and provide the tutorials and resources to help developers succeed in this changing landscape. - -### Linux.com: What products do you offer and who is your target audience? - -van Leuffen: We currently offer one service level of our product Wercker; however, we’re developing an enterprise offering. Current organizations using Wercker range from startups, such as Open Listings, to larger companies and big agencies, like Pivotal Labs. - - -### Linux.com: What does this recently open-sourced CLI do? - -van Leuffen: Using the Wercker Command Line Interface (CLI), developers can spin up Docker containers on their desktop, automate their build and deploy processes and then deploy them to various cloud providers, like AWS, and scheduler and orchestration platforms, such as Mesosphere and Kubernetes. - -The Wercker Command Line Interface is available as an open source project on GitHub and runs on both OSX and Linux machines. - - --------------------------------------------------------------------------------- - -via: https://www.linux.com/news/enterprise/systems-management/887177-achieving-enterprise-ready-container-tools-with-werckers-open-source-cli - -作者：[Swapnil Bhartiya][a] -译者：[译者ID](https://github.com/译者ID) -校对：[校对者ID](https://github.com/校对者ID) - -本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 - -[a]:https://www.linux.com/community/forums/person/61003 -[1]:http://thenewstack.io/adopting-containers-enterprise/ -[2]:http://wercker.com/ -[3]:http://venturebeat.com/2016/01/28/wercker-raises-4-5-million-open-sources-its-command-line-tool/ -[4]:https://github.com/wercker/wercker - - diff --git a/sources/tech/20160301 Viper, the Python IoT Development Suite, is now Zerynth.md b/sources/tech/20160301 Viper, the Python IoT Development Suite, is now Zerynth.md deleted file mode 100644 index f732382bc6..0000000000 --- a/sources/tech/20160301 Viper, the Python IoT Development Suite, is now Zerynth.md +++ /dev/null @@ -1,35 +0,0 @@ -(翻译中 by runningwater) -Viper, the Python IoT Development Suite, is now Zerynth -============================================================ - - -![](http://www.open-electronics.org/wp-content/uploads/2016/02/Logo_Zerynth-636x144.png) - - -The startup that launched the tools to develop embedded solutions in Python language announced the brand change along with the first official release. - ->Exactly one year after the Kickstarter launch of the suite for developing Internet of Things solutions in Python language, **Viper becomes Zerynth**. It is definitely a big day for the startup that created a radically new way to approach the world of microcontrollers and connected devices, making professionals and makers able to design interactive solutions with reduced efforts and shorter time. - ->“We really believe in the uniqueness of our tools, this is why they deserve an adequate recognition. Viper was a great name for a product, but other notable companies had the same feeling many decades ago, with the result that this term was shared with too many other actors out there. We are grown now, and ready to take off fast and light, like the design processes that our tools are enabling”, says the Viper (now Zerynth), co-founders. - ->**Thousands of users** developed amazing connected solutions in just 9 months of life in Beta version. Built to be cross-platform, Zerynth’s tools are meant for high-level design of Internet/cloud-connected devices, interactive objects, artistic installations. They are: **Zerynth Studio**, a browser-based IDE for programming embedded devices in Python with cloud sync and board management features; **Zerynth Virtual Machine**: a multithreaded real-time OS that provides real hardware independence allowing code reuse on the entire ARM architecture; **Zerynth App**, a general purpose interface that turns any mobile into the controller and display for smart objects and IoT systems. - ->This modular set of tools, adaptable to different hardware and cloud infrastructures, can dramatically reduce the time to market and the overall development costs for makers, professionals and companies. - ->Now Zerynth celebrates its new name launching the **first official release** of the toolkit. Check it here [www.zerynth.com][1] - -![](http://www.open-electronics.org/wp-content/uploads/2016/02/Zerynth-Press-Release_Studio-Img-768x432.png) - --------------------------------------------------------------------------------- - -via: http://www.open-electronics.org/viper-the-python-iot-development-suite-is-now-zerynth/?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+OpenElectronics+%28Open+Electronics%29 - -作者：[Staff ][a] -译者：[runningwater](https://github.com/runningwater) -校对：[校对者ID](https://github.com/校对者ID) - -本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 - -[a]:http://www.open-electronics.org/author/staff/ -[1]: http://www.zerynth.com/ - diff --git a/sources/tech/20160309 Let’s Build A Web Server. Part 1.md b/sources/tech/20160309 Let’s Build A Web Server. Part 1.md new file mode 100644 index 0000000000..63f08f754d --- /dev/null +++ b/sources/tech/20160309 Let’s Build A Web Server. Part 1.md @@ -0,0 +1,151 @@ +Translating by StdioA +Let’s Build A Web Server. Part 1. +===================================== + +Out for a walk one day, a woman came across a construction site and saw three men working. She asked the first man, “What are you doing?” Annoyed by the question, the first man barked, “Can’t you see that I’m laying bricks?” Not satisfied with the answer, she asked the second man what he was doing. The second man answered, “I’m building a brick wall.” Then, turning his attention to the first man, he said, “Hey, you just passed the end of the wall. You need to take off that last brick.” Again not satisfied with the answer, she asked the third man what he was doing. And the man said to her while looking up in the sky, “I am building the biggest cathedral this world has ever known.” While he was standing there and looking up in the sky the other two men started arguing about the errant brick. The man turned to the first two men and said, “Hey guys, don’t worry about that brick. It’s an inside wall, it will get plastered over and no one will ever see that brick. Just move on to another layer.”1 + +The moral of the story is that when you know the whole system and understand how different pieces fit together (bricks, walls, cathedral), you can identify and fix problems faster (errant brick). + +What does it have to do with creating your own Web server from scratch? + +I believe to become a better developer you MUST get a better understanding of the underlying software systems you use on a daily basis and that includes programming languages, compilers and interpreters, databases and operating systems, web servers and web frameworks. And, to get a better and deeper understanding of those systems you MUST re-build them from scratch, brick by brick, wall by wall. + +Confucius put it this way: + +>“I hear and I forget.” + +![](https://ruslanspivak.com/lsbasi-part4/LSBAWS_confucius_hear.png) + +>“I see and I remember.” + +![](https://ruslanspivak.com/lsbasi-part4/LSBAWS_confucius_see.png) + +>“I do and I understand.” + +![](https://ruslanspivak.com/lsbasi-part4/LSBAWS_confucius_do.png) + +I hope at this point you’re convinced that it’s a good idea to start re-building different software systems to learn how they work. + +In this three-part series I will show you how to build your own basic Web server. Let’s get started. + +First things first, what is a Web server? + +![](https://ruslanspivak.com/lsbaws-part1/LSBAWS_HTTP_request_response.png) + +In a nutshell it’s a networking server that sits on a physical server (oops, a server on a server) and waits for a client to send a request. When it receives a request, it generates a response and sends it back to the client. The communication between a client and a server happens using HTTP protocol. A client can be your browser or any other software that speaks HTTP. + +What would a very simple implementation of a Web server look like? Here is my take on it. The example is in Python but even if you don’t know Python (it’s a very easy language to pick up, try it!) you still should be able to understand concepts from the code and explanations below: + +``` +import socket + +HOST, PORT = '', 8888 + +listen_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM) +listen_socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1) +listen_socket.bind((HOST, PORT)) +listen_socket.listen(1) +print 'Serving HTTP on port %s ...' % PORT +while True: + client_connection, client_address = listen_socket.accept() + request = client_connection.recv(1024) + print request + + http_response = """\ +HTTP/1.1 200 OK + +Hello, World! +""" + client_connection.sendall(http_response) + client_connection.close() +``` + +Save the above code as webserver1.py or download it directly from GitHub and run it on the command line like this + +``` +$ python webserver1.py +Serving HTTP on port 8888 … +``` + +Now type in the following URL in your Web browser’s address bar http://localhost:8888/hello, hit Enter, and see magic in action. You should see “Hello, World!” displayed in your browser like this: + +![](https://ruslanspivak.com/lsbaws-part1/browser_hello_world.png) + +Just do it, seriously. I will wait for you while you’re testing it. + +Done? Great. Now let’s discuss how it all actually works. + +First let’s start with the Web address you’ve entered. It’s called an URL and here is its basic structure: + +![](https://ruslanspivak.com/lsbaws-part1/LSBAWS_URL_Web_address.png) + +This is how you tell your browser the address of the Web server it needs to find and connect to and the page (path) on the server to fetch for you. Before your browser can send a HTTP request though, it first needs to establish a TCP connection with the Web server. Then it sends an HTTP request over the TCP connection to the server and waits for the server to send an HTTP response back. And when your browser receives the response it displays it, in this case it displays “Hello, World!” + +Let’s explore in more detail how the client and the server establish a TCP connection before sending HTTP requests and responses. To do that they both use so-called sockets. Instead of using a browser directly you are going to simulate your browser manually by using telnet on the command line. + +On the same computer you’re running the Web server fire up a telnet session on the command line specifying a host to connect to localhost and the port to connect to 8888 and then press Enter: + +``` +$ telnet localhost 8888 +Trying 127.0.0.1 … +Connected to localhost. +``` + +At this point you’ve established a TCP connection with the server running on your local host and ready to send and receive HTTP messages. In the picture below you can see a standard procedure a server has to go through to be able to accept new TCP connections. + +![](https://ruslanspivak.com/lsbaws-part1/LSBAWS_socket.png) + +In the same telnet session type GET /hello HTTP/1.1 and hit Enter: + +``` +$ telnet localhost 8888 +Trying 127.0.0.1 … +Connected to localhost. +GET /hello HTTP/1.1 + +HTTP/1.1 200 OK +Hello, World! +``` + +You’ve just manually simulated your browser! You sent an HTTP request and got an HTTP response back. This is the basic structure of an HTTP request: + +![](https://ruslanspivak.com/lsbaws-part1/LSBAWS_HTTP_request_anatomy.png) + +The HTTP request consists of the line indicating the HTTP method (GET, because we are asking our server to return us something), the path /hello that indicates a “page” on the server we want and the protocol version. + +For simplicity’s sake our Web server at this point completely ignores the above request line. You could just as well type in any garbage instead of “GET /hello HTTP/1.1” and you would still get back a “Hello, World!” response. + +Once you’ve typed the request line and hit Enter the client sends the request to the server, the server reads the request line, prints it and returns the proper HTTP response. + +Here is the HTTP response that the server sends back to your client (telnet in this case): + +![](https://ruslanspivak.com/lsbaws-part1/LSBAWS_HTTP_response_anatomy.png) + +Let’s dissect it. The response consists of a status line HTTP/1.1 200 OK, followed by a required empty line, and then the HTTP response body. + +The response status line HTTP/1.1 200 OK consists of the HTTP Version, the HTTP status code and the HTTP status code reason phrase OK. When the browser gets the response, it displays the body of the response and that’s why you see “Hello, World!” in your browser. + +And that’s the basic model of how a Web server works. To sum it up: The Web server creates a listening socket and starts accepting new connections in a loop. The client initiates a TCP connection and, after successfully establishing it, the client sends an HTTP request to the server and the server responds with an HTTP response that gets displayed to the user. To establish a TCP connection both clients and servers use sockets. + +Now you have a very basic working Web server that you can test with your browser or some other HTTP client. As you’ve seen and hopefully tried, you can also be a human HTTP client too, by using telnet and typing HTTP requests manually. + +Here’s a question for you: “How do you run a Django application, Flask application, and Pyramid application under your freshly minted Web server without making a single change to the server to accommodate all those different Web frameworks?” + +I will show you exactly how in Part 2 of the series. Stay tuned. + +BTW, I’m writing a book “Let’s Build A Web Server: First Steps” that explains how to write a basic web server from scratch and goes into more detail on topics I just covered. Subscribe to the mailing list to get the latest updates about the book and the release date. + +-------------------------------------------------------------------------------- + +via: https://ruslanspivak.com/lsbaws-part1/ + +作者：[Ruslan][a] +译者：[译者ID](https://github.com/译者ID) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://linkedin.com/in/ruslanspivak/ + + + diff --git a/sources/tech/20160314 15 podcasts for FOSS fans.md b/sources/tech/20160314 15 podcasts for FOSS fans.md deleted file mode 100644 index eae53102ad..0000000000 --- a/sources/tech/20160314 15 podcasts for FOSS fans.md +++ /dev/null @@ -1,80 +0,0 @@ -zpl1025 -15 podcasts for FOSS fans -============================= - -keyword : FOSS , podcast - -![](https://opensource.com/sites/default/files/styles/image-full-size/public/images/life/oss_podcasts.png?itok=3KwxsunX) - -I listen to a lot of podcasts. A lot. On my phone's podcatcher, I am subscribed to around 60 podcasts... and I think that only eight of those have podfaded (died). Unsurprisingly, a fairly sizeable proportion of those remaining alive-and-well subscriptions are shows with a specific interest or relevance to open source software. As I seek to resurrect my own comatose podcast from the nebulous realm of podfadery, I thought it would be great for us as a community to share what we're listening to. - ->Quick digression: I understand that there are a lot of "pod"-prefixed words in that first paragraph. Furthermore, I also know that the term itself is related to a proprietary device that, by most accounts, isn't even used for listening to these web-based audio broadcasts. However, the term 'webcast' died in the nineties and 'oggcast' never gathered a substantial foothold among the listening public. As such, in order to ensure that the most people actually know what I'm referring to, I'm essentially forced to use the web-anachronistic, but publicly recognized term, podcast. - -I should also mention that a number of these shows involve grown-ups using grown-up language (i.e. swearing). I've tried to indicate which shows these are by putting a red E next to their names, but please do your own due diligence if you're concerned about listening to these shows at work or with children around. - -The following lists are podcasts that I keep in heavy rotation (each sublist is listed in alphabetical order). In the first list are the ones I think of as my "general coverage" shows. They tend to either discuss general topics related to free and open source software, or they give a survey of multiple open source projects from one episode to the next. - -- [Bad Voltage][1] E — Regular contributor and community moderator here on Opensource.com, Jono Bacon, shares hosting dutes on this podcast with Jeremy Garcia, Stuart Langridge, and Bryan Lunduke, four friends with a variety of digressing and intersecting opinions. That's the most interesting part of the show for me. Of course, they also do product reviews and cover timely news relevant to free and open source software, but it's the banter that I stick around for. - -- [FLOSS Weekly][2] — The Twit network of podcasts is a long-time standby in technology broadcasts. Hosted by Randal Schwartz, FLOSS Weekly focuses on covering one open source project each week, typically by interviewing someone relevant in the development of that project. It's a really good show for getting exposed to new open source tools... or learning more about the programs you're already familiar with. - -- [Free as in Freedom][3] — Hosted by Bradley Kuhn and Karen Sandler, this show has a specific focus on legal and policy matters as it relates to both specific free and open source projects, as well as open culture in general. The show seems to have gone on a bit of a hiatus since its last episode in November of 2015, but I for one am immensely hopeful that Free as in Freedom emerges victoriously from its battle with being podfaded and returns to its regular bi-weekly schedule. - -- [GNU World Order][4] — I think that this show can be best descrbed as a free and open source variety show. Solo host, Klaatu, spends the majority of each show going in-depth at nearly tutorial level with a whole range of specific software tools and workflows. It's a really friendly way to get an open source neophyte up to speed with everything from understanding SSH to playing with digital painting and video. And there's a video component to the show, too, which certainly helps make some of these topics easier to follow. - -- [Hacker Public Radio][5] — This is just a well-executed version of a fantastic concept. Hacker Public Radio (HPR) is a community-run daily (well, working-week daily) podcast with a focus on "anything of interest to hackers." Sure there are wide swings in audio quality from show to show, but it's an open platform where anyone can share what they know (or what they think) in that topic space. Show topics include 3D printing, hardware hacking, conference interviews, and more. There are even long-running tutorial series and an audio book club. The monthly recap episodes are particularly useful if you're having trouble picking a place to start. And best of all, you can record your own episode and add it to the schedule. In fact, they actively encourage it. - -My next list of open source podcasts are a bit more specific to particular topics or software packages in the free and open source ecosystem. - -- [Blender Podcast][6] — Although this podcast is very specific to one particular application—Blender, in case you couldn't guess—many of the topics are relevant to issues faced by users and developers of open source other softrware programs. Hosts Thomas Dinges and Campbell Barton—both on the core development team for Blender—discuss the latest happenings in the Blender community, sometimes with a guest. The release schedule is a bit sporadic, but one of the things I really like about this particular show is the fact that they talk about both user issues and developer issues... and the various intersections of the two. It's a great way for each part of the community to gain insight from the other. - -- [Sunday Morning Linux Review][7] — As it's name indicates, SMLR offers a weekly review of topics relevant to Linux. Since around the end of last year, the show has seen a bit of a restructuring. However, that has not detracted from its quality. Tony Bemus, Mary Tomich, and Tom Lawrence deliver a lot of good information, and you can catch them recording their shows live through their website (if you happen to have free time on your Sundays). - -- [LinuxLUGcast][8] — The LinuxLUGcast is a community podcast that's really a recording of an online Linux Users Group (LUG) that meets on the first and third Friday of each month. The group meets (and records) via Mumble and discussions range from home builds with single-board computers like the Raspberry Pi to getting help with trying out a new distro. The LUG is open to everyone, but there is a rotating cast of regulars who've made themselves (and their IRC handles) recognizable fixtures on the show. (Full disclosure: I'm a regular on this one) - -- [The Open EdTech Podcast][9] — Thaj Sara's Open EdTech Podcast is a fairly new show that so far only has three episodes. However, since there's a really sizeable community of open source users in the field of education (both in teaching and in IT), this show serves an important and underserved segment of our community. I've spoken with Thaj via email and he assures me that new episodes are in the pipe. He just needs to set aside the time to edit them. - -- [The Linux Action Show][10] — It would be remiss of me to make a list of open source podcasts and not mention one of the stallwart fixtures in the space: The Linux Action Show. Chris Fisher and Noah Chelliah discuss current news as it pertains to Linux and open source topics while at the same time giving feature attention to specific projects or their own experiences using various open source tools. - -This next section is what I'm going to term my "honorable mention" section. These shows are either new or have a more tangential focus on open source software and culture. In any case, I still think readers of Opensource.com would enjoy listening to these shows. - -- [Blender Institute Podcast][11] — The Blender Institute—the more commercial creative production spin-off from the Blender Foundation—started hosting their own weekly podcast a few months ago. In the show, artists (and now a developer!) working at the Institute discuss the open content projects they're working on, answer questions about using Blender, and give great insight into how things go (or occasionally don't go) in their day-to-day work. - -- [Geek News Radio][12] E — There was a tangible sense of loss about a year ago when the hosts of Linux Outlaws hung up their mics. Well good news! A new show has sprung from its ashes. In episodes of Geek News Radio, Fab Scherschel and Dave Nicholas have a wider focus than Linux Outlaws did. Rather than being an actual news podcast, it's more akin to an informal discussion among friends about video games, movies, technology, and open source (of course). - -- [Geekrant][13] — Formerly known as the Everyday Linux Podcast, this show was rebranded at the start of the year to reflect kind of content that the hosts Mark Cockrell, Seth Anderson, and Chris Neves were already discussing. They do discuss open source software and culture, but they also give their own spin and opinions on topics of interest in general geek culture. Topics have a range that includes everything from popular media to network security. (P.S. Opensource.com content manager Jen Wike Huger was a guest on Episode 164.) - -- [Open Source Creative][14] E — In case you haven't read my little bio blurb, I also have my own podcast. In this show, I talk about news and topics that are [hopefully] of interest to artists and creatives who use free and open source tools. I record it during my work commute so episode length varies with traffic, and I haven't quite figured out a good way to do interviews safely, but if you listen while you're on your way to work, it'll be like we're carpooling. The show has been on a bit of hiatus for almost a year, but I've commited to making sure it comes back... and soon. - -- [Still Untitled][15] E — As you may have noticed from most of the selections on this list, I tend to lean toward the indie side of the spectrum, preferring to listen to shows by people with less of a "name." That said, this show really hits a good place for me. Hosts Adam Savage, Norman Chan, and Will Smith talk about all manner of interesting and geeky things. From Adam's adventures with Mythbusters to maker builds and book reviews, there's rarely ever a show that hasn't been fun for me to listen to. - -So there you go! I'm always looking for more interesting shows to listen to on my commute (as I'm sure many others are). What suggestions or recommendations do you have? - - - --------------------------------------------------------------------------------- - -via: https://opensource.com/life/16/3/open-source-podcasts - -作者：[Jason van Gumster][a] -译者：[译者ID](https://github.com/译者ID) -校对：[校对者ID](https://github.com/校对者ID) - -本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 - -[a]: https://opensource.com/users/jason-van-gumster -[1]: http://badvoltage.org/ -[2]: https://twit.tv/shows/floss-weekly -[3]: http://faif.us/ -[4]: http://gnuworldorder.info/ -[5]: http://hackerpublicradio.org/ -[6]: https://blender-podcast.org/ -[7]: http://smlr.us/ -[8]: http://linuxlugcast.com/ -[9]: http://openedtechpodcast.com/ -[10]: http://www.jupiterbroadcasting.com/tag/linux-action-show/ -[11]: http://podcast.blender.institute/ -[12]: http://sixgun.org/geeknewsradio -[13]: http://elementopie.com/geekrant-episodes -[14]: http://monsterjavaguns.com/podcast -[15]: http://www.tested.com/still-untitled-the-adam-savage-project/ diff --git a/sources/tech/20160314 Healthy Open Source.md b/sources/tech/20160314 Healthy Open Source.md deleted file mode 100644 index 57dd559284..0000000000 --- a/sources/tech/20160314 Healthy Open Source.md +++ /dev/null @@ -1,213 +0,0 @@ -Translating by yuba0604 -Healthy Open Source -============================ - -keyword: Node.js , opensource , project management , software - -*A walkthrough of the Node.js Foundation’s base contribution policy*. - -A lot has changed since io.js and Node.js merged under the Node.js Foundation. The most impressive change, and probably the change that is most relevant to the rest of the community and to open source in general, is the growth in contributors and committers to the project. - -A few years ago, Node.js had just a few committers (contributors with write access to the repository in order to merge code and triage bugs). The maintenance overhead for the few committers on Node.js Core was overwhelming and the project began to see a decline in both committers and outside contribution. This resulted in a corresponding decline in releases. - -Today, the Node.js project is divided into many components with a full org size of well over 400 members. Node.js Core now has over 50 committers and over 100 contributors per month. - -Through this growth we’ve found many tools that help scale the human infrastructure around an Open Source project. We also identified a few core values we believe are fundamental to modern Open Source: transparency, participation, and efficacy. As we continue to scale the way we do Open Source we try to find a balance of these values and adapt the practices we find help to fit the needs of each component of the Node.js project. - -Now that Node.js is in a good place, the foundation is looking to promote this kind of sustainability in the ecosystem. Part of this is a new umbrella for additional projects to enter the foundation, of which [Express was recently admitted][1], and the creation of this new contribution policy. - -This contribution policy is not universal. It’s meant as a starting point. Additions and alterations to this policy are encouraged so that the process used by each project fits its needs and can continue to change shape as the project grows and faces new challenges. - -The [current version][2] is hosted in the Node.js Foundation. We expect to iterate on this over time and encourage people to [log issues][3] with questions and feedback regarding the policy for future iterations. - -This document describes a very simple process suitable for most projects in the Node.js ecosystem. Projects are encouraged to adopt this whether they are hosted in the Node.js Foundation or not. - -The Node.js project is organized into over a hundred repositories and a few dozen Working Groups. There are large variations in contribution policy between many of these components because each one has different constraints. This document is a minimalist version of the processes and philosophy we’ve found works best everywhere. - -We believe that contributors should own their projects, and that includes contribution policies like this. While new foundation projects start with this policy we expect many of them to alter it or possibly diverge from it entirely to suite their own specific needs. - -The goal of this document is to create a contribution process that: - -* Encourages new contributions. - -* Encourages contributors to remain involved. - -* Avoids unnecessary processes and bureaucracy whenever possible. - -* Creates a transparent decision making process which makes it clear how contributors can be involved in decision making. - -Most contribution processes are created by maintainers who feel overwhelmed by outside contributions. These documents have traditionally been about processes that make life easier for a small group of maintainers, often at the cost of attracting new contributors. - -We’ve gone the opposite direction. The purpose of this policy is to gain contributors, to retain them as much as possible, and to use a much larger and growing contributor base to manage the corresponding influx of contributions. - -As projects mature, there’s a tendency to become top heavy and overly hierarchical as a means of quality control and this is enforced through process. We use process to add transparency that encourages participation which grows the code review pool which leads to better quality control. - -This document is based on much prior art in the Node.js community, io.js, and the Node.js project. - -This document is based on what we’ve learned growing the Node.js project. Not just the core project, which has been a massive undertaking, but also much smaller sub-projects like the website which have very different needs and, as a result, very different processes. - -When we began these reforms in the Node.js project, we were taking a lot of inspiration from the broader Node.js ecosystem. In particular, Rod Vagg’s [OPEN Open Source policy][4]. Rod’s work in levelup and nan is the basis for what we now call “liberal contribution policies.” - -### Vocabulary - -* A **Contributor** is any individual creating or commenting on an issue or pull request. - -* A **Committer** is a subset of contributors who have been given write access to the repository. - -* A **TC (Technical Committee)** is a group of committers representing the required technical expertise to resolve rare disputes. - -Every person who shows up to comment on an issue or submit code is a member of a project’s community. Just being able to see them means that they have crossed the line from being a user to being a contributor. - -Typically open source projects have had a single distinction for those that have write access to the repository and those empowered with decision making. We’ve found this to be inadequate and have separated this into two distinctions which we’ll dive into more a bit later. - -![](https://www.linux.com/images/stories/66866/healthy_1.png) - -healthy 1Looking at the community in and around a project as a bunch of concentric circles helps to visualize this. - -In the outermost circle are users, a subset of those users are contributors, a subset of contributors become committers who can merge code and triage issues. Finally, a smaller group of trusted experts who only get pulled in to the hard problems and can act as a tie-breaker in disputes. - -This is what a healthy project should look like. As the demands on the project from increased users rise, so do the contributors, and as contributors increase more are converted into committers. As the committer base grows, more of them rise to the level of expertise where they should be involved in higher level decision making. - -![](https://www.linux.com/images/stories/66866/healthy-2.png) - -If these groups don’t grow in proportion to each other they can’t carry the load imposed on them by outward growth. A project’s ability to convert people from each of these groups is the only way it can stay healthy if its user base is growing. - -This is what unhealthy projects look like in their earliest stages of dysfunction, but imagine that the committers bubble is so small you can’t actually read the word “committers” in it, and imagine this is a logarithmic scale. - -healthy-2A massive user base is pushing a lot of contributions onto a very small number of maintainers. - -This is when maintainers build processes and barriers to new contributions as a means to manage the workload. Often the problems the project is facing will be attributed to the tools the project is using, especially GitHub. - -In Node.js we had all the same problems, resolved them without a change in tooling, and today manage a growing workload much larger than most projects, and GitHub has not been a bottleneck. - -We know what happens to unhealthy projects over a long enough time period, more maintainers leave, contributions eventually fall, and **if we’re lucky** users leave it. When we aren’t so lucky adoption continues and years later we’re plagued with security and stability issues in widely adopt software that can’t be effectively maintained. - -The number of users a project has is a poor indicator of the health of the project, often it is the most used software that suffers the biggest contribution crisis. - -### Logging - -Log an issue for any question or problem you might have. When in doubt, log an issue, any additional policies about what to include will be provided in the responses. The only exception is security disclosures which should be sent privately. - -The first sentence is surprisingly controversial. A lot of maintainers complain that there isn’t a more heavy handed way of forcing people to read a document before they log an issue on GitHub. We have documents all over projects in the Node.js Foundation about writing good bug reports but, first and foremost, we encourage people to log something and try to avoid putting barriers in the way of that. - -Sure, we get bad bugs, but we have a ton of contributors who can immediately work with people who log them to educate them on better practices and treat it as an opportunity to educate. This is why we have documentation on writing good bugs, in order to educate contributors, not as a barrier to entry. - -Creating barriers to entry just reduces the number of people there’s a chance to identify, educate and potentially grow into greater contributors. - -Of course, never log a public issue about a security disclosure, ever. This is a bit vague about the best private venue because we can’t determine that for every project that adopts this policy, but we’re working on a responsible disclosure mechanism for the broader community (stay tuned). - -Committers may direct you to another repository, ask for additional clarifications, and add appropriate metadata before the issue is addressed. - -For smaller projects this isn’t a big deal but in Node.js we’ve had to continually break off work into other, more specific, repositories just to keep the volume on a single repo manageable. But all anyone has to do when someone puts something in the wrong place is direct them to the right one. - -Another benefit of growing the committer base is that there’s more people to deal with little things, like redirecting issues to other repos, or adding metadata to issues and PRs. This allows developers who are more specialized to focus on just a narrow subset of work rather than triaging issues. - -Please be courteous, respectful, and every participant is expected to follow the project’s Code of Conduct. - -One thing that can burn out a project is when people show up with a lot of hostility and entitlement. Most of the time this sentiment comes from a feeling that their input isn’t valued. No matter what, a few people will show up who are used to more hostile environments and it’s good to have these kinds of expectations explicit and written down. - -And each project should have a Code of Conduct, which is an extension of these expectations that makes people feel safe and respected. - -### Contributions - -Any change to resources in this repository must be through pull requests. This applies to all changes to documentation, code, binary files, etc. Even long term committers and TC members must use pull requests. - -No pull request can be merged without being reviewed. - -Every change needs to be a pull request. - -A Pull Request captures the entire discussion and review of a change. Allowing some subset of committers to slip things in without a Pull Request gives the impression to potential contributors that they they can’t be involved in the project because they don’t have access to a behind the scenes process or culture. - -This isn’t just a good practice, it’s a necessity in order to be transparent enough to attract new contributors. - -For non-trivial contributions, pull requests should sit for at least 36 hours to ensure that contributors in other timezones have time to review. Consideration should also be given to weekends and other holiday periods to ensure active committers all have reasonable time to become involved in the discussion and review process if they wish. - -Part of being open and inviting to more contributors is making the process accessible to people in timezones all over the world. We don’t want to add an artificial delay in small doc changes but for any change that needs a bit of consideration needs to give people in different parts of the world time to consider it. - -In Node.js we actually have an even longer timeline than this, 48 hours on weekdays and 72 on weekends. That might be too much for smaller projects so it is shorter in this base policy but as a project grows it may want to increase this as well. - -The default for each contribution is that it is accepted once no committer has an objection. During review committers may also request that a specific contributor who is most versed in a particular area gives a “LGTM” before the PR can be merged. There is no additional “sign off” process for contributions to land. Once all issues brought by committers are addressed it can be landed by any committer. - -A key part of the liberal contribution policies we’ve been building is an inversion of the typical code review process. Rather than the default mode for a change to be rejected until enough people sign off, we make the default for every change to land. This puts the onus on reviewers to note exactly what adjustments need to be made in order for it to land. - -For new contributors it’s a big leap just to get that initial code up and sent. Viewing the code review process as a series of small adjustments and education, rather than a quality control hierarchy, does a lot to encourage and retain these new contributors. - -It’s important not to build processes that encourage a project to be too top heavy, with a few people needing to sign off on every change. Instead, we just mention any committer than we think should weigh in on a specific review. In Node.js we have people who are the experts on OpenSSL, any change to crypto is going to need a LGTM from them. This kind of expertise forms naturally as a project grows and this is a good way to work with it without burning people out. - -In the case of an objection being raised in a pull request by another committer, all involved committers should seek to arrive at a consensus by way of addressing concerns being expressed by discussion, compromise on the proposed change, or withdrawal of the proposed change. - -This is what we call a lazy consensus seeking process. Most review comments and adjustments are uncontroversial and the process should optimize for getting them in without unnecessary process. When there is disagreement, try to reach an easy consensus among the committers. More than 90% of the time this is simple, easy and obvious. - -If a contribution is controversial and committers cannot agree about how to get it to land or if it should land then it should be escalated to the TC. TC members should regularly discuss pending contributions in order to find a resolution. It is expected that only a small minority of issues be brought to the TC for resolution and that discussion and compromise among committers be the default resolution mechanism. - -For the minority of changes that are controversial and don’t reach an easy consensus we escalate that to the TC. These are rare but when they do happen it’s good to reach a resolution quickly rather than letting things fester. Contentious issues tend to get a lot of attention, especially by those more casually involved in the project or even entirely outside of it, but they account for a relatively small amount of what the project does every day. - -### Becoming a Committer - -All contributors who land a non-trivial contribution should be on-boarded in a timely manner, and added as a committer, and be given write access to the repository. - -This is where we diverge sharply from open source tradition. - -Projects have historically guarded commit rights to their version control system. This made a lot of sense when we were using version control systems like subversion. A single contributor can inadvertently mess up a project pretty badly in older version control systems, but not so much in git. In git, there isn’t a lot that can’t be fixed and so most of the quality controls we put on guarding access are no longer necessary. - -Not every committer has the rights to release or make high level decisions, so we can be much more liberal about giving out commit rights. That increases the committer base for code review and bug triage. As a wider range of expertise in the committer pool smaller changes are reviewed and adjusted without the intervention of the more technical contributors, who can spend their time on reviews only they can do. - -This is they key to scaling contribution growth: committer growth. - -Committers are expected to follow this policy and continue to send pull requests, go through proper review, and have other committers merge their pull requests. - -This part is entirely redundant, but on purpose. Just a reminder even once someone is a committer their changes still flow through the same process they followed before. - -### TC Process - -The TC uses a “consensus seeking” process for issues that are escalated to the TC. The group tries to find a resolution that has no open objections among TC members. If a consensus cannot be reached that has no objections then a majority wins vote is called. It is also expected that the majority of decisions made by the TC are via a consensus seeking process and that voting is only used as a last-resort. - -The best solution tends to be the one everyone can agree to so you would think that consensus systems would be the norm. However, **pure consensus** systems incentivize obstructionism which we need to avoid. - -In pure consensus everyone essentially has a veto. So, if I don’t want something to happen I’m in a strong position of power over everyone that wants something to happen. They have to convince me, and I don’t have to convince anyone else of anything. - -To avoid this we use a system called “consensus seeking” which has a long history outside of open source. It’s quite simple, just attempt to reach a consensus, if a consensus can’t be reached then call for a majority wins vote. - -Just the fact that a vote **is a possibility** means that people can’t be obstructionists, whether someone favor a change or not, they have to convince their peers and if they aren’t willing to put in the work to convince their peers then they probably don’t involve themselves in that decision at all. - -The way these incentives play out is pretty impressive. We started using this process in io.js and adopted it in Node.js when we merged into the foundation. In that entire time we’ve never actually had to call for a vote, just the fact that we could is enough to keep everyone working together to find a solution and move forward. - -Resolution may involve returning the issue to committers with suggestions on how to move forward towards a consensus. It is not expected that a meeting of the TC will resolve all issues on its agenda during that meeting and may prefer to continue the discussion happening among the committers. - -A TC tries to resolve things in a timely manner so that people can make progress but often it’s better to provide some additional guidance that pushes the greater contributorship towards resolution without being heavy handed. - -Avoid creating big decision hierarchies. Instead, invest in a broad, growing and empowered contributorship that can make progress without intervention. We need to view a constant need for intervention by a few people to make any and every tough decision as the biggest obstacle to healthy Open Source. - -Members can be added to the TC at any time. Any committer can nominate another committer to the TC and the TC uses its standard consensus seeking process to evaluate whether or not to add this new member. Members who do not participate consistently at the level of a majority of the other members are expected to resign. - -The TC just uses the same consensus seeking process for adding new members as it uses for everything else. - -It’s a good idea to encourage committers to nominate people to the TC and not just wait around for TC members to notice the impact some people are having. Listening to the broader committers about who they see as having a big impact keeps the TC’s perspective inline with the rest of the project. - -As a project grows it’s important to add people from a variety of skill sets. If people are doing a lot of docs work, or test work, treat the investment they are making as equally valuable as the hard technical stuff. - -Projects should have the same ladder, user -> contributor -> commiters -> TC member, for every skill set they want to build into the project to keep it healthy. - -I often see long time maintainers worry about adding people who don’t understand every part of the project, as if they have to be involved in every decision. The reality is that people do know their limitations and want to defer hard decisions to people they know have more experience. - -Thanks to Greg [Wallace][5] and ashley [williams][6]. - --------------------------------------------------------------------------------- - -via: https://www.linux.com/news/biz-os/governance/892141-healthy-open-source - -作者：[Mikeal Rogers][a] -译者：[译者ID](https://github.com/译者ID) -校对：[校对者ID](https://github.com/校对者ID) - -本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 - -[a]:https://www.linux.com/community/forums/person/66928 - - -[1]: https://medium.com/@nodejs/node-js-foundation-to-add-express-as-an-incubator-project-225fa3008f70#.mc30mvj4m -[2]: https://github.com/nodejs/TSC/blob/master/BasePolicies/CONTRIBUTING.md -[3]: https://github.com/nodejs/TSC/issues -[4]: https://github.com/Level/community/blob/master/CONTRIBUTING.md -[5]: https://medium.com/@gtewallaceLF -[6]: https://medium.com/@ag_dubs diff --git a/sources/tech/20160406 Let’s Build A Web Server. Part 2.md b/sources/tech/20160406 Let’s Build A Web Server. Part 2.md new file mode 100644 index 0000000000..482352ac9a --- /dev/null +++ b/sources/tech/20160406 Let’s Build A Web Server. Part 2.md @@ -0,0 +1,427 @@ +Let’s Build A Web Server. Part 2. +=================================== + +Remember, in Part 1 I asked you a question: “How do you run a Django application, Flask application, and Pyramid application under your freshly minted Web server without making a single change to the server to accommodate all those different Web frameworks?” Read on to find out the answer. + +In the past, your choice of a Python Web framework would limit your choice of usable Web servers, and vice versa. If the framework and the server were designed to work together, then you were okay: + +![](https://ruslanspivak.com/lsbaws-part2/lsbaws_part2_before_wsgi.png) + +But you could have been faced (and maybe you were) with the following problem when trying to combine a server and a framework that weren’t designed to work together: + +![](https://ruslanspivak.com/lsbaws-part2/lsbaws_part2_after_wsgi.png) + +Basically you had to use what worked together and not what you might have wanted to use. + +So, how do you then make sure that you can run your Web server with multiple Web frameworks without making code changes either to the Web server or to the Web frameworks? And the answer to that problem became the Python Web Server Gateway Interface (or WSGI for short, pronounced “wizgy”). + +![](https://ruslanspivak.com/lsbaws-part2/lsbaws_part2_wsgi_idea.png) + +WSGI allowed developers to separate choice of a Web framework from choice of a Web server. Now you can actually mix and match Web servers and Web frameworks and choose a pairing that suits your needs. You can run Django, Flask, or Pyramid, for example, with Gunicorn or Nginx/uWSGI or Waitress. Real mix and match, thanks to the WSGI support in both servers and frameworks: + +![](https://ruslanspivak.com/lsbaws-part2/lsbaws_part2_wsgi_interop.png) + +So, WSGI is the answer to the question I asked you in Part 1 and repeated at the beginning of this article. Your Web server must implement the server portion of a WSGI interface and all modern Python Web Frameworks already implement the framework side of the WSGI interface, which allows you to use them with your Web server without ever modifying your server’s code to accommodate a particular Web framework. + +Now you know that WSGI support by Web servers and Web frameworks allows you to choose a pairing that suits you, but it is also beneficial to server and framework developers because they can focus on their preferred area of specialization and not step on each other’s toes. Other languages have similar interfaces too: Java, for example, has Servlet API and Ruby has Rack. + +It’s all good, but I bet you are saying: “Show me the code!” Okay, take a look at this pretty minimalistic WSGI server implementation: + +``` +# Tested with Python 2.7.9, Linux & Mac OS X +import socket +import StringIO +import sys + + +class WSGIServer(object): + + address_family = socket.AF_INET + socket_type = socket.SOCK_STREAM + request_queue_size = 1 + + def __init__(self, server_address): + # Create a listening socket + self.listen_socket = listen_socket = socket.socket( + self.address_family, + self.socket_type + ) + # Allow to reuse the same address + listen_socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1) + # Bind + listen_socket.bind(server_address) + # Activate + listen_socket.listen(self.request_queue_size) + # Get server host name and port + host, port = self.listen_socket.getsockname()[:2] + self.server_name = socket.getfqdn(host) + self.server_port = port + # Return headers set by Web framework/Web application + self.headers_set = [] + + def set_app(self, application): + self.application = application + + def serve_forever(self): + listen_socket = self.listen_socket + while True: + # New client connection + self.client_connection, client_address = listen_socket.accept() + # Handle one request and close the client connection. Then + # loop over to wait for another client connection + self.handle_one_request() + + def handle_one_request(self): + self.request_data = request_data = self.client_connection.recv(1024) + # Print formatted request data a la 'curl -v' + print(''.join( + '< {line}\n'.format(line=line) + for line in request_data.splitlines() + )) + + self.parse_request(request_data) + + # Construct environment dictionary using request data + env = self.get_environ() + + # It's time to call our application callable and get + # back a result that will become HTTP response body + result = self.application(env, self.start_response) + + # Construct a response and send it back to the client + self.finish_response(result) + + def parse_request(self, text): + request_line = text.splitlines()[0] + request_line = request_line.rstrip('\r\n') + # Break down the request line into components + (self.request_method, # GET + self.path, # /hello + self.request_version # HTTP/1.1 + ) = request_line.split() + + def get_environ(self): + env = {} + # The following code snippet does not follow PEP8 conventions + # but it's formatted the way it is for demonstration purposes + # to emphasize the required variables and their values + # + # Required WSGI variables + env['wsgi.version'] = (1, 0) + env['wsgi.url_scheme'] = 'http' + env['wsgi.input'] = StringIO.StringIO(self.request_data) + env['wsgi.errors'] = sys.stderr + env['wsgi.multithread'] = False + env['wsgi.multiprocess'] = False + env['wsgi.run_once'] = False + # Required CGI variables + env['REQUEST_METHOD'] = self.request_method # GET + env['PATH_INFO'] = self.path # /hello + env['SERVER_NAME'] = self.server_name # localhost + env['SERVER_PORT'] = str(self.server_port) # 8888 + return env + + def start_response(self, status, response_headers, exc_info=None): + # Add necessary server headers + server_headers = [ + ('Date', 'Tue, 31 Mar 2015 12:54:48 GMT'), + ('Server', 'WSGIServer 0.2'), + ] + self.headers_set = [status, response_headers + server_headers] + # To adhere to WSGI specification the start_response must return + # a 'write' callable. We simplicity's sake we'll ignore that detail + # for now. + # return self.finish_response + + def finish_response(self, result): + try: + status, response_headers = self.headers_set + response = 'HTTP/1.1 {status}\r\n'.format(status=status) + for header in response_headers: + response += '{0}: {1}\r\n'.format(*header) + response += '\r\n' + for data in result: + response += data + # Print formatted response data a la 'curl -v' + print(''.join( + '> {line}\n'.format(line=line) + for line in response.splitlines() + )) + self.client_connection.sendall(response) + finally: + self.client_connection.close() + + +SERVER_ADDRESS = (HOST, PORT) = '', 8888 + + +def make_server(server_address, application): + server = WSGIServer(server_address) + server.set_app(application) + return server + + +if __name__ == '__main__': + if len(sys.argv) < 2: + sys.exit('Provide a WSGI application object as module:callable') + app_path = sys.argv[1] + module, application = app_path.split(':') + module = __import__(module) + application = getattr(module, application) + httpd = make_server(SERVER_ADDRESS, application) + print('WSGIServer: Serving HTTP on port {port} ...\n'.format(port=PORT)) + httpd.serve_forever() +``` + +It’s definitely bigger than the server code in Part 1, but it’s also small enough (just under 150 lines) for you to understand without getting bogged down in details. The above server also does more - it can run your basic Web application written with your beloved Web framework, be it Pyramid, Flask, Django, or some other Python WSGI framework. + +Don’t believe me? Try it and see for yourself. Save the above code as webserver2.py or download it directly from GitHub. If you try to run it without any parameters it’s going to complain and exit. + +``` +$ python webserver2.py +Provide a WSGI application object as module:callable +``` + +It really wants to serve your Web application and that’s where the fun begins. To run the server the only thing you need installed is Python. But to run applications written with Pyramid, Flask, and Django you need to install those frameworks first. Let’s install all three of them. My preferred method is by using virtualenv. Just follow the steps below to create and activate a virtual environment and then install all three Web frameworks. + +``` +$ [sudo] pip install virtualenv +$ mkdir ~/envs +$ virtualenv ~/envs/lsbaws/ +$ cd ~/envs/lsbaws/ +$ ls +bin include lib +$ source bin/activate +(lsbaws) $ pip install pyramid +(lsbaws) $ pip install flask +(lsbaws) $ pip install django +``` + +At this point you need to create a Web application. Let’s start with Pyramid first. Save the following code as pyramidapp.py to the same directory where you saved webserver2.py or download the file directly from GitHub: + +``` +from pyramid.config import Configurator +from pyramid.response import Response + + +def hello_world(request): + return Response( + 'Hello world from Pyramid!\n', + content_type='text/plain', + ) + +config = Configurator() +config.add_route('hello', '/hello') +config.add_view(hello_world, route_name='hello') +app = config.make_wsgi_app() +``` + +Now you’re ready to serve your Pyramid application with your very own Web server: + +``` +(lsbaws) $ python webserver2.py pyramidapp:app +WSGIServer: Serving HTTP on port 8888 ... +``` + +You just told your server to load the ‘app’ callable from the python module ‘pyramidapp’ Your server is now ready to take requests and forward them to your Pyramid application. The application only handles one route now: the /hello route. Type http://localhost:8888/hello address into your browser, press Enter, and observe the result: + +![](https://ruslanspivak.com/lsbaws-part2/lsbaws_part2_browser_pyramid.png) + +You can also test the server on the command line using the ‘curl’ utility: + +``` +$ curl -v http://localhost:8888/hello +... +``` + +Check what the server and curl prints to standard output. + +Now onto Flask. Let’s follow the same steps. + +``` +from flask import Flask +from flask import Response +flask_app = Flask('flaskapp') + + +@flask_app.route('/hello') +def hello_world(): + return Response( + 'Hello world from Flask!\n', + mimetype='text/plain' + ) + +app = flask_app.wsgi_app +``` + +Save the above code as flaskapp.py or download it from GitHub and run the server as: + +``` +(lsbaws) $ python webserver2.py flaskapp:app +WSGIServer: Serving HTTP on port 8888 ... +``` + +Now type in the http://localhost:8888/hello into your browser and press Enter: + +![](https://ruslanspivak.com/lsbaws-part2/lsbaws_part2_browser_flask.png) + +Again, try ‘curl’ and see for yourself that the server returns a message generated by the Flask application: + +``` +$ curl -v http://localhost:8888/hello +... +``` + +Can the server also handle a Django application? Try it out! It’s a little bit more involved, though, and I would recommend cloning the whole repo and use djangoapp.py, which is part of the GitHub repository. Here is the source code which basically adds the Django ‘helloworld’ project (pre-created using Django’s django-admin.py startproject command) to the current Python path and then imports the project’s WSGI application. + +``` +import sys +sys.path.insert(0, './helloworld') +from helloworld import wsgi + + +app = wsgi.application +``` + +Save the above code as djangoapp.py and run the Django application with your Web server: + +``` +(lsbaws) $ python webserver2.py djangoapp:app +WSGIServer: Serving HTTP on port 8888 ... +``` + +Type in the following address and press Enter: + +![](https://ruslanspivak.com/lsbaws-part2/lsbaws_part2_browser_django.png) + +And as you’ve already done a couple of times before, you can test it on the command line, too, and confirm that it’s the Django application that handles your requests this time around: + +``` +$ curl -v http://localhost:8888/hello +... +``` + +Did you try it? Did you make sure the server works with those three frameworks? If not, then please do so. Reading is important, but this series is about rebuilding and that means you need to get your hands dirty. Go and try it. I will wait for you, don’t worry. No seriously, you must try it and, better yet, retype everything yourself and make sure that it works as expected. + +Okay, you’ve experienced the power of WSGI: it allows you to mix and match your Web servers and Web frameworks. WSGI provides a minimal interface between Python Web servers and Python Web Frameworks. It’s very simple and it’s easy to implement on both the server and the framework side. The following code snippet shows the server and the framework side of the interface: + +``` +def run_application(application): + """Server code.""" + # This is where an application/framework stores + # an HTTP status and HTTP response headers for the server + # to transmit to the client + headers_set = [] + # Environment dictionary with WSGI/CGI variables + environ = {} + + def start_response(status, response_headers, exc_info=None): + headers_set[:] = [status, response_headers] + + # Server invokes the ‘application' callable and gets back the + # response body + result = application(environ, start_response) + # Server builds an HTTP response and transmits it to the client + … + +def app(environ, start_response): + """A barebones WSGI app.""" + start_response('200 OK', [('Content-Type', 'text/plain')]) + return ['Hello world!'] + +run_application(app) +``` + +Here is how it works: + +1. The framework provides an ‘application’ callable (The WSGI specification doesn’t prescribe how that should be implemented) +2. The server invokes the ‘application’ callable for each request it receives from an HTTP client. It passes a dictionary ‘environ’ containing WSGI/CGI variables and a ‘start_response’ callable as arguments to the ‘application’ callable. +3. The framework/application generates an HTTP status and HTTP response headers and passes them to the ‘start_response’ callable for the server to store them. The framework/application also returns a response body. +4. The server combines the status, the response headers, and the response body into an HTTP response and transmits it to the client (This step is not part of the specification but it’s the next logical step in the flow and I added it for clarity) + +And here is a visual representation of the interface: + +![](https://ruslanspivak.com/lsbaws-part2/lsbaws_part2_wsgi_interface.png) + +So far, you’ve seen the Pyramid, Flask, and Django Web applications and you’ve seen the server code that implements the server side of the WSGI specification. You’ve even seen the barebones WSGI application code snippet that doesn’t use any framework. + +The thing is that when you write a Web application using one of those frameworks you work at a higher level and don’t work with WSGI directly, but I know you’re curious about the framework side of the WSGI interface, too because you’re reading this article. So, let’s create a minimalistic WSGI Web application/Web framework without using Pyramid, Flask, or Django and run it with your server: + +``` +def app(environ, start_response): + """A barebones WSGI application. + + This is a starting point for your own Web framework :) + """ + status = '200 OK' + response_headers = [('Content-Type', 'text/plain')] + start_response(status, response_headers) + return ['Hello world from a simple WSGI application!\n'] +``` + +Again, save the above code in wsgiapp.py file or download it from GitHub directly and run the application under your Web server as: + +``` +(lsbaws) $ python webserver2.py wsgiapp:app +WSGIServer: Serving HTTP on port 8888 ... +``` + +Type in the following address and press Enter. This is the result you should see: + +![](https://ruslanspivak.com/lsbaws-part2/lsbaws_part2_browser_simple_wsgi_app.png) + +You just wrote your very own minimalistic WSGI Web framework while learning about how to create a Web server! Outrageous. + +Now, let’s get back to what the server transmits to the client. Here is the HTTP response the server generates when you call your Pyramid application using an HTTP client: + +![](https://ruslanspivak.com/lsbaws-part2/lsbaws_part2_http_response.png) + +The response has some familiar parts that you saw in Part 1 but it also has something new. It has, for example, four HTTP headers that you haven’t seen before: Content-Type, Content-Length, Date, and Server. Those are the headers that a response from a Web server generally should have. None of them are strictly required, though. The purpose of the headers is to transmit additional information about the HTTP request/response. + +Now that you know more about the WSGI interface, here is the same HTTP response with some more information about what parts produced it: + +![](https://ruslanspivak.com/lsbaws-part2/lsbaws_part2_http_response_explanation.png) + +I haven’t said anything about the ‘environ’ dictionary yet, but basically it’s a Python dictionary that must contain certain WSGI and CGI variables prescribed by the WSGI specification. The server takes the values for the dictionary from the HTTP request after parsing the request. This is what the contents of the dictionary look like: + +![](https://ruslanspivak.com/lsbaws-part2/lsbaws_part2_environ.png） + +A Web framework uses the information from that dictionary to decide which view to use based on the specified route, request method etc., where to read the request body from and where to write errors, if any. + +By now you’ve created your own WSGI Web server and you’ve made Web applications written with different Web frameworks. And, you’ve also created your barebones Web application/Web framework along the way. It’s been a heck of a journey. Let’s recap what your WSGI Web server has to do to serve requests aimed at a WSGI application: + +- First, the server starts and loads an ‘application’ callable provided by your Web framework/application +- Then, the server reads a request +- Then, the server parses it +- Then, it builds an ‘environ’ dictionary using the request data +- Then, it calls the ‘application’ callable with the ‘environ’ dictionary and a ‘start_response’ callable as parameters and gets back a response body. +- Then, the server constructs an HTTP response using the data returned by the call to the ‘application’ object and the status and response headers set by the ‘start_response’ callable. +- And finally, the server transmits the HTTP response back to the client + +![](https://ruslanspivak.com/lsbaws-part2/lsbaws_part2_server_summary.png) + +That’s about all there is to it. You now have a working WSGI server that can serve basic Web applications written with WSGI compliant Web frameworks like Django, Flask, Pyramid, or your very own WSGI framework. The best part is that the server can be used with multiple Web frameworks without any changes to the server code base. Not bad at all. + +Before you go, here is another question for you to think about, “How do you make your server handle more than one request at a time?” + +Stay tuned and I will show you a way to do that in Part 3. Cheers! + +BTW, I’m writing a book “Let’s Build A Web Server: First Steps” that explains how to write a basic web server from scratch and goes into more detail on topics I just covered. Subscribe to the mailing list to get the latest updates about the book and the release date. + +-------------------------------------------------------------------------------- + +via: https://ruslanspivak.com/lsbaws-part2/ + +作者：[Ruslan][a] +译者：[译者ID](https://github.com/译者ID) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://github.com/rspivak/ + + + + + + diff --git a/sources/tech/20160416 A newcomer's guide to navigating OpenStack Infrastructure.md b/sources/tech/20160416 A newcomer's guide to navigating OpenStack Infrastructure.md deleted file mode 100644 index 25dc193fdc..0000000000 --- a/sources/tech/20160416 A newcomer's guide to navigating OpenStack Infrastructure.md +++ /dev/null @@ -1,88 +0,0 @@ -translating by kylepeng93 -A newcomer's guide to navigating OpenStack Infrastructure -=========================================================== - -New contributors to OpenStack are welcome, but having a road map for navigating within this maturing, fast-paced open source community doesn't hurt. At OpenStack Summit in Austin, [Paul Belanger][1] (Red Hat, Inc.), [Elizabeth K. Joseph][2] (HPE), and [Christopher Aedo][3] (IBM) will lead a session on [OpenStack Infrastructure for Beginners][4]. In this interview, they offer tips and resources to help onboard new OpenStack contributors. - -![](https://opensource.com/sites/default/files/images/life/Interview%20banner%20Q%26A.png) - -**Your talk description says you'll be "diving into the heart of infrastructure and explain everything you need to know about the systems that keep OpenStack working." That's a tall order for a 40-minute time slot. What are the top things beginners should know about OpenStack infrastructure?** - -**Elizabeth K. Joseph (EKJ)**: We don't use GitHub for OpenStack patches. This is something that trips up a lot of new contributors because we do maintain mirrors of all our repositories on GitHub for historical reasons. Instead we use a fully open source code review and continuous integration (CI) system maintained by the OpenStack Infrastructure team. Relatedly, since we run a CI system, every change proposed to OpenStack is tested before merging. - -**Paul Belanger (PB)**: A lot of passionate people in the project, so don't get discouraged if your patch gets a -1. - -**Christopher Aedo (CA)**: The community wants to help you succeed, don't be afraid to ask questions or ask for pointers to more information to improve your understanding. - -### Which online resources would you recommend for beginners to fill in the holes for what you can't cover in your talk? - -**PB**: Definitely our [OpenStack Project Infrastructure documentation][5]. At lot of effort has been taken to keep it up to date as much as possible. Every system used in running OpenStack as a project has a dedicated page, even the OpenStack cloud the Infrastructure teams is bringing online. - -**EKJ**: I'll echo what Paul said about the Infrastructure documentation, and add that we love seeing patches from folks who are learning. We often don't realize what we're missing in terms of documentation until someone asks. So read, learn, and then help us fill in the gaps. You can ask questions on the [openstack-infra mailing list][6] or in our IRC channel at #openstack-infra on Freenode. - -**CA**: I love [this detailed post][7] about building images, by Ian Wienand. - -### Which "gotchas" should new OpenStack contributors look out for? - -**EKJ**: Contributing is not just about submitting new code and new features; the OpenStack community places a very high value on doing code reviews. If you want people to look at a patch you submitted, consider reviewing some of the work of others and providing clear and constructive feedback. The more your fellow contributors know about your work and see you doing reviews, the more likely you'll get your code reviewed in a timely manner. - -**CA**: I see a lot of newcomers getting tripped up with [Gerrit][8]. Read through the [developer workflow][9] in the Developers Guide, and then maybe read through it one more time. If you're not used to Gerrit, it can seem confusing and overwhelming at first, but walking through a few code reviews usually makes it all come together. Also, I'm a big fan of IRC. It can be a great place to get help, but it's best if you can maintain a persistent presence so people can answer your questions even if you're not "there" at that particular moment. (Read [IRC, the secret to success in open source][10].) You don't need to be "always on," but the ability to easily scroll back in a channel and catch up on a conversation can be invaluable. - -**PB**: I agree with both Elizabeth and Chris—Gerrit is what to look out for. It is going to be the hub of your development effort. Not only will you be submitting code for people to review, but you'll also be reviewing other contributors' code. Watch out for the Gerrit UI; it can be confusing at times. I'd recommend trying out [Gertty][11], which is a console-based interface to the Gerrit Code Review system, which happens to be a project driven by OpenStack Infrastructure. - -### What resources do you recommend for beginners to help them network with other OpenStack contributors? - -**PB**: For me, it was using IRC and joining the #openstack-infra channel on Freenode ([IRC logs][12]). There is a lot of fantastic information and people in that channel. You get to see the day-to-day operations of the OpenStack project, and once you know how the project works, you'll have a better understanding on how to contribute to its future. - -**CA**: I want to second that note for IRC; staying on IRC throughout the day made a huge difference for me in terms of feeling informed and connected. It's also such a great way to get help when you're stuck with someone on one of the projects—the ones with active IRC channels always have someone around willing to get your issues sorted out. - -**EKJ**: The [openstack-dev mailing list][13] is quite important for staying up to date with news about projects you're working on inside of OpenStack, so I recommend subscribing to that. The mailing list uses subject tags to separate projects, so you can instruct your email client to use those and focus on threads that impact projects you care about. Beyond online resources, many OpenStack groups have popped up all over the world that serve the needs of both users and contributors to OpenStack, and many of them routinely have talks and events with key OpenStack contributors. You can search on Meetup.com in your area, or search on [groups.openstack.org][14] to see if there is an OpenStack group in your area. Finally, there are the [OpenStack Summits][15], which happen every six months, and where we'll be giving our Infrastructure talk. In their current format, the summits consist of both a user conference and a developer conference in one space to talk about everything related to OpenStack, past, present, and future. - -### In which areas does OpenStack need to improve to become more beginner-friendly? - -**PB**: I think our [account-setup][16] process could be made easier for new contributors, especially how many steps are needed to submit your first patch. There is a large cost to enroll into OpenStack development model, which maybe be too much for contributors; however, once enrolled, the model works fantastic for developers. - -**CA**: We have a very pro-developer community, but the focus is on developing OpenStack itself, with less consideration given to the users of OpenStack clouds. We need to bring in application developers and encourage more people to develop things that run beautifully on OpenStack clouds, and encourage them to share those apps in the [Community App Catalog][17]. We can do this by continuing to improve our API standards and by ensuring different libraries (like libcloud, phpopencloud, and others) continue to work reliably for developers. Oh, also by sponsoring more OpenStack hackathons! All these things can ease entry for newcomers, which will lead to them sticking around. - -**EKJ**: I've worked on open source software for many years, but for a large number of OpenStack developers, this is the first open source project they've every worked on. I've found that their proprietary software background doesn't prepare them for the open source ideals, methodologies, and collaboration techniques used in an open source project. I'd love to see us do a better job of welcoming people who have this proprietary software background and working with them so they can truly understand the value of what they're working on in the open source software community. - -### I think 2016 is shaping up to be the Year of the Open Source Haiku. Explain OpenStack to beginners via Haiku. - -**PB**: OpenStack runs clouds If you enjoy free software Submit your first patch - -**CA**: In the near future OpenStack will rule the world Help make it happen! - -**EKJ**: OpenStack is free Deploy on your own servers And run your own cloud! - -*Paul, Elizabeth*, and Christopher will be [speaking at OpenStack Summit][18] in Austin on Monday, April 25, starting at 11:15am. - - ------------------------------------------------------------------------------- - -via: https://opensource.com/business/16/4/interview-openstack-infrastructure-beginners - -作者：[linux.com][a] -译者：[译者ID](https://github.com/译者ID) -校对：[校对者ID](https://github.com/校对者ID) - -本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创翻译，[Linux中国](https://linux.cn/) 荣誉推出 - -[a]: http://rikkiendsley.com/ -[1]: https://twitter.com/pabelanger -[2]: https://twitter.com/pleia2 -[3]: https://twitter.com/docaedo -[4]: https://www.openstack.org/summit/austin-2016/summit-schedule/events/7337 -[5]: http://docs.openstack.org/infra/system-config/ -[6]: http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-infra -[7]: https://www.technovelty.org/openstack/image-building-in-openstack-ci.html -[8]: https://code.google.com/p/gerrit/ -[9]: http://docs.openstack.org/infra/manual/developers.html#development-workflow -[10]: https://developer.ibm.com/opentech/2015/12/20/irc-the-secret-to-success-in-open-source/ -[11]: https://pypi.python.org/pypi/gertty -[12]: http://eavesdrop.openstack.org/irclogs/%23openstack-infra/ -[13]: http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev -[14]: https://groups.openstack.org/ -[15]: https://www.openstack.org/summit/ -[16]: http://docs.openstack.org/infra/manual/developers.html#account-setup -[17]: https://apps.openstack.org/ -[18]: https://www.openstack.org/summit/austin-2016/summit-schedule/events/7337 diff --git a/sources/tech/20160512 Bitmap in Linux Kernel.md b/sources/tech/20160512 Bitmap in Linux Kernel.md deleted file mode 100644 index 06297fa204..0000000000 --- a/sources/tech/20160512 Bitmap in Linux Kernel.md +++ /dev/null @@ -1,398 +0,0 @@ -[Translating By cposture 20160520] -Data Structures in the Linux Kernel -================================================================================ - -Bit arrays and bit operations in the Linux kernel --------------------------------------------------------------------------------- - -Besides different [linked](https://en.wikipedia.org/wiki/Linked_data_structure) and [tree](https://en.wikipedia.org/wiki/Tree_%28data_structure%29) based data structures, the Linux kernel provides [API](https://en.wikipedia.org/wiki/Application_programming_interface) for [bit arrays](https://en.wikipedia.org/wiki/Bit_array) or `bitmap`. Bit arrays are heavily used in the Linux kernel and following source code files contain common `API` for work with such structures: - -* [lib/bitmap.c](https://github.com/torvalds/linux/blob/master/lib/bitmap.c) -* [include/linux/bitmap.h](https://github.com/torvalds/linux/blob/master/include/linux/bitmap.h) - -Besides these two files, there is also architecture-specific header file which provides optimized bit operations for certain architecture. We consider [x86_64](https://en.wikipedia.org/wiki/X86-64) architecture, so in our case it will be: - -* [arch/x86/include/asm/bitops.h](https://github.com/torvalds/linux/blob/master/arch/x86/include/asm/bitops.h) - -header file. As I just wrote above, the `bitmap` is heavily used in the Linux kernel. For example a `bit array` is used to store set of online/offline processors for systems which support [hot-plug](https://www.kernel.org/doc/Documentation/cpu-hotplug.txt) cpu (more about this you can read in the [cpumasks](https://0xax.gitbooks.io/linux-insides/content/Concepts/cpumask.html) part), a `bit array` stores set of allocated [irqs](https://en.wikipedia.org/wiki/Interrupt_request_%28PC_architecture%29) during initialization of the Linux kernel and etc. - -So, the main goal of this part is to see how `bit arrays` are implemented in the Linux kernel. Let's start. - -Declaration of bit array -================================================================================ - -Before we will look on `API` for bitmaps manipulation, we must know how to declare it in the Linux kernel. There are two common method to declare own bit array. The first simple way to declare a bit array is to array of `unsigned long`. For example: - -```C -unsigned long my_bitmap[8] -``` - -The second way is to use the `DECLARE_BITMAP` macro which is defined in the [include/linux/types.h](https://github.com/torvalds/linux/blob/master/include/linux/types.h) header file: - -```C -#define DECLARE_BITMAP(name,bits) \ - unsigned long name[BITS_TO_LONGS(bits)] -``` - -We can see that `DECLARE_BITMAP` macro takes two parameters: - -* `name` - name of bitmap; -* `bits` - amount of bits in bitmap; - -and just expands to the definition of `unsigned long` array with `BITS_TO_LONGS(bits)` elements, where the `BITS_TO_LONGS` macro converts a given number of bits to number of `longs` or in other words it calculates how many `8` byte elements in `bits`: - -```C -#define BITS_PER_BYTE 8 -#define DIV_ROUND_UP(n,d) (((n) + (d) - 1) / (d)) -#define BITS_TO_LONGS(nr) DIV_ROUND_UP(nr, BITS_PER_BYTE * sizeof(long)) -``` - -So, for example `DECLARE_BITMAP(my_bitmap, 64)` will produce: - -```python ->>> (((64) + (64) - 1) / (64)) -1 -``` - -and: - -```C -unsigned long my_bitmap[1]; -``` - -After we are able to declare a bit array, we can start to use it. - -Architecture-specific bit operations -================================================================================ - -We already saw above a couple of source code and header files which provide [API](https://en.wikipedia.org/wiki/Application_programming_interface) for manipulation of bit arrays. The most important and widely used API of bit arrays is architecture-specific and located as we already know in the [arch/x86/include/asm/bitops.h](https://github.com/torvalds/linux/blob/master/arch/x86/include/asm/bitops.h) header file. - -First of all let's look at the two most important functions: - -* `set_bit`; -* `clear_bit`. - -I think that there is no need to explain what these function do. This is already must be clear from their name. Let's look on their implementation. If you will look into the [arch/x86/include/asm/bitops.h](https://github.com/torvalds/linux/blob/master/arch/x86/include/asm/bitops.h) header file, you will note that each of these functions represented by two variants: [atomic](https://en.wikipedia.org/wiki/Linearizability) and not. Before we will start to dive into implementations of these functions, first of all we must to know a little about `atomic` operations. - -In simple words atomic operations guarantees that two or more operations will not be performed on the same data concurrently. The `x86` architecture provides a set of atomic instructions, for example [xchg](http://x86.renejeschke.de/html/file_module_x86_id_328.html) instruction, [cmpxchg](http://x86.renejeschke.de/html/file_module_x86_id_41.html) instruction and etc. Besides atomic instructions, some of non-atomic instructions can be made atomic with the help of the [lock](http://x86.renejeschke.de/html/file_module_x86_id_159.html) instruction. It is enough to know about atomic operations for now, so we can begin to consider implementation of `set_bit` and `clear_bit` functions. - -First of all, let's start to consider `non-atomic` variants of this function. Names of non-atomic `set_bit` and `clear_bit` starts from double underscore. As we already know, all of these functions are defined in the [arch/x86/include/asm/bitops.h](https://github.com/torvalds/linux/blob/master/arch/x86/include/asm/bitops.h) header file and the first function is `__set_bit`: - -```C -static inline void __set_bit(long nr, volatile unsigned long *addr) -{ - asm volatile("bts %1,%0" : ADDR : "Ir" (nr) : "memory"); -} -``` - -As we can see it takes two arguments: - -* `nr` - number of bit in a bit array. -* `addr` - address of a bit array where we need to set bit. - -Note that the `addr` parameter is defined with `volatile` keyword which tells to compiler that value maybe changed by the given address. The implementation of the `__set_bit` is pretty easy. As we can see, it just contains one line of [inline assembler](https://en.wikipedia.org/wiki/Inline_assembler) code. In our case we are using the [bts](http://x86.renejeschke.de/html/file_module_x86_id_25.html) instruction which selects a bit which is specified with the first operand (`nr` in our case) from the bit array, stores the value of the selected bit in the [CF](https://en.wikipedia.org/wiki/FLAGS_register) flags register and set this bit. - -Note that we can see usage of the `nr`, but there is `addr` here. You already might guess that the secret is in `ADDR`. The `ADDR` is the macro which is defined in the same header code file and expands to the string which contains value of the given address and `+m` constraint: - -```C -#define ADDR BITOP_ADDR(addr) -#define BITOP_ADDR(x) "+m" (*(volatile long *) (x)) -``` - -Besides the `+m`, we can see other constraints in the `__set_bit` function. Let's look on they and try to understand what do they mean: - -* `+m` - represents memory operand where `+` tells that the given operand will be input and output operand; -* `I` - represents integer constant; -* `r` - represents register operand - -Besides these constraint, we also can see - the `memory` keyword which tells compiler that this code will change value in memory. That's all. Now let's look at the same function but at `atomic` variant. It looks more complex that its `non-atomic` variant: - -```C -static __always_inline void -set_bit(long nr, volatile unsigned long *addr) -{ - if (IS_IMMEDIATE(nr)) { - asm volatile(LOCK_PREFIX "orb %1,%0" - : CONST_MASK_ADDR(nr, addr) - : "iq" ((u8)CONST_MASK(nr)) - : "memory"); - } else { - asm volatile(LOCK_PREFIX "bts %1,%0" - : BITOP_ADDR(addr) : "Ir" (nr) : "memory"); - } -} -``` - -First of all note that this function takes the same set of parameters that `__set_bit`, but additionally marked with the `__always_inline` attribute. The `__always_inline` is macro which defined in the [include/linux/compiler-gcc.h](https://github.com/torvalds/linux/blob/master/include/linux/compiler-gcc.h) and just expands to the `always_inline` attribute: - -```C -#define __always_inline inline __attribute__((always_inline)) -``` - -which means that this function will be always inlined to reduce size of the Linux kernel image. Now let's try to understand implementation of the `set_bit` function. First of all we check a given number of bit at the beginning of the `set_bit` function. The `IS_IMMEDIATE` macro defined in the same [header](https://github.com/torvalds/linux/blob/master/arch/x86/include/asm/bitops.h) file and expands to the call of the builtin [gcc](https://en.wikipedia.org/wiki/GNU_Compiler_Collection) function: - -```C -#define IS_IMMEDIATE(nr) (__builtin_constant_p(nr)) -``` - -The `__builtin_constant_p` builtin function returns `1` if the given parameter is known to be constant at compile-time and returns `0` in other case. We no need to use slow `bts` instruction to set bit if the given number of bit is known in compile time constant. We can just apply [bitwise or](https://en.wikipedia.org/wiki/Bitwise_operation#OR) for byte from the give address which contains given bit and masked number of bits where high bit is `1` and other is zero. In other case if the given number of bit is not known constant at compile-time, we do the same as we did in the `__set_bit` function. The `CONST_MASK_ADDR` macro: - -```C -#define CONST_MASK_ADDR(nr, addr) BITOP_ADDR((void *)(addr) + ((nr)>>3)) -``` - -expands to the give address with offset to the byte which contains a given bit. For example we have address `0x1000` and the number of bit is `0x9`. So, as `0x9` is `one byte + one bit` our address with be `addr + 1`: - -```python ->>> hex(0x1000 + (0x9 >> 3)) -'0x1001' -``` - -The `CONST_MASK` macro represents our given number of bit as byte where high bit is `1` and other bits are `0`: - -```C -#define CONST_MASK(nr) (1 << ((nr) & 7)) -``` - -```python ->>> bin(1 << (0x9 & 7)) -'0b10' -``` - -In the end we just apply bitwise `or` for these values. So, for example if our address will be `0x4097` and we need to set `0x9` bit: - -```python ->>> bin(0x4097) -'0b100000010010111' ->>> bin((0x4097 >> 0x9) | (1 << (0x9 & 7))) -'0b100010' -``` - -the `ninth` bit will be set. - -Note that all of these operations are marked with `LOCK_PREFIX` which is expands to the [lock](http://x86.renejeschke.de/html/file_module_x86_id_159.html) instruction which guarantees atomicity of this operation. - -As we already know, besides the `set_bit` and `__set_bit` operations, the Linux kernel provides two inverse functions to clear bit in atomic and non-atomic context. They are `clear_bit` and `__clear_bit`. Both of these functions are defined in the same [header file](https://github.com/torvalds/linux/blob/master/arch/x86/include/asm/bitops.h) and takes the same set of arguments. But not only arguments are similar. Generally these functions are very similar on the `set_bit` and `__set_bit`. Let's look on the implementation of the non-atomic `__clear_bit` function: - -```C -static inline void __clear_bit(long nr, volatile unsigned long *addr) -{ - asm volatile("btr %1,%0" : ADDR : "Ir" (nr)); -} -``` - -Yes. As we see, it takes the same set of arguments and contains very similar block of inline assembler. It just uses the [btr](http://x86.renejeschke.de/html/file_module_x86_id_24.html) instruction instead of `bts`. As we can understand form the function's name, it clears a given bit by the given address. The `btr` instruction acts like `btr`. This instruction also selects a given bit which is specified in the first operand, stores its value in the `CF` flag register and clears this bit in the given bit array which is specifed with second operand. - -The atomic variant of the `__clear_bit` is `clear_bit`: - -```C -static __always_inline void -clear_bit(long nr, volatile unsigned long *addr) -{ - if (IS_IMMEDIATE(nr)) { - asm volatile(LOCK_PREFIX "andb %1,%0" - : CONST_MASK_ADDR(nr, addr) - : "iq" ((u8)~CONST_MASK(nr))); - } else { - asm volatile(LOCK_PREFIX "btr %1,%0" - : BITOP_ADDR(addr) - : "Ir" (nr)); - } -} -``` - -and as we can see it is very similar on `set_bit` and just contains two differences. The first difference it uses `btr` instruction to clear bit when the `set_bit` uses `bts` instruction to set bit. The second difference it uses negated mask and `and` instruction to clear bit in the given byte when the `set_bit` uses `or` instruction. - -That's all. Now we can set and clear bit in any bit array and and we can go to other operations on bitmasks. - -Most widely used operations on a bit arrays are set and clear bit in a bit array in the Linux kernel. But besides this operations it is useful to do additional operations on a bit array. Yet another widely used operation in the Linux kernel - is to know is a given bit set or not in a bit array. We can achieve this with the help of the `test_bit` macro. This macro is defined in the [arch/x86/include/asm/bitops.h](https://github.com/torvalds/linux/blob/master/arch/x86/include/asm/bitops.h) header file and expands to the call of the `constant_test_bit` or `variable_test_bit` depends on bit number: - -```C -#define test_bit(nr, addr) \ - (__builtin_constant_p((nr)) \ - ? constant_test_bit((nr), (addr)) \ - : variable_test_bit((nr), (addr))) -``` - -So, if the `nr` is known in compile time constant, the `test_bit` will be expanded to the call of the `constant_test_bit` function or `variable_test_bit` in other case. Now let's look at implementations of these functions. Let's start from the `variable_test_bit`: - -```C -static inline int variable_test_bit(long nr, volatile const unsigned long *addr) -{ - int oldbit; - - asm volatile("bt %2,%1\n\t" - "sbb %0,%0" - : "=r" (oldbit) - : "m" (*(unsigned long *)addr), "Ir" (nr)); - - return oldbit; -} -``` - -The `variable_test_bit` function takes similar set of arguments as `set_bit` and other function take. We also may see inline assembly code here which executes [bt](http://x86.renejeschke.de/html/file_module_x86_id_22.html) and [sbb](http://x86.renejeschke.de/html/file_module_x86_id_286.html) instruction. The `bt` or `bit test` instruction selects a given bit which is specified with first operand from the bit array which is specified with the second operand and stores its value in the [CF](https://en.wikipedia.org/wiki/FLAGS_register) bit of flags register. The second `sbb` instruction substracts first operand from second and subscrtact value of the `CF`. So, here write a value of a given bit number from a given bit array to the `CF` bit of flags register and execute `sbb` instruction which calculates: `00000000 - CF` and writes the result to the `oldbit`. - -The `constant_test_bit` function does the same as we saw in the `set_bit`: - -```C -static __always_inline int constant_test_bit(long nr, const volatile unsigned long *addr) -{ - return ((1UL << (nr & (BITS_PER_LONG-1))) & - (addr[nr >> _BITOPS_LONG_SHIFT])) != 0; -} -``` - -It generates a byte where high bit is `1` and other bits are `0` (as we saw in `CONST_MASK`) and applies bitwise [and](https://en.wikipedia.org/wiki/Bitwise_operation#AND) to the byte which contains a given bit number. - -The next widely used bit array related operation is to change bit in a bit array. The Linux kernel provides two helper for this: - -* `__change_bit`; -* `change_bit`. - -As you already can guess, these two variants are atomic and non-atomic as for example `set_bit` and `__set_bit`. For the start, let's look at the implementation of the `__change_bit` function: - -```C -static inline void __change_bit(long nr, volatile unsigned long *addr) -{ - asm volatile("btc %1,%0" : ADDR : "Ir" (nr)); -} -``` - -Pretty easy, is not it? The implementation of the `__change_bit` is the same as `__set_bit`, but instead of `bts` instruction, we are using [btc](http://x86.renejeschke.de/html/file_module_x86_id_23.html). This instruction selects a given bit from a given bit array, stores its value in the `CF` and changes its value by the applying of complement operation. So, a bit with value `1` will be `0` and vice versa: - -```python ->>> int(not 1) -0 ->>> int(not 0) -1 -``` - -The atomic version of the `__change_bit` is the `change_bit` function: - -```C -static inline void change_bit(long nr, volatile unsigned long *addr) -{ - if (IS_IMMEDIATE(nr)) { - asm volatile(LOCK_PREFIX "xorb %1,%0" - : CONST_MASK_ADDR(nr, addr) - : "iq" ((u8)CONST_MASK(nr))); - } else { - asm volatile(LOCK_PREFIX "btc %1,%0" - : BITOP_ADDR(addr) - : "Ir" (nr)); - } -} -``` - -It is similar on `set_bit` function, but also has two differences. The first difference is `xor` operation instead of `or` and the second is `bts` instead of `bts`. - -For this moment we know the most important architecture-specific operations with bit arrays. Time to look at generic bitmap API. - -Common bit operations -================================================================================ - -Besides the architecture-specific API from the [arch/x86/include/asm/bitops.h](https://github.com/torvalds/linux/blob/master/arch/x86/include/asm/bitops.h) header file, the Linux kernel provides common API for manipulation of bit arrays. As we know from the beginning of this part, we can find it in the [include/linux/bitmap.h](https://github.com/torvalds/linux/blob/master/include/linux/bitmap.h) header file and additionally in the * [lib/bitmap.c](https://github.com/torvalds/linux/blob/master/lib/bitmap.c) source code file. But before these source code files let's look into the [include/linux/bitops.h](https://github.com/torvalds/linux/blob/master/include/linux/bitops.h) header file which provides a set of useful macro. Let's look on some of they. - -First of all let's look at following four macros: - -* `for_each_set_bit` -* `for_each_set_bit_from` -* `for_each_clear_bit` -* `for_each_clear_bit_from` - -All of these macros provide iterator over certain set of bits in a bit array. The first macro iterates over bits which are set, the second does the same, but starts from a certain bits. The last two macros do the same, but iterates over clear bits. Let's look on implementation of the `for_each_set_bit` macro: - -```C -#define for_each_set_bit(bit, addr, size) \ - for ((bit) = find_first_bit((addr), (size)); \ - (bit) < (size); \ - (bit) = find_next_bit((addr), (size), (bit) + 1)) -``` - -As we may see it takes three arguments and expands to the loop from first set bit which is returned as result of the `find_first_bit` function and to the last bit number while it is less than given size. - -Besides these four macros, the [arch/x86/include/asm/bitops.h](https://github.com/torvalds/linux/blob/master/arch/x86/include/asm/bitops.h) provides API for rotation of `64-bit` or `32-bit` values and etc. - -The next [header](https://github.com/torvalds/linux/blob/master/include/linux/bitmap.h) file which provides API for manipulation with a bit arrays. For example it provdes two functions: - -* `bitmap_zero`; -* `bitmap_fill`. - -To clear a bit array and fill it with `1`. Let's look on the implementation of the `bitmap_zero` function: - -```C -static inline void bitmap_zero(unsigned long *dst, unsigned int nbits) -{ - if (small_const_nbits(nbits)) - *dst = 0UL; - else { - unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long); - memset(dst, 0, len); - } -} -``` - -First of all we can see the check for `nbits`. The `small_const_nbits` is macro which defined in the same header [file](https://github.com/torvalds/linux/blob/master/include/linux/bitmap.h) and looks: - -```C -#define small_const_nbits(nbits) \ - (__builtin_constant_p(nbits) && (nbits) <= BITS_PER_LONG) -``` - -As we may see it checks that `nbits` is known constant in compile time and `nbits` value does not overflow `BITS_PER_LONG` or `64`. If bits number does not overflow amount of bits in a `long` value we can just set to zero. In other case we need to calculate how many `long` values do we need to fill our bit array and fill it with [memset](http://man7.org/linux/man-pages/man3/memset.3.html). - -The implementation of the `bitmap_fill` function is similar on implementation of the `biramp_zero` function, except we fill a given bit array with `0xff` values or `0b11111111`: - -```C -static inline void bitmap_fill(unsigned long *dst, unsigned int nbits) -{ - unsigned int nlongs = BITS_TO_LONGS(nbits); - if (!small_const_nbits(nbits)) { - unsigned int len = (nlongs - 1) * sizeof(unsigned long); - memset(dst, 0xff, len); - } - dst[nlongs - 1] = BITMAP_LAST_WORD_MASK(nbits); -} -``` - -Besides the `bitmap_fill` and `bitmap_zero` functions, the [include/linux/bitmap.h](https://github.com/torvalds/linux/blob/master/include/linux/bitmap.h) header file provides `bitmap_copy` which is similar on the `bitmap_zero`, but just uses [memcpy](http://man7.org/linux/man-pages/man3/memcpy.3.html) instead of [memset](http://man7.org/linux/man-pages/man3/memset.3.html). Also it provides bitwise operations for bit array like `bitmap_and`, `bitmap_or`, `bitamp_xor` and etc. We will not consider implementation of these functions because it is easy to understand implementations of these functions if you understood all from this part. Anyway if you are interested how did these function implemented, you may open [include/linux/bitmap.h](https://github.com/torvalds/linux/blob/master/include/linux/bitmap.h) header file and start to research. - -That's all. - -Links -================================================================================ - -* [bitmap](https://en.wikipedia.org/wiki/Bit_array) -* [linked data structures](https://en.wikipedia.org/wiki/Linked_data_structure) -* [tree data structures](https://en.wikipedia.org/wiki/Tree_%28data_structure%29) -* [hot-plug](https://www.kernel.org/doc/Documentation/cpu-hotplug.txt) -* [cpumasks](https://0xax.gitbooks.io/linux-insides/content/Concepts/cpumask.html) -* [IRQs](https://en.wikipedia.org/wiki/Interrupt_request_%28PC_architecture%29) -* [API](https://en.wikipedia.org/wiki/Application_programming_interface) -* [atomic operations](https://en.wikipedia.org/wiki/Linearizability) -* [xchg instruction](http://x86.renejeschke.de/html/file_module_x86_id_328.html) -* [cmpxchg instruction](http://x86.renejeschke.de/html/file_module_x86_id_41.html) -* [lock instruction](http://x86.renejeschke.de/html/file_module_x86_id_159.html) -* [bts instruction](http://x86.renejeschke.de/html/file_module_x86_id_25.html) -* [btr instruction](http://x86.renejeschke.de/html/file_module_x86_id_24.html) -* [bt instruction](http://x86.renejeschke.de/html/file_module_x86_id_22.html) -* [sbb instruction](http://x86.renejeschke.de/html/file_module_x86_id_286.html) -* [btc instruction](http://x86.renejeschke.de/html/file_module_x86_id_23.html) -* [man memcpy](http://man7.org/linux/man-pages/man3/memcpy.3.html) -* [man memset](http://man7.org/linux/man-pages/man3/memset.3.html) -* [CF](https://en.wikipedia.org/wiki/FLAGS_register) -* [inline assembler](https://en.wikipedia.org/wiki/Inline_assembler) -* [gcc](https://en.wikipedia.org/wiki/GNU_Compiler_Collection) - - ------------------------------------------------------------------------------- - -via: https://github.com/0xAX/linux-insides/blob/master/DataStructures/bitmap.md - -作者：[0xAX][a] -译者：[译者ID](https://github.com/译者ID) -校对：[校对者ID](https://github.com/校对者ID) - -本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创翻译，[Linux中国](https://linux.cn/) 荣誉推出 - -[a]: https://twitter.com/0xAX diff --git a/sources/tech/20160518 Python 3 - An Intro to Encryption.md b/sources/tech/20160518 Python 3 - An Intro to Encryption.md deleted file mode 100644 index 3a840114d3..0000000000 --- a/sources/tech/20160518 Python 3 - An Intro to Encryption.md +++ /dev/null @@ -1,280 +0,0 @@ -[Cathon is Translating...] - -Python 3: An Intro to Encryption -=================================== - -Python 3 doesn’t have very much in its standard library that deals with encryption. Instead, you get hashing libraries. We’ll take a brief look at those in the chapter, but the primary focus will be on the following 3rd party packages: PyCrypto and cryptography. We will learn how to encrypt and decrypt strings with both of these libraries. - ---- - -### Hashing - -If you need secure hashes or message digest algorithms, then Python’s standard library has you covered in the **hashlib** module. It includes the FIPS secure hash algorithms SHA1, SHA224, SHA256, SHA384, and SHA512 as well as RSA’s MD5 algorithm. Python also supports the adler32 and crc32 hash functions, but those are in the **zlib** module. - -One of the most popular uses of hashes is storing the hash of a password instead of the password itself. Of course, the hash has to be a good one or it can be decrypted. Another popular use case for hashes is to hash a file and then send the file and its hash separately. Then the person receiving the file can run a hash on the file to see if it matches the hash that was sent. If it does, then that means no one has changed the file in transit. - - -Let’s try creating an md5 hash: - -``` ->>> import hashlib ->>> md5 = hashlib.md5() ->>> md5.update('Python rocks!') -Traceback (most recent call last): - File "", line 1, in - md5.update('Python rocks!') -TypeError: Unicode-objects must be encoded before hashing ->>> md5.update(b'Python rocks!') ->>> md5.digest() -b'\x14\x82\xec\x1b#d\xf6N}\x16*+[\x16\xf4w' -``` - -Let’s take a moment to break this down a bit. First off, we import **hashlib** and then we create an instance of an md5 HASH object. Next we add some text to the hash object and we get a traceback. It turns out that to use the md5 hash, you have to pass it a byte string instead of a regular string. So we try that and then call it’s **digest** method to get our hash. If you prefer the hex digest, we can do that too: - -``` ->>> md5.hexdigest() -'1482ec1b2364f64e7d162a2b5b16f477' -``` - -There’s actually a shortcut method of creating a hash, so we’ll look at that next when we create our sha512 hash: - -``` ->>> sha = hashlib.sha1(b'Hello Python').hexdigest() ->>> sha -'422fbfbc67fe17c86642c5eaaa48f8b670cbed1b' -``` - -As you can see, we can create our hash instance and call its digest method at the same time. Then we print out the hash to see what it is. I chose to use the sha1 hash as it has a nice short hash that will fit the page better. But it’s also less secure, so feel free to try one of the others. - ---- - -### Key Derivation - -Python has pretty limited support for key derivation built into the standard library. In fact, the only method that hashlib provides is the **pbkdf2_hmac** method, which is the PKCS#5 password-based key derivation function 2. It uses HMAC as its psuedorandom function. You might use something like this for hashing your password as it supports a salt and iterations. For example, if you were to use SHA-256 you would need a salt of at least 16 bytes and a minimum of 100,000 iterations. - -As a quick aside, a salt is just random data that you use as additional input into your hash to make it harder to “unhash” your password. Basically it protects your password from dictionary attacks and pre-computed rainbow tables. - -Let’s look at a simple example: - -``` ->>> import binascii ->>> dk = hashlib.pbkdf2_hmac(hash_name='sha256', - password=b'bad_password34', - salt=b'bad_salt', - iterations=100000) ->>> binascii.hexlify(dk) -b'6e97bad21f6200f9087036a71e7ca9fa01a59e1d697f7e0284cd7f9b897d7c02' -``` - -Here we create a SHA256 hash on a password using a lousy salt but with 100,000 iterations. Of course, SHA is not actually recommended for creating keys of passwords. Instead you should use something like **scrypt** instead. Another good option would be the 3rd party package, bcrypt. It is designed specifically with password hashing in mind. - ---- - -### PyCryptodome - -The PyCrypto package is probably the most well known 3rd party cryptography package for Python. Sadly PyCrypto’s development stopping in 2012. Others have continued to release the latest version of PyCryto so you can still get it for Python 3.5 if you don’t mind using a 3rd party’s binary. For example, I found some binary Python 3.5 wheels for PyCrypto on Github (https://github.com/sfbahr/PyCrypto-Wheels). - -Fortunately there is a fork of the project called PyCrytodome that is a drop-in replacement for PyCrypto. To install it for Linux, you can use the following pip command: - - -``` -pip install pycryptodome -``` - -Windows is a bit different: - -``` -pip install pycryptodomex -``` - -If you run into issues, it’s probably because you don’t have the right dependencies installed or you need a compiler for Windows. Check out the PyCryptodome [website][1] for additional installation help or to contact support. - -Also worth noting is that PyCryptodome has many enhancements over the last version of PyCrypto. It is well worth your time to visit their home page and see what new features exist. - -### Encrypting a String - -Once you’re done checking their website out, we can move on to some examples. For our first trick, we’ll use DES to encrypt a string: - -``` ->>> from Crypto.Cipher import DES ->>> key = 'abcdefgh' ->>> def pad(text): - while len(text) % 8 != 0: - text += ' ' - return text ->>> des = DES.new(key, DES.MODE_ECB) ->>> text = 'Python rocks!' ->>> padded_text = pad(text) ->>> encrypted_text = des.encrypt(text) -Traceback (most recent call last): - File "", line 1, in - encrypted_text = des.encrypt(text) - File "C:\Programs\Python\Python35-32\lib\site-packages\Crypto\Cipher\blockalgo.py", line 244, in encrypt - return self._cipher.encrypt(plaintext) -ValueError: Input strings must be a multiple of 8 in length ->>> encrypted_text = des.encrypt(padded_text) ->>> encrypted_text -b'>\xfc\x1f\x16x\x87\xb2\x93\x0e\xfcH\x02\xd59VQ' -``` - -This code is a little confusing, so let’s spend some time breaking it down. First off, it should be noted that the key size for DES encryption is 8 bytes, which is why we set our key variable to a size letter string. The string that we will be encrypting must be a multiple of 8 in length, so we create a function called **pad** that can pad any string out with spaces until it’s a multiple of 8. Next we create an instance of DES and some text that we want to encrypt. We also create a padded version of the text. Just for fun, we attempt to encrypt the original unpadded variant of the string which raises a **ValueError**. Here we learn that we need that padded string after all, so we pass that one in instead. As you can see, we now have an encrypted string! - -Of course the example wouldn’t be complete if we didn’t know how to decrypt our string: - -``` ->>> des.decrypt(encrypted_text) -b'Python rocks! ' -``` - -Fortunately, that is very easy to accomplish as all we need to do is call the **decrypt** method on our des object to get our decrypted byte string back. Our next task is to learn how to encrypt and decrypt a file with PyCrypto using RSA. But first we need to create some RSA keys! - -### Create an RSA Key - -If you want to encrypt your data with RSA, then you’ll need to either have access to a public / private RSA key pair or you will need to generate your own. For this example, we will just generate our own. Since it’s fairly easy to do, we will do it in Python’s interpreter: - -``` ->>> from Crypto.PublicKey import RSA ->>> code = 'nooneknows' ->>> key = RSA.generate(2048) ->>> encrypted_key = key.exportKey(passphrase=code, pkcs=8, - protection="scryptAndAES128-CBC") ->>> with open('/path_to_private_key/my_private_rsa_key.bin', 'wb') as f: - f.write(encrypted_key) ->>> with open('/path_to_public_key/my_rsa_public.pem', 'wb') as f: - f.write(key.publickey().exportKey()) -``` - -First we import **RSA** from **Crypto.PublicKey**. Then we create a silly passcode. Next we generate an RSA key of 2048 bits. Now we get to the good stuff. To generate a private key, we need to call our RSA key instance’s **exportKey** method and give it our passcode, which PKCS standard to use and which encryption scheme to use to protect our private key. Then we write the file out to disk. - -Next we create our public key via our RSA key instance’s **publickey** method. We used a shortcut in this piece of code by just chaining the call to exportKey with the publickey method call to write it to disk as well. - -### Encrypting a File - -Now that we have both a private and a public key, we can encrypt some data and write it to a file. Here’s a pretty standard example: - -``` -from Crypto.PublicKey import RSA -from Crypto.Random import get_random_bytes -from Crypto.Cipher import AES, PKCS1_OAEP - -with open('/path/to/encrypted_data.bin', 'wb') as out_file: - recipient_key = RSA.import_key( - open('/path_to_public_key/my_rsa_public.pem').read()) - session_key = get_random_bytes(16) - - cipher_rsa = PKCS1_OAEP.new(recipient_key) - out_file.write(cipher_rsa.encrypt(session_key)) - - cipher_aes = AES.new(session_key, AES.MODE_EAX) - data = b'blah blah blah Python blah blah' - ciphertext, tag = cipher_aes.encrypt_and_digest(data) - - out_file.write(cipher_aes.nonce) - out_file.write(tag) - out_file.write(ciphertext) -``` - -The first three lines cover our imports from PyCryptodome. Next we open up a file to write to. Then we import our public key into a variable and create a 16-byte session key. For this example we are going to be using a hybrid encryption method, so we use PKCS#1 OAEP, which is Optimal asymmetric encryption padding. This allows us to write a data of an arbitrary length to the file. Then we create our AES cipher, create some data and encrypt the data. This will return the encrypted text and the MAC. Finally we write out the nonce, MAC (or tag) and the encrypted text. - -As an aside, a nonce is an arbitrary number that is only used for crytographic communication. They are usually random or pseudorandom numbers. For AES, it must be at least 16 bytes in length. Feel free to try opening the encrypted file in your favorite text editor. You should just see gibberish. - -Now let’s learn how to decrypt our data: - -``` -from Crypto.PublicKey import RSA -from Crypto.Cipher import AES, PKCS1_OAEP - -code = 'nooneknows' - -with open('/path/to/encrypted_data.bin', 'rb') as fobj: - private_key = RSA.import_key( - open('/path_to_private_key/my_rsa_key.pem').read(), - passphrase=code) - - enc_session_key, nonce, tag, ciphertext = [ fobj.read(x) - for x in (private_key.size_in_bytes(), - 16, 16, -1) ] - - cipher_rsa = PKCS1_OAEP.new(private_key) - session_key = cipher_rsa.decrypt(enc_session_key) - - cipher_aes = AES.new(session_key, AES.MODE_EAX, nonce) - data = cipher_aes.decrypt_and_verify(ciphertext, tag) - -print(data) -``` - -If you followed the previous example, this code should be pretty easy to parse. In this case, we are opening our encrypted file for reading in binary mode. Then we import our private key. Note that when you import the private key, you must give it your passcode. Otherwise you will get an error. Next we read in our file. You will note that we read in the private key first, then the next 16 bytes for the nonce, which is followed by the next 16 bytes which is the tag and finally the rest of the file, which is our data. - -Then we need to decrypt our session key, recreate our AES key and decrypt the data. - -You can use PyCryptodome to do much, much more. However we need to move on and see what else we can use for our cryptographic needs in Python. - ---- - -### The cryptography package - -The **cryptography** package aims to be “cryptography for humans” much like the **requests** library is “HTTP for Humans”. The idea is that you will be able to create simple cryptographic recipes that are safe and easy-to-use. If you need to, you can drop down to low=level cryptographic primitives, which require you to know what you’re doing or you might end up creating something that’s not very secure. - -If you are using Python 3.5, you can install it with pip, like so: - -``` -pip install cryptography -``` - -You will see that cryptography installs a few dependencies along with itself. Assuming that they all completed successfully, we can try encrypting some text. Let’s give the **Fernet** symmetric encryption algorithm. The Fernet algorithm guarantees that any message you encrypt with it cannot be manipulated or read without the key you define. Fernet also support key rotation via **MultiFernet**. Let’s take a look at a simple example: - -``` ->>> from cryptography.fernet import Fernet ->>> cipher_key = Fernet.generate_key() ->>> cipher_key -b'APM1JDVgT8WDGOWBgQv6EIhvxl4vDYvUnVdg-Vjdt0o=' ->>> cipher = Fernet(cipher_key) ->>> text = b'My super secret message' ->>> encrypted_text = cipher.encrypt(text) ->>> encrypted_text -(b'gAAAAABXOnV86aeUGADA6mTe9xEL92y_m0_TlC9vcqaF6NzHqRKkjEqh4d21PInEP3C9HuiUkS9f' - b'6bdHsSlRiCNWbSkPuRd_62zfEv3eaZjJvLAm3omnya8=') ->>> decrypted_text = cipher.decrypt(encrypted_text) ->>> decrypted_text -b'My super secret message' -``` - -First off we need to import Fernet. Next we generate a key. We print out the key to see what it looks like. As you can see, it’s a random byte string. If you want, you can try running the **generate_key** method a few times. The result will always be different. Next we create our Fernet cipher instance using our key. - -Now we have a cipher we can use to encrypt and decrypt our message. The next step is to create a message worth encrypting and then encrypt it using the **encrypt** method. I went ahead and printed our the encrypted text so you can see that you can no longer read the text. To **decrypt** our super secret message, we just call decrypt on our cipher and pass it the encrypted text. The result is we get a plain text byte string of our message. - ---- - -### Wrapping Up - -This chapter barely scratched the surface of what you can do with PyCryptodome and the cryptography packages. However it does give you a decent overview of what can be done with Python in regards to encrypting and decrypting strings and files. Be sure to read the documentation and start experimenting to see what else you can do! - ---- - -### Related Reading - -PyCrypto Wheels for Python 3 on [github][2] - -PyCryptodome [documentation][3] - -Python’s Cryptographic [Services][4] - -The cryptography package’s [website][5] - ------------------------------------------------------------------------------- - -via: http://www.blog.pythonlibrary.org/2016/05/18/python-3-an-intro-to-encryption/ - -作者：[Mike][a] -译者：[译者ID](https://github.com/译者ID) -校对：[校对者ID](https://github.com/校对者ID) - -本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创翻译，[Linux中国](https://linux.cn/) 荣誉推出 - -[a]:http://www.blog.pythonlibrary.org/author/mld/ -[1]: http://pycryptodome.readthedocs.io/en/latest/ -[2]: https://github.com/sfbahr/PyCrypto-Wheels -[3]: http://pycryptodome.readthedocs.io/en/latest/src/introduction.html -[4]: https://docs.python.org/3/library/crypto.html -[5]: https://cryptography.io/en/latest/ diff --git a/sources/tech/20160530 Install LEMP with MariaDB 10, PHP 7 and HTTP 2.0 Support for Nginx on Ubuntu 16.04.md b/sources/tech/20160530 Install LEMP with MariaDB 10, PHP 7 and HTTP 2.0 Support for Nginx on Ubuntu 16.04.md deleted file mode 100644 index ef713fff0f..0000000000 --- a/sources/tech/20160530 Install LEMP with MariaDB 10, PHP 7 and HTTP 2.0 Support for Nginx on Ubuntu 16.04.md +++ /dev/null @@ -1,304 +0,0 @@ -Translating by strugglingyouth - -Install LEMP with MariaDB 10, PHP 7 and HTTP 2.0 Support for Nginx on Ubuntu 16.04 -===================================================================================== - - -The LEMP stack is an acronym which represents is a group of packages (Linux OS, Nginx web server, MySQL\MariaDB database and PHP server-side dynamic programming language) which are used to deploy dynamic web applications and web pages. - -![](http://www.tecmint.com/wp-content/uploads/2016/05/Install-Nginx-with-FastCGI-on-Ubuntu-16.04.png) ->Install Nginx with MariaDB 10, PHP 7 and HTTP 2.0 Support on Ubuntu 16.04 - -This tutorial will guide you on how to install a LEMP stack (Nginx with MariaDB and PHP7) on Ubuntu 16.04 server. - -Requirements - -[Installation of Ubuntu 16.04 Server Edition][1] - -### Step 1: Install the Nginx Web Server - -#### 1. Nginx is a modern and resources efficient web server used to display web pages to visitors on the internet. We’ll start by installing Nginx web server from Ubuntu official repositories by using the [apt command line][2]. - -``` -$ sudo apt-get install nginx -``` - -![](http://www.tecmint.com/wp-content/uploads/2016/05/Install-Nginx-on-Ubuntu-16.04.png) ->Install Nginx on Ubuntu 16.04 - -#### 2. Next, issue the [netstat][3] and [systemctl][4] commands in order to confirm if Nginx is started and binds on port 80. - -``` -$ netstat -tlpn -``` - -![](http://www.tecmint.com/wp-content/uploads/2016/05/Check-Nginx-Network-Port-Connection.png) ->Check Nginx Network Port Connection - -``` -$ sudo systemctl status nginx.service -``` - -![](http://www.tecmint.com/wp-content/uploads/2016/05/Check-Nginx-Service-Status.png) ->Check Nginx Service Status - -Once you have the confirmation that the server is started you can open a browser and navigate to your server IP address or DNS record using HTTP protocol in order to visit Nginx default web page. - -``` -http://IP-Address -``` - -![](http://www.tecmint.com/wp-content/uploads/2016/05/Verify-Nginx-Webpage.png) ->Verify Nginx Webpage - -### Step 2: Enable Nginx HTTP/2.0 Protocol - -#### 3. The HTTP/2.0 protocol which is build by default in the latest release of Nginx binaries on Ubuntu 16.04 works only in conjunction with SSL and promises a huge speed improvement in loading web SSL web pages. - -To enable the protocol in Nginx on Ubuntu 16.04, first navigate to Nginx available sites configuration files and backup the default configuration file by issuing the below command. - -``` -$ cd /etc/nginx/sites-available/ -$ sudo mv default default.backup -``` - -![](http://www.tecmint.com/wp-content/uploads/2016/05/Backup-Nginx-Sites-Configuration-File.png) ->Backup Nginx Sites Configuration File - -#### 4. Then, using a text editor create a new default page with the below instructions: - -``` -server { - listen 443 ssl http2 default_server; - listen [::]:443 ssl http2 default_server; - - root /var/www/html; - - index index.html index.htm index.php; - - server_name 192.168.1.13; - - location / { - try_files $uri $uri/ =404; - } - - ssl_certificate /etc/nginx/ssl/nginx.crt; - ssl_certificate_key /etc/nginx/ssl/nginx.key; - - ssl_protocols TLSv1 TLSv1.1 TLSv1.2; - ssl_prefer_server_ciphers on; - ssl_ciphers EECDH+CHACHA20:EECDH+AES128:RSA+AES128:EECDH+AES256:RSA+AES256:EECDH+3DES:RSA+3DES:!MD5; - ssl_dhparam /etc/nginx/ssl/dhparam.pem; - ssl_session_cache shared:SSL:20m; - ssl_session_timeout 180m; - resolver 8.8.8.8 8.8.4.4; - add_header Strict-Transport-Security "max-age=31536000; - #includeSubDomains" always; - - - location ~ \.php$ { - include snippets/fastcgi-php.conf; - fastcgi_pass unix:/run/php/php7.0-fpm.sock; - } - - location ~ /\.ht { - deny all; - } - -} - -server { - listen 80; - listen [::]:80; - server_name 192.168.1.13; - return 301 https://$server_name$request_uri; -} -``` - -![](http://www.tecmint.com/wp-content/uploads/2016/05/Enable-Nginx-HTTP-2-Protocol.png) ->Enable Nginx HTTP 2 Protocol - -The above configuration snippet enables the use of `HTTP/2.0` by adding the http2 parameter to all SSL listen directives. - -Also, the last part of the excerpt enclosed in server directive is used to redirect all non-SSL traffic to SSL/TLS default host. Also, replace the `server_name` directive to match your own IP address or DNS record (FQDN preferably). - -#### 5. Once you finished editing Nginx default configuration file with the above settings, generate and list the SSL certificate file and key by executing the below commands. - -Fill the certificate with your own custom settings and pay attention to Common Name setting to match your DNS FQDN record or your server IP address that will be used to access the web page. - -``` -$ sudo mkdir /etc/nginx/ssl -$ sudo openssl req -x509 -nodes -days 365 -newkey rsa:2048 -keyout /etc/nginx/ssl/nginx.key -out /etc/nginx/ssl/nginx.crt -$ ls /etc/nginx/ssl/ -``` - -![](http://www.tecmint.com/wp-content/uploads/2016/05/Generate-SSL-Certificate-and-Key.png) ->Generate SSL Certificate and Key for Nginx - -#### 6. Also, create a strong DH cypher, which was changed on the above configuration file on `ssl_dhparam` instruction line, by issuing the below command: - -``` -$ sudo openssl dhparam -out /etc/nginx/ssl/dhparam.pem 2048 -``` - -![](http://www.tecmint.com/wp-content/uploads/2016/05/Create-Diffie-Hellman-Key.png) ->Create Diffie-Hellman Key - -#### 7. Once the `Diffie-Hellman` key has been created, verify if Nginx configuration file is correctly written and can be applied by Nginx web server and restart the daemon to reflect changes by running the below commands. - -``` -$ sudo nginx -t -$ sudo systemctl restart nginx.service -``` - -![](http://www.tecmint.com/wp-content/uploads/2016/05/Check-Nginx-Configuration.png) ->Check Nginx Configuration - -#### 8. In order to test if Nginx uses HTTP/2.0 protocol issue the below command. The presence of `h2` advertised protocol confirms that Nginx has been successfully configured to use HTTP/2.0 protocol. All modern up-to-date browsers should support this protocol by default. - -``` -$ openssl s_client -connect localhost:443 -nextprotoneg '' -``` - -![](http://www.tecmint.com/wp-content/uploads/2016/05/Test-Nginx-HTTP-2-Protocol.png) ->Test Nginx HTTP 2.0 Protocol - -### Step 3: Install PHP 7 Interpreter - -Nginx can be used with PHP dynamic processing language interpreter to generate dynamic web content with the help of FastCGI process manager obtained by installing the php-fpm binary package from Ubuntu official repositories. - -#### 9. In order to grab PHP7.0 and the additional packages that will allow PHP to communicate with Nginx web server issue the below command on your server console: - -``` -$ sudo apt install php7.0 php7.0-fpm -``` - -![](http://www.tecmint.com/wp-content/uploads/2016/05/Install-PHP-7-PHP-FPM-for-Ngin.png) ->Install PHP 7 and PHP-FPM for Ngin - -#### 10. Once the PHP7.0 interpreter has been successfully installed on your machine, start and check php7.0-fpm daemon by issuing the below command: - -``` -$ sudo systemctl start php7.0-fpm -$ sudo systemctl status php7.0-fpm -``` - -![](http://www.tecmint.com/wp-content/uploads/2016/05/Start-Verify-php-fpm-Service.png) ->Start and Verify php-fpm Service - -#### 11. The current configuration file of Nginx is already configured to use PHP FastCGI process manager in order to server dynamic content. - -The server block that enables Nginx to use PHP interpreter is presented on the below excerpt, so no further modifications of default Nginx configuration file are required. - -``` -location ~ \.php$ { - include snippets/fastcgi-php.conf; - fastcgi_pass unix:/run/php/php7.0-fpm.sock; - } -``` - -Below is a screenshot of what instructions you need to uncomment and modify is case of an original Nginx default configuration file. - - -![](http://www.tecmint.com/wp-content/uploads/2016/05/Enable-PHP-FastCGI-for-Nginx.png) ->Enable PHP FastCGI for Nginx - -#### 12. To test Nginx web server relation with PHP FastCGI process manager create a PHP `info.php` test configuration file by issuing the below command and verify the settings by visiting this configuration file using the below address: `http://IP_or domain/info.php`. - -``` -$ sudo su -c 'echo "" |tee /var/www/html/info.php' -``` - -![](http://www.tecmint.com/wp-content/uploads/2016/05/Create-PHP-Info-File.png) ->Create PHP Info File - -![](http://www.tecmint.com/wp-content/uploads/2016/05/Verify-PHP-FastCGI-Info.png) ->Verify PHP FastCGI Info - -Also check if HTTP/2.0 protocol is advertised by the server by locating the line `$_SERVER[‘SERVER_PROTOCOL’]` on PHP Variables block as illustrated on the below screenshot. - -![](http://www.tecmint.com/wp-content/uploads/2016/05/Check-HTTP-2.0-Protocol-Info.png) ->Check HTTP 2.0 Protocol Info - -#### 13. In order to install extra PHP7.0 modules use the `apt search php7.0` command to find a PHP module and install it. - -Also, try to install the following PHP modules which can come in handy in case you are planning to [install WordPress][5] or other CMS. - -``` -$ sudo apt install php7.0-mcrypt php7.0-mbstring -``` - -![](http://www.tecmint.com/wp-content/uploads/2016/05/Install-PHP-7-Modules.png) ->Install PHP 7 Modules - -#### 14. To register the PHP extra modules just restart PHP-FPM daemon by issuing the below command. - -``` -$ sudo systemctl restart php7.0-fpm.service -``` - -### Step 4: Install MariaDB Database - -#### 15. Finally, in order to complete our LEMP stack we need the MariaDB database component to store and manage website data. - -Install MariaDB database management system by running the below command and restart PHP-FPM service in order to use MySQL module to access the database. - -``` -$ sudo apt install mariadb-server mariadb-client php7.0-mysql -$ sudo systemctl restart php7.0-fpm.service -``` - -![](http://www.tecmint.com/wp-content/uploads/2016/05/Install-MariaDB-for-Nginx.png) ->Install MariaDB for Nginx - -#### 16. To secure the MariaDB installation, run the security script provided by the binary package from Ubuntu repositories which will ask you set a root password, remove anonymous users, disable root login remotely and remove test database. - -Run the script by issuing the below command and answer all questions with yes. Use the below screenshot as a guide. - -``` -$ sudo mysql_secure_installation -``` - -![](http://www.tecmint.com/wp-content/uploads/2016/05/Secure-MariaDB-Installation-for-Nginx.png) ->Secure MariaDB Installation for Nginx - -#### 17. To configure MariaDB so that ordinary users can access the database without system sudo privileges, go to MySQL command line interface with root privileges and run the below commands on MySQL interpreter: - -``` -$ sudo mysql -MariaDB> use mysql; -MariaDB> update user set plugin=’‘ where User=’root’; -MariaDB> flush privileges; -MariaDB> exit -``` - -![](http://www.tecmint.com/wp-content/uploads/2016/05/MariaDB-User-Permissions.png) ->MariaDB User Permissions - -Finally, login to MariaDB database and run an arbitrary command without root privileges by executing the below command: - -``` -$ mysql -u root -p -e 'show databases' -``` - -![](http://www.tecmint.com/wp-content/uploads/2016/05/Check-MariaDB-Databases.png) ->Check MariaDB Databases - -That’ all! Now you have a **LEMP** stack configured on **Ubuntu 16.04** server that allows you to deploy complex dynamic web applications that can interact with databases. - --------------------------------------------------------------------------------- - -via: http://www.tecmint.com/install-nginx-mariadb-php7-http2-on-ubuntu-16-04/?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+tecmint+%28Tecmint%3A+Linux+Howto%27s+Guide%29 - -作者：[Matei Cezar ][a] -译者：[译者ID](https://github.com/译者ID) -校对：[校对者ID](https://github.com/校对者ID) - -本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 - -[a]: http://www.tecmint.com/author/cezarmatei/ -[1]: http://www.tecmint.com/installation-of-ubuntu-16-04-server-edition/ -[2]: http://www.tecmint.com/apt-advanced-package-command-examples-in-ubuntu/ -[3]: http://www.tecmint.com/20-netstat-commands-for-linux-network-management/ -[4]: http://www.tecmint.com/manage-services-using-systemd-and-systemctl-in-linux/ -[5]: http://www.tecmint.com/install-wordpress-using-lamp-or-lemp-on-rhel-centos-fedora/ diff --git a/sources/tech/20160531 Writing online multiplayer game with python and asyncio - part 2.md b/sources/tech/20160531 Writing online multiplayer game with python and asyncio - part 2.md new file mode 100644 index 0000000000..75df13d9b5 --- /dev/null +++ b/sources/tech/20160531 Writing online multiplayer game with python and asyncio - part 2.md @@ -0,0 +1,234 @@ +chunyang-wen translating +Writing online multiplayer game with python and asyncio - Part 2 +================================================================== + +![](https://7webpages.com/media/cache/fd/d1/fdd1f8f8bbbf4166de5f715e6ed0ac00.gif) + +Have you ever made an asynchronous Python app? Here I’ll tell you how to do it and in the next part, show it on a [working example][1] - a popular Snake game, designed for multiple players. + +see the intro and theory about how to [Get Asynchronous [part 1]][2] + +[Play the game][3] + +### 3. Writing game loop + +The game loop is a heart of every game. It runs continuously to get player's input, update state of the game and render the result on the screen. In online games the loop is divided into client and server parts, so basically there are two loops which communicate over the network. Usually, client role is to get player's input, such as keypress or mouse movement, pass this data to a server and get back the data to render. The server side is processing all the data coming from players, updating game's state, doing necessary calculations to render next frame and passes back the result, such as new placement of game objects. It is very important not to mix client and server roles without a solid reason. If you start doing game logic calculations on the client side, you can easily go out of sync with other clients, and your game can also be created by simply passing any data from the client side. + +A game loop iteration is often called a tick. Tick is an event meaning that current game loop iteration is over and the data for the next frame(s) is ready. +In the next examples we will use the same client, which connects to a server from a web page using WebSocket. It runs a simple loop which passes pressed keys' codes to the server and displays all messages that come from the server. [Client source code is located here][4]. + +#### Example 3.1: Basic game loop + +[Example 3.1 source code][5] + +We will use [aiohttp][6] library to create a game server. It allows creating web servers and clients based on asyncio. A good thing about this library is that it supports normal http requests and websockets at the same time. So we don't need other web servers to render game's html page. + +Here is how we run the server: + +``` +app = web.Application() +app["sockets"] = [] + +asyncio.ensure_future(game_loop(app)) + +app.router.add_route('GET', '/connect', wshandler) +app.router.add_route('GET', '/', handle) + +web.run_app(app) +``` + +web.run_app is a handy shortcut to create server's main task and to run asyncio event loop with it's run_forever() method. I suggest you check the source code of this method to see how the server is actually created and terminated. + +An app is a dict-like object which can be used to share data between connected clients. We will use it to store a list of connected sockets. This list is then used to send notification messages to all connected clients. A call to asyncio.ensure_future() will schedule our main game_loop task which sends 'tick' message to clients every 2 seconds. This task will run concurrently in the same asyncio event loop along with our web server. + +There are 2 web request handlers: handle just serves a html page and wshandler is our main websocket server's task which handles interaction with game clients. With every connected client a new wshandler task is launched in the event loop. This task adds client's socket to the list, so that game_loop task may send messages to all the clients. Then it echoes every keypress back to the client with a message. + +In the launched tasks we are running worker loops over the main event loop of asyncio. A switch between tasks happens when one of them uses await statement to wait for a coroutine to finish. For instance, asyncio.sleep just passes execution back to a scheduler for a given amount of time, and ws.receive() is waiting for a message from websocket, while the scheduler may switch to some other task. + +After you open the main page in a browser and connect to the server, just try to press some keys. Their codes will be echoed back from the server and every 2 seconds this message will be overwritten by game loop's 'tick' message which is sent to all clients. + +So we have just created a server which is processing client's keypresses, while the main game loop is doing some work in the background and updates all clients periodically. + +#### Example 3.2: Starting game loop by request + +[Example 3.2 source code][7] + +In the previous example a game loop was running continuously all the time during the life of the server. But in practice, there is usually no sense to run game loop when no one is connected. Also, there may be different game "rooms" running on one server. In this concept one player "creates" a game session (a match in a multiplayer game or a raid in MMO for example) so other players may join it. Then a game loop runs while the game session continues. + +In this example we use a global flag to check if a game loop is running, and we start it when the first player connects. In the beginning, a game loop is not running, so the flag is set to False. A game loop is launched from the client's handler: + +``` + if app["game_is_running"] == False: + asyncio.ensure_future(game_loop(app)) +``` + +This flag is then set to True at the start of game loop() and then back to False in the end, when all clients are disconnected. + +#### Example 3.3: Managing tasks + +[Example 3.3 source code][8] + +This example illustrates working with task objects. Instead of storing a flag, we store game loop's task directly in our application's global dict. This may be not an optimal thing to do in a simple case like this, but sometimes you may need to control already launched tasks. +``` + if app["game_loop"] is None or \ + app["game_loop"].cancelled(): + app["game_loop"] = asyncio.ensure_future(game_loop(app)) +``` + +Here ensure_future() returns a task object that we store in a global dict; and when all users disconnect, we cancel it with + +``` + app["game_loop"].cancel() +``` + +This cancel() call tells scheduler not to pass execution to this coroutine anymore and sets its state to cancelled which then can be checked by cancelled() method. And here is one caveat worth to mention: when you have external references to a task object and exception happens in this task, this exception will not be raised. Instead, an exception is set to this task and may be checked by exception() method. Such silent fails are not useful when debugging a code. Thus, you may want to raise all exceptions instead. To do so you need to call result() method of unfinished task explicitly. This can be done in a callback: + +``` + app["game_loop"].add_done_callback(lambda t: t.result()) +``` + +Also if we are going to cancel this task in our code and we don't want to have CancelledError exception, it has a point checking its "cancelled" state: +``` + app["game_loop"].add_done_callback(lambda t: t.result() + if not t.cancelled() else None) +``` + +Note that this is required only if you store a reference to your task objects. In the previous examples all exceptions are raised directly without additional callbacks. + +#### Example 3.4: Waiting for multiple events + +[Example 3.4 source code][9] + +In many cases, you need to wait for multiple events inside client's handler. Beside a message from a client, you may need to wait for different types of things to happen. For instance, if your game's time is limited, you may wait for a signal from timer. Or, you may wait for a message from other process using pipes. Or, for a message from a different server in the network, using a distributed messaging system. + +This example is based on example 3.1 for simplicity. But in this case we use Condition object to synchronize game loop with connected clients. We do not keep a global list of sockets here as we are using sockets only within the handler. When game loop iteration ends, we notify all clients using Condition.notify_all() method. This method allows implementing publish/subscribe pattern within asyncio event loop. + +To wait for two events in the handler, first, we wrap awaitable objects in a task using ensure_future() + +``` + if not recv_task: + recv_task = asyncio.ensure_future(ws.receive()) + if not tick_task: + await tick.acquire() + tick_task = asyncio.ensure_future(tick.wait()) +``` + +Before we can call Condition.wait(), we need to acquire a lock behind it. That is why, we call tick.acquire() first. This lock is then released after calling tick.wait(), so other coroutines may use it too. But when we get a notification, a lock will be acquired again, so we need to release it calling tick.release() after received notification. + +We are using asyncio.wait() coroutine to wait for two tasks. + +``` + done, pending = await asyncio.wait( + [recv_task, + tick_task], + return_when=asyncio.FIRST_COMPLETED) +``` + +It blocks until either of tasks from the list is completed. Then it returns 2 lists: tasks which are done and tasks which are still running. If the task is done, we set it to None so it may be created again on the next iteration. + +#### Example 3.5: Combining with threads + +[Example 3.5 source code][10] + +In this example we combine asyncio loop with threads by running the main game loop in a separate thread. As I mentioned before, it's not possible to perform real parallel execution of python code with threads because of GIL. So it is not a good idea to use other thread to do heavy calculations. However, there is one reason to use threads with asyncio: this is the case when you need to use other libraries which do not support asyncio. Using these libraries in the main thread will simply block execution of the loop, so the only way to use them asynchronously is to run in a different thread. + +We run game loop using run_in_executor() method of asyncio loop and ThreadPoolExecutor. Note that game_loop() is not a coroutine anymore. It is a function that is executed in another thread. However, we need to interact with the main thread to notify clients on the game events. And while asyncio itself is not threadsafe, it has methods which allow running your code from another thread. These are call_soon_threadsafe() for normal functions and run_coroutine_threadsafe() for coroutines. We will put a code which notifies clients about game's tick to notify() coroutine and runs it in the main event loop from another thread. + +``` +def game_loop(asyncio_loop): + print("Game loop thread id {}".format(threading.get_ident())) + async def notify(): + print("Notify thread id {}".format(threading.get_ident())) + await tick.acquire() + tick.notify_all() + tick.release() + + while 1: + task = asyncio.run_coroutine_threadsafe(notify(), asyncio_loop) + # blocking the thread + sleep(1) + # make sure the task has finished + task.result() +``` + +When you launch this example, you will see that "Notify thread id" is equal to "Main thread id", this is because notify() coroutine is executed in the main thread. While sleep(1) call is executed in another thread, and, as a result, it will not block the main event loop. + +#### Example 3.6: Multiple processes and scaling up + +[Example 3.6 source code][11] + +One threaded server may work well, but it is limited to one CPU core. To scale the server beyond one core, we need to run multiple processes containing their own event loops. So we need a way for processes to interact with each other by exchanging messages or sharing game's data. Also in games, it is often required to perform heavy calculations, such as path finding and alike. These tasks are sometimes not possible to complete quickly within one game tick. It is not recommended to perform time-consuming calculations in coroutines, as it will block event processing, so in this case, it may be reasonable to pass the heavy task to other process running in parallel. + +The easiest way to utilize multiple cores is to launch multiple single core servers, like in the previous examples, each on a different port. You can do this with supervisord or similar process-controller system. Then, you may use a load balancer, such as HAProxy, to distribute connecting clients between the processes. There are different ways for processes to interact wich each other. One is to use network-based systems, which allows you to scale to multiple servers as well. There are already existing adapters to use popular messaging and storage systems with asyncio. Here are some examples: + +- [aiomcache][12] for memcached client +- [aiozmq][13] for zeroMQ +- [aioredis][14] for Redis storage and pub/sub + +You can find many other packages like this on github and pypi, most of them have "aio" prefix. + +Using network services may be effective to store persistent data and exchange some kind of messages. But its performance may be not enough if you need to perform real-time data processing that involves inter-process communications. In this case, a more appropriate way may be using standard unix pipes. asyncio has support for pipes and there is a [very low-level example of the server which uses pipes][15] in aiohttp repository. + +In the current example, we will use python's high-level [multiprocessing][16] library to instantiate new process to perform heavy calculations on a different core and to exchange messages with this process using multiprocessing.Queue. Unfortunately, the current implementation of multiprocessing is not compatible with asyncio. So every blocking call will block the event loop. But this is exactly the case where threads will be helpful because if we run multiprocessing code in a different thread, it will not block our main thread. All we need is to put all inter-process communications to another thread. This example illustrates this technique. It is very similar to multi-threading example above, but we create a new process from a thread. + +``` +def game_loop(asyncio_loop): + # coroutine to run in main thread + async def notify(): + await tick.acquire() + tick.notify_all() + tick.release() + + queue = Queue() + + # function to run in a different process + def worker(): + while 1: + print("doing heavy calculation in process {}".format(os.getpid())) + sleep(1) + queue.put("calculation result") + + Process(target=worker).start() + + while 1: + # blocks this thread but not main thread with event loop + result = queue.get() + print("getting {} in process {}".format(result, os.getpid())) + task = asyncio.run_coroutine_threadsafe(notify(), asyncio_loop) + task.result() +``` + +Here we run worker() function in another process. It contains a loop doing heavy calculations and putting results to the queue, which is an instance of multiprocessing.Queue. Then we get the results and notify clients in the main event loop from a different thread, exactly as in the example 3.5. This example is very simplified, it doesn't have a proper termination of the process. Also, in a real game, we would probably use the second queue to pass data to the worker. + +There is a project called [aioprocessing][17], which is a wrapper around multiprocessing that makes it compatible with asyncio. However, it uses exactly the same approach as described in this example - creating processes from threads. It will not give you any advantage, other than hiding these tricks behind a simple interface. Hopefully, in the next versions of Python, we will get a multiprocessing library based on coroutines and supports asyncio. + +>Important! If you are going to run another asyncio event loop in a different thread or sub-process created from main thread/process, you need to create a loop explicitly, using asyncio.new_event_loop(), otherwise, it will not work. + +-------------------------------------------------------------------------------- + +via: https://7webpages.com/blog/writing-online-multiplayer-game-with-python-and-asyncio-writing-game-loop/ + +作者：[Kyrylo Subbotin][a] +译者：[译者ID](https://github.com/译者ID) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://7webpages.com/blog/writing-online-multiplayer-game-with-python-and-asyncio-writing-game-loop/ +[1]: http://snakepit-game.com/ +[2]: https://7webpages.com/blog/writing-online-multiplayer-game-with-python-asyncio-getting-asynchronous/ +[3]: http://snakepit-game.com/ +[4]: https://github.com/7WebPages/snakepit-game/blob/master/simple/index.html +[5]: https://github.com/7WebPages/snakepit-game/blob/master/simple/game_loop_basic.py +[6]: http://aiohttp.readthedocs.org/ +[7]: https://github.com/7WebPages/snakepit-game/blob/master/simple/game_loop_handler.py +[8]: https://github.com/7WebPages/snakepit-game/blob/master/simple/game_loop_global.py +[9]: https://github.com/7WebPages/snakepit-game/blob/master/simple/game_loop_wait.py +[10]: https://github.com/7WebPages/snakepit-game/blob/master/simple/game_loop_thread.py +[11]: https://github.com/7WebPages/snakepit-game/blob/master/simple/game_loop_process.py +[12]: https://github.com/aio-libs/aiomcache +[13]: https://github.com/aio-libs/aiozmq +[14]: https://github.com/aio-libs/aioredis +[15]: https://github.com/KeepSafe/aiohttp/blob/master/examples/mpsrv.py +[16]: https://docs.python.org/3.5/library/multiprocessing.html +[17]: https://github.com/dano/aioprocessing diff --git a/sources/tech/20160602 Web Service Efficiency at Instagram with Python.md b/sources/tech/20160602 Web Service Efficiency at Instagram with Python.md new file mode 100644 index 0000000000..f637331336 --- /dev/null +++ b/sources/tech/20160602 Web Service Efficiency at Instagram with Python.md @@ -0,0 +1,73 @@ +Web Service Efficiency at Instagram with Python +=============================================== + +Instagram currently features the world’s largest deployment of the Django web framework, which is written entirely in Python. We initially chose to use Python because of its reputation for simplicity and practicality, which aligns well with our philosophy of “do the simple thing first.” But simplicity can come with a tradeoff: efficiency. Instagram has doubled in size over the last two years and recently crossed 500 million users, so there is a strong need to maximize web service efficiency so that our platform can continue to scale smoothly. In the past year we’ve made our efficiency program a priority, and over the last six months we’ve been able to maintain our user growth without adding new capacity to our Django tiers. In this post, we’ll share some of the tools we built and how we use them to optimize our daily deployment flow. + +### Why Efficiency? + +Instagram, like all software, is limited by physical constraints like servers and datacenter power. With these constraints in mind, there are two main goals we want to achieve with our efficiency program: + +1. Instagram should be able to serve traffic normally with continuous code rollouts in the case of lost capacity in one data center region, due to natural disaster, regional network issues, etc. +2. Instagram should be able to freely roll out new products and features without being blocked by capacity. + +To meet these goals, we realized we needed to persistently monitor our system and battle regression. + +### Defining Efficiency + +Web services are usually bottlenecked by available CPU time on each server. Efficiency in this context means using the same amount of CPU resources to do more work, a.k.a, processing more user requests per second (RPS). As we look for ways to optimize, our first challenge is trying to quantify our current efficiency. Up to this point, we were approximating efficiency using ‘Average CPU time per requests,’ but there were two inherent limitations to using this metric: + +1. Diversity of devices. Using CPU time for measuring CPU resources is not ideal because it is affected by both CPU models and CPU loads. +2. Request impacts data. Measuring CPU resource per request is not ideal because adding and removing light or heavy requests would also impact the efficiency metric using the per-requests measurement. + +Compared to CPU time, CPU instruction is a better metric, as it reports the same numbers regardless of CPU models and CPU loads for the same request. Instead of linking all our data to each user request, we chose to use a ‘per active user’ metric. We eventually landed on measuring efficiency by using ‘CPU instruction per active user during peak minute.’ With our new metric established, our next step was to learn more about our regressions by profiling Django. + +### Profiling the Django Service + +There are two major questions we want to answer by profiling our Django web service: + +1. Does a CPU regression happen? +2. What causes the CPU regression and how do we fix it? + +To answer the first question, we need to track the CPU-instruction-per-active-user metric. If this metric increases, we know a CPU regression has occurred. + +The tool we built for this purpose is called Dynostats. Dynostats utilizes Django middleware to sample user requests by a certain rate, recording key efficiency and performance metrics such as the total CPU instructions, end to end requests latency, time spent on accessing memcache and database services, etc. On the other hand, each request has multiple metadata that we can use for aggregation, such as the endpoint name, the HTTP return code of the request, the server name that serves this request, and the latest commit hash on the request. Having two aspects for a single request record is especially powerful because we can slice and dice on various dimensions that help us narrow down the cause of any CPU regression. For example, we can aggregate all requests by their endpoint names as shown in the time series chart below, where it is very obvious to spot if any regression happens on a specific endpoint. + +![](https://d262ilb51hltx0.cloudfront.net/max/800/1*3iouYiAchYBwzF-v0bALMw.png) + +CPU instructions matter for measuring efficiency — and they’re also the hardest to get. Python does not have common libraries that support direct access to the CPU hardware counters (CPU hardware counters are the CPU registers that can be programmed to measure performance metrics, such as CPU instructions). Linux kernel, on the other hand, provides the perf_event_open system call. Bridging through Python ctypes enables us to call the syscall function in standard C library, which also provides C compatible data types for programming the hardware counters and reading data from them. + + With Dynostats, we can already find CPU regressions and dig into the cause of the CPU regression, such as which endpoint gets impacted most, who committed the changes that actually cause the CPU regression, etc. However, when a developer is notified that their changes have caused a CPU regression, they usually have a hard time finding the problem. If it was obvious, the regression probably wouldn’t have been committed in the first place! + + That’s why we needed a Python profiler that the developer can use to find the root cause of the regression (once Dynostats identifies it). Instead of starting from scratch, we decided to make slight alterations to cProfile, a readily available Python profiler. The cProfile module normally provides a set of statistics describing how long and how often various parts of a program were executed. Instead of measuring in time, we took cProfile and replaced the timer with a CPU instruction counter that reads from hardware counters. The data is created at the end of the sampled requests and sent to some data pipelines. We also send metadata similar to what we have in Dynostats, such as server name, cluster, region, endpoint name, etc. +On the other side of the data pipeline, we created a tailer to consume the data. The main functionality of the tailer is to parse the cProfile stats data and create entities that represent Python function-level CPU instructions. By doing so, we can aggregate CPU instructions by Python functions, making it easier to tell which functions contribute to CPU regression. + +### Monitoring and Alerting Mechanism + +At Instagram, we [deploy our backend 30–50 times a day][1]. Any one of these deployments can contain troublesome CPU regressions. Since each rollout usually includes at least one diff, it is easy to identify the cause of any regression. Our efficiency monitoring mechanism includes scanning the CPU instruction in Dynostats before and after each rollout, and sending out alerts when the change exceeds a certain threshold. For the CPU regressions happening over longer periods of time, we also have a detector to scan daily and weekly changes for the most heavily loaded endpoints. + + Deploying new changes is not the only thing that can trigger a CPU regression. In many cases, the new features or new code paths are controlled by global environment variables (GEV). There are very common practices for rolling out new features to a subset of users on a planned schedule. We added this information as extra metadata fields for each request in Dynostats and cProfile stats data. Grouping requests by those fields reveal possible CPU regressions caused by turning the GEVs. This enables us to catch CPU regressions before they can impact performance. + +### What’s Next? + +Dynostats and our customized cProfile, along with the monitoring and alerting mechanism we’ve built to support them, can effectively identify the culprit for most CPU regressions. These developments have helped us recover more than 50% of unnecessary CPU regressions, which would have otherwise gone unnoticed. + + There are still areas where we can improve and make it easier to embed into Instagram’s daily deployment flow: + +1. The CPU instruction metric is supposed to be more stable than other metrics like CPU time, but we still observe variances that make our alerting noisy. Keeping signal:noise ratio reasonably low is important so that developers can focus on the real regressions. This could be improved by introducing the concept of confidence intervals and only alarm when it is high. For different endpoints, the threshold of variation could also be set differently. +2. One limitation for detecting CPU regressions by GEV change is that we have to manually enable the logging of those comparisons in Dynostats. As the number of GEVs increases and more features are developed, this wont scale well. Instead, we could leverage an automatic framework that schedules the logging of these comparisons and iterates through all GEVs, and send alerts when regressions are detected. +3. cProfile needs some enhancement to handle wrapper functions and their children functions better. + +With the work we’ve put into building the efficiency framework for Instagram’s web service, we are confident that we will keep scaling our service infrastructure using Python. We’ve also started to invest more into the Python language itself, and are beginning to explore moving our Python from version 2 to 3. We will continue to explore this and more experiments to keep improving both infrastructure and developer efficiency, and look forward to sharing more soon. + +-------------------------------------------------------------------------------- + +via: https://engineering.instagram.com/web-service-efficiency-at-instagram-with-python-4976d078e366#.tiakuoi4p + +作者：[Min Ni][a] +译者：[译者ID](https://github.com/译者ID) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://engineering.instagram.com/@InstagramEng?source=post_header_lockup +[1]: https://engineering.instagram.com/continuous-deployment-at-instagram-1e18548f01d1#.p5adp7kcz diff --git a/sources/tech/20160604 Microfluidic cooling may prevent the demise of Moore's Law.md b/sources/tech/20160604 Microfluidic cooling may prevent the demise of Moore's Law.md new file mode 100644 index 0000000000..0dbd772a31 --- /dev/null +++ b/sources/tech/20160604 Microfluidic cooling may prevent the demise of Moore's Law.md @@ -0,0 +1,68 @@ +Translating by ivo-wang +Microfluidic cooling may prevent the demise of Moore's Law +============================================================ + +![](http://tr1.cbsistatic.com/hub/i/r/2015/12/09/a7cb82d1-96e8-43b5-bfbd-d4593869b230/resize/620x/9607388a284e3a61a39f4399a9202bd7/networkingistock000042544852agsandrew.jpg) +>Image: iStock/agsandrew + +Existing technology's inability to keep microchips cool is fast becoming the number one reason why [Moore's Law][1] may soon meet its demise. + +In the ongoing need for digital speed, scientists and engineers are working hard to squeeze more transistors and support circuitry onto an already-crowded piece of silicon. However, as complex as that seems, it pales in comparison to the [problem of heat buildup][2]. + +"Right now, we're limited in the power we can put into microchips," says John Ditri, principal investigator at Lockheed Martin in [this press release][3]. "One of the biggest challenges is managing the heat. If you can manage the heat, you can use fewer chips, and that means using less material, which results in cost savings as well as reduced system size and weight. If you manage the heat and use the same number of chips, you'll get even greater performance in your system." + +Resistance to the flow of electrons through silicon causes the heat, and packing so many transistors in such a small space creates enough heat to destroy components. One way to eliminate heat buildup is to reduce the flow of electrons by [using photonics at the chip level][4]. However, photonic technology is not without its set of problems. + +SEE: [Silicon photonics will revolutionize data centers in 2015][5] + +### Microfluid cooling might be the answer + +To seek out other solutions, the Defense Advanced Research Projects Agency (DARPA) has initiated a program called [ICECool Applications][6] (Intra/Interchip Enhanced Cooling). "ICECool is exploring disruptive thermal technologies that will mitigate thermal limitations on the operation of military electronic systems while significantly reducing the size, weight, and power consumption," explains the [GSA website FedBizOpps.gov][7]. + +What is unique about this method of cooling is the push to use a combination of intra- and/or inter-chip microfluidic cooling and on-chip thermal interconnects. + +![](http://tr4.cbsistatic.com/hub/i/r/2016/05/25/fd3d0d17-bd86-4d25-a89a-a7050c4d59c4/resize/300x/e9c18034bde66526310c667aac92fbf5/microcooling-1.png) +>MicroCooling 1 Image: DARPA + +The [DARPA ICECool Application announcement][8] notes, "Such miniature intra- and/or inter-chip passages (see right) may take the form of axial micro-channels, radial passages, and/or cross-flow passages, and may involve micro-pores and manifolded structures to distribute and re-direct liquid flow, including in the form of localized liquid jets, in the most favorable manner to meet the specified heat flux and heat density metrics." + +Using the above technology, engineers at Lockheed Martin have experimentally demonstrated how on-chip cooling is a significant improvement. "Phase I of the ICECool program verified the effectiveness of Lockheed's embedded microfluidic cooling approach by showing a four-times reduction in thermal resistance while cooling a thermal demonstration die dissipating 1 kW/cm2 die-level heat flux with multiple local 30 kW/cm2 hot spots," mentions the Lockheed Martin press release. + +In phase II of the Lockheed Martin project, the engineers focused on RF amplifiers. The press release continues, "Utilizing its ICECool technology, the team has been able to demonstrate greater than six times increase in RF output power from a given amplifier while still running cooler than its conventionally cooled counterpart." + +### Moving to production + +Confident of the technology, Lockheed Martin is already designing and building a functional microfluidic cooled transmit antenna. Lockheed Martin is also collaborating with Qorvo to integrate its thermal solution with Qorvo's high-performance [GaN process][9]. + +The authors of the research paper [DARPA's Intra/Interchip Enhanced Cooling (ICECool) Program][10] suggest ICECool Applications will produce a paradigm shift in the thermal management of electronic systems. "ICECool Apps performers will define and demonstrate intra-chip and inter-chip thermal management approaches that are tailored to specific applications and this approach will be consistent with the materials sets, fabrication processes, and operating environment of the intended application." + +If this microfluidic technology is as successful as scientists and engineers suggest, it seems Moore's Law does have a fighting chance. + +For more about networking, subscribe to our Data Centers newsletter. + +[SUBSCRIBE](https://secure.techrepublic.com/user/login/?regSource=newsletter-button&position=newsletter-button&appId=true&redirectUrl=http%3A%2F%2Fwww.techrepublic.com%2Farticle%2Fmicrofluidic-cooling-may-prevent-the-demise-of-moores-law%2F&) + +-------------------------------------------------------------------------------- + +via: http://www.techrepublic.com/article/microfluidic-cooling-may-prevent-the-demise-of-moores-law/ + +作者：[Michael Kassner][a] +译者：[译者ID](https://github.com/译者ID) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: http://www.techrepublic.com/search/?a=michael+kassner +[1]: http://www.intel.com/content/www/us/en/history/museum-gordon-moore-law.html +[2]: https://books.google.com/books?id=mfec2Zw_b7wC&pg=PA154&lpg=PA154&dq=does+heat+destroy+transistors&source=bl&ots=-aNdbMD7FD&sig=XUUiaYG_6rcxHncx4cI4Cqe3t20&hl=en&sa=X&ved=0ahUKEwif4M_Yu_PMAhVL7oMKHW3GC3cQ6AEITTAH#v=onepage&q=does%20heat%20destroy%20transis +[3]: http://www.lockheedmartin.com/us/news/press-releases/2016/march/160308-mst-cool-technology-turns-down-the-heat-on-high-tech-equipment.html +[4]: http://www.techrepublic.com/article/silicon-photonics-will-revolutionize-data-centers-in-2015/ +[5]: http://www.techrepublic.com/article/silicon-photonics-will-revolutionize-data-centers-in-2015/ +[6]: https://www.fbo.gov/index?s=opportunity&mode=form&id=0be99f61fbac0501828a9d3160883b97&tab=core&_cview=1 +[7]: https://www.fbo.gov/index?s=opportunity&mode=form&id=0be99f61fbac0501828a9d3160883b97&tab=core&_cview=1 +[8]: https://www.fbo.gov/index?s=opportunity&mode=form&id=0be99f61fbac0501828a9d3160883b97&tab=core&_cview=1 +[9]: http://electronicdesign.com/communications/what-s-difference-between-gaas-and-gan-rf-power-amplifiers +[10]: http://www.csmantech.org/Digests/2013/papers/050.pdf + + + diff --git a/sources/tech/20160606 Writing online multiplayer game with python and asyncio - part 3.md b/sources/tech/20160606 Writing online multiplayer game with python and asyncio - part 3.md new file mode 100644 index 0000000000..3c38af72ac --- /dev/null +++ b/sources/tech/20160606 Writing online multiplayer game with python and asyncio - part 3.md @@ -0,0 +1,138 @@ +chunyang-wen translating +Writing online multiplayer game with python and asyncio - Part 3 +================================================================= + +![](https://7webpages.com/media/cache/17/81/178135a6db5074c72a1394d31774c658.gif) + +In this series, we are making an asynchronous Python app on the example of a multiplayer [Snake game][1]. The previous article focused on [Writing Game Loop][2] and Part 1 was covering how to [Get Asynchronous][3]. + +You can find the code [here][4]. + +### 4. Making a complete game + +![](https://7webpages.com/static/img/14chs7.gif) + +#### 4.1 Project's overview + +In this part, we will review a design of a complete online game. It is a classic snake game with added multiplayer. You can try it yourself at (). A source code is located [in github repository][5]. The game consists of the following files: + +- [server.py][6] - a server handling main game loop and connections. +- [game.py][7] - a main Game class, which implements game's logic and most of the game's network protocol. +- [player.py][8] - Player class, containing individual player's data and snake's representation. This one is responsible for getting player's input and moving the snake accordingly. +- [datatypes.py][9] - basic data structures. +- [settings.py][10] - game settings, and it has descriptions in commentaries. +- [index.html][11] - all html and javascript client part in one file. + +#### 4.2 Inside a game loop + +Multiplayer snake game is a good example to learn because of its simplicity. All snakes move to one position every single frame, and frames are changing at a very slow rate, allowing you to watch how game engine is working actually. There is no instant reaction to player's keypresses because of the slow speed. A pressed key is remembered and then taken into account while calculating the next frame at the end of game loop's iteration. + +> Modern action games are running at much higher frame rates and often frame rates of server and client are not equal. Client frame rate usually depends on the client hardware performance, while server frame rate is fixed. A client may render several frames after getting the data corresponding to one "game tick". This allows to create smooth animations, which are only limited by client's performance. In this case, a server should pass not only current positions of the objects but also their moving directions, speeds and velocities. And while client frame rate is called FPS (frames per second), sever frame rate is called TPS (ticks per second). In this snake game example both values are equal, and one frame displayed by a client is calculated within one server's tick. + +We will use textmode-like play field, which is, in fact, a html table with one-char cells. All objects of the game are displayed with characters of different colors placed in table's cells. Most of the time client passes pressed keys' codes to the server and gets back play field updates with every "tick". An update from server consists of messages representing characters to render along with their coordinates and colors. So we are keeping all game logic on the server and we are sending to client only rendering data. In addition, we minimize the possibilities to hack the game by substituting its information sent over the network. + +#### 4.3 How does it work? + +The server in this game is close to Example 3.2 for simplicity. But instead of having a global list of connected websockets, we have one server-wide Game object. A Game instance contains a list of Player objects (inside self._players attribute) which represents players connected to this game, their personal data and websocket objects. Having all game-related data in a Game object also allows us to have multiple game rooms if we want to add such feature. In this case, we need to maintain multiple Game objects, one per game started. + +All interactions between server and clients are done with messages encoded in json. Message from the client containing only a number is interpreted as a code of the key pressed by the player. Other messages from client are sent in the following format: + +``` +[command, arg1, arg2, ... argN ] +``` + +Messages from server are sent as a list because there is often a bunch of messages to send at once (rendering data mostly): + +``` +[[command, arg1, arg2, ... argN ], ... ] +``` + +At the end of every game loop iteration, the next frame is calculated and sent to all the clients. Of course, we are not sending complete frame every time, but only a list of changes for the next frame. + +Note that players are not joining the game immediately after connecting to the server. The connection starts in "spectator" mode, so one can watch how others are playing. if the game is already started, or a "game over" screen from the previous game session. Then a player may press "Join" button to join the existing game or to create a new game if the game is not currently running (no other active players). In the later case, the play field is cleared before the start. + +The play field is stored in Game._world attribute, which is a 2d array made of nested lists. It is used to keep game field's state internally. Each element of an array represents a field's cell which is then rendered to a html table cell. It has a type of Char, which is a namedtuple consisting of a character and color. It is important to keep play field in sync with all the connected clients, so all updates to the play field should be made only along with sending corresponding messages to the clients. This is performed by Game.apply_render() method. It receives a list of Draw objects, which is then used to update play field internally and also to send render message to clients. + +We are using namedtuple not only because it is a good way to represent simple data structures, but also because it takes less space comparing to dict when sending in a json message. If you are sending complex data structures in a real game app, it is recommended to serialize them into a plain and shorter format or even pack in a binary format (such as bson instead of json) to minimize network traffic. + +ThePlayer object contains snake's representation in a deque object. This data type is similar to a list but is more effective for adding and removing elements on its sides, so it is ideal to represent a moving snake. The main method of the class is Player.render_move(), it returns rendering data to move player's snake to the next position. Basically, it renders snake's head in the new position and removes the last element where the tail was in the previous frame. In case the snake has eaten a digit and has to grow, a tail is not moving for a corresponding number of frames. The snake rendering data is used in Game.next_frame() method of the main class, which implements all game logic. This method renders all snake moves and checks for obstacles in front of every snake and also spawns digits and "stones". It is called directly from game_loop() to generate the next frame at every "tick". + +In case there is an obstacle in front of snake's head, a Game.game_over() method is called from Game.next_frame(). It notifies all connected clients about the dead snake (which is turned into stones by player.render_game_over() method) and updates top scores table. Player object's alive flag is set to False, so this player will be skipped when rendering the next frames, until joining the game once again. In case there are no more snakes alive, a "game over" message is rendered at the game field. Also, the main game loop will stop and set game.running flag to False, which will cause a game field to be cleared when some player will press "Join" button next time. + +Spawning of digits and stones is also happening while rendering every next frame, and it is determined by random values. A chance to spawn a digit or a stone can be changed in settings.py along with some other values. Note that digit spawning is happening for every live snake in the play field, so the more snakes are there, the more digits will appear, and they all will have enough food to consume. + +#### 4.4 Network protocol +List of messages sent from client + +Command | Parameters |Description +:-- |:-- |:-- +new_player | [name] |Setting player's nickname +join | |Player is joining the game + + +List of messages sent from server + +Command | Parameters |Description +:-- |:-- |:-- +handshake |[id] |Assign id to a player +world |[[(char, color), ...], ...] |Initial play field (world) map +reset_world | |Clean up world map, replacing all characters with spaces +render |[x, y, char, color] |Display character at position +p_joined |[id, name, color, score] |New player joined the game +p_gameover |[id] |Game ended for a player +p_score |[id, score] |Setting score for a player +top_scores |[[name, score, color], ...] |Update top scores table + +Typical messages exchange order + +Client -> Server |Server -> Client |Server -> All clients |Commentaries +:-- |:-- |:-- |:-- +new_player | | |Name passed to server + |handshake | |ID assigned + |world | |Initial world map passed + |top_scores | |Recent top scores table passed +join | | |Player pressed "Join", game loop started + | |reset_world |Command clients to clean up play field + | |render, render, ... |First game tick, first frame rendered +(key code) | | |Player pressed a key + | |render, render, ... |Second frame rendered + | |p_score |Snake has eaten a digit + | |render, render, ... |Third frame rendered + | | |... Repeat for a number of frames ... + | |p_gameover |Snake died when trying to eat an obstacle + | |top_scores |Updated top scores table (if updated) + +### 5. Conclusion + +To tell the truth, I really enjoy using the latest asynchronous capabilities of Python. The new syntax really makes a difference, so async code is now easily readable. It is obvious which calls are non-blocking and when the green thread switching is happening. So now I can claim with confidence that Python is a good tool for asynchronous programming. + +SnakePit has become very popular at 7WebPages team, and if you decide to take a break at your company, please, don’t forget to leave a feedback for us, say, on [Twitter][12] or [Facebook][13] . + +Get to know more from: + + + +-------------------------------------------------------------------------------- + +via: https://7webpages.com/blog/writing-online-multiplayer-game-with-python-and-asyncio-part-3/ + +作者：[Saheetha Shameer][a] +译者：[译者ID](https://github.com/译者ID) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://7webpages.com/blog/writing-online-multiplayer-game-with-python-and-asyncio-part-3/ +[1]: http://snakepit-game.com/ +[2]: https://7webpages.com/blog/writing-online-multiplayer-game-with-python-and-asyncio-writing-game-loop/ +[3]: https://7webpages.com/blog/writing-online-multiplayer-game-with-python-asyncio-getting-asynchronous/ +[4]: https://github.com/7WebPages/snakepit-game +[5]: https://github.com/7WebPages/snakepit-game +[6]: https://github.com/7WebPages/snakepit-game/blob/master/server.py +[7]: https://github.com/7WebPages/snakepit-game/blob/master/game.py +[8]: https://github.com/7WebPages/snakepit-game/blob/master/player.py +[9]: https://github.com/7WebPages/snakepit-game/blob/master/datatypes.py +[10]: https://github.com/7WebPages/snakepit-game/blob/master/settings.py +[11]: https://github.com/7WebPages/snakepit-game/blob/master/index.html +[12]: https://twitter.com/7WebPages +[13]: https://www.facebook.com/7WebPages/ diff --git a/sources/tech/20160608 Implementing Mandatory Access Control with SELinux or AppArmor in Linux.md b/sources/tech/20160608 Implementing Mandatory Access Control with SELinux or AppArmor in Linux.md index 65c8657dff..c4c6aecec6 100644 --- a/sources/tech/20160608 Implementing Mandatory Access Control with SELinux or AppArmor in Linux.md +++ b/sources/tech/20160608 Implementing Mandatory Access Control with SELinux or AppArmor in Linux.md @@ -1,3 +1,5 @@ +alim0x translating + Implementing Mandatory Access Control with SELinux or AppArmor in Linux =========================================================================== diff --git a/sources/tech/20160615 Excel Filter and Edit - Demonstrated in Pandas.md b/sources/tech/20160615 Excel Filter and Edit - Demonstrated in Pandas.md new file mode 100644 index 0000000000..348f66196f --- /dev/null +++ b/sources/tech/20160615 Excel Filter and Edit - Demonstrated in Pandas.md @@ -0,0 +1,327 @@ +Excel “Filter and Edit” - Demonstrated in Pandas +================================================== + +![](http://pbpython.com/images/Boolean-Indexing-Example.png) + +### Introduction + +I have heard from various people that my [previous][1] [articles][2] on common Excel tasks in pandas were useful in helping new pandas users translate Excel processes into equivalent pandas code. This article will continue that tradition by illustrating various pandas indexing examples using Excel’s Filter function as a model for understanding the process. + +One of the first things most new pandas users learn is basic data filtering. Despite working with pandas over the past few months, I recently realized that there was another benefit to the pandas filtering approach that I was not using in my day to day work. Namely that you can filter on a given set of columns but update another set of columns using a simplified pandas syntax. This is similar to what I’ll call the “Filter and Edit” process in Excel. + +This article will walk through some examples of filtering a pandas DataFrame and updating the data based on various criteria. Along the way, I will explain some more about panda’s indexing and how to use indexing methods such as .loc , .ix and .iloc to quickly and easily update a subset of data based on simple or complex criteria. + +### Excel: “Filter and Edit” + +Outside of the Pivot Table, one of the top go-to tools in Excel is the Filter. This simple tool allows a user to quickly filter and sort the data by various numeric, text and formatting criteria. Here is a basic screenshot of some sample data with data filtered by several different criteria: + +![](http://pbpython.com/images/filter-example.png) + +The Filter process is intuitive and is easy to grasp for even the most novice Excel user. I have also noticed that people will use this feature to select rows of data, then update additional columns based on the row criteria. The example below shows what I’m describing: + +![](http://pbpython.com/images/commission-example.png) + +In the example, I have filtered the data on Account Number, SKU and Unit Price. Then I manually added a Commission_Rate column and typed in 0.01 in each cell. The benefit to this approach is that it is easy to understand and can help someone manage relatively complex data without writing long Excel formulas or getting into VBA. The downside of this approach is that it is not repeatable and can be difficult for someone from the outside to understand which criteria were used for any filter. + +For instance, if you look at the screenshot about, there is no obvious way to tell what is filtered without looking at each column. Fortunately, we can do something very similar in pandas. Not surprisingly, it is easy in pandas to execute this “Filter and Edit” model with simple and clean code. + +### Boolean Indexing + +Now that you have a feel for the problem, I want to step through some details of boolean indexing in pandas. This is an important concept to understand if you want to understand pandas’ [Indexing and Selecting of Data][3] in the most broad sense. This idea may seem a little complex to the new pandas user (and maybe too basic for experienced users) but I think it is important to take some time and understand it. If you grasp this concept, the basic process of working with data in pandas will be more straightforward. + +Pandas supports indexing (or selecting data) by using labels, position based integers or a list of boolean values (True/False). Using a list of boolean values to select a row is called boolean indexing and will be the focus of the rest of this article. + +I find that my pandas workflow tends to focus mostly on using lists of boolean values for selecting my data. In other words, when I create pandas DataFrames, I tend to keep the default index in the DataFrame. Therefore the index is not really meaningful on its own and not straightforward for selecting data. + +>Key Point +> Boolean indexing is one (of several) powerful and useful ways of selecting rows of data in pandas. + +Let’s look at some example DataFrames to help clarify the what a boolean index in pandas does. + +First, we will create a very small DataFrame purely from a python list and use it to show how boolean indexing works. + +``` +import pandas as pd +sales = [('account', ['Jones LLC', 'Alpha Co', 'Blue Inc', 'Mega Corp']), + ('Total Sales', [150, 200, 75, 300]), + ('Country', ['US', 'UK', 'US', 'US'])] +df = pd.DataFrame.from_items(sales) +``` + + |account |Total Sales |Country +:--|:-- |:-- |: +0 |Jones LLC |150 |US +1 |Alpha Co |200 |UK +2 |Blue Inc |75 |US +3 |Mega Corp |300 |US + +Notice how the values 0-3, get automatically assigned to the rows? Those are the indices and they are not particularly meaningful in this data set but are useful to pandas and are important to understand for other use cases not described below. + +When we refer to boolean indexing, we simply mean that we can pass in a list of True or False values representing each row we want to view. + +In this case, if we want to view the data for Jones LLC, Blue Inc and Mega Corp, we can see that the True False list would look like this: + +``` +indices = [True, False, True, True] +``` + +It should be no surprise, that you can pass this list to your DataFrame and it will only display the rows where our value is True : + +``` +df[indices] +``` + + |account |Total Sales |Country +:--|:--|:--|:-- +0 |Jones LLC |150 |US +2 |Blue Inc |75 |US +3 |Mega Corp |300 |US + +Here is a visual of what just happened: + +![](http://pbpython.com/images/Boolean-Indexing-Example.png) + +This manual list creation of the index works but obviously is not scaleable or very useful for anything more than a trivial data set. Fortunately pandas makes it very easy to create these boolean indexes using a simple query language that should be familiar to someone that has used python (or any language for that matter). + +For an example, let’s look at all sales lines from the US. If we execute a python expression based on the Country column: + +``` +df.Country == 'US' +``` + +``` +0 True +1 False +2 True +3 True +Name: Country, dtype: bool +``` + +The example shows how pandas will take your traditional python logic, apply it to a DataFrame and return a list of boolean values. This list of boolean values can then be passed to the DataFrame to get the corresponding rows of data. + +In real code, you would not do this two step process. The shorthand method for doing this would typically look like this: + +``` +df[df["Country"] == 'US'] +``` + + |account |Total Sales |Country +:--|:--|:--|:-- +0 |Jones LLC |150| US +2 |Blue Inc |75 |US +3 |Mega Corp| 300| US + +While this concept is simple, you can write fairly complex logic to filter your data using the power of python. + +>Key Point +>In this example, `df[df.Country == 'US']` is equivalent to `df[df["Country"] == 'US']` The ‘.’ notation is cleaner but will not work when there are spaces in your column names. + +### Selecting the Columns + +Now that we have figured out how to select rows of data, how can we control which columns to display? In the example above, there’s no obvious way to do that. Pandas can support this use case using three types of location based indexing: .loc , iloc , and .ix . These functions also allow us to select columns in addition to the row selection we have seen so far. + +There is a lot of confusion about when to use .loc , iloc , or .ix . The quick summary of the difference is that: + +- .loc is used for label indexing +- .iloc is used for position based integers +- .ix is a shortcut that will try to use labels (like .loc ) but will fall back to position based integers (like .iloc ) + +So, the question is, which one should I use? I will profess that I get tripped up some times on this one too. I have found that I use .loc most frequently. Mainly because my data does not lend itself to meaningful position based indexing (in other words, I rarely find myself needing .iloc ) so I stick with .loc . + +To be fair each of these methods do have their place and are useful in many situations. One area in particular is when dealing with MultiIndex DataFrames. I will not cover that topic in this article - maybe in a future post. + +Now that we have covered this topic, let’s show how to filter a DataFrame on values in a row and select specific columns to display. + +Continuing with our example, what if we just want to show the account names that correspond to our index? Using .loc it is simple: + +``` +df.loc[[True, True, False, True], "account"] +``` + +``` +1 Alpha Co +2 Blue Inc +3 Mega Corp +Name: account, dtype: object +``` + +If you would like to see multiple columns, just pass a list: + +``` +df.loc[[True, True, False, True], ["account", "Country"]] +``` + + | account |Country +:--|:--|:-- +0 |Jones LLC| US +1 |Alpha Co |UK +3 |Mega Corp |US + +The real power is when you create more complex queries on your data. In this case, let’s show all account names and Countries where sales > 200: + +``` +df.loc[df["Total Sales"] > 200, ["account", "Country"]] +``` + + |account| Country + :--|:--|:-- +3 |Mega Corp| US + +This process can be thought of somewhat equivalent to Excel’s Filter we discussed above. You have the added benefit that you can also limit the number of columns you retrieve, not just the rows. + +### Editing Columns + +All of this is good background but where this process really shines is when you use a similar approach for updating one or more columns based on a row selection. + +For one simple example, let’s add a commission rate column to our data: + +``` +df["rate"] = 0.02 +``` + + | account |Total Sales| Country |rate +:--|:--|:--|:--|:-- +0 |Jones LLC |150 |US |0.02 +1 |Alpha Co |200 |UK |0.02 +2 |Blue Inc |75 |US |0.02 +3 |Mega Corp |300 |US |0.02 + +Let’s say that if you sold more than 100, your rate is 5%. The basic process is to setup a boolean index to select the columns, then assign the value to the rate column: + +``` +df.loc[df["Total Sales"] > 100, ["rate"]] = .05 +``` + + | account |Total Sales| Country| rate +:--|:--|:--|:--|:-- +0 |Jones LLC |150| US| 0.05 +1 |Alpha Co |200 |UK |0.05 +2| Blue Inc |75| US |0.02 +3 |Mega Corp |300| US| 0.05 + +Hopefully if you stepped through this article, this will make sense and that it will help you understand how this syntax works. Now you have the fundamentals of the “Filter and Edit” approach. The final section will show this process in a little more detail in Excel and pandas. + +### Bringing It All Together + +For the final example, we will create a simple commissions calculator using the following rules: + +- All commissions calculated at the transaction level +- Base commission on all sales is 2% +- All shirts will get a commission of 2.5% +- A special program is going on where selling > 10 belts in one transaction gets 4% commission +- There is a special bonus of $250 plus a 4.5% commission for all shoe sales > $1000 in a single transaction + +In order to do this in Excel, using the Filter and edit approach: + +- Add a commission column with 2% +- Add a bonus column of $0 +- Filter on shirts and change the vale to 2.5% +- Clear the filter +- Filter for belts and quantity > 10 and change the value to 4% +- Clear the filter +- Filter for shoes > $1000 and add commission and bonus values of 4.5% and $250 respectively + +I am not going to show a screen shot of each step but here is the last filter: + +![](http://pbpython.com/images/filter-2.png) + +This approach is simple enough to manipulate in Excel but it is not very repeatable nor audit-able. There are certainly other approaches to accomplish this in Excel - such as formulas or VBA. However, this Filter and Edit approach is common and is illustrative of the pandas logic. + +Now, let’s walk through the whole example in pandas. + +First, read in the [Excel file][4] and add a column with the 2% default rate: + +``` +import pandas as pd +df = pd.read_excel("https://github.com/chris1610/pbpython/blob/master/data/sample-sales-reps.xlsx?raw=true") +df["commission"] = .02 +df.head() +``` + + | account number| customer name| sales rep| sku |category |quantity |unit price| ext price| date| commission +:--|:--|:--|:--|:--|:--|:--|:--|:--|:--|:--|:-- +0 |680916 |Mueller and Sons |Loring Predovic |GP-14407 | Belt |19 |88.49 |1681.31 |2015-11-17 05:58:34| 0.02 +1 |680916 |Mueller and Sons |Loring Predovic |FI-01804| Shirt |3| 78.07| 234.21 |2016-02-13 04:04:11 |0.02 +2 |530925 |Purdy and Sons| Teagan O’Keefe |EO-54210 |Shirt |19 |30.21 |573.99 |2015-08-11 12:44:38 |0.02 +3 |14406| Harber, Lubowitz and Fahey| Esequiel Schinner| NZ-99565| Shirt| 12| 90.29 |1083.48 |2016-01-23 02:15:50 |0.02 +4 |398620| Brekke Ltd |Esequiel Schinner |NZ-99565 |Shirt |5| 72.64 |363.20 |2015-08-10 07:16:03 |0.02 + +The next commission rule is for all shirts to get 2.5% and Belt sales > 10 get a 4% rate: + +``` +df.loc[df["category"] == "Shirt", ["commission"]] = .025 +df.loc[(df["category"] == "Belt") & (df["quantity"] >= 10), ["commission"]] = .04 +df.head() +``` + +| account number |customer name |sales rep| sku |category |quantity| unit price| ext price |date |commission + :--|:--|:--|:--|:--|:--|:--|:--|:--|:--|:--|:-- +0 |680916| Mueller and Sons| Loring Predovic| GP-14407| Belt| 19 |88.49| 1681.31 |2015-11-17 05:58:34| 0.040 +1 |680916| Mueller and Sons| Loring Predovic| FI-01804| Shirt |3 |78.07 |234.21| 2016-02-13 04:04:11 |0.025 +2 |530925 |Purdy and Sons |Teagan O’Keefe| EO-54210 |Shirt| 19 |30.21 |573.99 |2015-08-11 12:44:38| 0.025 +3 |14406| Harber, Lubowitz and Fahey| Esequiel Schinner| NZ-99565| Shirt| 12| 90.29| 1083.48| 2016-01-23 02:15:50 |0.025 +4 |398620| Brekke Ltd| Esequiel Schinner| NZ-99565| Shirt| 5 |72.64 |363.20| 2015-08-10 07:16:03 |0.025 + +The final commission rule is to add the special bonus: + +``` +df["bonus"] = 0 +df.loc[(df["category"] == "Shoes") & (df["ext price"] >= 1000 ), ["bonus", "commission"]] = 250, 0.045 + +# Display a sample of rows that show this bonus +df.ix[3:7] +``` + +| account number| customer name |sales rep| sku |category| quantity| unit price| ext price| date| commission| bonus + :--|:--|:--|:--|:--|:--|:--|:--|:--|:--|:--|:--|:-- +3| 14406| Harber, Lubowitz and Fahey| Esequiel Schinner| NZ-99565| Shirt |12 |90.29| 1083.48 |2016-01-23 02:15:50 |0.025 |0 +4| 398620| Brekke Ltd| Esequiel Schinner |NZ-99565| Shirt| 5| 72.64| 363.20| 2015-08-10 07:16:03| 0.025| 0 +5| 282122| Connelly, Abshire and Von Beth| Skiles| GJ-90272| Shoes| 20| 96.62| 1932.40 |2016-03-17 10:19:05 |0.045 |250 +6 |398620 |Brekke Ltd| Esequiel Schinner |DU-87462 |Shirt| 10| 67.64 |676.40| 2015-11-25 22:05:36| 0.025| 0 +7| 218667| Jaskolski-O’Hara| Trish Deckow| DU-87462| Shirt |11| 91.86| 1010.46 |2016-04-24 15:05:58| 0.025| 0 + +In order to do the commissions calculation: + +``` +# Calculate the compensation for each row +df["comp"] = df["commission"] * df["ext price"] + df["bonus"] + +# Summarize and round the results by sales rep +df.groupby(["sales rep"])["comp"].sum().round(2) +``` + +``` +sales rep +Ansley Cummings 2169.76 +Beth Skiles 3028.60 +Esequiel Schinner 10451.21 +Loring Predovic 10108.60 +Shannen Hudson 5275.66 +Teagan O'Keefe 7989.52 +Trish Deckow 5807.74 +Name: comp, dtype: float64 +``` + +If you are interested, an example notebook is hosted on [github][5]. + +### Conclusion + +Thanks for reading through the article. I find that one of the biggest challenges for new users in learning how to use pandas is figuring out how to use their Excel-based knowledge to build an equivalent pandas-based solution. In many cases the pandas solution is going to be more robust, faster, easier to audit and more powerful. However, the learning curve can take some time. I hope that this example showing how to solve a problem using Excel’s Filter tool will be a useful guide for those just starting on this pandas journey. Good luck! + +-------------------------------------------------------------------------------- + +via: http://pbpython.com/excel-filter-edit.html + +作者：[Chris Moffitt ][a] +译者：[译者ID](https://github.com/译者ID) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创翻译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: http://pbpython.com/author/chris-moffitt.html +[1]: http://pbpython.com/excel-pandas-comp.html +[2]: http://pbpython.com/excel-pandas-comp-2.html +[3]: http://pandas.pydata.org/pandas-docs/stable/indexing.html +[4]: https://github.com/chris1610/pbpython/blob/master/data/sample-sales-reps.xlsx?raw=true +[5]: https://github.com/chris1610/pbpython/blob/master/notebooks/Commissions-Example.ipynb + diff --git a/sources/tech/20160616 6 Amazing Linux Distributions For Kids.md b/sources/tech/20160616 6 Amazing Linux Distributions For Kids.md deleted file mode 100644 index 4d6ecdfd8f..0000000000 --- a/sources/tech/20160616 6 Amazing Linux Distributions For Kids.md +++ /dev/null @@ -1,115 +0,0 @@ -[HaohongWANG Translating] -6 Amazing Linux Distributions For Kids -====================================== - -Linux and open source is the future and there is no doubt about that, and to see this come to a reality, a strong foundation has to be lied, by starting from the lowest level possible and that is exposing kids to Linux and teaching them how to use Linux operating systems. - -![](http://www.tecmint.com/wp-content/uploads/2016/05/Linux-Distros-For-Kids.png) ->Linux Distros For Kids - -Linux is a very powerful operating system and that is one of the reasons why it powers a lot of servers on the Internet. Though there have been concerns about its user friendliness which has brought about debate of how it will over take Mac OSX and Windows on desktop computers, I think users need to accept Linux as it is to realize its real power. - -Today, Linux powers a lot of machines out there, from mobile phones, to tablets, laptops, workstations, servers, supercomputers, cars, air traffic control systems, refrigerators and many more. With all this and more yet to come in the near future, as I had already stated at the beginning, Linux is the operating system for future computing. - ->Read Also: [30 Big Companies and Devices Running on Linux][1] - -Because the future belongs to the kids of today, then introducing them to technologies that will change the future is the way to go. Therefore they have to be introduced at an early stage to start learning computer technologies and Linux as a special case. - -One thing common to children is curiosity and early learning can help instill the a character of exploration in them when the learning environment is designed to suit them. - -Having looked some quick reasons why kids should learn Linux, let us now go through a list of exciting Linux distributions that you can introduce your kids to, so that they can start using and learning Linux. - -### Sugar on a Stick - -It is a project by Sugar Labs that aims at designing free tools to support learning among children by making them gain skills in exploring, discovering, creating and also reflecting on ideas. It is a non-profit organization led by volunteers. - -![](http://www.tecmint.com/wp-content/uploads/2016/05/Sugar-Neighborhood-View.png) ->Sugar Neighborhood View - -![](http://www.tecmint.com/wp-content/uploads/2016/05/Sugar-Activity-Library.png) ->Sugar Activity Library - -You can think of sugar as both a desktop and a collection of learning activities that help encourage active involvement from children who are learning. - -Visit Homepage: - -### Edubuntu - -This is a grassroots project that is based on the most popular Linux distribution today, Ubuntu. It is intended get schools, homes and communities to easily install and use free Ubuntu software. - -![](http://www.tecmint.com/wp-content/uploads/2016/05/Edubuntu-Apps.jpg) ->Edubuntu Desktop Apps - -It is supported by different groups of students, teachers, parents, stake holders and also hackers who believe in free learning and sharing of knowledge for self improvement and also community based development. - -The main aim of the project is to assemble a system that can offer free software to enhance learning and education by making it easy for users to install and also maintain software. - -Visit Homepage: - -### Doudou Linux - -It is designed specifically for children to experience ease in using a computer while building creative thinking in them. It provides simple yet educative applications that allows kids to learn and discover new ideas while using it. - -![](http://www.tecmint.com/wp-content/uploads/2016/05/Doudou-Linux.png) ->Doudou Linux - -One important thing about Doudou Linux is its content filtering feature, which prevents children from visiting restricted content on the web. For more kids protection, it also includes user privacy on the Internet, automatically removes adds from web pages and many more. - -Visit Homepage: - -### LinuxKidX - -It is a LiveCD based on Slackware Linux with a long list of educational software for kids to learn form. It uses KDE as the default Desktop Environment and includes software such as Ktouch a typing tutor, Kstars as virtual planetaruim, Kalzium a periodic table, KwordQuiz among others. - -![](http://www.tecmint.com/wp-content/uploads/2016/05/LinuxKidX.jpg) ->LinuxKidX - -Visit Homepage: - -### Ubermix - -It is a free software that is built from the ground based on Ubuntu Linux and is intended for educational purposes. It comes with over 60 free software reinstalled and helps to make learning and teaching easy for students and teachers respectively. - -![](http://www.tecmint.com/wp-content/uploads/2016/05/ubermix.png) ->Ubermix Linux - -Some of its features include 5 minutes installation and also few seconds quick recovery mechanism. It should work well well for teenage children. - -Visit Homepage: - -### Qimo - -I have added this to list because many readers are expected to ask about Qimo, but as of this writing, the Qimo for kids development team has retired from the project, therefore no more development it expected. - -![](http://www.tecmint.com/wp-content/uploads/2016/05/Qimo-Linux.png) ->Qimo Linux - -But you can still find most of the games for kids in Ubuntu and other Linux distributions. As they have mentioned, they are not done working on an educational software for kids and are developing an android application for children to improve their literacy skills. - -You can read more from their official website and expect more from them in the future. - -Visit Homepage: - -That is it for now, in case there are more Linux operating systems intended for kids or children out there, which I have not included in this list, you can let us know by leaving a comment. - -You can also let us know of what you think of introducing kids to Linux and the future of Linux especially on Desktop computers. - --------------------------------------------------------------------------------- - -via: http://www.tecmint.com/best-linux-distributions-for-kids/?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+tecmint+%28Tecmint%3A+Linux+Howto%27s+Guide%29 - - -作者：[Aaron Kili][a] -译者：[译者ID](https://github.com/译者ID) -校对：[校对者ID](https://github.com/校对者ID) - -本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 - -[a]: http://www.tecmint.com/author/aaronkili/ - -[1]: http://www.tecmint.com/big-companies-and-devices-running-on-gnulinux/ - - - - - diff --git a/sources/tech/20160616 Part 1 - Scientific Audio Processing How to read and write Audio files with Octave 4.0.0 on Ubuntu.md b/sources/tech/20160616 Part 1 - Scientific Audio Processing How to read and write Audio files with Octave 4.0.0 on Ubuntu.md new file mode 100644 index 0000000000..f35e0724a6 --- /dev/null +++ b/sources/tech/20160616 Part 1 - Scientific Audio Processing How to read and write Audio files with Octave 4.0.0 on Ubuntu.md @@ -0,0 +1,142 @@ +vim-kakali translating + + + +Scientific Audio Processing, Part I - How to read and write Audio files with Octave 4.0.0 on Ubuntu +================ + +Octave, the equivalent software to Matlab in Linux, has a number of functions and commands that allow the acquisition, recording, playback and digital processing of audio signals for entertainment applications, research, medical, or any other science areas. In this tutorial, we will use Octave V4.0.0 in Ubuntu and will start reading from audio files through writing and playing signals to emulate sounds used in a wide range of activities. + +Note that the main focus of this tutorial is not to install or learn to use an audio processing software already established, but rather to understand how it works from the point of view of design and audio engineering. + +### Prerequisites + +The first step is to install octave. Run the following commands in a terminal to add the Octave PPA in Ubuntu and install the software. + +``` +sudo apt-add-repository ppa:octave/stable +sudo apt-get update +sudo apt-get install octave +``` + +### Step 1: Opening Octave. + +In this step we open the software by clicking on its icon, we can change the work directory by clicking on the File Browser dropdown. + +![](https://www.howtoforge.com/images/how-to-read-and-write-audio-files-with-octave-4-in-ubuntu/initial.png) + +### Step 2: Audio Info + +The command "audioinfo" shows us relevant information about the audio file that we will process. + +``` +>> info = audioinfo ('testing.ogg') +``` + +![](https://www.howtoforge.com/images/how-to-read-and-write-audio-files-with-octave-4-in-ubuntu/audioinfo.png) + +### Step 3: Reading an audio File + +In this tutorial I will read and use ogg files for which it is feasible to read characteristics like sampling , audio type (stereo or mono), number of channels, etc. I should mention that for purposes of this tutorial, all the commands used will be executed in the terminal window of Octave. First, we have to save the ogg file in a variable. Note: it´s important that the file must be in the work path of Octave + +``` +>> file='yourfile.ogg' +``` + +``` +>> [M, fs] = audioread(file) +``` + +Where M is a matrix of one or two columns, depending on the number of channels and fs is the sampling frequency. + +![](https://www.howtoforge.com/images/how-to-read-and-write-audio-files-with-octave-4-in-ubuntu/reading.png) + +![](https://www.howtoforge.com/images/how-to-read-and-write-audio-files-with-octave-4-in-ubuntu/matrix.png) + +![](https://www.howtoforge.com/images/how-to-read-and-write-audio-files-with-octave-4-in-ubuntu/big/frequency.png) + +There are some options that we can use for reading audio files, such as: + +``` +>> [y, fs] = audioread (filename, samples) + +>> [y, fs] = audioread (filename, datatype) + +>> [y, fs] = audioread (filename, samples, datatype) +``` + +Where samples specifies starting and ending frames and datatype specifies the data type to return. We can assign values to any variable: + +``` +>> samples = [1, fs) + +>> [y, fs] = audioread (filename, samples) +``` + +And about datatype: + +``` +>> [y,Fs] = audioread(filename,'native') +``` + +If the value is 'native' then the type of data depends on how the data is stored in the audio file. + +### Step 4: Writing an audio file + +Creating the ogg file: + +For this purpose, we are going to generate an ogg file with values from a cosine. The sampling frequency that I will use is 44100 samples per second and the file will last for 10 seconds. The frequency of the cosine signal is 440 Hz. + +``` +>> filename='cosine.ogg'; +>> fs=44100; +>> t=0:1/fs:10; +>> w=2*pi*440*t; +>> signal=cos(w); +>> audiowrite(filename, signal, fs); +``` + +This creates a file named 'cosine.ogg' in our workspace that contains the cosine signal. + +![](https://www.howtoforge.com/images/how-to-read-and-write-audio-files-with-octave-4-in-ubuntu/cosinefile.png) + +If we play the 'cosine.ogg' file then this will reproduce a 440Hz tone which is equivalent to an 'A' musical tone. If we want to see the values saved in the file we have to 'read' the file with the 'audioread' function. In a further tutorial, we will see how to write an audio file with two channels. + +### Step 5: Playing an audio file + +Octave, by default, has an audio player that we can use for testing purposes. Use the following functions as example: + +``` + >> [y,fs]=audioread('yourfile.ogg'); +>> player=audioplayer(y, fs, 8) + + scalar structure containing the fields: + + BitsPerSample = 8 + CurrentSample = 0 + DeviceID = -1 + NumberOfChannels = 1 + Running = off + SampleRate = 44100 + TotalSamples = 236473 + Tag = + Type = audioplayer + UserData = [](0x0) +>> play(player); +``` + +In the next parts of the tutorial, we will see advanced audio processing features and possible use cases for scientific and commercial use. + +-------------------------------------------------------------------------------- + +via: https://www.howtoforge.com/tutorial/how-to-read-and-write-audio-files-with-octave-4-in-ubuntu/ + +作者：[David Duarte][a] +译者：[译者ID](https://github.com/译者ID) +校对：[校对ID](https://github.com/校对ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://twitter.com/intent/follow?original_referer=https%3A%2F%2Fwww.howtoforge.com%2Ftutorial%2Fhow-to-read-and-write-audio-files-with-octave-4-in-ubuntu%2F&ref_src=twsrc%5Etfw®ion=follow_link&screen_name=howtoforgecom&tw_p=followbutton + + diff --git a/sources/tech/20160618 An Introduction to Mocking in Python.md b/sources/tech/20160618 An Introduction to Mocking in Python.md new file mode 100644 index 0000000000..d28fae272d --- /dev/null +++ b/sources/tech/20160618 An Introduction to Mocking in Python.md @@ -0,0 +1,493 @@ +Mock 在 Python 中的使用介绍 +===================================== +http://www.oschina.net/translate/an-introduction-to-mocking-in-python?cmp +本文讲述的是 Python 中 Mock 的使用 + +**如何在避免测试你的耐心的情景下执行单元测试** + +通常，我们编写的软件会直接与我们称之为肮脏无比的服务交互。用外行人的话说：交互已设计好的服务对我们的应用程序很重要，但是这会带来我们不希望的副作用，也就是那些在我们自己测试的时候不希望的功能。例如：我们正在写一个社交 app，并且想要测试一下我们 "发布到 Facebook" 的新功能，但是不想每次运行测试集的时候真的发布到 Facebook。 + + +Python 的单元测试库包含了一个名为 unittest.mock 或者可以称之为依赖的子包，简言之为 mock——其提供了极其强大和有用的方法，通过它们可以模拟和打桩我们不希望的副作用。 + + +>Source | + +注意：mock [最近收录][1]到了 Python 3.3 的标准库中；先前发布的版本必须通过 [PyPI][2] 下载 Mock 库。 + +### +### Fear System Calls + +再举另一个例子，思考一个我们会在余文讨论的系统调用。不难发现，这些系统调用都是主要的模拟对象：无论你是正在写一个可以弹出 CD 驱动的脚本，还是一个用来删除 /tmp 下过期的缓存文件的 Web 服务，这些调用都是在你的单元测试上下文中不希望的副作用。 + +> 作为一个开发者，你需要更关心你的库是否成功地调用了一个可以弹出 CD 的系统函数，而不是切身经历 CD 托盘每次在测试执行的时候都打开了。 + +作为一个开发者，你需要更关心你的库是否成功地调用了一个可以弹出 CD 的系统函数（使用了正确的参数等等），而不是切身经历 CD 托盘每次在测试执行的时候都打开了。（或者更糟糕的是，很多次，在一个单元测试运行期间多个测试都引用了弹出代码！） + +同样，保持你的单元测试的效率和性能意味着需要让如此多的 "缓慢代码" 远离自动测试，比如文件系统和网络访问。 + +对于我们首个例子，我们要从原始形式到使用 mock 地重构一个标准 Python 测试用例。我们会演示如何使用 mock 写一个测试用例使我们的测试更加智能、快速，并且能展示更多关于我们软件的工作原理。 + +### 一个简单的删除函数 + +有时，我们都需要从文件系统中删除文件，因此，让我们在 Python 中写一个可以使我们的脚本更加轻易完成此功能的函数。 + +``` +#!/usr/bin/env python +# -*- coding: utf-8 -*- + +import os + +def rm(filename): + os.remove(filename) +``` + +很明显，我们的 rm 方法此时无法提供比相关 os.remove 方法更多的功能，但我们的基础代码会逐步改善，允许我们在这里添加更多的功能。 + +让我们写一个传统的测试用例，即，没有使用 mock： + +``` +#!/usr/bin/env python +# -*- coding: utf-8 -*- + +from mymodule import rm + +import os.path +import tempfile +import unittest + +class RmTestCase(unittest.TestCase): + + tmpfilepath = os.path.join(tempfile.gettempdir(), "tmp-testfile") + + def setUp(self): + with open(self.tmpfilepath, "wb") as f: + f.write("Delete me!") + + def test_rm(self): + # remove the file + rm(self.tmpfilepath) + # test that it was actually removed + self.assertFalse(os.path.isfile(self.tmpfilepath), "Failed to remove the file.") +``` + +我们的测试用例相当简单，但是当它每次运行的时候，它都会创建一个临时文件并且随后删除。此外，我们没有办法测试我们的 rm 方法是否正确地将我们的参数向下传递给 os.remove 调用。我们可以基于以上的测试认为它做到了，但还有很多需要改进的地方。 + +### 使用 Mock 重构 + +让我们使用 mock 重构我们的测试用例： + +``` +#!/usr/bin/env python +# -*- coding: utf-8 -*- + +from mymodule import rm + +import mock +import unittest + +class RmTestCase(unittest.TestCase): + + @mock.patch('mymodule.os') + def test_rm(self, mock_os): + rm("any path") + # test that rm called os.remove with the right parameters + mock_os.remove.assert_called_with("any path") +``` + +使用这些重构，我们从根本上改变了该测试用例的运行方式。现在，我们有一个可以用于验证其他功能的内部对象。 + +### 潜在陷阱 + +第一件需要注意的事情就是，我们使用了位于 mymodule.os 且用于模拟对象的 mock.patch 方法装饰器，并且将该 mock 注入到我们的测试用例方法。相比在 mymodule.os 引用它，那么只是模拟 os 本身，会不会更有意义呢？ +One of the first things that should stick out is that we’re using the mock.patch method decorator to mock an object located at mymodule.os, and injecting that mock into our test case method. Wouldn’t it make more sense to just mock os itself, rather than the reference to it at mymodule.os? + +当然，当涉及到导入和管理模块，Python 的用法非常灵活。在运行时，mymodule 模块拥有被导入到本模块局部作用域的 os。因此，如果我们模拟 os，我们是看不到模拟在 mymodule 模块中的作用的。 + +这句话需要深刻地记住： + +> 模拟测试一个项目，只需要了解它用在哪里，而不是它从哪里来。 +> Mock an item where it is used, not where it came from. + +如果你需要为 myproject.app.MyElaborateClass 模拟 tempfile 模块，你可能需要 +If you need to mock the tempfile module for myproject.app.MyElaborateClass, you probably need to apply the mock to myproject.app.tempfile, as each module keeps its own imports. + +先将那个陷阱置身事外，让我们继续模拟。 +With that pitfall out of the way, let’s keep mocking. + +### 向 ‘rm’ 中加入验证 + +之前定义的 rm 方法相当的简单。在盲目地删除之前，我们倾向于拿它来验证一个路径是否存在，并验证其是否是一个文件。让我们重构 rm 使其变得更加智能: + + +``` +#!/usr/bin/env python +# -*- coding: utf-8 -*- + +import os +import os.path + +def rm(filename): + if os.path.isfile(filename): + os.remove(filename) +``` + +很好。现在，让我们调整测试用例来保持测试的覆盖程度。 + +``` +#!/usr/bin/env python +# -*- coding: utf-8 -*- + +from mymodule import rm + +import mock +import unittest + +class RmTestCase(unittest.TestCase): + + @mock.patch('mymodule.os.path') + @mock.patch('mymodule.os') + def test_rm(self, mock_os, mock_path): + # set up the mock + mock_path.isfile.return_value = False + + rm("any path") + + # test that the remove call was NOT called. + self.assertFalse(mock_os.remove.called, "Failed to not remove the file if not present.") + + # make the file 'exist' + mock_path.isfile.return_value = True + + rm("any path") + + mock_os.remove.assert_called_with("any path") +``` + +我们的测试用例完全改变了。现在我们可以在没有任何副作用下核实并验证方法的内部功能。 + +### 将文件删除作为服务 + +到目前为止，我们只是对函数功能提供模拟测试，并没对需要传递参数的对象和实例的方法进行模拟测试。接下来我们将介绍如何对对象的方法进行模拟测试。 + +首先，我们将rm方法重构成一个服务类。实际上将这样一个简单的函数转换成一个对象，在本质上，这不是一个合理的需求，但它能够帮助我们了解mock的关键概念。让我们开始重构: + +``` +#!/usr/bin/env python +# -*- coding: utf-8 -*- + +import os +import os.path + +class RemovalService(object): + """A service for removing objects from the filesystem.""" + + def rm(filename): + if os.path.isfile(filename): + os.remove(filename) +``` + +### 你会注意到我们的测试用例没有太大的变化 +### You’ll notice that not much has changed in our test case: + +``` +#!/usr/bin/env python +# -*- coding: utf-8 -*- + +from mymodule import RemovalService + +import mock +import unittest + +class RemovalServiceTestCase(unittest.TestCase): + + @mock.patch('mymodule.os.path') + @mock.patch('mymodule.os') + def test_rm(self, mock_os, mock_path): + # instantiate our service + reference = RemovalService() + + # set up the mock + mock_path.isfile.return_value = False + + reference.rm("any path") + + # test that the remove call was NOT called. + self.assertFalse(mock_os.remove.called, "Failed to not remove the file if not present.") + + # make the file 'exist' + mock_path.isfile.return_value = True + + reference.rm("any path") + + mock_os.remove.assert_called_with("any path") +``` + +很好，我们知道 RemovalService 会如期工作。接下来让我们创建另一个服务，将其声明为一个依赖 +Great, so we now know that the RemovalService works as planned. Let’s create another service which declares it as a dependency: + +``` +#!/usr/bin/env python +# -*- coding: utf-8 -*- + +import os +import os.path + +class RemovalService(object): + """A service for removing objects from the filesystem.""" + + def rm(self, filename): + if os.path.isfile(filename): + os.remove(filename) + + +class UploadService(object): + + def __init__(self, removal_service): + self.removal_service = removal_service + + def upload_complete(self, filename): + self.removal_service.rm(filename) +``` + +Since we already have test coverage on the RemovalService, we’re not going to validate internal functionality of the rm method in our tests of UploadService. Rather, we’ll simply test (without side-effects, of course) that UploadService calls the RemovalService.rm method, which we know “just works™” from our previous test case. + +There are two ways to go about this: + +1. Mock out the RemovalService.rm method itself. +2. Supply a mocked instance in the constructor of UploadService. + +As both methods are often important in unit-testing, we’ll review both. + +### Option 1: Mocking Instance Methods + +The mock library has a special method decorator for mocking object instance methods and properties, the @mock.patch.object decorator: + +``` +#!/usr/bin/env python +# -*- coding: utf-8 -*- + +from mymodule import RemovalService, UploadService + +import mock +import unittest + +class RemovalServiceTestCase(unittest.TestCase): + + @mock.patch('mymodule.os.path') + @mock.patch('mymodule.os') + def test_rm(self, mock_os, mock_path): + # instantiate our service + reference = RemovalService() + + # set up the mock + mock_path.isfile.return_value = False + + reference.rm("any path") + + # test that the remove call was NOT called. + self.assertFalse(mock_os.remove.called, "Failed to not remove the file if not present.") + + # make the file 'exist' + mock_path.isfile.return_value = True + + reference.rm("any path") + + mock_os.remove.assert_called_with("any path") + + +class UploadServiceTestCase(unittest.TestCase): + + @mock.patch.object(RemovalService, 'rm') + def test_upload_complete(self, mock_rm): + # build our dependencies + removal_service = RemovalService() + reference = UploadService(removal_service) + + # call upload_complete, which should, in turn, call `rm`: + reference.upload_complete("my uploaded file") + + # check that it called the rm method of any RemovalService + mock_rm.assert_called_with("my uploaded file") + + # check that it called the rm method of _our_ removal_service + removal_service.rm.assert_called_with("my uploaded file") +``` + +Great! We’ve validated that the UploadService successfully calls our instance’s rm method. Notice anything interesting in there? The patching mechanism actually replaced the rm method of all RemovalService instances in our test method. That means that we can actually inspect the instances themselves. If you want to see more, try dropping in a breakpoint in your mocking code to get a good feel for how the patching mechanism works. + +### Pitfall: Decorator Order + +When using multiple decorators on your test methods, order is important, and it’s kind of confusing. Basically, when mapping decorators to method parameters, [work backwards][3]. Consider this example: + +``` +@mock.patch('mymodule.sys') + @mock.patch('mymodule.os') + @mock.patch('mymodule.os.path') + def test_something(self, mock_os_path, mock_os, mock_sys): + pass +``` + +Notice how our parameters are matched to the reverse order of the decorators? That’s partly because of [the way that Python works][4]. With multiple method decorators, here’s the order of execution in pseudocode: + +``` +patch_sys(patch_os(patch_os_path(test_something))) +``` + +Since the patch to sys is the outermost patch, it will be executed last, making it the last parameter in the actual test method arguments. Take note of this well and use a debugger when running your tests to make sure that the right parameters are being injected in the right order. + +### Option 2: Creating Mock Instances + +Instead of mocking the specific instance method, we could instead just supply a mocked instance to UploadService with its constructor. I prefer option 1 above, as it’s a lot more precise, but there are many cases where option 2 might be efficient or necessary. Let’s refactor our test again: + +``` +#!/usr/bin/env python +# -*- coding: utf-8 -*- + +from mymodule import RemovalService, UploadService + +import mock +import unittest + +class RemovalServiceTestCase(unittest.TestCase): + + @mock.patch('mymodule.os.path') + @mock.patch('mymodule.os') + def test_rm(self, mock_os, mock_path): + # instantiate our service + reference = RemovalService() + + # set up the mock + mock_path.isfile.return_value = False + + reference.rm("any path") + + # test that the remove call was NOT called. + self.assertFalse(mock_os.remove.called, "Failed to not remove the file if not present.") + + # make the file 'exist' + mock_path.isfile.return_value = True + + reference.rm("any path") + + mock_os.remove.assert_called_with("any path") + + +class UploadServiceTestCase(unittest.TestCase): + + def test_upload_complete(self, mock_rm): + # build our dependencies + mock_removal_service = mock.create_autospec(RemovalService) + reference = UploadService(mock_removal_service) + + # call upload_complete, which should, in turn, call `rm`: + reference.upload_complete("my uploaded file") + + # test that it called the rm method + mock_removal_service.rm.assert_called_with("my uploaded file") +``` + +In this example, we haven’t even had to patch any functionality, we simply create an auto-spec for the RemovalService class, and then inject this instance into our UploadService to validate the functionality. + +The [mock.create_autospec][5] method creates a functionally equivalent instance to the provided class. What this means, practically speaking, is that when the returned instance is interacted with, it will raise exceptions if used in illegal ways. More specifically, if a method is called with the wrong number of arguments, an exception will be raised. This is extremely important as refactors happen. As a library changes, tests break and that is expected. Without using an auto-spec, our tests will still pass even though the underlying implementation is broken. + +### Pitfall: The mock.Mock and mock.MagicMock Classes + +The mock library also includes two important classes upon which most of the internal functionality is built upon: [mock.Mock][6] and mock.MagicMock. When given a choice to use a mock.Mock instance, a mock.MagicMock instance, or an auto-spec, always favor using an auto-spec, as it helps keep your tests sane for future changes. This is because mock.Mock and mock.MagicMock accept all method calls and property assignments regardless of the underlying API. Consider the following use case: + +``` +class Target(object): + def apply(value): + return value + +def method(target, value): + return target.apply(value) +``` + +We can test this with a mock.Mock instance like this: + +``` +class MethodTestCase(unittest.TestCase): + + def test_method(self): + target = mock.Mock() + + method(target, "value") + + target.apply.assert_called_with("value") +``` + +This logic seems sane, but let’s modify the Target.apply method to take more parameters: + +``` +class Target(object): + def apply(value, are_you_sure): + if are_you_sure: + return value + else: + return None +``` + +Re-run your test, and you’ll find that it still passes. That’s because it isn’t built against your actual API. This is why you should always use the create_autospec method and the autospec parameter with the @patch and @patch.object decorators. + +### Real-World Example: Mocking a Facebook API Call + +To finish up, let’s write a more applicable real-world example, one which we mentioned in the introduction: posting a message to Facebook. We’ll write a nice wrapper class and a corresponding test case. + +``` +import facebook + +class SimpleFacebook(object): + + def __init__(self, oauth_token): + self.graph = facebook.GraphAPI(oauth_token) + + def post_message(self, message): + """Posts a message to the Facebook wall.""" + self.graph.put_object("me", "feed", message=message) +``` + +Here’s our test case, which checks that we post the message without actually posting the message: + +``` +import facebook +import simple_facebook +import mock +import unittest + +class SimpleFacebookTestCase(unittest.TestCase): + + @mock.patch.object(facebook.GraphAPI, 'put_object', autospec=True) + def test_post_message(self, mock_put_object): + sf = simple_facebook.SimpleFacebook("fake oauth token") + sf.post_message("Hello World!") + + # verify + mock_put_object.assert_called_with(message="Hello World!") +``` + +As we’ve seen so far, it’s really simple to start writing smarter tests with mock in Python. + +### Mocking in python Conclusion + +Python’s mock library, if a little confusing to work with, is a game-changer for [unit-testing][7]. We’ve demonstrated common use-cases for getting started using mock in unit-testing, and hopefully this article will help [Python developers][8] overcome the initial hurdles and write excellent, tested code. + +-------------------------------------------------------------------------------- + +via: http://slviki.com/index.php/2016/06/18/introduction-to-mocking-in-python/ + +作者：[Dasun Sucharith][a] +译者：[译者ID](https://github.com/译者ID) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创翻译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: http://www.slviki.com/ +[1]: http://www.python.org/dev/peps/pep-0417/ +[2]: https://pypi.python.org/pypi/mock +[3]: http://www.voidspace.org.uk/python/mock/patch.html#nesting-patch-decorators +[4]: http://docs.python.org/2/reference/compound_stmts.html#function-definitions +[5]: http://www.voidspace.org.uk/python/mock/helpers.html#autospeccing +[6]: http://www.voidspace.org.uk/python/mock/mock.html +[7]: http://www.toptal.com/qa/how-to-write-testable-code-and-why-it-matters +[8]: http://www.toptal.com/python diff --git a/sources/tech/20160621 Docker Datacenter in AWS and Azure in Few Clicks.md b/sources/tech/20160621 Docker Datacenter in AWS and Azure in Few Clicks.md new file mode 100644 index 0000000000..d9431155ff --- /dev/null +++ b/sources/tech/20160621 Docker Datacenter in AWS and Azure in Few Clicks.md @@ -0,0 +1,139 @@ +translated by pspkforever +DOCKER DATACENTER IN AWS AND AZURE IN A FEW CLICKS +=================================================== + +Introducing Docker Datacenter AWS Quickstart and Azure Marketplace Templates production-ready, high availability deployments in just a few clicks. + +The Docker Datacenter AWS Quickstart uses a CloudFormation templates and pre-built templates on Azure Marketplace to make it easier than ever to deploy an enterprise CaaS Docker environment on public cloud infrastructures. + +The Docker Datacenter Container as a Service (CaaS) platform for agile application development provides container and cluster orchestration and management that is simple, secure and scalable for enterprises of any size. With our new cloud templates pre-built for Docker Datacenter, developers and IT operations can frictionlessly move dockerized applications to an Amazon EC2 or Microsoft Azure environment without any code changes. Now businesses can quickly realize greater efficiency of computing and operations resources and Docker supported container management and orchestration in just a few steps. + +### What is Docker Datacenter? + +Docker Datacenter includes Docker Universal Control Plane, Docker Trusted Registry (DTR), CS Docker Engine with commercial support & subscription to align to your application SLAs: + +- Docker Universal Control Plane (UCP), an enterprise-grade cluster management solution that helps you manage your whole cluster from a single pane of glass +- Docker Trusted Registry (DTR), an image storage solution that helps securely store and manage the Docker images. +- Commercially Supported (CS) Docker Engines + +![](http://img.scoop.it/lVraAJgJbjAKqfWCLtLuZLnTzqrqzN7Y9aBZTaXoQ8Q=) + +### Deploy on AWS in a single click with the Docker Datacenter AWS Quick Start + +With AWS Quick Start reference deployments you can rapidly deploy Docker containers on the AWS cloud, adhering to Docker and AWS best practices. The Docker Datacenter Quick Start uses CloudFormation templates that are modular and customizable so you can layer additional functionality on top or modify them for your own Docker deployments. + +[Docker Datacenter for AWS Quickstart](https://youtu.be/aUx7ZdFSkXU) + +#### Architecture + +![](http://img.scoop.it/sZ3_TxLba42QB-r_6vuApLnTzqrqzN7Y9aBZTaXoQ8Q=) + +The AWS Cloudformation starts the installation process by creating all the required AWS resources such as the VPC, security groups, public and private subnets, internet gateways, NAT gateways, and S3 bucket. + +It then launches the first UCP controller instances and goes through the installation process of Docker engine and UCP containers. It backs the Root CAs created by the first UCP controllers to S3. Once the first UCP controller is up and running, the process of creating the other UCP controllers, the UCP cluster nodes, and the first DTR replica is triggered. Similar to the first UCP controller node, all other nodes are started by installing Docker Commercially Supported engine, followed by running the UCP and DTR containers to join the cluster. Two ELBs, one for UCP and one for DTR, are launched and automatically configured to provide resilient load balancing across the two AZs. + +Additionally, UCP controllers and nodes are launched in an ASG to provide scaling functionality if needed. This architecture ensures that both UCP and DTR instances are spread across both AZs to ensure resiliency and high-availability. Route53 is used to dynamically register and configure UCP and DTR in your private or public HostedZone. + +![](http://img.scoop.it/HM7Ag6RFvMXvZ_iBxRgKo7nTzqrqzN7Y9aBZTaXoQ8Q=) + +### Key functionality of this Quickstart templates includes the following: + +- Creates a New VPC, Private and Public Subnets in different AZs, ELBs, NAT Gateways, Internet Gateways, AutoScaling Groups- all based on AWS best practices +- Creates an S3 bucket for DDC to be used for cert backup and DTR image storage ( requires additional configuration in DTR ) +- Deploys 3 UCP Controllers across multiple AZs within your VPC +- Creates a UCP ELB with preconfigured health checks +- Creates a DNS record and attaches it to UCP ELB +- Deploys a scalable cluster of UCP nodes +- Backs up UCP Root CAs to S3 +- Create a 3 DTR Replicas across multiple AZs within your VPC +- Creates a DTR with preconfigured health checks +- Creates a DNS record and attaches it to DTR ELB + +[Download the AWS Quick Start Guide to Learn More](https://s3.amazonaws.com/quickstart-reference/docker/latest/doc/docker-datacenter-on-the-aws-cloud.pdf) + +### Getting Started with Docker Datacenter for AWS + +1. Go to [Docker Store][1] to get your [30 day free trial][2] or [contact sales][4]. +2. At confirmation, you’ll be prompted to “Launch Stack” and you’ll be directed to the AWS Cloudformation portal. +3. Confirm your AWS Region that you’d like to launch this stack in +4. Provide the required parameters +5. Confirm and Launch. +6. Once complete, click on outputs tab to see the URLs of UCP/DTR, default username, and password, and S3 bucket name. + +[Request up to $2000 AWS credit for Docker Datacenter](https://aws.amazon.com/mp/contactdocker/) + +### Deploy on Azure with pre-built templates on Azure Marketplace + +Docker Datacenter is available as pre-built template on Azure Marketplace for you to run instantly on Azure across various datacenters globally. Customers can choose to deploy Docker Datacenter from various VM choices offered on Azure as it fits their needs. + +#### Architecture + +![](http://img.scoop.it/V9SpuBCoAnUnkRL3J-FRFLnTzqrqzN7Y9aBZTaXoQ8Q=) + +The Azure deployment process begins by entering some basic information about the user including, the admin username for ssh-ing into all the nodes (OS level admin user) and the name of the resource group. You can think of the resource group as a collection of resources that has a lifecycle and deployment boundary. You can read more about resource groups here: + +Next you will enter the details of the cluster, including: VM size for UCP controllers, Number of Controllers (default is 3), VM size for UCP nodes, Number of UCP nodes (default is 1, max of 10), VM size for DTR nodes, Number of DTR nodes (default is 3), Virtual Network Name and Address (ex. 10.0.0.1/19). Regarding networking, you will have 2 subnets: the first subnet is for the UCP controller nodes and the second subnet is for the DTR and UCP nodes. + +Lastly you will click OK to complete deployment. Provisioning should take about 15-19 minutes for small clusters with a few additional minutes for larger ones. + +![](http://img.scoop.it/DXPM5-GXP0j2kEhno0kdRLnTzqrqzN7Y9aBZTaXoQ8Q=) + +![](http://img.scoop.it/321ElkCf6rqb7u_-nlGPtrnTzqrqzN7Y9aBZTaXoQ8Q=) + +#### How to Deploy in Azure + +1. Register for [a 30 day free trial][5] license of Docker Datacenter or [contact sales][6]. +2. [Go to Docker Datacenter on the Microsoft Azure Marketplace][7] +3. [Review Deployment Documents][8] + +Get Started by registering for a Docker Datacenter license and you’ll be prompted with the ability to launch either the AWS or Azure templates. + +- [Get a 30 day trial license][9] +- [Understand Docker Datacenter architecture with this video][10] +- [Watch demo videos][11] +- [Get $75 AWS credit torwards your deployment][12] + +### Learn More about Docker + +- New to Docker? Try our 10 min [online tutorial][20] +- Share images, automate builds, and more with [a free Docker Hub account][21] +- Read the Docker [1.12 Release Notes][22] +- Subscribe to [Docker Weekly][23] +- Sign up for upcoming [Docker Online Meetups][24] +- Attend upcoming [Docker Meetups][25] +- Watch [DockerCon EU 2015 videos][26] +- Start [contributing to Docker][27] + + + +-------------------------------------------------------------------------------- + +via: https://blog.docker.com/2016/06/docker-datacenter-aws-azure-cloud/ + +作者：[Trisha McCanna][a] +译者：[译者ID](https://github.com/译者ID) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://blog.docker.com/author/trisha/ +[1]: https://store.docker.com/login?next=%2Fbundles%2Fdocker-datacenter%2Fpurchase?plan=free-trial +[2]: https://store.docker.com/login?next=%2Fbundles%2Fdocker-datacenter%2Fpurchase?plan=free-trial +[4]: https://goto.docker.com/contact-us.html +[5]: https://store.docker.com/login?next=%2Fbundles%2Fdocker-datacenter%2Fpurchase?plan=free-trial +[6]: https://goto.docker.com/contact-us.html +[7]: https://azure.microsoft.com/en-us/marketplace/partners/docker/dockerdatacenterdocker-datacenter/ +[8]: https://success.docker.com/Datacenter/Apply/Docker_Datacenter_on_Azure +[9]: http://www.docker.com/trial +[10]: https://www.youtube.com/playlist?list=PLkA60AVN3hh8tFH7xzI5Y-vP48wUiuXfH +[11]: https://www.youtube.com/playlist?list=PLkA60AVN3hh8a8JaIOA5Q757KiqEjPKWr +[12]: https://aws.amazon.com/quickstart/promo/ +[20]: https://docs.docker.com/engine/understanding-docker/ +[21]: https://hub.docker.com/ +[22]: https://docs.docker.com/release-notes/ +[23]: https://www.docker.com/subscribe_newsletter/ +[24]: http://www.meetup.com/Docker-Online-Meetup/ +[25]: https://www.docker.com/community/meetup-groups +[26]: https://www.youtube.com/playlist?list=PLkA60AVN3hh87OoVra6MHf2L4UR9xwJkv +[27]: https://docs.docker.com/contributing/contributing/ + diff --git a/sources/tech/20160621 Flatpak brings standalone apps to Linux.md b/sources/tech/20160621 Flatpak brings standalone apps to Linux.md new file mode 100644 index 0000000000..c2c1b51e7b --- /dev/null +++ b/sources/tech/20160621 Flatpak brings standalone apps to Linux.md @@ -0,0 +1,35 @@ +翻译中：by zky001 +Flatpak brings standalone apps to Linux +=== + +![](https://cdn.fedoramagazine.org/wp-content/uploads/2016/06/flatpak-945x400.jpg) + +The development team behind [Flatpak][1] has [just announced the general availability][2] of the Flatpak desktop application framework. Flatpak (which was also known during development as xdg-app) provides the ability for an application — bundled as a Flatpak — to be installed and run easily and consistently on many different Linux distributions. Applications bundled as Flatpaks also have the ability to be sandboxed for security, isolating them from your operating system, and other applications. Check out the [Flatpak website][3], and the [press release][4] for more information on the tech that makes up the Flatpak framework. + +### Installing Flatpak on Fedora + +For users wanting to run applications bundled as Flatpaks, installation on Fedora is easy, with Flatpak already available in the official Fedora 23 and Fedora 24 repositories. The Flatpak website has [full details on installation on Fedora][5], as well as how to install on Arch, Debian, Mageia, and Ubuntu. [Many applications][6] have builds already bundled with Flatpak — including LibreOffice, and nightly builds of popular graphics applications Inkscape and GIMP. + +### For Application Developers + +If you are an application developer, the Flatpak website also contains some great resources on getting started [bundling and distributing your applications with Flatpak][7]. These resources contain information on using Flakpak SDKs to build standalone, sandboxed Flatpak applications. + + +-------------------------------------------------------------------------------- + +via: https://fedoramagazine.org/introducing-flatpak/ + +作者：[Ryan Lerch][a] +译者：[zky001](https://github.com/zky001) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://fedoramagazine.org/introducing-flatpak/ +[1]: http://flatpak.org/ +[2]: http://flatpak.org/press/2016-06-21-flatpak-released.html +[3]: http://flatpak.org/ +[4]: http://flatpak.org/press/2016-06-21-flatpak-released.html +[5]: http://flatpak.org/getting.html +[6]: http://flatpak.org/apps.html +[7]: http://flatpak.org/developer.html diff --git a/sources/tech/20160623 72% Of The People I Follow On Twitter Are Men.md b/sources/tech/20160623 72% Of The People I Follow On Twitter Are Men.md new file mode 100644 index 0000000000..71a23511e9 --- /dev/null +++ b/sources/tech/20160623 72% Of The People I Follow On Twitter Are Men.md @@ -0,0 +1,88 @@ +Translating by Flowsnow! +72% Of The People I Follow On Twitter Are Men +=============================================== + +![](https://emptysqua.re/blog/gender-of-twitter-users-i-follow/abacus.jpg) + +At least, that's my estimate. Twitter does not ask users their gender, so I [have written a program that guesses][1] based on their names. Among those who follow me, the distribution is even worse: 83% are men. None are gender-nonbinary as far as I can tell. + +The way to fix the first number is not mysterious: I should notice and seek more women experts tweeting about my interests, and follow them. + +The second number, on the other hand, I can merely influence, but I intend to improve it as well. My network on Twitter should represent of the software industry's diverse future, not its unfair present. + +### How Did I Measure It? + +I set out to estimate the gender distribution of the people I follow—my "friends" in Twitter's jargon—and found it surprisingly hard. [Twitter analytics][2] readily shows me the converse, an estimate of my followers' gender: + +![](https://emptysqua.re/blog/gender-of-twitter-users-i-follow/twitter-analytics.png) + +So, Twitter analytics divides my followers' accounts among male, female, and unknown, and tells me the ratio of the first two groups. (Gender-nonbinary folk are absent here—they're lumped in with the Twitter accounts of organizations, and those whose gender is simply unknown.) But Twitter doesn't tell me the ratio of my friends. That [which is measured improves][3], so I searched for a service that would measure this number for me, and found [FollowerWonk][4]. + +FollowerWonk guesses my friends are 71% men. Is this a good guess? For the sake of validation, I compare FollowerWonk's estimate of my followers to Twitter's estimate: + +**Twitter analytics** + + |men |women +:-- |:-- |:-- +Followers |83% |17% + +**FollowerWonk** + + |men |women +:-- |:-- |:-- +Followers |81% |19% +Friends I follow |72% |28% + +My followers show up 81% male here, close to the Twitter analytics number. So far so good. If FollowerWonk and Twitter agree on the gender ratio of my followers, that suggests FollowerWonk's estimate of the people I follow (which Twitter doesn't analyze) is reasonably good. With it, I can make a habit of measuring my numbers, and improve them. + +At $30 a month, however, checking my friends' gender distribution with FollowerWonk is a pricey habit. I don't need all its features anyhow. Can I solve only the gender-distribution problem economically? + +Since FollowerWonk's numbers seem reasonable, I tried to reproduce them. Using Python and [some nice Philadelphians' Twitter][5] API wrapper, I began downloading the profiles of all my friends and followers. I immediately found that Twitter's rate limits are miserly, so I randomly sampled only a subset of users instead. + +I wrote a rudimentary program that searches for a pronoun announcement in each of my friends' profiles. For example, a profile description that includes "she/her" probably belongs to a woman, a description with "they/them" is probably nonbinary. But most don't state their pronouns: for these, the best gender-correlated information is the "name" field: for example, @gvanrossum's name field is "Guido van Rossum", and the first name "Guido" suggests that @gvanrossum is male. Where pronouns were not announced, I decided to use first names to estimate my numbers. + +My script passes parts of each name to the SexMachine library to guess gender. [SexMachine][6] has predictable downfalls, like mistaking "Brooklyn Zen Center" for a woman named "Brooklyn", but its estimates are as good as FollowerWonk's and Twitter's: + + + + |nonbinary |men |women |no gender,unknown +:-- |:-- |:-- |:-- |:-- +Friends I follow |1 |168 |66 |173 + |0% |72% |28% | +Followers |0 |459 |108 |433 + |0% |81% |19% | + +(Based on all 408 friends and a sample of 1000 followers.) + +### Know Your Number + +I want you to check your Twitter network's gender distribution, too. So I've deployed "Proportional" to PythonAnywhere's handy service for $10 a month: + +> + +The application may rate-limit you or otherwise fail, so use it gently. The [code is on GitHub][7]. It includes a command-line tool, as well. + +Who is represented in your network on Twitter? Are you speaking and listening to the same unfairly distributed group who have been talking about software for the last few decades, or does your network look like the software industry of the future? Let's know our numbers and improve them. + + + + + +-------------------------------------------------------------------------------- + +via: https://emptysqua.re/blog/gender-of-twitter-users-i-follow/ + +作者：[A. Jesse Jiryu Davis][a] +译者：[译者ID](https://github.com/译者ID) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://disqus.com/by/AJesseJiryuDavis/ +[1]: https://www.proporti.onl/ +[2]: https://analytics.twitter.com/ +[3]: http://english.stackexchange.com/questions/14952/that-which-is-measured-improves +[4]: https://moz.com/followerwonk/ +[5]: https://github.com/bear/python-twitter/graphs/contributors +[6]: https://pypi.python.org/pypi/SexMachine/ +[7]: https://github.com/ajdavis/twitter-gender-distribution diff --git a/sources/tech/20160624 DAISY A Linux-compatible text format for the visually impaired.md b/sources/tech/20160624 DAISY A Linux-compatible text format for the visually impaired.md new file mode 100644 index 0000000000..4bf5ccaf42 --- /dev/null +++ b/sources/tech/20160624 DAISY A Linux-compatible text format for the visually impaired.md @@ -0,0 +1,46 @@ +DAISY : A Linux-compatible text format for the visually impaired +================================================================= + + +![](https://opensource.com/sites/default/files/styles/image-full-size/public/images/education/osdc-lead_books.png?itok=K8wqfPT5) +>Image by : +Image by Kate Ter Haar. Modified by opensource.com. CC BY-SA 2.0. + +If you're blind or visually impaired like I am, you usually require various levels of hardware or software to do things that people who can see take for granted. One among these is specialized formats for reading print books: Braille (if you know how to read it) or specialized text formats such as DAISY. + +### What is DAISY? + +DAISY stands for Digital Accessible Information System. It's an open standard used almost exclusively by the blind to read textbooks, periodicals, newspapers, fiction, you name it. It was founded in the mid '90s by [The DAISY Consortium][1], a group of organizations dedicated to producing a set of standards that would allow text to be marked up in a way that would make it easy to read, skip around in, annotate, and otherwise manipulate text in much the same way a sighted user would. + +The current version of DAISY 3.0, was released in mid-2005 and is a complete rewrite of the standard. It was created with the goal of making it much easier to write books complying with it. It's worth noting that DAISY can support plain text only, audio recordings (in PCM Wave or MPEG Layer III format) only, or a combination of text and audio. Specialized software can read these books and allow users to set bookmarks and navigate a book as easily as a sighted person would with a print book. + +### How does DAISY work? + +DAISY, regardless of the specific version, works a bit like this: You have your main navigation file (ncc.html in DAISY 2.02) that contains metadata about the book, such as author's name, copyright date, how many pages the book has, etc. This file is a valid XML document in the case of DAISY 3.0, with DTD (document type definition) files being highly recommended to be included with each book. + +In the navigation control file is markup describing precise positions—either text caret offsets in the case of text navigation or time down to the millisecond in the case of audio recordings—that allows the software to skip to that exact point in the book much as a sighted person would turn to a chapter page. It's worth noting that this navigation control file only contains positions for the main, and largest, elements of a book. + +The smaller elements are handled by SMIL (synchronized multimedia integration language) files. These files contain position points for each chapter in the book. The level of navigation depends heavily on how well the book was marked up. Think of it like this: If a print book has no chapter headings, you will have a hard time figuring out which chapter you're in. If a DAISY book is badly marked up, you might only be able to navigate to the start of the book, or possibly only to the table of contents. If a book is marked up badly enough (or missing markup entirely), your DAISY reading software is likely to simply ignore it. + +### Why the need for specialized software? + +You may be wondering why, if DAISY is little more than HTML, XML, and audio files, you would need specialized software to read and manipulate it. Technically speaking, you don't. The specialized software is mostly for convenience. In Linux, for example, a simple web browser can be used to open the books and read them. If you click on the XML file in a DAISY 3 book, all the software will generally do is read the spines of the books you give it access to and create a list of them that you click on to open. If a book is badly marked up, it won't show up in this list. + +Producing DAISY is another matter entirely, and usually requires either specialized software or enough knowledge of the specifications to modify general-purpose software to parse it. + +### Conclusion + +Fortunately, DAISY is a dying standard. While it is very good at what it does, the need for specialized software to produce it has set us apart from the normal sighted world, where readers use a variety of formats to read their books electronically. This is why the DAISY consortium has succeeded DAISY with EPUB, version 3, which supports what are called media overlays. This is basically an EPUB book with optional audio or video. Since EPUB shares a lot of DAISY's XML markup, some software that can read DAISY can see EPUB books but usually cannot read them. This means that once the websites that provide books for us switch over to this open format, we will have a much larger selection of software to read our books. + +-------------------------------------------------------------------------------- + +via: https://opensource.com/life/16/5/daisy-linux-compatible-text-format-visually-impaired + +作者：[Kendell Clark][a] +译者：[译者ID](https://github.com/译者ID) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创翻译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://opensource.com/users/kendell-clark +[1]: http://www.daisy.org diff --git a/sources/tech/20160626 Backup Photos While Traveling With an Ipad Pro and a Raspberry Pi.md b/sources/tech/20160626 Backup Photos While Traveling With an Ipad Pro and a Raspberry Pi.md new file mode 100644 index 0000000000..b7b3e8d5f1 --- /dev/null +++ b/sources/tech/20160626 Backup Photos While Traveling With an Ipad Pro and a Raspberry Pi.md @@ -0,0 +1,407 @@ +Backup Photos While Traveling With an Ipad Pro and a Raspberry Pi +=================================================================== + +![](http://www.movingelectrons.net/images/bkup_photos_main.jpg) +>Backup Photos While Traveling - Gear. + +### Introduction + +I’ve been on a quest to finding the ideal travel photo backup solution for a long time. Relying on just tossing your SD cards in your camera bag after they are full during a trip is a risky move that leaves you too exposed: SD cards can be lost or stolen, data can get corrupted or cards can get damaged in transit. Backing up to another medium - even if it’s just another SD card - and leaving that in a safe(r) place while traveling is the best practice. Ideally, backing up to a remote location would be the way to go, but that may not be practical depending on where you are traveling to and Internet availability in the region. + +My requirements for the ideal backup procedure are: + +1. Use an iPad to manage the process instead of a laptop. I like to travel light and since most of my trips are business related (i.e. non-photography related), I’d hate to bring my personal laptop along with my business laptop. My iPad, however; is always with me, so using it as a tool just makes sense. +2. Use as few hardware devices as practically possible. +3. Connection between devices should be secure. I’ll be using this setup in hotels and airports, so closed and encrypted connection between devices is ideal. +4. The whole process should be sturdy and reliable. I’ve tried other options using router/combo devices and [it didn’t end up well][1]. + +### The Setup + +I came up with a setup that meets the above criteria and is also flexible enough to expand on it in the future. It involves the use of the following gear: + +1. [iPad Pro 9.7][2] inches. It’s the most powerful, small and lightweight iOS device at the time of writing. Apple pencil is not really needed, but it’s part of my gear as I so some editing on the iPad Pro while on the road. All the heavy lifting will be done by the Raspberry Pi, so any other device capable of connecting through SSH would fit the bill. +2. [Raspberry Pi 3][3] with Raspbian installed. +3. [Micro SD card][4] for Raspberry Pi and a Raspberry Pi [box/case][5]. +5. [128 GB Pen Drive][6]. You can go bigger, but 128 GB is enough for my user case. You can also get a portable external hard drive like [this one][7], but the Raspberry Pi may not provide enough power through its USB port, which means you would have to get a [powered USB hub][8], along with the needed cables, defeating the purpose of having a lightweight and minimalistic setup. +6. [SD card reader][9] +7. [SD Cards][10]. I use several as I don’t wait for one to fill up before using a different one. That allows me to spread photos I take on a single trip amongst several cards. + +The following diagram shows how these devices will be interacting with each other. + +![](http://www.movingelectrons.net/images/bkup_photos_diag.jpg) +>Backup Photos While Traveling - Process Diagram. + +The Raspberry Pi will be configured to act as a secured Hot Spot. It will create its own WPA2-encrypted WiFi network to which the iPad Pro will connect. Although there are many online tutorials to create an Ad Hoc (i.e. computer-to-computer) connection with the Raspberry Pi, which is easier to setup; that connection is not encrypted and it’s relatively easy for other devices near you to connect to it. Therefore, I decided to go with the WiFi option. + +The camera’s SD card will be connected to one of the Raspberry Pi’s USB ports through an SD card reader. Additionally, a high capacity Pen Drive (128 GB in my case) will be permanently inserted in one of the USB ports on the Raspberry Pi. I picked the [Sandisk Ultra Fit][11] because of its tiny size. The main idea is to have the Raspberry Pi backup the photos from the SD Card to the Pen Drive with the help of a Python script. The backup process will be incremental, meaning that only changes (i.e. new photos taken) will be added to the backup folder each time the script runs, making the process really fast. This is a huge advantage if you take a lot of photos or if you shoot in RAW format. The iPad will be used to trigger the Python script and to browse the SD Card and Pen Drive as needed. + +As an added benefit, if the Raspberry Pi is connected to Internet through a wired connection (i.e. through the Ethernet port), it will be able to share the Internet connection with the devices connected to its WiFi network. + +### 1. Raspberry Pi Configuration + +This is the part where we roll up our sleeves and get busy as we’ll be using Raspbian’s command-line interface (CLI) . I’ll try to be as descriptive as possible so it’s easy to go through the process. + +#### Install and Configure Raspbian + +Connect a keyboard, mouse and an LCD monitor to the Raspberry Pi. Insert the Micro SD in the Raspberry Pi’s slot and proceed to install Raspbian per the instructions in the [official site][12]. + +After the installation is done, go to the CLI (Terminal in Raspbian) and type: + +``` +sudo apt-get update +sudo apt-get upgrade +``` + +This will upgrade all software on the machine. I configured the Raspberry Pi to connect to the local network and changed the default password as a safety measure. + +By default SSH is enabled on Raspbian, so all sections below can be done from a remote machine. I also configured RSA authentication, but that’s optional. More info about it [here][13]. + +This is a screenshot of the SSH connection to the Raspberry Pi from [iTerm][14] on Mac: + +##### Creating Encrypted (WPA2) Access Point + +The installation was made based on [this][15] article, it was optimized for my user case. + +##### 1. Install Packages + +We need to type the following to install the required packages: + +``` +sudo apt-get install hostapd +sudo apt-get install dnsmasq +``` + +hostapd allows to use the built-in WiFi as an access point. dnsmasq is a combined DHCP and DNS server that’s easy to configure. + +##### 2. Edit dhcpcd.conf + +Connect to the Raspberry Pi through Ethernet. Interface configuration on the Raspbery Pi is handled by dhcpcd, so first we tell it to ignore wlan0 as it will be configured with a static IP address. + +Open up the dhcpcd configuration file with sudo nano `/etc/dhcpcd.conf` and add the following line to the bottom of the file: + +``` +denyinterfaces wlan0 +``` + +Note: This must be above any interface lines that may have been added. + +##### 3. Edit interfaces + +Now we need to configure our static IP. To do this, open up the interface configuration file with sudo nano `/etc/network/interfaces` and edit the wlan0 section so that it looks like this: + +``` +allow-hotplug wlan0 +iface wlan0 inet static + address 192.168.1.1 + netmask 255.255.255.0 + network 192.168.1.0 + broadcast 192.168.1.255 +# wpa-conf /etc/wpa_supplicant/wpa_supplicant.conf +``` + +Also, the wlan1 section was edited to be: + +``` +#allow-hotplug wlan1 +#iface wlan1 inet manual +# wpa-conf /etc/wpa_supplicant/wpa_supplicant.conf +``` + +Important: Restart dhcpcd with sudo service dhcpcd restart and then reload the configuration for wlan0 with `sudo ifdown eth0; sudo ifup wlan0`. + +##### 4. Configure Hostapd + +Next, we need to configure hostapd. Create a new configuration file with `sudo nano /etc/hostapd/hostapd.conf with the following contents: + +``` +interface=wlan0 + +# Use the nl80211 driver with the brcmfmac driver +driver=nl80211 + +# This is the name of the network +ssid=YOUR_NETWORK_NAME_HERE + +# Use the 2.4GHz band +hw_mode=g + +# Use channel 6 +channel=6 + +# Enable 802.11n +ieee80211n=1 + +# Enable QoS Support +wmm_enabled=1 + +# Enable 40MHz channels with 20ns guard interval +ht_capab=[HT40][SHORT-GI-20][DSSS_CCK-40] + +# Accept all MAC addresses +macaddr_acl=0 + +# Use WPA authentication +auth_algs=1 + +# Require clients to know the network name +ignore_broadcast_ssid=0 + +# Use WPA2 +wpa=2 + +# Use a pre-shared key +wpa_key_mgmt=WPA-PSK + +# The network passphrase +wpa_passphrase=YOUR_NEW_WIFI_PASSWORD_HERE + +# Use AES, instead of TKIP +rsn_pairwise=CCMP +``` + +Now, we also need to tell hostapd where to look for the config file when it starts up on boot. Open up the default configuration file with `sudo nano /etc/default/hostapd` and find the line `#DAEMON_CONF=""` and replace it with `DAEMON_CONF="/etc/hostapd/hostapd.conf"`. + +##### 5. Configure Dnsmasq + +The shipped dnsmasq config file contains tons of information on how to use it, but we won’t be using all the options. I’d recommend moving it (rather than deleting it), and creating a new one with + +``` +sudo mv /etc/dnsmasq.conf /etc/dnsmasq.conf.orig +sudo nano /etc/dnsmasq.conf +``` + +Paste the following into the new file: + +``` +interface=wlan0 # Use interface wlan0 +listen-address=192.168.1.1 # Explicitly specify the address to listen on +bind-interfaces # Bind to the interface to make sure we aren't sending things elsewhere +server=8.8.8.8 # Forward DNS requests to Google DNS +domain-needed # Don't forward short names +bogus-priv # Never forward addresses in the non-routed address spaces. +dhcp-range=192.168.1.50,192.168.1.100,12h # Assign IP addresses in that range with a 12 hour lease time +``` + +##### 6. Set up IPV4 forwarding + +One of the last things that we need to do is to enable packet forwarding. To do this, open up the sysctl.conf file with `sudo nano /etc/sysctl.conf`, and remove the # from the beginning of the line containing `net.ipv4.ip_forward=1`. This will enable it on the next reboot. + +We also need to share our Raspberry Pi’s internet connection to our devices connected over WiFi by the configuring a NAT between our wlan0 interface and our eth0 interface. We can do this by writing a script with the following lines. + +``` +sudo iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE +sudo iptables -A FORWARD -i eth0 -o wlan0 -m state --state RELATED,ESTABLISHED -j ACCEPT +sudo iptables -A FORWARD -i wlan0 -o eth0 -j ACCEPT +``` + +I named the script hotspot-boot.sh and made it executable with: + +``` +sudo chmod 755 hotspot-boot.sh +``` + +The script should be executed when the Raspberry Pi boots. There are many ways to accomplish this, and this is the way I went with: + +1. Put the file in `/home/pi/scripts`. +2. Edit the rc.local file by typing `sudo nano /etc/rc.local` and place the call to the script before the line that reads exit 0 (more information [here][16]). + +This is how the rc.local file looks like after editing it. + +``` +#!/bin/sh -e +# +# rc.local +# +# This script is executed at the end of each multiuser runlevel. +# Make sure that the script will "exit 0" on success or any other +# value on error. +# +# In order to enable or disable this script just change the execution +# bits. +# +# By default this script does nothing. + +# Print the IP address +_IP=$(hostname -I) || true +if [ "$_IP" ]; then + printf "My IP address is %s\n" "$_IP" +fi + +sudo /home/pi/scripts/hotspot-boot.sh & + +exit 0 + +``` + +#### Installing Samba and NTFS Compatibility. + +We also need to install the following packages to enable the Samba protocol and allow the File Browser App to see the connected devices to the Raspberry Pi as shared folders. Also, ntfs-3g provides NTFS compatibility in case we decide to connect a portable hard drive to the Raspberry Pi. + +``` +sudo apt-get install ntfs-3g +sudo apt-get install samba samba-common-bin +``` + +You can follow [this][17] article for details on how to configure Samba. + +Important Note: The referenced article also goes through the process of mounting external hard drives on the Raspberry Pi. We won’t be doing that because, at the time of writing, the current version of Raspbian (Jessie) auto-mounts both the SD Card and the Pendrive to `/media/pi/` when the device is turned on. The article also goes over some redundancy features that we won’t be using. + +### 2. Python Script + +Now that the Raspberry Pi has been configured, we need to work on the script that will actually backup/copy our photos. Note that this script just provides certain degree of automation to the backup process. If you have a basic knowledge of using the Linux/Raspbian CLI, you can just SSH into the Raspberry Pi and copy yourself all photos from one device to the other by creating the needed folders and using either the cp or the rsync command. We’ll be using the rsync method on the script as it’s very reliable and allows for incremental backups. + +This process relies on two files: the script itself and the configuration file `backup_photos.conf`. The latter just have a couple of lines indicating where the destination drive (Pendrive) is mounted and what folder has been mounted to. This is what it looks like: + +``` +mount folder=/media/pi/ +destination folder=PDRIVE128GB +``` + +Important: Do not add any additional spaces between the `=` symbol and the words to both sides of it as the script will break (definitely an opportunity for improvement). + +Below is the Python script, which I named `backup_photos.py` and placed in `/home/pi/scripts/`. I included comments in between the lines of code to make it easier to follow. + +``` +#!/usr/bin/python3 + +import os +import sys +from sh import rsync + +''' +The script copies an SD Card mounted on /media/pi/ to a folder with the same name +created in the destination drive. The destination drive's name is defined in +the .conf file. + + +Argument: label/name of the mounted SD Card. +''' + +CONFIG_FILE = '/home/pi/scripts/backup_photos.conf' +ORIGIN_DEV = sys.argv[1] + +def create_folder(path): + + print ('attempting to create destination folder: ',path) + if not os.path.exists(path): + try: + os.mkdir(path) + print ('Folder created.') + except: + print ('Folder could not be created. Stopping.') + return + else: + print ('Folder already in path. Using that instead.') + + + +confFile = open(CONFIG_FILE,'rU') +#IMPORTANT: rU Opens the file with Universal Newline Support, +#so \n and/or \r is recognized as a new line. + +confList = confFile.readlines() +confFile.close() + + +for line in confList: + line = line.strip('\n') + + try: + name , value = line.split('=') + + if name == 'mount folder': + mountFolder = value + elif name == 'destination folder': + destDevice = value + + + except ValueError: + print ('Incorrect line format. Passing.') + pass + + +destFolder = mountFolder+destDevice+'/'+ORIGIN_DEV +create_folder(destFolder) + +print ('Copying files...') + +# Comment out to delete files that are not in the origin: +# rsync("-av", "--delete", mountFolder+ORIGIN_DEV, destFolder) +rsync("-av", mountFolder+ORIGIN_DEV+'/', destFolder) + +print ('Done.') +``` + +### 3. iPad Pro Configuration + +Since all the heavy-lifting will be done on the Raspberry Pi and no files will be transferred through the iPad Pro, which was a huge disadvantage in [one of the workflows I tried before][18]; we just need to install [Prompt 2][19] on the iPad to access the Raspeberry Pi through SSH. Once connected, you can either run the Python script or copy the files manually. + +![](http://www.movingelectrons.net/images/bkup_photos_ipad&rpi_prompt.jpg) +>SSH Connection to Raspberry Pi From iPad Using Prompt. + +Since we installed Samba, we can access USB devices connected to the Raspberry Pi in a more graphical way. You can stream videos, copy and move files between devices. [File Browser][20] is perfect for that. + +### 4. Putting it All Together + +Let’s suppose that `SD32GB-03` is the label of an SD card connected to one of the USB ports on the Raspberry Pi. Also, let’s suppose that `PDRIVE128GB` is the label of the Pendrive, also connected to the device and defined on the `.conf` file as indicated above. If we wanted to backup the photos on the SD Card, we would need to go through the following steps: + +1. Turn on Raspberry Pi so that drives are mounted automatically. +2. Connect to the WiFi network generated by the Raspberry Pi. +3. Connect to the Raspberry Pi through SSH using the [Prompt][21] App. +4. Type the following once you are connected: + +``` +python3 backup_photos.py SD32GB-03 +``` + +The first backup my take some minutes depending on how much of the card is used. That means you need to keep the connection alive to the Raspberry Pi from the iPad. You can get around this by using the [nohup][22] command before running the script. + +``` +nohup python3 backup_photos.py SD32GB-03 & +``` + +![](http://www.movingelectrons.net/images/bkup_photos_ipad&rpi_finished.png) +>iTerm Screenshot After Running Python Script. + +### Further Customization + +I installed a VNC server to access Raspbian’s graphical interface from another computer or the iPad through [Remoter App][23]. I’m looking into installing [BitTorrent Sync][24] for backing up photos to a remote location while on the road, which would be the ideal setup. I’ll expand this post once I have a workable solution. + +Feel free to either include your comments/questions below or reach out to me. My contact info is at the footer of this page. + + +-------------------------------------------------------------------------------- + +via: http://www.movingelectrons.net/blog/2016/06/26/backup-photos-while-traveling-with-a-raspberry-pi.html + +作者：[Editor][a] +译者：[译者ID](https://github.com/译者ID) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: http://www.movingelectrons.net/blog/2016/06/26/backup-photos-while-traveling-with-a-raspberry-pi.html +[1]: http://bit.ly/1MVVtZi +[2]: http://www.amazon.com/dp/B01D3NZIMA/?tag=movinelect0e-20 +[3]: http://www.amazon.com/dp/B01CD5VC92/?tag=movinelect0e-20 +[4]: http://www.amazon.com/dp/B010Q57T02/?tag=movinelect0e-20 +[5]: http://www.amazon.com/dp/B01F1PSFY6/?tag=movinelect0e-20 +[6]: http://amzn.to/293kPqX +[7]: http://amzn.to/290syFY +[8]: http://amzn.to/290syFY +[9]: http://amzn.to/290syFY +[10]: http://amzn.to/290syFY +[11]: http://amzn.to/293kPqX +[12]: https://www.raspberrypi.org/downloads/noobs/ +[13]: https://www.raspberrypi.org/documentation/remote-access/ssh/passwordless.md +[14]: https://www.iterm2.com/ +[15]: https://frillip.com/using-your-raspberry-pi-3-as-a-wifi-access-point-with-hostapd/ +[16]: https://www.raspberrypi.org/documentation/linux/usage/rc-local.md +[17]: http://www.howtogeek.com/139433/how-to-turn-a-raspberry-pi-into-a-low-power-network-storage-device/ +[18]: http://bit.ly/1MVVtZi +[19]: https://itunes.apple.com/us/app/prompt-2/id917437289?mt=8&uo=4&at=11lqkH +[20]: https://itunes.apple.com/us/app/filebrowser-access-files-on/id364738545?mt=8&uo=4&at=11lqkH +[21]: https://itunes.apple.com/us/app/prompt-2/id917437289?mt=8&uo=4&at=11lqkH +[22]: https://en.m.wikipedia.org/wiki/Nohup +[23]: https://itunes.apple.com/us/app/remoter-pro-vnc-ssh-rdp/id519768191?mt=8&uo=4&at=11lqkH +[24]: https://getsync.com/ diff --git a/sources/tech/20160627 TOP 5 BEST VIDEO EDITING SOFTWARE FOR LINUX IN 2016.md b/sources/tech/20160627 TOP 5 BEST VIDEO EDITING SOFTWARE FOR LINUX IN 2016.md new file mode 100644 index 0000000000..4faee7eaef --- /dev/null +++ b/sources/tech/20160627 TOP 5 BEST VIDEO EDITING SOFTWARE FOR LINUX IN 2016.md @@ -0,0 +1,150 @@ +name1e5s translating + +TOP 5 BEST VIDEO EDITING SOFTWARE FOR LINUX IN 2016 +===================================================== + +![](https://itsfoss.com/wp-content/uploads/2016/06/linux-video-ditor-software.jpg) + +Brief: Tiwo discusses the best video editors for Linux, their pros and cons and the installation method for Ubuntu-based distros in this article. + +We have discussed [best photo management applications for Linux][1], [best code editors for Linux][2] in similar articles in the past. Today we shall see the best video editing software for Linux. + +When asked about free video editing software, Windows Movie Maker and iMovie is what most people often suggest. + +Unfortunately, both of them are not available for GNU/Linux. But you don’t need to worry about it, we have pooled together a list of best free video editors for you. + +### BEST VIDEO EDITOR APPS FOR LINUX + +Let’s have a look at the top 5 best free video editing software for Linux below : + +#### 1. KDENLIVE + +![](https://itsfoss.com/wp-content/uploads/2016/06/kdenlive-free-video-editor-on-ubuntu.jpg) + +[Kdenlive][3] is a free and [open source][4] video editing software from KDE that provides dual video monitors, a multi-track timeline, clip list, customizable layout support, basic effects, and basic transitions. +It supports wide variety of file formats and a wide range of camcorders and cameras including Low resolution camcorder (Raw and AVI DV editing), Mpeg2, mpeg4 and h264 AVCHD (small cameras and camcorders), High resolution camcorder files, including HDV and AVCHD camcorders, Professional camcorders, including XDCAM-HD™ streams, IMX™ (D10) streams, DVCAM (D10) , DVCAM, DVCPRO™, DVCPRO50™ streams and DNxHD™ streams. + +You can install it from terminal by running the following command : + +``` +sudo apt-get install kdenlive +``` + +Or, open Ubuntu Software Center then search Kdenlive. + +#### 2. OPENSHOT + +![](https://itsfoss.com/wp-content/uploads/2016/06/openshot-free-video-editor-on-ubuntu.jpg) + +[OpenShot][5] is the second choice in our list of Linux video editing software. OpenShot can help you create the film that supports for transitions, effects, adjusting audio levels, and of course, it support of most formats and codecs. + +You can also export your film to DVD, upload to YouTube, Vimeo, Xbox 360, and many other common formats. OpenShot is simpler than kdenlive. So if you need a video editor with a simple UI OpenShot is a good choice. + +The latest version is 2.0.7. You can install OpenShot video editor by run the following command from terminal window : + +``` +sudo apt-get install openshot +``` + +It needs to download 25 MB, and 70 MB disk space after installed. + +#### 3. FLOWBLADE MOVIE EDITOR + +![](https://itsfoss.com/wp-content/uploads/2016/06/flowblade-movie-editor-on-ubuntu.jpg) + +[Flowblade Movie Editor][6] is a multitrack non-linear video editor for Linux. It is free and open source. It comes with a stylish and modern user interface. + +Written in Python, it is designed to provide a fast, and precise. Flowblade has focused on providing the best possible experience on Linux and other free platforms. So there’s no Windows and OS X version for now. + +To install Flowblade in Ubuntu and other Ubuntu based systems, use the command below: + +``` +sudo apt-get install flowblade +``` + +#### 4. LIGHTWORKS + +![](https://itsfoss.com/wp-content/uploads/2016/06/lightworks-running-on-ubuntu-16.04.jpg) + +If you looking for a video editor software that has more feature, this is the answer. [Lightworks][7] is a cross-platform professional video editor, available for Linux, Mac OS X and Windows. + +It is an award winning professional [non-linear editing][8] (NLE) software that supports resolutions up to 4K as well as video in SD and HD formats. + +This application has two versions: Lightworks Free and Lightworks Pro. While free version doesn’t support Vimeo (H.264 / MPEG-4) and YouTube (H.264 / MPEG-4)- Up to 2160p (4K UHD), Blu-ray, and H.264/MP4 export option with configurable bitrate setting, then pro version is. + +- Lightworks Free +- Lightworks Pro + +Pro version has more features such as higher resolution support, 4K and Blue Ray support etc. + +##### HOW TO INSTALL LIGHTWORKS? + +Unlike the other video editors, installing Lightwork is not as straight forward as running a single command. Don’t worry, it’s not that complicated either. + +- Step 1 – You can get the package from [Lightworks Downloads Page][9]. The package’s size about 79,5 MB. + +>Please note: There’s no Linux 32-bit support. + +- Step 2 – Once downloaded, you can install it using [Gdebi package installer][10]. Gdebi automatically downloads the dependency : + +![](https://itsfoss.com/wp-content/uploads/2016/06/Installing-lightworks-on-ubuntu.jpg) + +- Step 3 – Now you can open it from Ubuntu dashboard, or your Linux distro’s menu. + +- Step 4 – It needs an account when you use it for first time. Click at Not Registerd? button to register. Don’t worry, it’s free! + +- Step 5 – After your account has been verified, now login. + +Now the Lightworks is ready to use. + +Need Lightworks video tutorial? Get them at [Lightworks video tutorials Page][11]. + +#### 5. BLENDER + +![](https://itsfoss.com/wp-content/uploads/2016/06/blender-running-on-ubuntu-16.04.jpg) + +Blender is a professional, industry-grade open source, cross platform video editor. It is popular for 3D works. Blender has been used in several Hollywood movies including Spider Man series. + +Although originally designed for produce 3D modeling, but it can also be used for video editing and input capabilities with a variety of formats. The Video Editor includes: + +- Live preview, luma waveform, chroma vectorscope and histogram displays +- Audio mixing, syncing, scrubbing and waveform visualization +- Up to 32 slots for adding video, images, audio, scenes, masks and effects +- Speed control, adjustment layers, transitions, keyframes, filters and more. + +The latest version can be downloaded from [Blender Download Page][12]. + +### WHICH IS THE BEST VIDEO EDITING SOFTWARE? + +If you need a simple video editor, OpenShot, Kdenlive or Flowblade is a good choice. These are suitable for beginners and a system with standard specification. + +Then if you have a high-end computer, and need advanced features you can go out with Lightworks. If you are looking for more advanced features, Blender has got your back. + +So that’s all I can write about 5 best video editing software for Linux such as Ubuntu, Linux Mint, Elementary, and other Linux distributions. Share with us which video editor you like the most. + +-------------------------------------------------------------------------------- + +via: https://itsfoss.com/best-video-editing-software-linux/ + +作者：[Tiwo Satriatama][a] +译者：[译者ID](https://github.com/译者ID) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创翻译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://itsfoss.com/author/tiwo/ +[1]: https://itsfoss.com/linux-photo-management-software/ +[2]: https://itsfoss.com/best-modern-open-source-code-editors-for-linux/ +[3]: https://kdenlive.org/ +[4]: https://itsfoss.com/tag/open-source/ +[5]: http://www.openshot.org/ +[6]: http://jliljebl.github.io/flowblade/ +[7]: https://www.lwks.com/ +[8]: https://en.wikipedia.org/wiki/Non-linear_editing_system +[9]: https://www.lwks.com/index.php?option=com_lwks&view=download&Itemid=206 +[10]: https://itsfoss.com/gdebi-default-ubuntu-software-center/ +[11]: https://www.lwks.com/videotutorials +[12]: https://www.blender.org/download/ + + + diff --git a/sources/tech/20160630 18 Best IDEs for C+C++ Programming or Source Code Editors on Linux.md b/sources/tech/20160630 18 Best IDEs for C+C++ Programming or Source Code Editors on Linux.md new file mode 100644 index 0000000000..01fb7c5c22 --- /dev/null +++ b/sources/tech/20160630 18 Best IDEs for C+C++ Programming or Source Code Editors on Linux.md @@ -0,0 +1,305 @@ +translating by fw8899 +18 Best IDEs for C/C++ Programming or Source Code Editors on Linux +====================================================================== + +C++, an extension of well known C language, is an excellent, powerful and general purpose programming language that offers modern and generic programming features for developing large-scale applications ranging from video games, search engines, other computer software to operating systems. + +C++ is highly reliable and also enables low-level memory manipulation for more advanced programming requirements. + +![](http://www.tecmint.com/wp-content/uploads/2016/06/Best-Linux-IDE-Editors.png) + +There are several text editors out there that programmers can use to write C/C++ code, but IDE have come up to offer comprehensive facilities and components for easy and ideal programming. + +In this article, we shall look at some of the best IDE’s you can find on the Linux platform for C++ or any other programming. + +### 1. Netbeans for C/C++ Development + +Netbeans is a free, open-source and popular cross-platform IDE for C/C++ and many other programming languages. Its fully extensible using community developed plugins. + +It includes project types and templates for C/C++ and you can build applications using static and dynamic libraries. Additionally, you can reuse existing code to create your projects, and also use drag and drop feature to import binary files into it to build applications from the ground. + +Let us look at some of its features: + +- The C/C++ editor is well integrated with multi-session [GNU GDB][1] debugger tool. +- Support for code assistance +- C++11 support +- Create and run C/C++ tests from within +- Qt toolkit support +- Support for automatic packaging of compiled application into .tar, .zip and many more archive files +- Support for multiple compilers such as GNU, Clang/LLVM, Cygwin, Oracle Solaris Studio and MinGW +- Support for remote development +- File navigation +- Source inspection + +![](http://www.tecmint.com/wp-content/uploads/2016/06/NetBeans-IDE.png) +>Visit Homepage: + +### 2. Code::Blocks + +Code::Blocks is a free, highly extensible and configurable, cross-platform C++ IDE built to offer users the most demanded and ideal features. It delivers a consistent user interface and feel. + +And most importantly, you can extend its functionality by using plugins developed by users, some of the plugins are part of Code::Blocks release and many are not, written by individual users not part of the Code::Block development team. + +Its features are categorized into compiler, debugger and interface features and these include: + +Multiple compiler support including GCC, clang, Borland C++ 5.5, digital mars plus many more +Very fast, no need for makefiles +Multi-target projects +Workspace that supports combining of projects +Interfaces GNU GDB +Support for full breakpoints including code breakpoints, data breakpoints, breakpoint conditions plus many more +display local functions symbols and arguments +custom memory dump and syntax highlighting +Customizable and extensible interface plus many more other features including those added through user built plugins + +![](http://www.tecmint.com/wp-content/uploads/2016/06/CodeBlocks-IDE-for-Linux.png) +>Visit Homepage: + +### 3. Eclipse CDT(C/C++ Development Tooling) + +Eclipse is a well known open-source, cross-platform IDE in the programming arena. It offers users a great GUI with support for drag and drop functionality for easy arrangement of interface elements. + +The Eclipse CDT is a project based on the primary Eclipse platform and it provides a full functional C/C++ IDE with following features: + +- Supports project creation +- Managed build for various toolchains +- Standard make build +- Source navigation +- Several knowledge tools such as call graph, type hierarchy, in-built browser, macro definition browser +- Code editor with support for syntax highlighting +- Support for folding and hyperlink navigation +- Source code refactoring plus code generation +- Tools for visual debugging such as memory, registers +- Disassembly viewers and many more + +![](http://www.tecmint.com/wp-content/uploads/2016/06/Eclipse-IDE-for-Linux.png) +>Visit Homepage: + +### 4. CodeLite IDE + +CodeLite is also a free, open-source, cross-platform IDE designed and built specifically for C/C++, JavaScript (Node.js) and PHP programming. + +Some of its main features include: + +- Code completion, and it offers two code completion engines +- Supports several compilers including GCC, clang/VC++ +- Displays errors as code glossary +- Clickable errors via build tab +- Support for LLDB next generation debugger +- GDB support +- Support for refactoring +- Code navigation +- Remote development using built-in SFTP +- Source control plugins +- RAD (Rapid Application Development) tool for developing wxWidgets-based apps plus many more features + +![](http://www.tecmint.com/wp-content/uploads/2016/06/Codelite-IDE.png) +>Visit Homepage: + +### 6. Bluefish Editor + +Bluefish is a more than just a normal editor, it is a lightweight, fast editor that offers programmers IDE like features for developing websites, writing scripts and software code. It is multi-platform, runs on Linux, Mac OSX, FreeBSD, OpenBSD, Solaris and Windows, and also supports many programming languages including C/C++. + +It is feature rich including the ones listed below: + +- Multiple document interface +- Supports recursive opening of files based on filename patterns or content pattern +- Offers a very powerful search and replace functionality +- Snippet sidebar +- Support for integrating external filters of your own, pipe documents using commands such as awk, sed, sort plus custom built scripts +- Supports full screen editing +- Site uploader and downloader +- Multiple encoding support and many more other features + +![](http://www.tecmint.com/wp-content/uploads/2016/06/BlueFish-IDE-Editor-for-Linux.png) +>Visit Homepage: + +### 7. Brackets Code Editor + +Brackets is a modern and open-source text editor designed specifically for web designing and development. It is highly extensible through plugins, therefore C/C++ programmers can use it by installing the C/C++/Objective-C pack extension, this pack is designed to enhance C/C++ code writing and to offer IDE like features. + +![](http://www.tecmint.com/wp-content/uploads/2016/06/Brackets-Code-Editor-for-Linux.png) +>Visit Homepage: + +### 8. Atom Code Editor + +Atom is also a modern, open-source, multi-platform text editor that can run on Linux, Windows or Mac OS X. It is also hackable down to its base, therefore users can customize it to meet their code writing demands. + +It is fully featured and some of its main features include: + +- Built-in package manager +- Smart auto-completion +- In-built file browser +- Find and replace functionality and many more + +![](http://www.tecmint.com/wp-content/uploads/2016/06/Atom-Code-Editor-for-Linux.png) +>Visit Homepage: >https://atom.io/> +>Installation Instructions: + +### 9. Sublime Text Editor + +Sublime Text is a well refined, multi-platform text editor designed and developed for code, markup and prose. You can use it for writing C/C++ code and offers a great user interface. + +It’s features list comprises of: + +- Multiple selections +- Command palette +- Goto anything functionality +- Distraction free mode +- Split editing +- Instant project switching support +- Highly customizable +- Plugin API support based on Python plus other small features + +![](http://www.tecmint.com/wp-content/uploads/2016/06/Sublime-Code-Editor-for-Linux.png) +>Visit Homepage: +>Installation Instructions: + +### 10. JetBrains CLion + +CLion is a non-free, powerful and cross-platform IDE for C/C++ programming. It is a fully integrated C/C++ development environment for programmers, providing Cmake as a project model, an embedded terminal window and a keyboard oriented approach to code writing. + +It also offers a smart and modern code editor plus many more exciting features to enable an ideal code writing environment and these features include: + +- Supports several languages other than C/C++ +- Easy navigation to symbol declarations or context usage +- Code generation and refactoring +- Editor customization +- On-the-fly code analysis +- An integrated code debugger +- Supports Git, Subversion, Mercurial, CVS, Perforce(via plugin) and TFS +- Seamlessly integrates with Google test frameworks +- Support for Vim text editor via Vim-emulation plugin + +![](http://www.tecmint.com/wp-content/uploads/2016/06/JetBains-CLion-IDE.png) +>Visit Homepage: + +### 11. Microsoft’s Visual Studio Code Editor + +Visual Studio is a rich, fully integrated, cross-platform development environment that runs on Linux, Windows and Mac OS X. It was recently made open-source to Linux users and it has redefined code editing, offering users every tool needed for building every app for multiple platforms including Windows, Android, iOS and the web. + +It is feature full, with features categorized under application development, application lifecycle management, and extend and integrate features. You can read a comprehensive features list from the Visual Studio website. + +![](http://www.tecmint.com/wp-content/uploads/2016/06/Visual-Studio-Code-Editor.png) +>Visit Homepage: + +### 12. KDevelop + +KDevelop is just another free, open-source and cross-platform IDE that works on Linux, Solaris, FreeBSD, Windows, Mac OSX and other Unix-like operating systems. It is based on the KDevPlatform, KDE and Qt libraries. KDevelop is highly extensible through plugins and feature rich with the following notable features: + +- Support for Clang-based C/C++ plugin +- KDE 4 config migration support +- Revival of Oketa plugin support +- Support for different line editings in various views and plugins +- Support for Grep view and Uses widget to save vertical space plus many more + +![](http://www.tecmint.com/wp-content/uploads/2016/06/KDevelop-IDE-Editor.png) +>Visit Homepage: + +### 13. Geany IDE + +Geany is a free, fast, lightweight and cross-platform IDE developed to work with few dependencies and also operate independently from popular Linux desktops such as GNOME and KDE. It requires GTK2 libraries for functionality. + +Its features list consists of the following: + +- Support for syntax highlighting +- Code folding +- Call tips +- Symbol name auto completion +- Symbol lists +- Code navigation +- A simple project management tool +- In-built system to compile and run a users code +- Extensible through plugins + +![](http://www.tecmint.com/wp-content/uploads/2016/06/Geany-IDE-for-Linux.png) +>Visit Homepage: + +### 14. Ajunta DeveStudio + +Ajunta DevStudio is a simple GNOME yet powerful software development studio that supports several programming languages including C/C++. + +It offers advanced programming tools such as project management, GUI designer, interactive debugger, application wizard, source editor, version control plus so many other facilities. Additionally, to above features, Ajunta DevStudio also has some other great IDE features and these include: + +- Simple user interface +- Extensible with plugins +- Integrated Glade for WYSIWYG UI development +- Project wizards and templates +- Integrated GDB debugger +- In-built file manager +- Integrated DevHelp for context sensitive programming help +- Source code editor with features such as syntax highlighting, smart indentation, auto-indentation, code folding/hiding, text zooming plus many more + +![](http://www.tecmint.com/wp-content/uploads/2016/06/Anjuta-DevStudio-for-Linux.png) +>Visit Homepage: + +### 15. The GNAT Programming Studio + +The GNAT Programming Studio is a free easy to use IDE designed and developed to unify the interaction between a developer and his/her code and software. + +Built for ideal programming by facilitating source navigation while highlighting important sections and ideas of a program. It is also designed to offer a high-level of programming comfortability, enabling users to developed comprehensive systems from the ground. + +It is feature rich with the following features: + +- - Intuitive user interface +- Developer friendly +- Multi-lingual and multi-platform +- Flexible MDI(multiple document interface) +- Highly customizable +- Fully extensible with preferred tools + +![](http://www.tecmint.com/wp-content/uploads/2016/06/GNAT-Programming-Studio.jpg) +>Visit Homepage: + +### 16. Qt Creator + +It is a non-free, cross-platform IDE designed for creation of connected devices, UIs and applications. Qt creator enables users to do more of creation than actual coding of applications. + +It can be used to create mobile and desktop applications, and also connected embedded devices. + +Some of its features include: + +- Sophisticated code editor +- Support for version control +- Project and build management tools +- Multi-screen and multi-platform support for easy switching between build targets plus many more + +![](http://www.tecmint.com/wp-content/uploads/2016/06/Qt-Creator.png) +>Visit Homepage: + +### 17. Emacs Editor + +Emacs is a free, powerful, highly extensible and customizable, cross-platform text editors you can use on Linux, Solaris, FreeBSD, NetBSD, OpenBSD, Windows and Mac OS X. + +The core of Emacs is also an interpreter for Emacs Lisp which is a language under the Lisp programming language. As of this writing, the latest release of GNU Emacs is version 24.5 and the fundamental and notable features of Emacs include: + +- Content-aware editing modes +- Full Unicode support +- Highly customizable using GUI or Emacs Lisp code +- A packaging system for downloading and installing extensions +- Ecosystem of functionalities beyond normal text editing including project planner, mail, calender and news reader plus many more +- A complete built-in documentation plus user tutorials and many more + +![](http://www.tecmint.com/wp-content/uploads/2016/06/Emacs-Editor.png) +>Visit Homepage: https://www.gnu.org/software/emacs/ + +### 18. VI/VIM Editor + +Vim an improved version of VI editor, is a free, powerful, popular and highly configurable text editor. It is built to enable efficient text editing, and offers exciting editor features for Unix/Linux users, therefore, it is also a good option for writing and editing C/C++ code. + +Generally, IDEs offer more programming comfortability then traditional text editors, therefore it is always a good idea to use them. They come with exciting features and offer a comprehensive development environment, sometimes programmers are caught up between choosing the best IDE to use for C/C++ programming. + +There many other IDEs you can find out there and download from the Internet, but trying out several of them can help you find that which suites your needs. + +-------------------------------------------------------------------------------- + +via: http://www.tecmint.com/best-linux-ide-editors-source-code-editors/ + +作者：[Aaron Kili][a] +译者：[译者ID](https://github.com/译者ID) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: http://www.tecmint.com/author/aaronkili/ +[1]: http://www.tecmint.com/debug-source-code-in-linux-using-gdb/ diff --git a/sources/tech/20160701 CANONICAL CONSIDERING TO DROP 32 BIT SUPPORT IN UBUNTU.md b/sources/tech/20160701 CANONICAL CONSIDERING TO DROP 32 BIT SUPPORT IN UBUNTU.md new file mode 100644 index 0000000000..ad51164ed4 --- /dev/null +++ b/sources/tech/20160701 CANONICAL CONSIDERING TO DROP 32 BIT SUPPORT IN UBUNTU.md @@ -0,0 +1,43 @@ +(翻译中 by runningwater) +CANONICAL CONSIDERING TO DROP 32 BIT SUPPORT IN UBUNTU +======================================================== + +![](https://itsfoss.com/wp-content/uploads/2016/06/Ubuntu-32-bit-goes-for-a-toss-.jpg) + +Yesterday, developer [Dimitri John Ledkov][1] wrote a message on the [Ubuntu Mailing list][2] calling for the end of i386 support by Ubuntu 18.10. Ledkov argues that more software is being developed with 64-bit support. He is also concerned that it will be difficult to provide security support for the aging i386 architecture. + +Ledkov also argues that building i386 images is not free, but takes quite a bit of Canonical’s resources. + +>Building i386 images is not “for free”, it comes at the cost of utilizing our build farm, QA and validation time. Whilst we have scalable build-farms, i386 still requires all packages, autopackage tests, and ISOs to be revalidated across our infrastructure. As well as take up mirror space & bandwidth. + +Ledkov offers a plan where the 16.10, 17.04, and 17.10 versions of Ubuntu will continue to have i386 kernels, netboot installers, and cloud images, but drop i386 ISO for desktop and server. The 18.04 LTS would then drop support for i386 kernels, netboot installers, and cloud images, but still provide the ability for i386 programs to run on 64-bit architecture. Then, 18.10 would end the i386 port and limit legacy 32-bit applications to snaps, containers, and virtual machines. + +Ledkov’s plan had not been accepted yet, but it shows a definite push toward eliminating 32-bit support. + +### GOOD NEWS + +Don’t despair yet. this will not affect the distros used to resurrect your old system. [Martin Wimpress][3], the creator of [Ubuntu MATE][4], revealed during a discussion on Googl+ that these changes will only affect mainline Ubuntu. + +>The i386 archive will continue to exist into 18.04 and flavours can continue to elect to build i386 isos. There is however a security concern, in that some larger applications (Firefox, Chromium, LibreOffice) are already presenting challenges in terms of applying some security patches to older LTS releases. So flavours are being asked to be mindful of the support period they can reasonably be expected to support i386 versions for. + +### THOUGHTS + +I understand why they need to make this move from a security standpoint, but it’s going to make people move away from mainline Ubuntu to either one of the flavors or a different architecture. Thankfully, we have alternative [lightweight Linux distributions][5]. + + +-------------------------------------------------------------------------------- + +via: https://itsfoss.com/ubuntu-32-bit-support-drop/?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+ItsFoss+%28Its+FOSS%21+An+Open+Source+Blog%29 + +作者：[John Paul][a] +译者：[runningwater](https://github.com/runningwater) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://itsfoss.com/author/john/ +[1]: https://plus.google.com/+DimitriJohnLedkov +[2]: https://lists.ubuntu.com/archives/ubuntu-devel-discuss/2016-June/016661.html +[3]: https://twitter.com/m_wimpress +[4]: http://ubuntu-mate.org/ +[5]: https://itsfoss.com/lightweight-linux-beginners/ diff --git a/sources/tech/20160705 Building a data science portfolio - Machine learning project.md b/sources/tech/20160705 Building a data science portfolio - Machine learning project.md new file mode 100644 index 0000000000..ca57b2e83c --- /dev/null +++ b/sources/tech/20160705 Building a data science portfolio - Machine learning project.md @@ -0,0 +1,845 @@ +Building a data science portfolio: Machine learning project +=========================================================== + +>This is the third in a series of posts on how to build a Data Science Portfolio. If you like this and want to know when the next post in the series is released, you can [subscribe at the bottom of the page][1]. + +Data science companies are increasingly looking at portfolios when making hiring decisions. One of the reasons for this is that a portfolio is the best way to judge someone’s real-world skills. The good news for you is that a portfolio is entirely within your control. If you put some work in, you can make a great portfolio that companies are impressed by. + +The first step in making a high-quality portfolio is to know what skills to demonstrate. The primary skills that companies want in data scientists, and thus the primary skills they want a portfolio to demonstrate, are: + +- Ability to communicate +- Ability to collaborate with others +- Technical competence +- Ability to reason about data +- Motivation and ability to take initiative + +Any good portfolio will be composed of multiple projects, each of which may demonstrate 1-2 of the above points. This is the third post in a series that will cover how to make a well-rounded data science portfolio. In this post, we’ll cover how to make the second project in your portfolio, and how to build an end to end machine learning project. At the end, you’ll have a project that shows your ability to reason about data, and your technical competence. [Here’s][2] the completed project if you want to take a look. + +### An end to end project + +As a data scientist, there are times when you’ll be asked to take a dataset and figure out how to [tell a story with it][3]. In times like this, it’s important to communicate very well, and walk through your process. Tools like Jupyter notebook, which we used in a previous post, are very good at helping you do this. The expectation here is that the deliverable is a presentation or document summarizing your findings. + +However, there are other times when you’ll be asked to create a project that has operational value. A project with operational value directly impacts the day-to-day operations of a company, and will be used more than once, and often by multiple people. A task like this might be “create an algorithm to forecast our churn rate”, or “create a model that can automatically tag our articles”. In cases like this, storytelling is less important than technical competence. You need to be able to take a dataset, understand it, then create a set of scripts that can process that data. It’s often important that these scripts run quickly, and use minimal system resources like memory. It’s very common that these scripts will be run several times, so the deliverable becomes the scripts themselves, not a presentation. The deliverable is often integrated into operational flows, and may even be user-facing. + +The main components of building an end to end project are: + +- Understanding the context +- Exploring the data and figuring out the nuances +- Creating a well-structured project, so its easy to integrate into operational flows +- Writing high-performance code that runs quickly and uses minimal system resources +- Documenting the installation and usage of your code well, so others can use it + +In order to effectively create a project of this kind, we’ll need to work with multiple files. Using a text editor like [Atom][4], or an IDE like [PyCharm][5] is highly recommended. These tools will allow you to jump between files, and edit files of different types, like markdown files, Python files, and csv files. Structuring your project so it’s easy to version control and upload to collaborative coding tools like [Github][6] is also useful. + +![](https://www.dataquest.io/blog/images/end_to_end/github.png) +>This project on Github. + +We’ll use our editing tools along with libraries like [Pandas][7] and [scikit-learn][8] in this post. We’ll make extensive use of Pandas [DataFrames][9], which make it easy to read in and work with tabular data in Python. + +### Finding good datasets + +A good dataset for an end to end portfolio project can be hard to find. [The dataset][10] needs to be sufficiently large that memory and performance constraints come into play. It also needs to potentially be operationally useful. For instance, this dataset, which contains data on the admission criteria, graduation rates, and graduate future earnings for US colleges would be a great dataset to use to tell a story. However, as you think about the dataset, it becomes clear that there isn’t enough nuance to build a good end to end project with it. For example, you could tell someone their potential future earnings if they went to a specific college, but that would be a quick lookup without enough nuance to demonstrate technical competence. You could also figure out if colleges with higher admissions standards tend to have graduates who earn more, but that would be more storytelling than operational. + +These memory and performance constraints tend to come into play when you have more than a gigabyte of data, and when you have some nuance to what you want to predict, which involves running algorithms over the dataset. + +A good operational dataset enables you to build a set of scripts that transform the data, and answer dynamic questions. A good example would be a dataset of stock prices. You would be able to predict the prices for the next day, and keep feeding new data to the algorithm as the markets closed. This would enable you to make trades, and potentially even profit. This wouldn’t be telling a story – it would be adding direct value. + +Some good places to find datasets like this are: + +- [/r/datasets][11] – a subreddit that has hundreds of interesting datasets. +- [Google Public Datasets][12] – public datasets available through Google BigQuery. +- [Awesome datasets][13] – a list of datasets, hosted on Github. + +As you look through these datasets, think about what questions someone might want answered with the dataset, and think if those questions are one-time (“how did housing prices correlate with the S&P 500?”), or ongoing (“can you predict the stock market?”). The key here is to find questions that are ongoing, and require the same code to be run multiple times with different inputs (different data). + +For the purposes of this post, we’ll look at [Fannie Mae Loan Data][14]. Fannie Mae is a government sponsored enterprise in the US that buys mortgage loans from other lenders. It then bundles these loans up into mortgage-backed securities and resells them. This enables lenders to make more mortgage loans, and creates more liquidity in the market. This theoretically leads to more homeownership, and better loan terms. From a borrowers perspective, things stay largely the same, though. + +Fannie Mae releases two types of data – data on loans it acquires, and data on how those loans perform over time. In the ideal case, someone borrows money from a lender, then repays the loan until the balance is zero. However, some borrowers miss multiple payments, which can cause foreclosure. Foreclosure is when the house is seized by the bank because mortgage payments cannot be made. Fannie Mae tracks which loans have missed payments on them, and which loans needed to be foreclosed on. This data is published quarterly, and lags the current date by 1 year. As of this writing, the most recent dataset that’s available is from the first quarter of 2015. + +Acquisition data, which is published when the loan is acquired by Fannie Mae, contains information on the borrower, including credit score, and information on their loan and home. Performance data, which is published every quarter after the loan is acquired, contains information on the payments being made by the borrower, and the foreclosure status, if any. A loan that is acquired may have dozens of rows in the performance data. A good way to think of this is that the acquisition data tells you that Fannie Mae now controls the loan, and the performance data contains a series of status updates on the loan. One of the status updates may tell us that the loan was foreclosed on during a certain quarter. + +![](https://www.dataquest.io/blog/images/end_to_end/foreclosure.jpg) +>A foreclosed home being sold. + +### Picking an angle + +There are a few directions we could go in with the Fannie Mae dataset. We could: + +- Try to predict the sale price of a house after it’s foreclosed on. +- Predict the payment history of a borrower. +- Figure out a score for each loan at acquisition time. + +The important thing is to stick to a single angle. Trying to focus on too many things at once will make it hard to make an effective project. It’s also important to pick an angle that has sufficient nuance. Here are examples of angles without much nuance: + +- Figuring out which banks sold loans to Fannie Mae that were foreclosed on the most. +- Figuring out trends in borrower credit scores. +- Exploring which types of homes are foreclosed on most often. +- Exploring the relationship between loan amounts and foreclosure sale prices + +All of the above angles are interesting, and would be great if we were focused on storytelling, but aren’t great fits for an operational project. + +With the Fannie Mae dataset, we’ll try to predict whether a loan will be foreclosed on in the future by only using information that was available when the loan was acquired. In effect, we’ll create a “score” for any mortgage that will tell us if Fannie Mae should buy it or not. This will give us a nice foundation to build on, and will be a great portfolio piece. + +### Understanding the data + +Let’s take a quick look at the raw data files. Here are the first few rows of the acquisition data from quarter 1 of 2012: + +``` +100000853384|R|OTHER|4.625|280000|360|02/2012|04/2012|31|31|1|23|801|N|C|SF|1|I|CA|945||FRM| +100003735682|R|SUNTRUST MORTGAGE INC.|3.99|466000|360|01/2012|03/2012|80|80|2|30|794|N|P|SF|1|P|MD|208||FRM|788 +100006367485|C|PHH MORTGAGE CORPORATION|4|229000|360|02/2012|04/2012|67|67|2|36|802|N|R|SF|1|P|CA|959||FRM|794 +``` + +Here are the first few rows of the performance data from quarter 1 of 2012: + +``` +100000853384|03/01/2012|OTHER|4.625||0|360|359|03/2042|41860|0|N|||||||||||||||| +100000853384|04/01/2012||4.625||1|359|358|03/2042|41860|0|N|||||||||||||||| +100000853384|05/01/2012||4.625||2|358|357|03/2042|41860|0|N|||||||||||||||| +``` + +Before proceeding too far into coding, it’s useful to take some time and really understand the data. This is more critical in operational projects – because we aren’t interactively exploring the data, it can be harder to spot certain nuances unless we find them upfront. In this case, the first step is to read the materials on the Fannie Mae site: + +- [Overview][15] +- [Glossary of useful terms][16] +- [FAQs][17] +- [Columns in the Acquisition and Performance files][18] +- [Sample Acquisition data file][19] +- [Sample Performance data file][20] + +After reading through these files, we know some key facts that will help us: + +- There’s an Acquisition file and a Performance file for each quarter, starting from the year 2000 to present. There’s a 1 year lag in the data, so the most recent data is from 2015 as of this writing. +- The files are in text format, with a pipe (|) as a delimiter. +- The files don’t have headers, but we have a list of what each column is. +- All together, the files contain data on 22 million loans. +- Because the Performance files contain information on loans acquired in previous years, there will be more performance data for loans acquired in earlier years (ie loans acquired in 2014 won’t have much performance history). + +These small bits of information will save us a ton of time as we figure out how to structure our project and work with the data. + +### Structuring the project + +Before we start downloading and exploring the data, it’s important to think about how we’ll structure the project. When building an end-to-end project, our primary goals are: + +- Creating a solution that works +- Having a solution that runs quickly and uses minimal resources +- Enabling others to easily extend our work +- Making it easy for others to understand our code +- Writing as little code as possible + +In order to achieve these goals, we’ll need to structure our project well. A well structured project follows a few principles: + +- Separates data files and code files. +- Separates raw data from generated data. +- Has a README.md file that walks people through installing and using the project. +- Has a requirements.txt file that contains all the packages needed to run the project. +- Has a single settings.py file that contains any settings that are used in other files. + - For example, if you are reading the same file from multiple Python scripts, it’s useful to have them all import settings and get the file name from a centralized place. +- Has a .gitignore file that prevents large or secret files from being committed. +- Breaks each step in our task into a separate file that can be executed separately. + - For example, we may have one file for reading in the data, one for creating features, and one for making predictions. +- Stores intermediate values. For example, one script may output a file that the next script can read. + - This enables us to make changes in our data processing flow without recalculating everything. + +Our file structure will look something like this shortly: + +``` +loan-prediction +├── data +├── processed +├── .gitignore +├── README.md +├── requirements.txt +├── settings.py +``` + +### Creating the initial files + +To start with, we’ll need to create a loan-prediction folder. Inside that folder, we’ll need to make a data folder and a processed folder. The first will store our raw data, and the second will store any intermediate calculated values. + +Next, we’ll make a .gitignore file. A .gitignore file will make sure certain files are ignored by git and not pushed to Github. One good example of such a file is the .DS_Store file created by OSX in every folder. A good starting point for a .gitignore file is here. We’ll also want to ignore the data files because they are very large, and the Fannie Mae terms prevent us from redistributing them, so we should add two lines to the end of our file: + +``` +data +processed +``` + +[Here’s][21] an example .gitignore file for this project. + +Next, we’ll need to create README.md, which will help people understand the project. .md indicates that the file is in markdown format. Markdown enables you write plain text, but also add some fancy formatting if you want. [Here’s][22] a guide on markdown. If you upload a file called README.md to Github, Github will automatically process the markdown, and show it to anyone who views the project. [Here’s][23] an example. + +For now, we just need to put a simple description in README.md: + +``` +Loan Prediction +----------------------- + +Predict whether or not loans acquired by Fannie Mae will go into foreclosure. Fannie Mae acquires loans from other lenders as a way of inducing them to lend more. Fannie Mae releases data on the loans it has acquired and their performance afterwards [here](http://www.fanniemae.com/portal/funding-the-market/data/loan-performance-data.html). +``` + +Now, we can create a requirements.txt file. This will make it easy for other people to install our project. We don’t know exactly what libraries we’ll be using yet, but here’s a good starting point: + +``` +pandas +matplotlib +scikit-learn +numpy +ipython +scipy +``` + +The above libraries are the most commonly used for data analysis tasks in Python, and its fair to assume that we’ll be using most of them. [Here’s][24] an example requirements file for this project. + +After creating requirements.txt, you should install the packages. For this post, we’ll be using Python 3. If you don’t have Python installed, you should look into using [Anaconda][25], a Python installer that also installs all the packages listed above. + +Finally, we can just make a blank settings.py file, since we don’t have any settings for our project yet. + +### Acquiring the data + +Once we have the skeleton of our project, we can get the raw data. + +Fannie Mae has some restrictions around acquiring the data, so you’ll need to sign up for an account. You can find the download page [here][26]. After creating an account, you’ll be able to download as few or as many loan data files as you want. The files are in zip format, and are reasonably large after decompression. + +For the purposes of this blog post, we’ll download everything from Q1 2012 to Q1 2015, inclusive. We’ll then need to unzip all of the files. After unzipping the files, remove the original .zip files. At the end, the loan-prediction folder should look something like this: + +``` +loan-prediction +├── data +│ ├── Acquisition_2012Q1.txt +│ ├── Acquisition_2012Q2.txt +│ ├── Performance_2012Q1.txt +│ ├── Performance_2012Q2.txt +│ └── ... +├── processed +├── .gitignore +├── README.md +├── requirements.txt +├── settings.py +``` + +After downloading the data, you can use the head and tail shell commands to look at the lines in the files. Do you see any columns that aren’t needed? It might be useful to consult the [pdf of column names][27] while doing this. + +### Reading in the data + +There are two issues that make our data hard to work with right now: + +- The acquisition and performance datasets are segmented across multiple files. +- Each file is missing headers. + +Before we can get started on working with the data, we’ll need to get to the point where we have one file for the acquisition data, and one file for the performance data. Each of the files will need to contain only the columns we care about, and have the proper headers. One wrinkle here is that the performance data is quite large, so we should try to trim some of the columns if we can. + +The first step is to add some variables to settings.py, which will contain the paths to our raw data and our processed data. We’ll also add a few other settings that will be useful later on: + +``` +DATA_DIR = "data" +PROCESSED_DIR = "processed" +MINIMUM_TRACKING_QUARTERS = 4 +TARGET = "foreclosure_status" +NON_PREDICTORS = [TARGET, "id"] +CV_FOLDS = 3 +``` + +Putting the paths in settings.py will put them in a centralized place and make them easy to change down the line. When referring to the same variables in multiple files, it’s easier to put them in a central place than edit them in every file when you want to change them. [Here’s][28] an example settings.py file for this project. + +The second step is to create a file called assemble.py that will assemble all the pieces into 2 files. When we run python assemble.py, we’ll get 2 data files in the processed directory. + +We’ll then start writing code in assemble.py. We’ll first need to define the headers for each file, so we’ll need to look at [pdf of column names][29] and create lists of the columns in each Acquisition and Performance file: + +``` +HEADERS = { + "Acquisition": [ + "id", + "channel", + "seller", + "interest_rate", + "balance", + "loan_term", + "origination_date", + "first_payment_date", + "ltv", + "cltv", + "borrower_count", + "dti", + "borrower_credit_score", + "first_time_homebuyer", + "loan_purpose", + "property_type", + "unit_count", + "occupancy_status", + "property_state", + "zip", + "insurance_percentage", + "product_type", + "co_borrower_credit_score" + ], + "Performance": [ + "id", + "reporting_period", + "servicer_name", + "interest_rate", + "balance", + "loan_age", + "months_to_maturity", + "maturity_date", + "msa", + "delinquency_status", + "modification_flag", + "zero_balance_code", + "zero_balance_date", + "last_paid_installment_date", + "foreclosure_date", + "disposition_date", + "foreclosure_costs", + "property_repair_costs", + "recovery_costs", + "misc_costs", + "tax_costs", + "sale_proceeds", + "credit_enhancement_proceeds", + "repurchase_proceeds", + "other_foreclosure_proceeds", + "non_interest_bearing_balance", + "principal_forgiveness_balance" + ] +} +``` + +The next step is to define the columns we want to keep. Since all we’re measuring on an ongoing basis about the loan is whether or not it was ever foreclosed on, we can discard many of the columns in the performance data. We’ll need to keep all the columns in the acquisition data, though, because we want to maximize the information we have about when the loan was acquired (after all, we’re predicting if the loan will ever be foreclosed or not at the point it’s acquired). Discarding columns will enable us to save disk space and memory, while also speeding up our code. + +``` +SELECT = { + "Acquisition": HEADERS["Acquisition"], + "Performance": [ + "id", + "foreclosure_date" + ] +} +``` + +Next, we’ll write a function to concatenate the data sets. The below code will: + +- Import a few needed libraries, including settings. +- Define a function concatenate, that: + - Gets the names of all the files in the data directory. + - Loops through each file. + - If the file isn’t the right type (doesn’t start with the prefix we want), we ignore it. + - Reads the file into a [DataFrame][30] with the right settings using the Pandas [read_csv][31] function. + - Sets the separator to | so the fields are read in correctly. + - The data has no header row, so sets header to None to indicate this. + - Sets names to the right value from the HEADERS dictionary – these will be the column names of our DataFrame. + - Picks only the columns from the DataFrame that we added in SELECT. +- Concatenates all the DataFrames together. +- Writes the concatenated DataFrame back to a file. + +``` +import os +import settings +import pandas as pd + +def concatenate(prefix="Acquisition"): + files = os.listdir(settings.DATA_DIR) + full = [] + for f in files: + if not f.startswith(prefix): + continue + + data = pd.read_csv(os.path.join(settings.DATA_DIR, f), sep="|", header=None, names=HEADERS[prefix], index_col=False) + data = data[SELECT[prefix]] + full.append(data) + + full = pd.concat(full, axis=0) + + full.to_csv(os.path.join(settings.PROCESSED_DIR, "{}.txt".format(prefix)), sep="|", header=SELECT[prefix], index=False) +``` + +We can call the above function twice with the arguments Acquisition and Performance to concatenate all the acquisition and performance files together. The below code will: + +- Only execute if the script is called from the command line with python assemble.py. +- Concatenate all the files, and result in two files: + - `processed/Acquisition.txt` + - `processed/Performance.txt` + +``` +if __name__ == "__main__": + concatenate("Acquisition") + concatenate("Performance") +``` + +We now have a nice, compartmentalized assemble.py that’s easy to execute, and easy to build off of. By decomposing the problem into pieces like this, we make it easy to build our project. Instead of one messy script that does everything, we define the data that will pass between the scripts, and make them completely separate from each other. When you’re working on larger projects, it’s a good idea to do this, because it makes it much easier to change individual pieces without having unexpected consequences on unrelated pieces of the project. + +Once we finish the assemble.py script, we can run python assemble.py. You can find the complete assemble.py file [here][32]. + +This will result in two files in the processed directory: + +``` +loan-prediction +├── data +│ ├── Acquisition_2012Q1.txt +│ ├── Acquisition_2012Q2.txt +│ ├── Performance_2012Q1.txt +│ ├── Performance_2012Q2.txt +│ └── ... +├── processed +│ ├── Acquisition.txt +│ ├── Performance.txt +├── .gitignore +├── assemble.py +├── README.md +├── requirements.txt +├── settings.py +``` + +### Computing values from the performance data + +The next step we’ll take is to calculate some values from processed/Performance.txt. All we want to do is to predict whether or not a property is foreclosed on. To figure this out, we just need to check if the performance data associated with a loan ever has a foreclosure_date. If foreclosure_date is None, then the property was never foreclosed on. In order to avoid including loans with little performance history in our sample, we’ll also want to count up how many rows exist in the performance file for each loan. This will let us filter loans without much performance history from our training data. + +One way to think of the loan data and the performance data is like this: + +![](https://github.com/LCTT/wiki-images/blob/master/TranslateProject/ref_img/001.png) + +As you can see above, each row in the Acquisition data can be related to multiple rows in the Performance data. In the Performance data, foreclosure_date will appear in the quarter when the foreclosure happened, so it should be blank prior to that. Some loans are never foreclosed on, so all the rows related to them in the Performance data have foreclosure_date blank. + +We need to compute foreclosure_status, which is a Boolean that indicates whether a particular loan id was ever foreclosed on, and performance_count, which is the number of rows in the performance data for each loan id. + +There are a few different ways to compute the counts we want: + +- We could read in all the performance data, then use the Pandas groupby method on the DataFrame to figure out the number of rows associated with each loan id, and also if the foreclosure_date is ever not None for the id. + - The upside of this method is that it’s easy to implement from a syntax perspective. + - The downside is that reading in all 129236094 lines in the data will take a lot of memory, and be extremely slow. +- We could read in all the performance data, then use apply on the acquisition DataFrame to find the counts for each id. + - The upside is that it’s easy to conceptualize. + - The downside is that reading in all 129236094 lines in the data will take a lot of memory, and be extremely slow. +- We could iterate over each row in the performance dataset, and keep a separate dictionary of counts. + - The upside is that the dataset doesn’t need to be loaded into memory, so it’s extremely fast and memory-efficient. + - The downside is that it will take slightly longer to conceptualize and implement, and we need to parse the rows manually. + +Loading in all the data will take quite a bit of memory, so let’s go with the third option above. All we need to do is to iterate through all the rows in the Performance data, while keeping a dictionary of counts per loan id. In the dictionary, we’ll keep track of how many times the id appears in the performance data, as well as if foreclosure_date is ever not None. This will give us foreclosure_status and performance_count. + +We’ll create a new file called annotate.py, and add in code that will enable us to compute these values. In the below code, we’ll: + +- Import needed libraries. +- Define a function called count_performance_rows. + - Open processed/Performance.txt. This doesn’t read the file into memory, but instead opens a file handler that can be used to read in the file line by line. + - Loop through each line in the file. + - Split the line on the delimiter (|) + - Check if the loan_id is not in the counts dictionary. + - If not, add it to counts. + - Increment performance_count for the given loan_id because we’re on a row that contains it. + - If date is not None, then we know that the loan was foreclosed on, so set foreclosure_status appropriately. + +``` +import os +import settings +import pandas as pd + +def count_performance_rows(): + counts = {} + with open(os.path.join(settings.PROCESSED_DIR, "Performance.txt"), 'r') as f: + for i, line in enumerate(f): + if i == 0: + # Skip header row + continue + loan_id, date = line.split("|") + loan_id = int(loan_id) + if loan_id not in counts: + counts[loan_id] = { + "foreclosure_status": False, + "performance_count": 0 + } + counts[loan_id]["performance_count"] += 1 + if len(date.strip()) > 0: + counts[loan_id]["foreclosure_status"] = True + return counts +``` + +### Getting the values + +Once we create our counts dictionary, we can make a function that will extract values from the dictionary if a loan_id and a key are passed in: + +``` +def get_performance_summary_value(loan_id, key, counts): + value = counts.get(loan_id, { + "foreclosure_status": False, + "performance_count": 0 + }) + return value[key] +``` + +The above function will return the appropriate value from the counts dictionary, and will enable us to assign a foreclosure_status value and a performance_count value to each row in the Acquisition data. The [get][33] method on dictionaries returns a default value if a key isn’t found, so this enables us to return sensible default values if a key isn’t found in the counts dictionary. + +### Annotating the data + +We’ve already added a few functions to annotate.py, but now we can get into the meat of the file. We’ll need to convert the acquisition data into a training dataset that can be used in a machine learning algorithm. This involves a few things: + +- Converting all columns to numeric. +- Filling in any missing values. +- Assigning a performance_count and a foreclosure_status to each row. +- Removing any rows that don’t have a lot of performance history (where performance_count is low). + +Several of our columns are strings, which aren’t useful to a machine learning algorithm. However, they are actually categorical variables, where there are a few different category codes, like R, S, and so on. We can convert these columns to numeric by assigning a number to each category label: + +![](https://github.com/LCTT/wiki-images/blob/master/TranslateProject/ref_img/002.png) + +Converting the columns this way will allow us to use them in our machine learning algorithm. + +Some of the columns also contain dates (first_payment_date and origination_date). We can split these dates into 2 columns each: + +![](https://github.com/LCTT/wiki-images/blob/master/TranslateProject/ref_img/003.png) +In the below code, we’ll transform the Acquisition data. We’ll define a function that: + +- Creates a foreclosure_status column in acquisition by getting the values from the counts dictionary. +- Creates a performance_count column in acquisition by getting the values from the counts dictionary. +- Converts each of the following columns from a string column to an integer column: + - channel + - seller + - first_time_homebuyer + - loan_purpose + - property_type + - occupancy_status + - property_state + - product_type +- Converts first_payment_date and origination_date to 2 columns each: + - Splits the column on the forward slash. + - Assigns the first part of the split list to a month column. + - Assigns the second part of the split list to a year column. + - Deletes the column. + - At the end, we’ll have first_payment_month, first_payment_year, origination_month, and origination_year. +- Fills any missing values in acquisition with -1. + +``` +def annotate(acquisition, counts): + acquisition["foreclosure_status"] = acquisition["id"].apply(lambda x: get_performance_summary_value(x, "foreclosure_status", counts)) + acquisition["performance_count"] = acquisition["id"].apply(lambda x: get_performance_summary_value(x, "performance_count", counts)) + for column in [ + "channel", + "seller", + "first_time_homebuyer", + "loan_purpose", + "property_type", + "occupancy_status", + "property_state", + "product_type" + ]: + acquisition[column] = acquisition[column].astype('category').cat.codes + + for start in ["first_payment", "origination"]: + column = "{}_date".format(start) + acquisition["{}_year".format(start)] = pd.to_numeric(acquisition[column].str.split('/').str.get(1)) + acquisition["{}_month".format(start)] = pd.to_numeric(acquisition[column].str.split('/').str.get(0)) + del acquisition[column] + + acquisition = acquisition.fillna(-1) + acquisition = acquisition[acquisition["performance_count"] > settings.MINIMUM_TRACKING_QUARTERS] + return acquisition +``` + +### Pulling everything together + +We’re almost ready to pull everything together, we just need to add a bit more code to annotate.py. In the below code, we: + +- Define a function to read in the acquisition data. +- Define a function to write the processed data to processed/train.csv +- If this file is called from the command line, like python annotate.py: + - Read in the acquisition data. + - Compute the counts for the performance data, and assign them to counts. + - Annotate the acquisition DataFrame. + - Write the acquisition DataFrame to train.csv. + +``` +def read(): + acquisition = pd.read_csv(os.path.join(settings.PROCESSED_DIR, "Acquisition.txt"), sep="|") + return acquisition + +def write(acquisition): + acquisition.to_csv(os.path.join(settings.PROCESSED_DIR, "train.csv"), index=False) + +if __name__ == "__main__": + acquisition = read() + counts = count_performance_rows() + acquisition = annotate(acquisition, counts) + write(acquisition) +``` + +Once you’re done updating the file, make sure to run it with python annotate.py, to generate the train.csv file. You can find the complete annotate.py file [here][34]. + +The folder should now look like this: + +``` +loan-prediction +├── data +│ ├── Acquisition_2012Q1.txt +│ ├── Acquisition_2012Q2.txt +│ ├── Performance_2012Q1.txt +│ ├── Performance_2012Q2.txt +│ └── ... +├── processed +│ ├── Acquisition.txt +│ ├── Performance.txt +│ ├── train.csv +├── .gitignore +├── annotate.py +├── assemble.py +├── README.md +├── requirements.txt +├── settings.py +``` + +### Finding an error metric + +We’re done with generating our training dataset, and now we’ll just need to do the final step, generating predictions. We’ll need to figure out an error metric, as well as how we want to evaluate our data. In this case, there are many more loans that aren’t foreclosed on than are, so typical accuracy measures don’t make much sense. + +If we read in the training data, and check the counts in the foreclosure_status column, here’s what we get: + +``` +import pandas as pd +import settings + +train = pd.read_csv(os.path.join(settings.PROCESSED_DIR, "train.csv")) +train["foreclosure_status"].value_counts() +``` + +``` +False 4635982 +True 1585 +Name: foreclosure_status, dtype: int64 +``` + +Since so few of the loans were foreclosed on, just checking the percentage of labels that were correctly predicted will mean that we can make a machine learning model that predicts False for every row, and still gets a very high accuracy. Instead, we’ll want to use a metric that takes the class imbalance into account, and ensures that we predict foreclosures accurately. We don’t want too many false positives, where we make predict that a loan will be foreclosed on even though it won’t, or too many false negatives, where we predict that a loan won’t be foreclosed on, but it is. Of these two, false negatives are more costly for Fannie Mae, because they’re buying loans where they may not be able to recoup their investment. + +We’ll define false negative rate as the number of loans where the model predicts no foreclosure but the the loan was actually foreclosed on, divided by the number of total loans that were actually foreclosed on. This is the percentage of actual foreclosures that the model “Missed”. Here’s a diagram: + +![](https://github.com/LCTT/wiki-images/blob/master/TranslateProject/ref_img/004.png) + +In the diagram above, 1 loan was predicted as not being foreclosed on, but it actually was. If we divide this by the number of loans that were actually foreclosed on, 2, we get the false negative rate, 50%. We’ll use this as our error metric, so we can evaluate our model’s performance. + +### Setting up the classifier for machine learning + +We’ll use cross validation to make predictions. With cross validation, we’ll divide our data into 3 groups. Then we’ll do the following: + +- Train a model on groups 1 and 2, and use the model to make predictions for group 3. +- Train a model on groups 1 and 3, and use the model to make predictions for group 2. +- Train a model on groups 2 and 3, and use the model to make predictions for group 1. + +Splitting it up into groups this way means that we never train a model using the same data we’re making predictions for. This avoids overfitting. If we overfit, we’ll get a falsely low false negative rate, which makes it hard to improve our algorithm or use it in the real world. + +[Scikit-learn][35] has a function called [cross_val_predict][36] which will make it easy to perform cross validation. + +We’ll also need to pick an algorithm to use to make predictions. We need a classifier that can do [binary classification][37]. The target variable, foreclosure_status only has two values, True and False. + +We’ll use [logistic regression][38], because it works well for binary classification, runs extremely quickly, and uses little memory. This is due to how the algorithm works – instead of constructing dozens of trees, like a random forest, or doing expensive transformations, like a support vector machine, logistic regression has far fewer steps involving fewer matrix operations. + +We can use the [logistic regression classifier][39] algorithm that’s implemented in scikit-learn. The only thing we need to pay attention to is the weights of each class. If we weight the classes equally, the algorithm will predict False for every row, because it is trying to minimize errors. However, we care much more about foreclosures than we do about loans that aren’t foreclosed on. Thus, we’ll pass balanced to the class_weight keyword argument of the [LogisticRegression][40] class, to get the algorithm to weight the foreclosures more to account for the difference in the counts of each class. This will ensure that the algorithm doesn’t predict False for every row, and instead is penalized equally for making errors in predicting either class. + +### Making predictions + +Now that we have the preliminaries out of the way, we’re ready to make predictions. We’ll create a new file called predict.py that will use the train.csv file we created in the last step. The below code will: + +- Import needed libraries. +- Create a function called cross_validate that: + - Creates a logistic regression classifier with the right keyword arguments. + - Creates a list of columns that we want to use to train the model, removing id and foreclosure_status. + - Run cross validation across the train DataFrame. + - Return the predictions. + + +``` +import os +import settings +import pandas as pd +from sklearn import cross_validation +from sklearn.linear_model import LogisticRegression +from sklearn import metrics + +def cross_validate(train): + clf = LogisticRegression(random_state=1, class_weight="balanced") + + predictors = train.columns.tolist() + predictors = [p for p in predictors if p not in settings.NON_PREDICTORS] + + predictions = cross_validation.cross_val_predict(clf, train[predictors], train[settings.TARGET], cv=settings.CV_FOLDS) + return predictions +``` + +### Predicting error + +Now, we just need to write a few functions to compute error. The below code will: + +- Create a function called compute_error that: + - Uses scikit-learn to compute a simple accuracy score (the percentage of predictions that matched the actual foreclosure_status values). +- Create a function called compute_false_negatives that: + - Combines the target and the predictions into a DataFrame for convenience. + - Finds the false negative rate. +- Create a function called compute_false_positives that: + - Combines the target and the predictions into a DataFrame for convenience. + - Finds the false positive rate. + - Finds the number of loans that weren’t foreclosed on that the model predicted would be foreclosed on. + - Divide by the total number of loans that weren’t foreclosed on. + +``` +def compute_error(target, predictions): + return metrics.accuracy_score(target, predictions) + +def compute_false_negatives(target, predictions): + df = pd.DataFrame({"target": target, "predictions": predictions}) + return df[(df["target"] == 1) & (df["predictions"] == 0)].shape[0] / (df[(df["target"] == 1)].shape[0] + 1) + +def compute_false_positives(target, predictions): + df = pd.DataFrame({"target": target, "predictions": predictions}) + return df[(df["target"] == 0) & (df["predictions"] == 1)].shape[0] / (df[(df["target"] == 0)].shape[0] + 1) +``` + +### Putting it all together + +Now, we just have to put the functions together in predict.py. The below code will: + +- Read in the dataset. +- Compute cross validated predictions. +- Compute the 3 error metrics above. +- Print the error metrics. + +``` +def read(): + train = pd.read_csv(os.path.join(settings.PROCESSED_DIR, "train.csv")) + return train + +if __name__ == "__main__": + train = read() + predictions = cross_validate(train) + error = compute_error(train[settings.TARGET], predictions) + fn = compute_false_negatives(train[settings.TARGET], predictions) + fp = compute_false_positives(train[settings.TARGET], predictions) + print("Accuracy Score: {}".format(error)) + print("False Negatives: {}".format(fn)) + print("False Positives: {}".format(fp)) +``` + +Once you’ve added the code, you can run python predict.py to generate predictions. Running everything shows that our false negative rate is .26, which means that of the foreclosed loans, we missed predicting 26% of them. This is a good start, but can use a lot of improvement! + +You can find the complete predict.py file [here][41]. + +Your file tree should now look like this: + +``` +loan-prediction +├── data +│ ├── Acquisition_2012Q1.txt +│ ├── Acquisition_2012Q2.txt +│ ├── Performance_2012Q1.txt +│ ├── Performance_2012Q2.txt +│ └── ... +├── processed +│ ├── Acquisition.txt +│ ├── Performance.txt +│ ├── train.csv +├── .gitignore +├── annotate.py +├── assemble.py +├── predict.py +├── README.md +├── requirements.txt +├── settings.py +``` + +### Writing up a README + +Now that we’ve finished our end to end project, we just have to write up a README.md file so that other people know what we did, and how to replicate it. A typical README.md for a project should include these sections: + +- A high level overview of the project, and what the goals are. +- Where to download any needed data or materials. +- Installation instructions. + - How to install the requirements. +- Usage instructions. + - How to run the project. + - What you should see after each step. +- How to contribute to the project. + - Good next steps for extending the project. + +[Here’s][42] a sample README.md for this project. + +### Next steps + +Congratulations, you’re done making an end to end machine learning project! You can find a complete example project [here][43]. It’s a good idea to upload your project to [Github][44] once you’ve finished it, so others can see it as part of your portfolio. + +There are still quite a few angles left to explore with this data. Broadly, we can split them up into 3 categories – extending this project and making it more accurate, finding other columns to predict, and exploring the data. Here are some ideas: + +- Generate more features in annotate.py. +- Switch algorithms in predict.py. +- Try using more data from Fannie Mae than we used in this post. +- Add in a way to make predictions on future data. The code we wrote will still work if we add more data, so we can add more past or future data. +- Try seeing if you can predict if a bank should have issued the loan originally (vs if Fannie Mae should have acquired the loan). + - Remove any columns from train that the bank wouldn’t have known at the time of issuing the loan. + - Some columns are known when Fannie Mae bought the loan, but not before. + - Make predictions. +- Explore seeing if you can predict columns other than foreclosure_status. + - Can you predict how much the property will be worth at sale time? +- Explore the nuances between performance updates. + - Can you predict how many times the borrower will be late on payments? + - Can you map out the typical loan lifecycle? +- Map out data on a state by state or zip code by zip code level. + - Do you see any interesting patterns? + +If you build anything interesting, please let us know in the comments! + +If you liked this, you might like to read the other posts in our ‘Build a Data Science Porfolio’ series: + +- [Storytelling with data][45]. +- [How to setup up a data science blog][46]. + + +-------------------------------------------------------------------------------- + +via: https://www.dataquest.io/blog/data-science-portfolio-machine-learning/ + +作者：[Vik Paruchuri][a] +译者：[译者ID](https://github.com/译者ID) +校对：[校对ID](https://github.com/校对ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://www.dataquest.io/blog +[1]: https://www.dataquest.io/blog/data-science-portfolio-machine-learning/#email-signup +[2]: https://github.com/dataquestio/loan-prediction +[3]: https://www.dataquest.io/blog/data-science-portfolio-project/ +[4]: https://atom.io/ +[5]: https://www.jetbrains.com/pycharm/ +[6]: https://github.com/ +[7]: http://pandas.pydata.org/ +[8]: http://scikit-learn.org/ +[9]: http://pandas.pydata.org/pandas-docs/stable/generated/pandas.DataFrame.html +[10]: https://collegescorecard.ed.gov/data/ +[11]: https://reddit.com/r/datasets +[12]: https://cloud.google.com/bigquery/public-data/#usa-names +[13]: https://github.com/caesar0301/awesome-public-datasets +[14]: http://www.fanniemae.com/portal/funding-the-market/data/loan-performance-data.html +[15]: http://www.fanniemae.com/portal/funding-the-market/data/loan-performance-data.html +[16]: https://loanperformancedata.fanniemae.com/lppub-docs/lppub_glossary.pdf +[17]: https://loanperformancedata.fanniemae.com/lppub-docs/lppub_faq.pdf +[18]: https://loanperformancedata.fanniemae.com/lppub-docs/lppub_file_layout.pdf +[19]: https://loanperformancedata.fanniemae.com/lppub-docs/acquisition-sample-file.txt +[20]: https://loanperformancedata.fanniemae.com/lppub-docs/performance-sample-file.txt +[21]: https://github.com/dataquestio/loan-prediction/blob/master/.gitignore +[22]: https://github.com/adam-p/markdown-here/wiki/Markdown-Cheatsheet +[23]: https://github.com/dataquestio/loan-prediction +[24]: https://github.com/dataquestio/loan-prediction/blob/master/requirements.txt +[25]: https://www.continuum.io/downloads +[26]: https://loanperformancedata.fanniemae.com/lppub/index.html +[27]: https://loanperformancedata.fanniemae.com/lppub-docs/lppub_file_layout.pdf +[28]: https://github.com/dataquestio/loan-prediction/blob/master/settings.py +[29]: https://loanperformancedata.fanniemae.com/lppub-docs/lppub_file_layout.pdf +[30]: http://pandas.pydata.org/pandas-docs/stable/generated/pandas.DataFrame.html +[31]: http://pandas.pydata.org/pandas-docs/stable/generated/pandas.read_csv.html +[32]: https://github.com/dataquestio/loan-prediction/blob/master/assemble.py +[33]: https://docs.python.org/3/library/stdtypes.html#dict.get +[34]: https://github.com/dataquestio/loan-prediction/blob/master/annotate.py +[35]: http://scikit-learn.org/ +[36]: http://scikit-learn.org/stable/modules/generated/sklearn.cross_validation.cross_val_predict.html +[37]: https://en.wikipedia.org/wiki/Binary_classification +[38]: https://en.wikipedia.org/wiki/Logistic_regression +[39]: http://scikit-learn.org/stable/modules/generated/sklearn.linear_model.LogisticRegression.html +[40]: http://scikit-learn.org/stable/modules/generated/sklearn.linear_model.LogisticRegression.html +[41]: https://github.com/dataquestio/loan-prediction/blob/master/predict.py +[42]: https://github.com/dataquestio/loan-prediction/blob/master/README.md +[43]: https://github.com/dataquestio/loan-prediction +[44]: https://www.github.com/ +[45]: https://www.dataquest.io/blog/data-science-portfolio-project/ +[46]: https://www.dataquest.io/blog/how-to-setup-a-data-science-blog/ diff --git a/sources/tech/20160717 BEST TEXT EDITORS FOR LINUX COMMAND LINE.md b/sources/tech/20160717 BEST TEXT EDITORS FOR LINUX COMMAND LINE.md new file mode 100644 index 0000000000..80f4b1439c --- /dev/null +++ b/sources/tech/20160717 BEST TEXT EDITORS FOR LINUX COMMAND LINE.md @@ -0,0 +1,95 @@ +Translating by chenzhijun + + +BEST TEXT EDITORS FOR LINUX COMMAND LINE +========================================== + +![](https://itsfoss.com/wp-content/uploads/2016/07/Best-Command-Line-Text-Editors-for-Linux.jpg) + +A text editor is a must have application for any operating system. We have no dearth of [best modern editors for Linux][1]. But those are GUI based editors. + +As you know, the real power of Linux lies in the command line. And when you are working in command line, you would need a text editor that could work right inside the terminal. + +For that purpose, today we are going to make a list of best command line text editors for Linux. + +### [VIM][2] + +If you’re on Linux for quite some time, you must have heard about Vim. Vim is an extensively configurable, cross-platform and highly efficient text editor. + +Almost every Linux distribution comes with Vim pre-installed. It is extremely popular for its wide range of features. + +![](https://itsfoss.com/wp-content/uploads/2016/07/vim.png) +>Vim User Interface + +Vim can be quite agonizing for first-time users. I remember the first time I tried to edit a text file with Vim, I was completely puzzled. I couldn’t type a single letter on it and the funny part is, I couldn’t even figure out how to close this thing. If you are going to use Vim, you have to be determined for climbing up a very steep learning curve. + +But after you have gone through all that, combed through some documentations, remembered its commands and shortcuts you will find that the hassle was worth it. You can bend Vim to your will – customizing its interface however it seems fit to you, give your workflow a boost by using various user scripts, plugins and so on. Vim supports syntax highlighting, macro recording and action history. + +As in the official site, it is stated that, + +>**Vim: The power tool for everyone!** + +It is completely up to you how you will use it. You can just use it for simple text editing, or you can customize it to behave as a full-fledged IDE. + +### [GNU EMACS][3] + +GNU Emacs is undoubtedly one of the most powerful text editor out there. If you have heard about both Vim and Emacs, you should know that both of these editors have a very loyal fan-base and often they are very serious about their text editor of choice. And you can find lots of humor and stuff on the internet about it: + +Suggested Read [Download Linux Wallpapers That Are Also Cheat Sheets][4] + +![](https://itsfoss.com/wp-content/uploads/2016/07/vi-emacs-768x426.png) +>Vim vs Emacs + +Emacs is cross-platform and has both command-line and graphical user interface. It is also very rich with various features and, most importantly, extensible. + +![](https://itsfoss.com/wp-content/uploads/2016/07/emacs.png) +>Emacs User Interface + +Just as Vim, Emacs too comes with a steep learning curve. But once you master it, you can completely leverage its power. Emacs can handle just about any types of text files. The interface is customizable to suit your workflow. It supports macro recording and shortcuts. + +The unique power of Emacs is that it can be transformed into something completely different from a text editor. There is a large collection of modules that can transform the application for using in completely different scenarios, like – calendar, news reader, word processor etc. You can even play games in Emacs! + +### [NANO][5] + +When it comes to simplicity, Nano is the one. Unlike Vim or Emacs, the learning curve for nano is almost flat. + +If you want to simply create & edit a text file and get on with your life, look no further than Nano. + +![](https://itsfoss.com/wp-content/uploads/2016/07/nano.png) +>Nano User Interface + +The shortcuts available on Nano are displayed at the bottom of the user interface. Nano includes only the basic functions of a text editor. + +It is minimal and perfectly suitable for editing system & configuration files. For those who doesn’t need advanced features from a command-line text editor, Nano is the perfect match. + +### OTHERS + +There is one more editor I’d like to mention: + +[The Nice Editor (ne)][6]: The official site says, + +>If you have the resources and the patience to use emacs or the right mental twist to use vi then probably ne is not for you. + +Basically, ne features many advanced features like Vim or Emacs, including – scripting and macro recording. But it comes with a more intuitive control and not so steep learning curve. + +### WHAT DO YOU THINK? + +I know that if you are a seasoned Linux user, you’ll say these are the obvious candidates for the list of best command line text editors for Linux. Therefore, I would like to ask you, if there are some other command line text editors for Linux that you want to share with us? + +-------------------------------------------------------------------------------- + +via: https://itsfoss.com/command-line-text-editors-linux/?utm_source=newsletter&utm_medium=email&utm_campaign=ubuntu_forums_hacked_new_skype_for_linux_and_more_linux_stories + +作者：[Munif Tanjim][a] +译者：[译者ID](https://github.com/译者ID) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://itsfoss.com/author/munif/ +[1]: https://itsfoss.com/best-modern-open-source-code-editors-for-linux/ +[2]: http://www.vim.org/ +[3]: https://www.gnu.org/software/emacs/ +[4]: https://itsfoss.com/download-linux-wallpapers-cheat-sheets/ +[5]: http://www.nano-editor.org/ +[6]: http://ne.di.unimi.it/ diff --git a/sources/tech/20160724 Terminator A Linux Terminal Emulator With Multiple Terminals In One Window.md b/sources/tech/20160724 Terminator A Linux Terminal Emulator With Multiple Terminals In One Window.md new file mode 100644 index 0000000000..2f1b393c80 --- /dev/null +++ b/sources/tech/20160724 Terminator A Linux Terminal Emulator With Multiple Terminals In One Window.md @@ -0,0 +1,86 @@ +sevenot translating +Terminator A Linux Terminal Emulator With Multiple Terminals In One Window +============================================================================= + +![](http://www.linuxandubuntu.com/uploads/2/1/1/5/21152474/lots-of-terminals-in-terminator_1.jpg?659) + +Each Linux distribution has a default terminal emulator for interacting with system through commands. But the default terminal app might not be perfect for you. There are so many terminal apps that will provide you more functionalities to perform more tasks simultaneously to sky-rocket speed of your work. Such useful terminal emulators include Terminator, a multi-windows supported free terminal emulator for your Linux system. + +### What Is Linux Terminal Emulator? + +A Linux terminal emulator is a program that lets you interact with the shell. All Linux distributions come with a default Linux terminal app that let you pass commands to the shell. + +### Terminator, A Free Linux Terminal App + +Terminator is a Linux terminal emulator that provides several features that your default terminal app does not support. It provides the ability to create multiple terminals in one window and faster your work progress. Other than multiple windows, it allows you to change other properties such as, terminal fonts, fonts colour, background colour and so on. Let's see how we can install and use Terminator in different Linux distributions. + +### How To Install Terminator In Linux? + +#### Install Terminator In Ubuntu Based Distributions + +Terminator is available in the default Ubuntu repository. So you don't require to add any additional PPA. Just use APT or Software App to install it in Ubuntu. + +``` +sudo apt-get install terminator +``` + +In case Terminator is not available in your default repository, just compile Terminator from source code. + +[DOWNLOAD SOURCE CODE][1] + +Download Terminator source code and extract it on your desktop. Now open your default terminal & cd into the extracted folder. + +Now use the following command to install Terminator - + +``` +sudo ./setup.py install +``` + +#### Install Terminator In Fedora & Other Derivatives + +``` +dnf install terminator +``` + +#### Install Terminator In OpenSuse + +[INSTALL IN OPENSUSE][2] + +### How To Use Multiple Terminals In One Window? + +After you have installed Terminator, simply open multiple terminals in one window. Simply right click and divide. + +![](http://www.linuxandubuntu.com/uploads/2/1/1/5/21152474/multiple-terminals-in-terminator_orig.jpg) + +![](http://www.linuxandubuntu.com/uploads/2/1/1/5/21152474/multiple-terminals-in-terminator-emulator.jpg?697) + +You can create as many terminals as you want, if you can manage them. + +![](http://www.linuxandubuntu.com/uploads/2/1/1/5/21152474/lots-of-terminals-in-terminator.jpg?706) + +### Customise Terminals + +Right click the terminal and click Properties. Now you can customise fonts, fonts colour, title colour & background and terminal fonts colour & background. + +![](http://www.linuxandubuntu.com/uploads/2/1/1/5/21152474/customize-terminator-interface.jpg?702) + +![](http://www.linuxandubuntu.com/uploads/2/1/1/5/21152474/free-terminal-emulator_orig.jpg) + +### Conclusion & What Is Your Favorite Terminal Emulator? + +Terminator is an advanced terminal emulator and it also let you customize the interface. If you have not yet switched from your default terminal emulator then just try this one. I know you'll like it. If you're using any other free terminal emulator, then let us know your favorite terminal emulator. Also don't forget to share this article with your friends. Perhaps your friends are searching for something like this. + + +-------------------------------------------------------------------------------- + +via: http://www.tecmint.com/mandatory-access-control-with-selinux-or-apparmor-linux/ + +作者：[author][a] +译者：[译者ID](https://github.com/译者ID) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: http://www.linuxandubuntu.com/home/terminator-a-linux-terminal-emulator-with-multiple-terminals-in-one-window +[1]: https://launchpad.net/terminator/+download +[2]: http://software.opensuse.org/download.html?project=home%3AKorbi123&package=terminator diff --git a/sources/tech/20160726 How to restore older file versions in Git.md b/sources/tech/20160726 How to restore older file versions in Git.md new file mode 100644 index 0000000000..675167aaad --- /dev/null +++ b/sources/tech/20160726 How to restore older file versions in Git.md @@ -0,0 +1,182 @@ +translated by strugglingyouth +How to restore older file versions in Git +============================================= + +![](https://opensource.com/sites/default/files/styles/image-full-size/public/images/life/file_system.jpg?itok=s2b60oIB) + +In today's article you will learn how to find out where you are in the history of your project, how to restore older file versions, and how to make Git branches so you can safely conduct wild experiments. + +Where you are in the history of your Git project, much like your location in the span of a rock album, is determined by a marker called HEAD (like the playhead of a tape recorder or record player). To move HEAD around in your own Git timeline, use the git checkout command. + +There are two ways to use the git checkout command. A common use is to restore a file from a previous commit, and you can also rewind your entire tape reel and go in an entirely different direction. + +### Restore a file + +This happens when you realize you've utterly destroyed an otherwise good file. We all do it; we get a file to a great place, we add and commit it, and then we decide that what it really needs is one last adjustment, and the file ends up completely unrecognizable. + +To restore it to its former glory, use git checkout from the last known commit, which is HEAD: + +``` +$ git checkout HEAD filename +``` + +If you accidentally committed a bad version of a file and need to yank a version from even further back in time, look in your Git log to see your previous commits, and then check it out from the appropriate commit: + +``` +$ git log --oneline +79a4e5f bad take +f449007 The second commit +55df4c2 My great project, first commit. + +$ git checkout 55df4c2 filename + +``` + +Now the older version of the file is restored into your current position. (You can see your current status at any time with the git status command.) You need to add the file because it has changed, and then commit it: + +``` +$ git add filename +$ git commit -m 'restoring filename from first commit.' +``` + +Look in your Git log to verify what you did: + +``` +$ git log --oneline +d512580 restoring filename from first commit +79a4e5f bad take +f449007 The second commit +55df4c2 My great project, first commit. +``` + +Essentially, you have rewound the tape and are taping over a bad take. So you need to re-record the good take. + +### Rewind the timeline + +The other way to check out a file is to rewind the entire Git project. This introduces the idea of branches, which are, in a way, alternate takes of the same song. + +When you go back in history, you rewind your Git HEAD to a previous version of your project. This example rewinds all the way back to your original commit: + +``` +$ git log --oneline +d512580 restoring filename from first commit +79a4e5f bad take +f449007 The second commit +55df4c2 My great project, first commit. + +$ git checkout 55df4c2 +``` + +When you rewind the tape in this way, if you hit the record button and go forward, you are destroying your future work. By default, Git assumes you do not want to do this, so it detaches HEAD from the project and lets you work as needed without accidentally recording over something you have recorded later. + +If you look at your previous version and realise suddenly that you want to re-do everything, or at least try a different approach, then the safe way to do that is to create a new branch. You can think of this process as trying out a different version of the same song, or creating a remix. The original material exists, but you're branching off and doing your own version for fun. + +To get your Git HEAD back down on blank tape, make a new branch: + +``` +$ git checkout -b remix +Switched to a new branch 'remix' +``` + +Now you've moved back in time, with an alternate and clean workspace in front of you, ready for whatever changes you want to make. + +You can do the same thing without moving in time. Maybe you're perfectly happy with how your progress is going, but would like to switch to a temporary workspace just to try some crazy ideas out. That's a perfectly acceptable workflow, as well: + +``` +$ git status +On branch master +nothing to commit, working directory clean + +$ git checkout -b crazy_idea +Switched to a new branch 'crazy_idea' +``` + +Now you have a clean workspace where you can sandbox some crazy new ideas. Once you're done, you can either keep your changes, or you can forget they ever existed and switch back to your master branch. + +To forget your ideas in shame, change back to your master branch and pretend your new branch doesn't exist: + +``` +$ git checkout master +``` + +To keep your crazy ideas and pull them back into your master branch, change back to your master branch and merge your new branch: + +``` +$ git checkout master +$ git merge crazy_idea +``` + +Branches are powerful aspects of git, and it's common for developers to create a new branch immediately after cloning a repository; that way, all of their work is contained on their own branch, which they can submit for merging to the master branch. Git is pretty flexible, so there's no "right" or "wrong" way (even a master branch can be distinguished from what remote it belongs to), but branching makes it easy to separate tasks and contributions. Don't get too carried away, but between you and me, you can have as many Git branches as you please. They're free! + +### Working with remotes + +So far you've maintained a Git repository in the comfort and privacy of your own home, but what about when you're working with other people? + +There are several different ways to set Git up so that many people can work on a project at once, so for now we'll focus on working on a clone, whether you got that clone from someone's personal Git server or their GitHub page, or from a shared drive on the same network. + +The only difference between working on your own private Git repository and working on something you want to share with others is that at some point, you need to push your changes to someone else's repository. We call the repository you are working in a local repository, and any other repository a remote. + +When you clone a repository with read and write permissions from another source, your clone inherits the remote from whence it came as its origin. You can see a clone's remote: + +``` +$ git remote --verbose +origin seth@example.com:~/myproject.Git (fetch) +origin seth@example.com:~/myproject.Git (push) +``` + +Having a remote origin is handy because it is functionally an offsite backup, and it also allows someone else to be working on the project. + +If your clone didn't inherit a remote origin, or if you choose to add one later, use the git remote command: + +``` +$ git remote add seth@example.com:~/myproject.Git +``` + +If you have changed files and want to send them to your remote origin, and have read and write permissions to the repository, use git push. The first time you push changes, you must also send your branch information. It is a good practice to not work on master, unless you've been told to do so: + +``` +$ git checkout -b seth-dev +$ git add exciting-new-file.txt +$ git commit -m 'first push to remote' +$ git push -u origin HEAD +``` + +This pushes your current location (HEAD, naturally) and the branch it exists on to the remote. After you've pushed your branch once, you can drop the -u option: + +``` +$ git add another-file.txt +$ git commit -m 'another push to remote' +$ git push origin HEAD +``` + +### Merging branches + +When you're working alone in a Git repository you can merge test branches into your master branch whenever you want. When working in tandem with a contributor, you'll probably want to review their changes before merging them into your master branch: + +``` +$ git checkout contributor +$ git pull +$ less blah.txt # review the changed files +$ git checkout master +$ git merge contributor +``` + +If you are using GitHub or GitLab or something similar, the process is different. There, it is traditional to fork the project and treat it as though it is your own repository. You can work in the repository and send changes to your GitHub or GitLab account without getting permission from anyone, because it's your repository. + +If you want the person you forked it from to receive your changes, you create a pull request, which uses the web service's backend to send patches to the real owner, and allows them to review and pull in your changes. + +Forking a project is usually done on the web service, but the Git commands to manage your copy of the project are the same, even the push process. Then it's back to the web service to open a pull request, and the job is done. + +In our next installment we'll look at some convenience add-ons to help you integrate Git comfortably into your everyday workflow. + +-------------------------------------------------------------------------------- + +via: https://opensource.com/life/16/7/how-restore-older-file-versions-git + +作者：[Seth Kenlon][a] +译者：[译者ID](https://github.com/译者ID) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://opensource.com/users/seth diff --git a/sources/tech/20160802 3 graphical tools for Git.md b/sources/tech/20160802 3 graphical tools for Git.md new file mode 100644 index 0000000000..c09afed48b --- /dev/null +++ b/sources/tech/20160802 3 graphical tools for Git.md @@ -0,0 +1,117 @@ +3 graphical tools for Git +============================= + +![](https://opensource.com/sites/default/files/styles/image-full-size/public/images/government/BUSINESS_meritladder.png?itok=4CAH2wV0) + +In this article, we'll take a look at some convenience add-ons to help you integrate Git comfortably into your everyday workflow. + +I learned Git before many of these fancy interfaces existed, and my workflow is frequently text-based anyway, so most of the inbuilt conveniences of Git suit me pretty well. It is always best, in my opinion, to understand how Git works natively. However, it is always nice to have options, so these are some of the ways you can start using Git outside of the terminal. + +### Git in KDE Dolphin + +I am a KDE user, if not always within the Plasma desktop, then as my application layer in Fluxbox. Dolphin is an excellent file manager with lots of options and plenty of secret little features. Particularly useful are all the plugins people develop for it, one of which is a nearly-complete Git interface. Yes, you can manage your Git repositories natively from the comfort of your own desktop. + +But first, you'll need to make sure the add-ons are installed. Some distros come with a filled-to-the-brim KDE, while others give you just the basics, so if you don't see the Git options in the next few steps, search your repository for something like dolphin-extras or dolphin-plugins. + +To activate Git integration, go to the Settings menu in any Dolphin window and select Configure Dolphin. + +In the Configure Dolphin window, click on the Services icon in the left column. + +In the Services panel, scroll through the list of available plugins until you find Git. + +![](https://opensource.com/sites/default/files/4_dolphinconfig.jpg) + +Save your changes and close your Dolphin window. When you re-launch Dolphin, navigate to a Git repository and have a look around. Notice that all icons now have emblems: green boxes for committed files, solid green boxes for modified files, no icon for untracked files, and so on. + +Your right-click menu now has contextual Git options when invoked inside a Git repository. You can initiate a checkout, push or pull when clicking inside a Dolphin window, and you can even do a git add or git remove on your files. + +![](https://opensource.com/sites/default/files/4_dolphingit.jpg) + +You can't clone a repository or change remote paths in Dolphin, but will have to drop to a terminal, which is just an F4 away. + +Frankly, this feature of KDE is so kool [sic] that this article could just end here. The integration of Git in your native file manager makes working with Git almost transparent; everything you need to do just happens no matter what stage of the process you are in. Git in the terminal, and Git waiting for you when you switch to the GUI. It is perfection. + +But wait, there's more! + +### Sparkleshare + +From the other side of the desktop pond comes SparkleShare, a project that uses a file synchronization model ("like Dropbox!") that got started by some GNOME developers. It is not integrated into any specific part of GNOME, so you can use it on all platforms. + +If you run Linux, install SparkleShare from your software repository. Other operating systems should download from the SparkleShare website. You can safely ignore the instructions on the SparkleShare website, which are for setting up a SparkleShare server, which is not what we will do here. You certainly can set up a SparkleShare server if you want, but SparkleShare is compatible with any Git repository, so you don't need to create your own server. + +After it is installed, launch SparkleShare from your applications menu. Step through the setup wizard, which is two steps plus a brief tutorial, and optionally set SparkleShare as a startup item for your desktop. + +![](https://opensource.com/sites/default/files/4_sparklesetup.jpg) + +An orange SparkleShare directory is now in your system tray. Currently, SparkleShare is oblivious to anything on your computer, so you need to add a hosted project. + +To add a directory for SparkleShare to track, click the SparkleShare icon in your system tray and select Add Hosted Project. + +![](https://opensource.com/sites/default/files/4_sparklehost.jpg) + +SparkleShare can work with self-hosted Git projects, or projects hosted on public Git services like GitHub and Bitbucket. For full access, you'll probably need to use the Client ID that SparkleShare provides to you. This is an SSH key acting as the authentication token for the service you use for hosting, including your own Git server, which should also use SSH public key authentication rather than password login. Copy the Client ID into the authorized_hosts file of your Git user on your server, or into the SSH key panel of your Git host. + +After configuring the host you want to use, SparkleShare downloads the Git project, including, at your option, the commit history. Find the files in ~/SparkleShare. + +Unlike Dolphin's Git integration, SparkleShare is unnervingly invisible. When you make a change, it quietly syncs the change to your remote project. For many people, that is a huge benefit: all the power of Git with none of the maintenance. To me, it is unsettling, because I like to govern what I commit and which branch I use. + +SparkleShare may not be for everyone, but it is a powerful and simple Git solution that shows how different open source projects fit together in perfect harmony to create something unique. + +### Git-cola + +Yet another model of working with Git repositories is less native and more of a monitoring approach; rather than using an integrated application to interact directly with your Git project, you can use a desktop client to monitor changes in your project and deal with each change in whatever way you choose. An advantage to this approach is focus. You might not care about all 125 files in your project when only three of them are actively being worked on, so it is helpful to bring them to the forefront. + +If you thought there were a lot of Git web hosts out there, you haven't seen anything yet. [Git clients for your desktop][1] are a dime-a-dozen. In fact, Git actually ships with an inbuilt graphical Git client. The most cross-platform and most configurable of them all is the open source Git-cola client, written in Python and Qt. + +If you're on Linux, Git-cola may be in your software repository. Otherwise, just download it from the site and install it: + +``` +$ python setup.py install +``` + +When Git-cola launches, you're given three buttons to open an existing repository, create a new repo, or clone an existing repository. + +Whichever you choose, at some point you end up with a Git repository. Git-cola, and indeed most desktop clients that I've used, don't try to be your interface into your repository; they leave that up to your normal operating system tools. In other words, I might start a repository with Git-cola, but then I would open that repository in Thunar or Emacs to start my work. Leaving Git-cola open as a monitor works quite well, because as you create new files, or change existing ones, they appear in Git-cola's Status panel. + +The default layout of Git-cola is a little non-linear. I prefer to move from left-to-right, and because Git-cola happens to be very configurable, you're welcome to change your layout. I set mine up so that the left-most panel is Status, showing any changes made to my current branch, then to the right, a Diff panel in case I want to review a change, and the Actions panel for quick-access buttons to common tasks, and finally the right-most panel is a Commit panel where I can write commit messages. + +![](https://opensource.com/sites/default/files/4_gitcola.jpg) + +Even if you use a different layout, this is the general flow of Git-cola: + +Changes appear in the Status panel. Right-click a change entry, or select a file and click the Stage button in the Action panel, to stage a file. + +A staged file's icon changes to a green triangle to indicate that it has been both modified and staged. You can unstage a file by right-clicking and selecting Unstage Selected, or by clicking the Unstage button in the Actions panel. + +Review your changes in the Diff panel. + +When you are ready to commit, enter a commit message and click the Commit button. + +There are other buttons in the Actions panel for other common tasks like a git pull or git push. The menus round out the task list, with dedicated actions for branching, reviewing diffs, rebasing, and a lot more. + +I tend to think of Git-cola as a kind of floating panel for my file manager (and I only use Git-cola when Dolphin is not available). On one hand, it's less interactive than a fully integrated and Git-aware file manager, but on the other, it offers practically everything that raw Git does, so it's actually more powerful. + +There are plenty of graphical Git clients. Some are paid software with no source code available, others are viewers only, others attempt to reinvent Git with special terms that are specific to the client ("sync" instead of "push"..?), and still others are platform-specific. Git-Cola has consistently been the easiest to use on any platform, and the one that stays closest to pure Git so that users learn Git whilst using it, and experts feel comfortable with the interface and terminology. + +### Git or graphical? + +I don't generally use graphical tools to access Git; mostly I use the ones I've discussed when helping other people find a comfortable interface for themselves. At the end of the day, though, it comes down to what fits with how you work. I like terminal-based Git because it integrates well with Emacs, but on a day where I'm working mostly in Inkscape, I might naturally fall back to using Git in Dolphin because I'm in Dolphin anyway. + +It's up to you how you use Git; the most important thing to remember is that Git is meant to make your life easier and those crazy ideas you have for your work safer to try out. Get familiar with the way Git works, and then use Git from whatever angle you find works best for you. + +In our next installment, we will learn how to set up and manage a Git server, including user access and management, and running custom scripts. + + + +-------------------------------------------------------------------------------- + +via: https://opensource.com/life/16/8/graphical-tools-git + +作者：[Seth Kenlon][a] +译者：[译者ID](https://github.com/译者ID) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://opensource.com/users/seth +[1]: https://git-scm.com/downloads/guis diff --git a/sources/tech/LFCS/Part 11 - How to Manage and Create LVM Using vgcreate, lvcreate and lvextend Commands.md b/sources/tech/LFCS/Part 11 - How to Manage and Create LVM Using vgcreate, lvcreate and lvextend Commands.md deleted file mode 100644 index 4d2a9d7a13..0000000000 --- a/sources/tech/LFCS/Part 11 - How to Manage and Create LVM Using vgcreate, lvcreate and lvextend Commands.md +++ /dev/null @@ -1,206 +0,0 @@ -Part 11 - How to Manage and Create LVM Using vgcreate, lvcreate and lvextend Commands -============================================================================================ - -Because of the changes in the LFCS exam requirements effective Feb. 2, 2016, we are adding the necessary topics to the [LFCS series][1] published here. To prepare for this exam, your are highly encouraged to use the [LFCE series][2] as well. - -![](http://www.tecmint.com/wp-content/uploads/2016/03/Manage-LVM-and-Create-LVM-Partition-in-Linux.png) ->LFCS: Manage LVM and Create LVM Partition – Part 11 - -One of the most important decisions while installing a Linux system is the amount of storage space to be allocated for system files, home directories, and others. If you make a mistake at that point, growing a partition that has run out of space can be burdensome and somewhat risky. - -**Logical Volumes Management** (also known as **LVM**), which have become a default for the installation of most (if not all) Linux distributions, have numerous advantages over traditional partitioning management. Perhaps the most distinguishing feature of LVM is that it allows logical divisions to be resized (reduced or increased) at will without much hassle. - -The structure of the LVM consists of: - -* One or more entire hard disks or partitions are configured as physical volumes (PVs). -* A volume group (**VG**) is created using one or more physical volumes. You can think of a volume group as a single storage unit. -* Multiple logical volumes can then be created in a volume group. Each logical volume is somewhat equivalent to a traditional partition – with the advantage that it can be resized at will as we mentioned earlier. - -In this article we will use three disks of **8 GB** each (**/dev/sdb**, **/dev/sdc**, and **/dev/sdd**) to create three physical volumes. You can either create the PVs directly on top of the device, or partition it first. - -Although we have chosen to go with the first method, if you decide to go with the second (as explained in [Part 4 – Create Partitions and File Systems in Linux][3] of this series) make sure to configure each partition as type `8e`. - -### Creating Physical Volumes, Volume Groups, and Logical Volumes - -To create physical volumes on top of **/dev/sdb**, **/dev/sdc**, and **/dev/sdd**, do: - -``` -# pvcreate /dev/sdb /dev/sdc /dev/sdd -``` - -You can list the newly created PVs with: - -``` -# pvs -``` - -and get detailed information about each PV with: - -``` -# pvdisplay /dev/sdX -``` - -(where **X** is b, c, or d) - -If you omit `/dev/sdX` as parameter, you will get information about all the PVs. - -To create a volume group named `vg00` using `/dev/sdb` and `/dev/sdc` (we will save `/dev/sdd` for later to illustrate the possibility of adding other devices to expand storage capacity when needed): - -``` -# vgcreate vg00 /dev/sdb /dev/sdc -``` - -As it was the case with physical volumes, you can also view information about this volume group by issuing: - -``` -# vgdisplay vg00 -``` - -Since `vg00` is formed with two **8 GB** disks, it will appear as a single **16 GB** drive: - -![](http://www.tecmint.com/wp-content/uploads/2016/03/List-LVM-Volume-Groups.png) ->List LVM Volume Groups - -When it comes to creating logical volumes, the distribution of space must take into consideration both current and future needs. It is considered good practice to name each logical volume according to its intended use. - -For example, let’s create two LVs named `vol_projects` (**10 GB**) and `vol_backups` (remaining space), which we can use later to store project documentation and system backups, respectively. - -The `-n` option is used to indicate a name for the LV, whereas `-L` sets a fixed size and `-l` (lowercase L) is used to indicate a percentage of the remaining space in the container VG. - -``` -# lvcreate -n vol_projects -L 10G vg00 -# lvcreate -n vol_backups -l 100%FREE vg00 -``` - -As before, you can view the list of LVs and basic information with: - -``` -# lvs -``` - -and detailed information with - -``` -# lvdisplay -``` - -To view information about a single **LV**, use **lvdisplay** with the **VG** and **LV** as parameters, as follows: - -``` -# lvdisplay vg00/vol_projects -``` - -![](http://www.tecmint.com/wp-content/uploads/2016/03/List-Logical-Volume.png) ->List Logical Volume - -In the image above we can see that the LVs were created as storage devices (refer to the LV Path line). Before each logical volume can be used, we need to create a filesystem on top of it. - -We’ll use ext4 as an example here since it allows us both to increase and reduce the size of each LV (as opposed to xfs that only allows to increase the size): - -``` -# mkfs.ext4 /dev/vg00/vol_projects -# mkfs.ext4 /dev/vg00/vol_backups -``` - -In the next section we will explain how to resize logical volumes and add extra physical storage space when the need arises to do so. - -### Resizing Logical Volumes and Extending Volume Groups - -Now picture the following scenario. You are starting to run out of space in `vol_backups`, while you have plenty of space available in `vol_projects`. Due to the nature of LVM, we can easily reduce the size of the latter (say **2.5 GB**) and allocate it for the former, while resizing each filesystem at the same time. - -Fortunately, this is as easy as doing: - -``` -# lvreduce -L -2.5G -r /dev/vg00/vol_projects -# lvextend -l +100%FREE -r /dev/vg00/vol_backups -``` - -![](http://www.tecmint.com/wp-content/uploads/2016/03/Resize-Reduce-Logical-Volume-and-Volume-Group.png) ->Resize Reduce Logical Volume and Volume Group - -It is important to include the minus `(-)` or plus `(+)` signs while resizing a logical volume. Otherwise, you’re setting a fixed size for the LV instead of resizing it. - -It can happen that you arrive at a point when resizing logical volumes cannot solve your storage needs anymore and you need to buy an extra storage device. Keeping it simple, you will need another disk. We are going to simulate this situation by adding the remaining PV from our initial setup (`/dev/sdd`). - -To add `/dev/sdd` to `vg00`, do - -``` -# vgextend vg00 /dev/sdd -``` - -If you run vgdisplay `vg00` before and after the previous command, you will see the increase in the size of the VG: - -``` -# vgdisplay vg00 -``` - -![](http://www.tecmint.com/wp-content/uploads/2016/03/List-Volume-Group-Size.png) ->Check Volume Group Disk Size - -Now you can use the newly added space to resize the existing LVs according to your needs, or to create additional ones as needed. - -### Mounting Logical Volumes on Boot and on Demand - -Of course there would be no point in creating logical volumes if we are not going to actually use them! To better identify a logical volume we will need to find out what its `UUID` (a non-changing attribute that uniquely identifies a formatted storage device) is. - -To do that, use blkid followed by the path to each device: - -``` -# blkid /dev/vg00/vol_projects -# blkid /dev/vg00/vol_backups -``` - -![](http://www.tecmint.com/wp-content/uploads/2016/03/Find-Logical-Volume-UUID.png) ->Find Logical Volume UUID - -Create mount points for each LV: - -``` -# mkdir /home/projects -# mkdir /home/backups -``` - -and insert the corresponding entries in `/etc/fstab` (make sure to use the UUIDs obtained before): - -``` -UUID=b85df913-580f-461c-844f-546d8cde4646 /home/projects ext4 defaults 0 0 -UUID=e1929239-5087-44b1-9396-53e09db6eb9e /home/backups ext4 defaults 0 0 -``` - -Then save the changes and mount the LVs: - -``` -# mount -a -# mount | grep home -``` - -![](http://www.tecmint.com/wp-content/uploads/2016/03/Find-Logical-Volume-UUID.png) ->Find Logical Volume UUID - -When it comes to actually using the LVs, you will need to assign proper `ugo+rwx` permissions as explained in [Part 8 – Manage Users and Groups in Linux][4] of this series. - -### Summary - -In this article we have introduced [Logical Volume Management][5], a versatile tool to manage storage devices that provides scalability. When combined with RAID (which we explained in [Part 6 – Create and Manage RAID in Linux][6] of this series), you can enjoy not only scalability (provided by LVM) but also redundancy (offered by RAID). - -In this type of setup, you will typically find `LVM` on top of `RAID`, that is, configure RAID first and then configure LVM on top of it. - -If you have questions about this article, or suggestions to improve it, feel free to reach us using the comment form below. - --------------------------------------------------------------------------------- - -via: http://www.tecmint.com/linux-basic-shell-scripting-and-linux-filesystem-troubleshooting/ - -作者：[Gabriel Cánepa][a] -译者：[译者ID](https://github.com/译者ID) -校对：[校对者ID](https://github.com/校对者ID) - -本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创翻译，[Linux中国](https://linux.cn/) 荣誉推出 - -[a]: http://www.tecmint.com/author/gacanepa/ -[1]: http://www.tecmint.com/sed-command-to-create-edit-and-manipulate-files-in-linux/ -[2]: http://www.tecmint.com/installing-network-services-and-configuring-services-at-system-boot/ -[3]: http://www.tecmint.com/create-partitions-and-filesystems-in-linux/ -[4]: http://www.tecmint.com/manage-users-and-groups-in-linux/ -[5]: http://www.tecmint.com/create-lvm-storage-in-linux/ -[6]: http://www.tecmint.com/creating-and-managing-raid-backups-in-linux/ diff --git a/sources/tech/LFCS/Part 12 - How to Explore Linux with Installed Help Documentations and Tools.md b/sources/tech/LFCS/Part 12 - How to Explore Linux with Installed Help Documentations and Tools.md deleted file mode 100644 index 60903d5cce..0000000000 --- a/sources/tech/LFCS/Part 12 - How to Explore Linux with Installed Help Documentations and Tools.md +++ /dev/null @@ -1,181 +0,0 @@ -翻译申请 tresspassing2 -Part 12 - LFCS: How to Explore Linux with Installed Help Documentations and Tools -================================================================================== - -Because of the changes in the LFCS exam requirements effective Feb. 2, 2016, we are adding the necessary topics to the [LFCS series][1] published here. To prepare for this exam, your are highly encouraged to use the [LFCE series][2] as well. - -![](http://www.tecmint.com/wp-content/uploads/2016/03/Explore-Linux-with-Documentation-and-Tools.png) ->LFCS: Explore Linux with Installed Documentations and Tools – Part 12 - -Once you get used to working with the command line and feel comfortable doing so, you realize that a regular Linux installation includes all the documentation you need to use and configure the system. - -Another good reason to become familiar with command line help tools is that in the [LFCS][3] and [LFCE][4] exams, those are the only sources of information you can use – no internet browsing and no googling. It’s just you and the command line. - -For that reason, in this article we will give you some tips to effectively use the installed docs and tools in order to prepare to pass the **Linux Foundation Certification** exams. - -### Linux Man Pages - -A man page, short for manual page, is nothing less and nothing more than what the word suggests: a manual for a given tool. It contains the list of options (with explanation) that the command supports, and some man pages even include usage examples as well. - -To open a man page, use the **man command** followed by the name of the tool you want to learn more about. For example: - -``` -# man diff -``` - -will open the manual page for `diff`, a tool used to compare text files line by line (to exit, simply hit the q key.). - -Let’s say we want to compare two text files named `file1` and `file2` in Linux. These files contain the list of packages that are installed in two Linux boxes with the same distribution and version. - -Doing a `diff` between `file1` and `file2` will tell us if there is a difference between those lists: - -``` -# diff file1 file2 -``` - -![](http://www.tecmint.com/wp-content/uploads/2016/03/Compare-Two-Text-Files-in-Linux.png) ->Compare Two Text Files in Linux - -where the `<` sign indicates lines missing in `file2`. If there were lines missing in `file1`, they would be indicated by the `>` sign instead. - -On the other hand, **7d6** means line **#7** in file should be deleted in order to match `file2` (same with **24d22** and **41d38**), and 65,67d61 tells us we need to remove lines **65** through **67** in file one. If we make these corrections, both files will then be identical. - -Alternatively, you can display both files side by side using the `-y` option, according to the man page. You may find this helpful to more easily identify missing lines in files: - -``` -# diff -y file1 file2 -``` - -![](http://www.tecmint.com/wp-content/uploads/2016/03/Compare-and-List-Difference-of-Two-Files.png) ->Compare and List Difference of Two Files - -Also, you can use `diff` to compare two binary files. If they are identical, `diff` will exit silently without output. Otherwise, it will return the following message: “**Binary files X and Y differ**”. - -### The –help Option - -The `--help` option, available in many (if not all) commands, can be considered a short manual page for that specific command. Although it does not provide a comprehensive description of the tool, it is an easy way to obtain information on the usage of a program and a list of its available options at a quick glance. - -For example, - -``` -# sed --help -``` - -shows the usage of each option available in sed (the stream editor). - -One of the classic examples of using `sed` consists of replacing characters in files. Using the `-i` option (described as “**edit files in place**”), you can edit a file without opening it. If you want to make a backup of the original contents as well, use the `-i` option followed by a SUFFIX to create a separate file with the original contents. - -For example, to replace each occurrence of the word `Lorem` with `Tecmint` (case insensitive) in `lorem.txt` and create a new file with the original contents of the file, do: - -``` -# less lorem.txt | grep -i lorem -# sed -i.orig 's/Lorem/Tecmint/gI' lorem.txt -# less lorem.txt | grep -i lorem -# less lorem.txt.orig | grep -i lorem -``` - -Please note that every occurrence of `Lorem` has been replaced with `Tecmint` in `lorem.txt`, and the original contents of `lorem.txt` has been saved to `lorem.txt.orig`. - -![](http://www.tecmint.com/wp-content/uploads/2016/03/Replace-A-String-in-File.png) ->Replace A String in Files - -### Installed Documentation in /usr/share/doc - -This is probably my favorite pick. If you go to `/usr/share/doc` and do a directory listing, you will see lots of directories with the names of the installed tools in your Linux system. - -According to the [Filesystem Hierarchy Standard][5], these directories contain useful information that might not be in the man pages, along with templates and configuration files to make configuration easier. - -For example, let’s consider `squid-3.3.8` (version may vary from distribution to distribution) for the popular HTTP proxy and [squid cache server][6]. - -Let’s `cd` into that directory: - -``` -# cd /usr/share/doc/squid-3.3.8 -``` - -and do a directory listing: - -``` -# ls -``` - -![](http://www.tecmint.com/wp-content/uploads/2016/03/List-Files-in-Linux.png) ->Linux Directory Listing with ls Command - -You may want to pay special attention to `QUICKSTART` and `squid.conf.documented`. These files contain an extensive documentation about Squid and a heavily commented configuration file, respectively. For other packages, the exact names may differ (as **QuickRef** or **00QUICKSTART**, for example), but the principle is the same. - -Other packages, such as the Apache web server, provide configuration file templates inside `/usr/share/doc`, that will be helpful when you have to configure a standalone server or a virtual host, to name a few cases. - -### GNU info Documentation - -You can think of info documents as man pages on steroids. As such, they not only provide help for a specific tool, but also they do so with hyperlinks (yes, hyperlinks in the command line!) that allow you to navigate from a section to another using the arrow keys and Enter to confirm. - -Perhaps the most illustrative example is: - -``` -# info coreutils -``` - -Since coreutils contains the [basic file, shell and text manipulation utilities][7] which are expected to exist on every operating system, you can reasonably expect a detailed description for each one of those categories in info **coreutils**. - -![](http://www.tecmint.com/wp-content/uploads/2016/03/Info-Coreutils.png) ->Info Coreutils - -As it is the case with man pages, you can exit an info document by pressing the `q` key. - -Additionally, GNU info can be used to display regular man pages as well when followed by the tool name. For example: - -``` -# info tune2fs -``` - -will return the man page of **tune2fs**, the ext2/3/4 filesystems management tool. - -And now that we’re at it, let’s review some of the uses of **tune2fs**: - -Display information about the filesystem on top of **/dev/mapper/vg00-vol_backups**: - -``` -# tune2fs -l /dev/mapper/vg00-vol_backups -``` - -Set a filesystem volume name (Backups in this case): - -``` -# tune2fs -L Backups /dev/mapper/vg00-vol_backups -``` - -Change the check intervals and `/` or mount counts (use the `-c` option to set a number of mount counts and `/` or the `-i` option to set a check interval, where **d=days, w=weeks, and m=months**). - -``` -# tune2fs -c 150 /dev/mapper/vg00-vol_backups # Check every 150 mounts -# tune2fs -i 6w /dev/mapper/vg00-vol_backups # Check every 6 weeks -``` - -All of the above options can be listed with the `--help` option, or viewed in the man page. - -### Summary - -Regardless of the method that you choose to invoke help for a given tool, knowing that they exist and how to use them will certainly come in handy in the exam. Do you know of any other tools that can be used to look up documentation? Feel free to share with the Tecmint community using the form below. - -Questions and other comments are more than welcome as well. - --------------------------------------------------------------------------------- - -via: http://www.tecmint.com/linux-basic-shell-scripting-and-linux-filesystem-troubleshooting/ - -作者：[Gabriel Cánepa][a] -译者：[译者ID](https://github.com/译者ID) -校对：[校对者ID](https://github.com/校对者ID) - -本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创翻译，[Linux中国](https://linux.cn/) 荣誉推出 - -[a]:http://www.tecmint.com/author/gacanepa/ -[1]: http://www.tecmint.com/sed-command-to-create-edit-and-manipulate-files-in-linux/ -[2]: http://www.tecmint.com/installing-network-services-and-configuring-services-at-system-boot/ -[3]: http://www.tecmint.com/sed-command-to-create-edit-and-manipulate-files-in-linux/ -[4]: http://www.tecmint.com/installing-network-services-and-configuring-services-at-system-boot/ -[5]: http://www.tecmint.com/linux-directory-structure-and-important-files-paths-explained/ -[6]: http://www.tecmint.com/configure-squid-server-in-linux/ -[7]: http://www.tecmint.com/sed-command-to-create-edit-and-manipulate-files-in-linux/ -[8]: diff --git a/sources/tech/LFCS/Part 13 - How to Configure and Troubleshoot Grand Unified Bootloader (GRUB).md b/sources/tech/LFCS/Part 13 - How to Configure and Troubleshoot Grand Unified Bootloader (GRUB).md deleted file mode 100644 index cf24c51b58..0000000000 --- a/sources/tech/LFCS/Part 13 - How to Configure and Troubleshoot Grand Unified Bootloader (GRUB).md +++ /dev/null @@ -1,185 +0,0 @@ -Part 13 - LFCS: How to Configure and Troubleshoot Grand Unified Bootloader (GRUB) -===================================================================================== - -Because of the changes in the LFCS exam requirements effective Feb. 2, 2016, we are adding the necessary topics to the [LFCS series][1] published here. To prepare for this exam, your are highly encouraged to use the [LFCE series][2] as well. - -![](http://www.tecmint.com/wp-content/uploads/2016/03/Configure-Troubleshoot-Grub-Boot-Loader.png) ->LFCS: Configure and Troubleshoot Grub Boot Loader – Part 13 - -In this article we will introduce you to GRUB and explain why a boot loader is necessary, and how it adds versatility to the system. - -The [Linux boot process][3] from the time you press the power button of your computer until you get a fully-functional system follows this high-level sequence: - -* 1. A process known as **POST** (**Power-On Self Test**) performs an overall check on the hardware components of your computer. -* 2. When **POST** completes, it passes the control over to the boot loader, which in turn loads the Linux kernel in memory (along with **initramfs**) and executes it. The most used boot loader in Linux is the **GRand Unified Boot loader**, or **GRUB** for short. -* 3. The kernel checks and accesses the hardware, and then runs the initial process (mostly known by its generic name “**init**”) which in turn completes the system boot by starting services. - -In Part 7 of this series (“[SysVinit, Upstart, and Systemd][4]”) we introduced the [service management systems and tools][5] used by modern Linux distributions. You may want to review that article before proceeding further. - -### Introducing GRUB Boot Loader - -Two major **GRUB** versions (**v1** sometimes called **GRUB Legacy** and **v2**) can be found in modern systems, although most distributions use **v2** by default in their latest versions. Only **Red Hat Enterprise Linux 6** and its derivatives still use **v1** today. - -Thus, we will focus primarily on the features of **v2** in this guide. - -Regardless of the **GRUB** version, a boot loader allows the user to: - -* 1). modify the way the system behaves by specifying different kernels to use, -* 2). choose between alternate operating systems to boot, and -* 3). add or edit configuration stanzas to change boot options, among other things. - -Today, **GRUB** is maintained by the **GNU** project and is well documented in their website. You are encouraged to use the [GNU official documentation][6] while going through this guide. - -When the system boots you are presented with the following **GRUB** screen in the main console. Initially, you are prompted to choose between alternate kernels (by default, the system will boot using the latest kernel) and are allowed to enter a **GRUB** command line (with `c`) or edit the boot options (by pressing the `e` key). - -![](http://www.tecmint.com/wp-content/uploads/2016/03/GRUB-Boot-Screen.png) ->GRUB Boot Screen - -One of the reasons why you would consider booting with an older kernel is a hardware device that used to work properly and has started “acting up” after an upgrade (refer to [this link][7] in the AskUbuntu forums for an example). - -The **GRUB v2** configuration is read on boot from `/boot/grub/grub.cfg` or `/boot/grub2/grub.cfg`, whereas `/boot/grub/grub.conf` or `/boot/grub/menu.lst` are used in **v1**. These files are NOT to be edited by hand, but are modified based on the contents of `/etc/default/grub` and the files found inside `/etc/grub.d`. - -In a **CentOS 7**, here’s the configuration file that is created when the system is first installed: - -``` -GRUB_TIMEOUT=5 -GRUB_DISTRIBUTOR="$(sed 's, release .*$,,g' /etc/system-release)" -GRUB_DEFAULT=saved -GRUB_DISABLE_SUBMENU=true -GRUB_TERMINAL_OUTPUT="console" -GRUB_CMDLINE_LINUX="vconsole.keymap=la-latin1 rd.lvm.lv=centos_centos7-2/swap crashkernel=auto vconsole.font=latarcyrheb-sun16 rd.lvm.lv=centos_centos7-2/root rhgb quiet" -GRUB_DISABLE_RECOVERY="true" -``` - -In addition to the online documentation, you can also find the GNU GRUB manual using info as follows: - -``` -# info grub -``` - -If you’re interested specifically in the options available for /etc/default/grub, you can invoke the configuration section directly: - -``` -# info -f grub -n 'Simple configuration' -``` - -Using the command above you will find out that `GRUB_TIMEOUT` sets the time between the moment when the initial screen appears and the system automatic booting begins unless interrupted by the user. When this variable is set to `-1`, boot will not be started until the user makes a selection. - -When multiple operating systems or kernels are installed in the same machine, `GRUB_DEFAULT` requires an integer value that indicates which OS or kernel entry in the GRUB initial screen should be selected to boot by default. The list of entries can be viewed not only in the splash screen shown above, but also using the following command: - -### In CentOS and openSUSE: - -``` -# awk -F\' '$1=="menuentry " {print $2}' /boot/grub2/grub.cfg -``` - -### In Ubuntu: - -``` -# awk -F\' '$1=="menuentry " {print $2}' /boot/grub/grub.cfg -``` - -In the example shown in the below image, if we wish to boot with the kernel version **3.10.0-123.el7.x86_64** (4th entry), we need to set `GRUB_DEFAULT` to `3` (entries are internally numbered beginning with zero) as follows: - -``` -GRUB_DEFAULT=3 -``` - -![](http://www.tecmint.com/wp-content/uploads/2016/03/Boot-System-with-Old-Kernel-Version.png) ->Boot System with Old Kernel Version - -One final GRUB configuration variable that is of special interest is `GRUB_CMDLINE_LINUX`, which is used to pass options to the kernel. The options that can be passed through GRUB to the kernel are well documented in the [Kernel Parameters file][8] and in [man 7 bootparam][9]. - -Current options in my **CentOS 7** server are: - -``` -GRUB_CMDLINE_LINUX="vconsole.keymap=la-latin1 rd.lvm.lv=centos_centos7-2/swap crashkernel=auto vconsole.font=latarcyrheb-sun16 rd.lvm.lv=centos_centos7-2/root rhgb quiet" -``` - -Why would you want to modify the default kernel parameters or pass extra options? In simple terms, there may be times when you need to tell the kernel certain hardware parameters that it may not be able to determine on its own, or to override the values that it would detect. - -This happened to me not too long ago when I tried **Vector Linux**, a derivative of **Slackware**, on my 10-year old laptop. After installation it did not detect the right settings for my video card so I had to modify the kernel options passed through GRUB in order to make it work. - -Another example is when you need to bring the system to single-user mode to perform maintenance tasks. You can do this by appending the word single to `GRUB_CMDLINE_LINUX` and rebooting: - -``` -GRUB_CMDLINE_LINUX="vconsole.keymap=la-latin1 rd.lvm.lv=centos_centos7-2/swap crashkernel=auto vconsole.font=latarcyrheb-sun16 rd.lvm.lv=centos_centos7-2/root rhgb quiet single" -``` - -After editing `/etc/defalt/grub`, you will need to run `update-grub` (Ubuntu) or `grub2-mkconfig -o /boot/grub2/grub.cfg` (**CentOS** and **openSUSE**) afterwards to update `grub.cfg` (otherwise, changes will be lost upon boot). - -This command will process the boot configuration files mentioned earlier to update `grub.cfg`. This method ensures changes are permanent, while options passed through GRUB at boot time will only last during the current session. - -### Fixing Linux GRUB Issues - -If you install a second operating system or if your GRUB configuration file gets corrupted due to human error, there are ways you can get your system back on its feet and be able to boot again. - -In the initial screen, press `c` to get a GRUB command line (remember that you can also press `e` to edit the default boot options), and use help to bring the available commands in the GRUB prompt: - -![](http://www.tecmint.com/wp-content/uploads/2016/03/Fix-Grub-Issues-in-Linux.png) ->Fix Grub Configuration Issues in Linux - -We will focus on **ls**, which will list the installed devices and filesystems, and we will examine what it finds. In the image below we can see that there are 4 hard drives (`hd0` through `hd3`). - -Only `hd0` seems to have been partitioned (as evidenced by msdos1 and msdos2, where 1 and 2 are the partition numbers and msdos is the partitioning scheme). - -Let’s now examine the first partition on `hd0` (**msdos1**) to see if we can find GRUB there. This approach will allow us to boot Linux and there use other high level tools to repair the configuration file or reinstall GRUB altogether if it is needed: - -``` -# ls (hd0,msdos1)/ -``` - -As we can see in the highlighted area, we found the `grub2` directory in this partition: - -![](http://www.tecmint.com/wp-content/uploads/2016/03/Find-Grub-Configuration.png) ->Find Grub Configuration - -Once we are sure that GRUB resides in (**hd0,msdos1**), let’s tell GRUB where to find its configuration file and then instruct it to attempt to launch its menu: - -``` -set prefix=(hd0,msdos1)/grub2 -set root=(hd0,msdos1) -insmod normal -normal -``` - -![](http://www.tecmint.com/wp-content/uploads/2016/03/Find-and-Launch-Grub-Menu.png) ->Find and Launch Grub Menu - -Then in the GRUB menu, choose an entry and press **Enter** to boot using it. Once the system has booted you can issue the `grub2-install /dev/sdX` command (change `sdX` with the device you want to install GRUB on). The boot information will then be updated and all related files be restored. - -``` -# grub2-install /dev/sdX -``` - -Other more complex scenarios are documented, along with their suggested fixes, in the [Ubuntu GRUB2 Troubleshooting guide][10]. The concepts explained there are valid for other distributions as well. - -### Summary - -In this article we have introduced you to GRUB, indicated where you can find documentation both online and offline, and explained how to approach an scenario where a system has stopped booting properly due to a bootloader-related issue. - -Fortunately, GRUB is one of the tools that is best documented and you can easily find help either in the installed docs or online using the resources we have shared in this article. - -Do you have questions or comments? Don’t hesitate to let us know using the comment form below. We look forward to hearing from you! - --------------------------------------------------------------------------------- - -via: http://www.tecmint.com/linux-basic-shell-scripting-and-linux-filesystem-troubleshooting/ - -作者：[Gabriel Cánepa][a] -译者：[译者ID](https://github.com/译者ID) -校对：[校对者ID](https://github.com/校对者ID) - -本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创翻译，[Linux中国](https://linux.cn/) 荣誉推出 - -[a]: http://www.tecmint.com/author/gacanepa/ -[1]: http://www.tecmint.com/sed-command-to-create-edit-and-manipulate-files-in-linux/ -[2]: http://www.tecmint.com/installing-network-services-and-configuring-services-at-system-boot/ -[3]: http://www.tecmint.com/linux-boot-process/ -[4]: http://www.tecmint.com/linux-boot-process-and-manage-services/ -[5]: http://www.tecmint.com/best-linux-log-monitoring-and-management-tools/ -[6]: http://www.gnu.org/software/grub/manual/ -[7]: http://askubuntu.com/questions/82140/how-can-i-boot-with-an-older-kernel-version -[8]: https://www.kernel.org/doc/Documentation/kernel-parameters.txt -[9]: http://man7.org/linux/man-pages/man7/bootparam.7.html -[10]: https://help.ubuntu.com/community/Grub2/Troubleshooting diff --git a/sources/tech/awk/20160725 Part 10 - Learn How to Use Awk Built-in Variables.md b/sources/tech/awk/20160725 Part 10 - Learn How to Use Awk Built-in Variables.md new file mode 100644 index 0000000000..9b66a0cbfe --- /dev/null +++ b/sources/tech/awk/20160725 Part 10 - Learn How to Use Awk Built-in Variables.md @@ -0,0 +1,120 @@ +Being translated by ChrisLeeGit +Learn How to Use Awk Built-in Variables – Part 10 +================================================= + +As we uncover the section of Awk features, in this part of the series, we shall walk through the concept of built-in variables in Awk. There are two types of variables you can use in Awk, these are; user-defined variables, which we covered in Part 8 and built-in variables. + +![](http://www.tecmint.com/wp-content/uploads/2016/07/Awk-Built-in-Variables-Examples.png) +>Awk Built in Variables Examples + +Built-in variables have values already defined in Awk, but we can also carefully alter those values, the built-in variables include: + +- `FILENAME` : current input file name( do not change variable name) +- `FR` : number of the current input line (that is input line 1, 2, 3… so on, do not change variable name) +- `NF` : number of fields in current input line (do not change variable name) +- `OFS` : output field separator +- `FS` : input field separator +- `ORS` : output record separator +- `RS` : input record separator + +Let us proceed to illustrate the use of some of the Awk built-in variables above: + +To read the filename of the current input file, you can use the `FILENAME` built-in variable as follows: + +``` +$ awk ' { print FILENAME } ' ~/domains.txt +``` + +![](http://www.tecmint.com/wp-content/uploads/2016/07/Awk-FILENAME-Variable.png) +>Awk FILENAME Variable + +You will realize that, the filename is printed out for each input line, that is the default behavior of Awk when you use `FILENAME` built-in variable. + +Using `NR` to count the number of lines (records) in an input file, remember that, it also counts the empty lines, as we shall see in the example below. + +When we view the file domains.txt using cat command, it contains 14 lines with text and empty 2 lines: + +``` +$ cat ~/domains.txt +``` + +![](http://www.tecmint.com/wp-content/uploads/2016/07/Print-Contents-of-File.png) +>Print Contents of File + + +``` +$ awk ' END { print "Number of records in file is: ", NR } ' ~/domains.txt +``` + +![](http://www.tecmint.com/wp-content/uploads/2016/07/Awk-Count-Number-of-Lines.png) +>Awk Count Number of Lines + +To count the number of fields in a record or line, we use the NR built-in variable as follows: + +``` +$ cat ~/names.txt +``` + +![](http://www.tecmint.com/wp-content/uploads/2016/07/List-File-Contents.png) +>List File Contents + +``` +$ awk '{ print "Record:",NR,"has",NF,"fields" ; }' ~/names.txt +``` + +![](http://www.tecmint.com/wp-content/uploads/2016/07/Awk-Count-Number-of-Fields-in-File.png) +>Awk Count Number of Fields in File + +Next, you can also specify an input field separator using the FS built-in variable, it defines how Awk divides input lines into fields. + +The default value for FS is space and tab, but we can change the value of FS to any character that will instruct Awk to divide input lines accordingly. + +There are two methods to do this: + +- one method is to use the FS built-in variable +- and the second is to invoke the -F Awk option + +Consider the file /etc/passwd on a Linux system, the fields in this file are divided using the : character, so we can specify it as the new input field separator when we want to filter out certain fields as in the following examples: + +We can use the `-F` option as follows: + +``` +$ awk -F':' '{ print $1, $4 ;}' /etc/passwd +``` + +![](http://www.tecmint.com/wp-content/uploads/2016/07/Awk-Filter-Fields-in-Password-File.png) +>Awk Filter Fields in Password File + +Optionally, we can also take advantage of the FS built-in variable as below: + +``` +$ awk ' BEGIN { FS=“:” ; } { print $1, $4 ; } ' /etc/passwd +``` + +![](http://www.tecmint.com/wp-content/uploads/2016/07/Filter-Fields-in-File-Using-Awk.png) +>Filter Fields in File Using Awk + +To specify an output field separator, use the OFS built-in variable, it defines how the output fields will be separated using the character we use as in the example below: + +``` +$ awk -F':' ' BEGIN { OFS="==>" ;} { print $1, $4 ;}' /etc/passwd +``` + +![](http://www.tecmint.com/wp-content/uploads/2016/07/Add-Separator-to-Field-in-File.png) +>Add Separator to Field in File + +In this Part 10, we have explored the idea of using Awk built-in variables which come with predefined values. But we can also change these values, though, it is not recommended to do so unless you know what you are doing, with adequate understanding. + +After this, we shall progress to cover how we can use shell variables in Awk command operations, therefore, stay connected to Tecmint. + +-------------------------------------------------------------------------------- + +via: http://www.tecmint.com/awk-built-in-variables-examples/?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+tecmint+%28Tecmint%3A+Linux+Howto%27s+Guide%29 + +作者：[Aaron Kili][a] +译者：[ChrisLeeGit](https://github.com/chrisleegit) +校对：[校对ID](https://github.com/校对ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: http://www.tecmint.com/author/aaronkili/ diff --git a/sources/tech/awk/20160802 Part 11 - How to Allow Awk to Use Shell Variables.md b/sources/tech/awk/20160802 Part 11 - How to Allow Awk to Use Shell Variables.md new file mode 100644 index 0000000000..b407050da7 --- /dev/null +++ b/sources/tech/awk/20160802 Part 11 - How to Allow Awk to Use Shell Variables.md @@ -0,0 +1,95 @@ +How to Allow Awk to Use Shell Variables – Part 11 +================================================== + +When we write shell scripts, we normally include other smaller programs or commands such as Awk operations in our scripts. In the case of Awk, we have to find ways of passing some values from the shell to Awk operations. + +This can be done by using shell variables within Awk commands, and in this part of the series, we shall learn how to allow Awk to use shell variables that may contain values we want to pass to Awk commands. + +There possibly two ways you can enable Awk to use shell variables: + +### 1. Using Shell Quoting + +Let us take a look at an example to illustrate how you can actually use shell quoting to substitute the value of a shell variable in an Awk command. In this example, we want to search for a username in the file /etc/passwd, filter and print the user’s account information. + +Therefore, we can write a `test.sh` script with the following content: + +``` +#!/bin/bash + +#read user input +read -p "Please enter username:" username + +#search for username in /etc/passwd file and print details on the screen +cat /etc/passwd | awk "/$username/ "' { print $0 }' +``` + +Thereafter, save the file and exit. + +Interpretation of the Awk command in the test.sh script above: + +``` +cat /etc/passwd | awk "/$username/ "' { print $0 }' +``` + +`"/$username/ "` – shell quoting used to substitute value of shell variable username in Awk command. The value of username is the pattern to be searched in the file /etc/passwd. + +Note that the double quote is outside the Awk script, `‘{ print $0 }’`. + +Then make the script executable and run it as follows: + +``` +$ chmod +x test.sh +$ ./text.sh +``` + +After running the script, you will be prompted to enter a username, type a valid username and hit Enter. You will view the user’s account details from the /etc/passwd file as below: + +![](http://www.tecmint.com/wp-content/uploads/2016/08/Shell-Script-to-Find-Username-in-Passwd-File.png) +>Shell Script to Find Username in Password File + +### 2. Using Awk’s Variable Assignment + +This method is much simpler and better in comparison to method one above. Considering the example above, we can run a simple command to accomplish the job. Under this method, we use the -v option to assign a shell variable to a Awk variable. + +Firstly, create a shell variable, username and assign it the name that we want to search in the /etc/passswd file: + +``` +username="aaronkilik" +``` + +Then type the command below and hit Enter: + +``` +# cat /etc/passwd | awk -v name="$username" ' $0 ~ name {print $0}' +``` + +![](http://www.tecmint.com/wp-content/uploads/2016/08/Find-Username-in-Password-File-Using-Awk.png) +>Find Username in Password File Using Awk + +Explanation of the above command: + +- `-v` – Awk option to declare a variable +- `username` – is the shell variable +- `name` – is the Awk variable +Let us take a careful look at `$0 ~ name` inside the Awk script, `' $0 ~ name {print $0}'`. Remember, when we covered Awk comparison operators in Part 4 of this series, one of the comparison operators was value ~ pattern, which means: true if value matches the pattern. + +The `output($0)` of cat command piped to Awk matches the pattern `(aaronkilik)` which is the name we are searching for in /etc/passwd, as a result, the comparison operation is true. The line containing the user’s account information is then printed on the screen. + +### Conclusion + +We have covered an important section of Awk features, that can help us use shell variables within Awk commands. Many times, you will write small Awk programs or commands within shell scripts and therefore, you need to have a clear understanding of how to use shell variables within Awk commands. + +In the next part of the Awk series, we shall dive into yet another critical section of Awk features, that is flow control statements. So stay tunned and let’s keep learning and sharing. + + +-------------------------------------------------------------------------------- + +via: http://www.tecmint.com/use-shell-script-variable-in-awk/?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+tecmint+%28Tecmint%3A+Linux+Howto%27s+Guide%29 + +作者：[Aaron Kili][a] +译者：[译者ID](https://github.com/译者ID) +校对：[校对ID](https://github.com/校对ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: http://www.tecmint.com/author/aaronkili/ diff --git a/translated/news/README.md b/translated/news/README.md deleted file mode 100644 index 98d53847b1..0000000000 --- a/translated/news/README.md +++ /dev/null @@ -1 +0,0 @@ -这里放新闻类文章，要求时效性 diff --git a/translated/share/README.md b/translated/share/README.md deleted file mode 100644 index e5e225858e..0000000000 --- a/translated/share/README.md +++ /dev/null @@ -1 +0,0 @@ -这里放分享类文章，包括各种软件的简单介绍、有用的书籍和网站等。 diff --git a/translated/talk/20151023 Mark Shuttleworth--The Man Behind Ubuntu Operating System.md b/translated/talk/20151023 Mark Shuttleworth--The Man Behind Ubuntu Operating System.md deleted file mode 100644 index 0d3547aeb9..0000000000 --- a/translated/talk/20151023 Mark Shuttleworth--The Man Behind Ubuntu Operating System.md +++ /dev/null @@ -1,126 +0,0 @@ -Mark Shuttleworth – Ubuntu 操作系统背后的人 -================================================================================ -![](http://1426826955.rsc.cdn77.org/wp-content/uploads/2015/10/Mark-Shuttleworth-652x445.jpg) - -**Mark Richard Shuttleworth** 是 Ubuntu 的创始人，他也有事被称作是 Debian 背后的那个人。他出生于1973年的 Welkom，南非。他不仅是个企业家，还是个太空游客——他是第一个前往太空旅行的独立非洲国家公民。 - -Mark 还在1996年成立了 **Thawte**，一家互联网安全企业，那是他还只是 University of Cape Town 的一名金融/IT学生。 - -在2000年，Mark 创立了 HBD，一家投资公司，同时他还创立了 Shuttleworth基金会，致力于给社会中有创新性的领袖提供资助——以奖金和投资等形式。 - - -> "移动设备对于个人电脑行业的未来而言至关重要。比如就在这个月，数据清晰地表明相对于平板电脑的发展，传统 PC 行业正在萎缩。所以如果我们想和个人电脑行业有关系，我们必须和移动设备行业有产生联系。移动互联网行业之所以有趣，还因为在这里没有盗版 Windows 操作系统。所以如果你为你的操作系统赢得了一台设备的市场份额，这台设备会持续使用你的操作系统。在传统 PC 行业，我们时不时得和 ‘免费 Windows’ 产生竞争，这一竞争困难的非常微妙。所以我们现在的目标是围绕 Ubuntu 和移动设备——手机和平板——为用户打造更深度的生态环境。" -> -> — Mark Shuttleworth - -在2002年，在俄罗斯的 Star City 接收完为期一年的训练后，他作为 Soyuz 任务代号 TM-34 的一员飞往了国际空间站。再后来，在面向有志于航空航天或者其科学相关的南非学生群体中，内完成了推广科学，编程，数学的演讲后，Mark 创立了 **Canonical Ltd**。此后直至2013年，他一直在领导 Ubuntu 操作系统的开发。 - - -现今，Shuttleworth 有英国与南非双重国籍并和18只可爱的鸭子住在英国的 Isle of Man 小岛上一处花园，一同的还有他一样可爱的女友 Claire，2 条黑母狗以及时不时经过的羊群。 - - -> "电脑不再只是一台电子设备了。他现在是你思维的延续，以及通向他人的入口。" -> -> — Mark Shuttleworth - -### Mark Shuttleworth 的早年生活### -正如我们之前提到的，Mark 出生在 Welkom，南非的橙色自由州。他是一名外科医生和护士学校教师的孩子。Mark 在 Western Province Preparatory School 就读并在1986年成为了学生会主席，一个学期后就读于 Rondebosch 男子高中，再之后入学 Bishops/Diocesan 学院并在1991年再次成为那里的学生会主席。 - -Mark 在 University of Cape Town 拿到了 Bachelor of Business Science degree in the Finance and Information Systems （译者：商业科学里的双学士学位，两个学科分别是金融和信息系统），他在学校就读是住在 Smuts Hall。他，作为学生，也在那里帮助安装了学校的第一条宿舍网络。 - ->“有无数的企业和国家佐证，引入开源政策能提高竞争力和效率。在不同层面上创造生产力对于公司和国家而言都是至关重要的。” -> -> — Mark Shuttleworth - -### Mark Shuttleworth 的职业生涯 ### - -Mark 在1995年创立 Thawte，公司专注于数字证书和互联网安全，然后他在1999年把公司卖给了 VeriSign，赚取了大约 5.75 亿美元。 - -2000年的时候，Mark 创立了 HBD 风险资本公司，这项事业成为了投资方和项目孵化器。2004年的时候，他创立了 Canonical Ltd. 以支持和鼓励自由软件开发项目的商业化，特别是 Ubuntu 操作系统的项目。直到2009年，Mark 才从 Canonical CEO 的位置上退下。 - -> “在 [DDC](https://en.wikipedia.org/wiki/DCC_Alliance) (译者:一个 Debian Gnu/Linux 开发者联盟) 的早期，我更倾向于让开发者做些他们自己的（内核开发）工作看看能弄出些什么。现在我们基本上已经完成了这个开发阶段了。” -> -> — Mark Shuttleworth - -### Linux、免费开源软件 与 Mark Shuttleworth ### - -在90年代末，Mark 作为 Debian 系统开发者的一员参与了项目。 - -2001年，Mark 创立了 Shuttleworth 基金会，这是个扎根南非的，非赢利性，专注于赞助社会创新，免费/教育用途开源软件的基金会，赞助过的项目包括 Freedom Toaster。 - -2004年的时候，Mark 通过出资开发 基于 Debian 的 Ubuntu 操作系统回归了免费软件界，这一切也经由他的公司，Canonical，完成。 - -2005年，Mark 出资建立了 Ubuntu 基金会并投入了一千万美元作为启动资金。在 Ubuntu 项目内，Mark 经常被一个朗朗上口的名字称呼——“**SABDFL (Self-Appointed Benevolent Dictator for Life)**”。为了能够找到足够多的能手开发这个巨大的项目，Mark 花费了6个月的时间在 Debian 的邮件列表里找到能手，这一切都是在他乘坐在南极洲的一艘破冰船——Kapitan Khlebnikov——上完成的。2005年，Mark 买下了 Impi Linux 65% 的股份。 - - -> “我呼吁电信公司的掌权者们尽快开发出跨洲际的高效信息传输服务。” -> -> — Mark Shuttleworth - -2006年，KDE 宣布 Shuttleworth 成为第一位 **patron** 级别赞助者——彼时 KDE 最高级别的赞助。这一赞助协议终止与2012年，取而代之的是 Kubuntu——一个运用 KDE 作为默认桌面环境的 Ubuntu 变种——的资金。 - -![](http://1426826955.rsc.cdn77.org/wp-content/uploads/2015/10/shuttleworth-kde.jpg) - -2009年，Shuttleworth 宣布他会从 CEO 退位以更好的关注与合作伙伴，产品设计和顾客体验。Jane Silber ——2004年起公司的COO——晋升CEO。 - -2010年，Mark 由于 Ubuntu 项目从 Open University 收到了荣誉学位。 - -2012年，Mark 和 Kenneth Rogoff 一同在牛津大学与 Peter Thiel 和 Garry Kasparov 就 **创新悖论**（The Innovation Enigma）展开辩论。 - -2013年，Mark 和 Ubuntu 一同被授予 **澳大利亚反个人隐私老大哥监控奖**（Austrian anti-privacy Big Brother Award），理由为把 Ubuntu 会把 Unity 桌面的搜索框的搜索结果发往 Canonical 服务器（译者：因此侵犯了个人隐私）。而一年前的2012年，Mark 曾经申明过这一过程极具匿名性。 - - -> “所有主流 PC 厂家现在都提供 Ubuntu 预安装选项。所以我们和业界的合作已经相当紧密了。但那些 PC 厂家对于给买家推广新东西这件事都很紧张。如果我们可以让买家习惯 Ubuntu 的桌面/平板/手机操作系统的体验，那他们也应该更愿意买预装 Ubuntu 的设备。因为没有哪个操作系统是通过抄袭模仿获得成功的。Android 很棒，如果我们想成功的话我们必须给市场带去更新更好的东西。整个环境都有停滞发展的危险，如果我们中没有人追寻未来的话。但如果你尝试去追寻未来了，那你必须接受不是所有人对未来的预见都和你一样这一事实。” -> -> — Mark Shuttleworth - -### Mark Shuttleworth 的太空之旅 ### - -Mark 在2002年由于作为世界第二名自费太空游客而闻名世界，同时他也是南非第一个旅行太空的人。这趟旅行 Mark 作为俄罗斯 Soyuz TM-34 的一名航空参与者加入，并支付了约两千万美元。2天后，Soyuz 太空梭抵达了国际空间站，在那里 Mark 呆了8天并参与了 AIDS 和 GENOME 研究的相关实验。2002年的晚些时候，Mark 乘坐 Soyuz TM-33 返回了地球。为了参与这趟旅行，Mark 花了一年时间准备与训练，包括7个月居住在俄罗斯的 Start City。 - - -![](http://1426826955.rsc.cdn77.org/wp-content/uploads/2015/10/Mark-Shuttleworth1.jpg) - -在太空中，Mark 与 Nelson Mandela 和另一个南非女孩 Michelle Foster （她问 Mark 要不要娶她）通过无线电进行了交谈。Mark 回避了结婚问题，在换话题之前他说他感到很荣幸。身患绝症的 Forster 和 Nelson Mandela 通过 Dream 基金会的赞助获得了与 Mark 交谈的机会。 - -归来后，Mark 在世界各地做了旅行，并和各地的学生就太空之旅发表了感言。 - - ->“粗略的统计数据表明 Ubuntu 的实际用户依然在增长。而我们的合作方——Dell，HP，Lenovo 和其他硬件生产商，以及游戏厂商 EA，Valve 都在加入我们——这让我觉得我们在引导一项很有意义的事业。” -> -> — Mark Shuttleworth - -### Mark Shuttleworth 的交通工具 ### - -Mark 有他自己的私人客机，Bombardier Global Express，经常被称为 Canonical 一号，但事实上此飞机是通过 HBD 风险投资公司注册拥有的。飞机侧面的喷绘龙图案是 HBD 风投公司的吉祥物，Norman。 - -### 与南非储蓄银行的法律冲突 ### - -在从南非转移25亿南非兰特去往 Isle of Man 的过程中，南非储蓄银行征收了 2.5 亿南非兰特的税金。Mark 上诉了，经过冗长的法庭唇枪舌战，南非储蓄银行被勒令返还 2.5 亿征税，以及其利息。Mark 宣布他会把这 2.5 亿存入信托基金，以用于帮助上诉宪法法院的案子。 - - -> “离境征税倒也不和宪法冲突。但离境征税的主要目的不是为了提高税收，而是通过监管资金流出来保护本国经济。” -> -> — 法官 Dikgang Moseneke - -2015年，南非宪法法院修正了低级法院的判决结果，并宣布了上述对于离岸征税的理解。 - -### Mark Shuttleworth 喜欢的东西 ### - -Cesária Évora, mp3s,Spring, Chelsea, finally seeing something obvious for first time, coming home, Sinatra, daydreaming, sundowners, flirting, d’Urberville, string theory, Linux, particle physics, Python, reincarnation, mig-29s, snow, travel, Mozilla, lime marmalade, body shots, the African bush, leopards, Rajasthan, Russian saunas, snowboarding, weightlessness, Iain m banks, broadband, Alastair Reynolds, fancy dress, skinny-dipping, flashes of insight, post-adrenaline euphoria, the inexplicable, convertibles, Clifton, country roads, international space station, machine learning, artificial intelligence, Wikipedia, Slashdot, kitesurfing, and Manx lanes. - -### Shuttleworth 不喜欢的东西 ### - -Admin, salary negotiations, legalese, and public speaking. - --------------------------------------------------------------------------------- - -via: http://www.unixmen.com/mark-shuttleworth-man-behind-ubuntu-operating-system/ - -作者：[M.el Khamlichi][a] -译者：[Moelf](https://github.com/Moelf) -校对：[校对者ID](https://github.com/校对者ID) - -本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 - -[a]:http://www.unixmen.com/author/pirat9/ diff --git a/translated/talk/20160506 Linus Torvalds Talks IoT Smart Devices Security Concerns and More.md b/translated/talk/20160506 Linus Torvalds Talks IoT Smart Devices Security Concerns and More.md new file mode 100644 index 0000000000..876f84f68e --- /dev/null +++ b/translated/talk/20160506 Linus Torvalds Talks IoT Smart Devices Security Concerns and More.md @@ -0,0 +1,48 @@ + +Linus Torvalds 谈及物联网，智能设备，安全连接等问题[video] +=========================================================================== + +![](https://www.linux.com/sites/lcom/files/styles/rendered_file/public/elc-linus-b.jpg?itok=6WwnCSjL) +>Dirk Hohndel 在嵌入式大会上采访 Linus Torvalds 。 + + + [嵌入式大会（Embedded Linux Conference）][0] 从在 San Diego 【译注：圣迭戈，美国加利福尼亚州的一个太平洋沿岸城市。】开始举办到现在已经有 11 年了，在 4 月 4 日到 6 日，Linus Torvalds 加入了会议的主题讨论。他是 Linux 内核的缔造者和最高决策者，也是“我们都在这里的原因”，在采访他的对话中，英特尔的 Linux 和开源技术总监 Dirk Hohndel 谈到了 Linux 在嵌入式和物联网应用程序领域的快速发展前景。Torvalds 很少出席嵌入式 Linux 大会，这些大会经常被 Linux 桌面、服务器和云技术夺去光芒。 +![](https://www.linux.com/sites/lcom/files/styles/floated_images/public/elc-linus_0.jpg?itok=FNPIDe8k) +>Linus Torvalds 在嵌入式 Linux 大会上的演讲。 + + +物联网是嵌入式大会的主题，也包括未来开放物联网的最高发展方向（OpenIoT Summit），这是采访 Torvalds 的主要话题。 + +Torvalds 对 Hohndel 说到，“或许你不会在物联网设备上看到 Linux 的影子，但是在你有一个核心设备的时候，你就会需要它。你需要智能设备尤其在你有 23 [物联网标准]的时候。如果你全部使用低级设备，它们没必要一定运行 Linux ,它们采用的标准稍微有点不同，所以你需要很多智能设备。我们将来也不会有一个完全开放的标准，只是给它一个统一的标准，但是你将会需要 4 分之 3 的主要协议，它们都是这些智能核心的转化形式。” + +当 Hohndel 问及在物联网的巨大安全漏洞的时候， Torvalds 神情如常。他说：“我不担心安全问题因为我们能做的不是很多，物联网如果遭受攻击是无法挽回的－这是事实。" + +Linux 缔造者看起来更关心的是一次性的嵌入式项目缺少及时的上游贡献，尽管他注意到近年来这些都有一些本质上的提升，特别是在硬件上的发展。 + +Torvalds 说：”嵌入式领域历来就很难与开源开发者有所联系，但是我认为这些都在发生改变，ARM 团队也已经很优秀了。内核维护者事实上也看到了硬件性能的提升。一切都在变好，但是昨天却不是这样的。” + +Torvalds 承认他在家经常使用桌面系统而不是嵌入式系统，并且在使用硬件的时候他有“两只左手”。 + +“我已经用电烙铁弄坏了很多东西。”他说到。“我真的不适合搞硬件开发。”；另一方面，Torvalds 设想如果他现在是个年轻人，他可能被 Raspberry Pi（树莓派） 和 BeagleBone（猎兔犬板）【译注:Beagle板实际是由TI支持的一个以教育（STEP）为目的的开源项目】欺骗。“最主要是原因是如果你善于焊接，那么你就仅仅是买到了一个新的板子。” + +同时，Torvalds 也承诺他要为 Linux 桌面再奋斗一个 25 年。他笑着说：“我要为它工作一生。” + +下面，请看完整视频。 + +获取关于嵌入式 Linux 和物联网的最新信息。进入 2016 年嵌入式 Linux 大会 150+ 分钟的会议全程。[现在观看][1]. +[video](https://youtu.be/tQKUWkR-wtM) + +-------------------------------------------------------------------------------- + +via: https://www.linux.com/news/linus-torvalds-talks-iot-smart-devices-security-concerns-and-more-video + +作者：[ERIC BROWN][a] +译者：[vim-kakali](https://github.com/vim-kakali) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://www.linux.com/users/ericstephenbrown +[0]: http://events.linuxfoundation.org/events/embedded-linux-conference +[1]: http://go.linuxfoundation.org/elc-openiot-summit-2016-videos?utm_source=lf&utm_medium=blog&utm_campaign=linuxcom + diff --git a/translated/talk/20160523 Driving cars into the future with Linux.md b/translated/talk/20160523 Driving cars into the future with Linux.md deleted file mode 100644 index 9b9d69d68c..0000000000 --- a/translated/talk/20160523 Driving cars into the future with Linux.md +++ /dev/null @@ -1,108 +0,0 @@ - -驾车通往未来Linux -=========================================== - -![](https://opensource.com/sites/default/files/styles/image-full-size/public/images/life/open-snow-car-osdc-lead.png?itok=IgYZ6mNY) - - -当我开车的时候不认为和 Linux 有多大联系，但是我肯定我是喜欢一个配备有系统的车子，让我按几个按钮语音就可以传给我的妻子母亲以及孩子。同样，这样的系统可以让我选择是否从云端流媒体收听音乐，卫星广播，以及传统的 AM/FM 收音机。我也会得到天气更新以及可以给我的车载信息娱乐 GPS 找到最快的下一个目的地[In-vehicle infotainment][1]，以及 IVI 作为行业知名产业，已经普及到最新的汽车生产商。 - -前段时间，我不得坐飞机飞跃数百英里，租一辆车。令人愉快的是，我发现我的租凭车配置了 IVI 技术。任何时候，我只要通过蓝牙连接，上传联系人到系统中，打电话回家给我的家人，让他们知道我已经安全到家了。然后“主人“会知道我再途中还是已经到他们家了。 - -在最近的 [news roundup][2]，Scott Nesbitt 引用一篇文章，说福特汽车公司是由它的开源 [Smart Device Link][3]（SDL）中间设备框架，对手汽车制造商，支持那个移动手机获得大量的支持。 SDL 是 [GENIVI Alliance][4] 的项目，一个非营利性的致力于建设中间件支持开源的车载信息娱乐系统。根据文献 [[Steven Crumb][5]，GENIVI 执行董事，他们 [membership][6] 很广，包括 Daimler 集团，现代，沃尔沃，日产，本田等等 170 个。 - -为了在同行业中保持竞争力，汽车企业需要一个中间设备系统，可以支持当今消费者提供的各种人机界面技术。无论您拥有 Android，iOS 或其他设备，汽车 OEM 厂商希望自己的系统单位能够支持这些。此外，这些的 IVI 系统必须有足够适应能力以支持移动技术的不断下降，半衰期。 OEM 厂商要提供价值服务，并在他们的 IVI 堆栈支持各种为他们的客户添加选择。进入 Linux 和开源软件。 - -除了 GENIVI 的努力下，[Linux Foundation][7] 赞助 [Automotive Grade Linux][8]（AGL）工作组，一个软件基金会，致力于寻找针对汽车应用的开源解决方案。虽然 AGL 初期将侧重于 IVI 系统，他们展望不同的分歧，包括 [telematics][9]，小心显示器和其他控制系统。 AGL 有超过 50 名成员在这个时候，包括捷豹，丰田，日产，并在 [recent press release][10] 宣布福特、马自达、三菱、和斯巴鲁加入。 - - -为了了解更多信息，我们在这一新鲜兴领域采访了两位领导人。明确地来说，我们想知道是如何被使用的 Linux 和开源软件，如果它们实际上是改变汽车行业的面貌。首先，我们谈谈 [Alison Chaiken][11]，在大集团技术的软件工程师和汽车 Linux 专家，网络安全和透明度。她曾任职于 [Alison Chaiken][11] 公司，诺基亚和斯坦福直线性加速器。然后我们用 [Steven Crumb][12]，GENIVI 执行董事，谁得到了在开源环境高性能计算（超级计算机和早期的云计算）开始聊天。他说，虽然他再不是一个程序员了，但是他喜欢帮助企业解决开源软件的实际业务问题。 - -### 采访 Alison Chaiken (by [Deb Nicholson][13]) - -#### 你是如何开始对汽车软件空间感兴趣的？ - -我是在诺基亚手机产品时， 2009 年该项目被取消。我想，下一步是什么？一位同事正在对 [MeeGo-IVI][15]，早期的汽车 Linux 发行版。 “Linux 在汽车是大了，” 我想，所以我在朝着这个方向努力。 - -#### 你能告诉我们你这些日子工作在哪些方面？ - -我目前正在启动为使用 Linux 系统增加大货车钻机的安全性和燃油经济性的先进巡航控制。我喜欢在这方面的工作，因为没有人会反对卡车得以提升。 - -#### 目前关于汽车已在近年来砍死几个人故事。开源代码方案可以帮助解决这个问题吗？ - -I presented a talk on precisely this topic, on how Linux can (and cannot) contribute to security solutions in automotive at Southern California Linux Expo 2016 ([Slides][16]). Notably, GENIVI and Automotive Grade Linux have published their code and both projects take patches via Git. Please send your fixes upstream! Many eyes make all bugs shallow. -我提出的谈话正是这一主题，就如何 Linux 可以（或不可以）在南加州 2016 年世博会作出贡献的安全解决方案的 Linux汽车([Slides][16])。值得注意的是，GENIVI 和汽车级 Linux 已经公布了他们的代码，这两个项目的 Git 通过采取补丁。请上游发送您的修复！许多眼睛都盯着肤浅的bugs。 - -#### 执法机构和保险公司可以找到很多有关数据用途的驱动程序。它将如何容易成为他们获取这些信息？ - -好问题。该专用短程通信标准（IEEE-1609），以保持匿名的 Wi-Fi 安全消息驱动程序。不过，如果你从你的车张贴到 Twitter，有人能够跟踪你。 - -#### 有什么可以开发人员和公民个人一起完成，以确保公民自由受到保护作为汽车技术发展的？ - -电子前沿基金会（EFF）一样对汽车保持的问题上，通过什么样的数据可以存储在汽车 “黑盒子”，并在 DMCA 的规定 1201 如何应用于汽车官方渠道评论已经出色的工作了。 - -#### 在未来几年令人兴奋的事情上，那些是你看到的驱动因素？ - -自适应巡航控制和防撞系统有足够的预付款来挽救生命。当他们通过运输车队的推出，我真的相信死亡人数会下降。如果这还不是令人兴奋的，我不知道是什么。此外，像自动化停车辅助功能，将会使汽车更容易驾驶，减少汽车相撞事故。 - -#### 有什么是需要人参与以及如何建造？ - -汽车 Linux 级开发是开放源代码的，运行在廉价硬件（如树莓派 Pi 2 和中等价位的 Renesas Porter board），任何人都可以购买。 GENIVI 汽车 Linux 的中间设备联盟有很多软件通过 Git 的公开。此外，还有很酷的 [OSVehicle open hardware][17] 汽车平台。 - -#### 这里是 Linux 软件和开放硬件，许多方面具有中等人数预算的参与。如果您有任何疑问，加入我们在 Freenode 上 IRC#automotive。 - -### 采访 Steven Crumb (by Don Watkins) - -#### 关于GENIVI's 对 IVI 为什么那么大 ? - -GENIVI 率先通过使用自由和开源软件，包括 Linux，像车载信息娱乐（IVI）系统的非安全关键汽车软件填补了汽车行业的巨大差距。作为消费者来到期望在他们的车辆相同的功能在智能手机上的软件，以支持 IVI 功能所需的量成倍增长。软件增加量也增加了建设 IVI 系统的成本，从而延缓了上市时间。 - -GENIVI 的使用开源软件和社区发展模式节省了汽车制造商和他们的软件提供商显著大量的资金，而显著减少了产品上市时间。我很兴奋，因为 GENIVI 我们很幸运慢慢从高度结构化和专有的方法来社区为基础的方法不断发展的组织​​领导排序在汽车行业的一场革命。我们还没有完成，但它一直是一个荣幸参加正在产生实实在在的好处的转换。 - -#### 你的庞大会员怎么才可以驱动 GENIVI 方向？ - -GENIVI 有很多会员和非会员促进我们的工作。与许多开源项目，任何公司都可以通过简单地贡献代码，修补程序和时间来检验影响的技术输出。随着中说，宝马，奔驰，现代汽车，捷豹路虎，标致雪铁龙，雷诺 / 日产和沃尔沃是所有积极采用者和贡献者 GENIVI 和其他许多 OEM 厂商已经在他们的汽车 IVI 解决方案，广泛使用 GENIVI 的软件。 - -#### 贡献的代码使用了什么许可证？ - -GENIVI 采用数量的许可证从（L）GPLv2 许可，以 MPLv2 到 Apache2.0。我们的一些工具使用 Eclipse 许可证。我们有一个[public licensing policy][18]，详细说明我们的许可偏好。 - -#### 一个人或一群人如何参与其中？重要的是如何对项目的持续成功的社区贡献？ - -GENIVI 完全做它开放发展的在([projects.genivi.org][19])，因此，有兴趣的人在汽车使用开源软件，欢迎参加。这就是说，该联盟能够通过公司 [joining GENIVI][20] 作为成员不断发展的开放基金。 GENIVI 会员享受各种各样的福利，而不是其中最重要的是在已经发展了近六年来 140 家公司全球社区参与。 - -社区是 GENIVI 非常重要的，我们不可能生产和维护我们发展了很多年没有贡献者一个活跃的社区有价值的软件。我们努力做出贡献 GENIVI 简单，只要加入一个 [邮件列表] [21] 并连接到人们在不同的软件项目。我们使用许多开源项目采用的标准做法，并提供高质量的工具和基础设施，以帮助开发人员有宾至如归的感觉，并富有成效。 - -无论在汽车软件某人的熟悉，欢迎他们加入我们的社区。人们已经改装车多年，所以对于许多人来说，是一种天然的抽奖，任何汽车。软件是汽车的新域，GENIVI 希望成为敞开的门有兴趣的人与汽车，开源软件的工作。 - -------------------------------- -via: https://opensource.com/business/16/5/interview-alison-chaiken-steven-crumb - -作者：[Don Watkins][a] -译者：[erlinux](https://github.com/erlinux) -校对：[校对者ID](https://github.com/校对者ID) - -本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创翻译，[Linux中国](https://linux.cn/) 荣誉推出 - -[a]: https://opensource.com/users/don-watkins -[1]: https://en.wikipedia.org/wiki/In_car_entertainment -[2]: https://opensource.com/life/16/1/weekly-news-jan-9 -[3]: http://projects.genivi.org/smartdevicelink/home -[4]: http://www.genivi.org/ -[5]: https://www.linkedin.com/in/stevecrumb -[6]: http://www.genivi.org/genivi-members -[7]: http://www.linuxfoundation.org/ -[8]: https://www.automotivelinux.org/ -[9]: https://en.wikipedia.org/wiki/Telematics -[10]: https://www.automotivelinux.org/news/announcement/2016/01/ford-mazda-mitsubishi-motors-and-subaru-join-linux-foundation-and -[11]: https://www.linkedin.com/in/alison-chaiken-3ba456b3 -[12]: https://www.linkedin.com/in/stevecrumb -[13]: https://opensource.com/users/eximious -[14]: https://en.wikipedia.org/wiki/MeeGo -[15]: http://webinos.org/deliverable-d026-target-platform-requirements-and-ipr/automotive/ -[16]: http://she-devel.com/Chaiken_automotive_cybersecurity.pdf -[17]: https://www.osvehicle.com/ -[18]: http://projects.genivi.org/how -[19]: http://projects.genivi.org/ -[20]: http://genivi.org/join -[21]: http://lists.genivi.org/mailman/listinfo/genivi-projects diff --git a/translated/talk/20160531 The Anatomy of a Linux User.md b/translated/talk/20160531 The Anatomy of a Linux User.md new file mode 100644 index 0000000000..a404697347 --- /dev/null +++ b/translated/talk/20160531 The Anatomy of a Linux User.md @@ -0,0 +1,58 @@ + + +一个 Linux 用户的故事 +================================ + + + +**一些新的 GNU/Linux 用户都很清楚的知道 Linux 不是 Windows .其他很多人都不是很清楚的知道．最好的发行版设计者努力保持新的思想** + +### Linux 的核心 + +不管怎么说，Ｎicky 都不是那种表面上看起来很值得注意的人．她已经三十岁了，却决定回到学校学习．她在海军待了６年时间直到她的老友给她一份新的工作，而且这份工作比她在军队的工作还好．在过去的军事分支服务期间发生了很多事情．我认识她还是她在军队工作的时候．她是８个州的货车运输业协商区域的管理者．那会我在达拉斯跑肉品包装工具的运输． +![](http://i2.wp.com/fossforce.com/wp-content/uploads/2016/05/anatomy.jpg?w=525) + + +Nicky 和我在 2006 年成为了好朋友．她很外向，并且有很强的好奇心，她几乎走过每个运输商走的路线．一个星期五晚上我们在灯光下有一场很激烈的争论，像这样的 达 30 分钟的争论在我们之间并不少见．或许这并不比油漆一个球场省事，但是气氛还是可以控制的住的，感觉就像是一个很恐怖的游戏．在这次争论的时候她问到我是否可以修复她的电脑． + +她知道我为了一些贫穷的孩子能拥有他们自己的电脑做出的努力，当她抱怨她的电脑很慢的时候，我提到了参加 Bill Gate 的 401k 计划［译注:这个计划是为那些为内部收益代码做过贡献的人们提供由税收定义的养老金账户．］．Nicky 说这是了解 Linux 的最佳时间． + +她的电脑相当好，它是一个带有 Dell 19 显示器的华硕电脑．不好的是，当不需要一些东西的时候，这个 Windows 电脑会强制性的显示所有的工具条和文本菜单．我们把电脑上的文件都做了备份之后就开始安装 Linux 了．我们一起完成了安装，并且我确信她知道了如何分区．不到一个小时，她的电脑上就有了一个漂亮的 PCLinuxOS 桌面． + +她会经常谈论她使用新系统的方法，系统看起来多么漂亮．她不曾提及的是，她几乎被她面前的井然有序的漂亮桌面吸引．她说她的桌面带有漂亮的"微光"．这是我在安装系统期间特意设置的．我每次在安装 Linux 的时候都会进行这样的配置．我想让每个 Linux 用户的桌面都配置这个漂亮的微光． + +大概第一周左右，她给我打电话或者发邮件问了一些常规的问题，但是最主要的问题还是她想知道怎样保存她打开的 Office 文件（OpenOffice）以至于她的同事也可以读这些文件．教一个人使用 Linux 或者 Open/LibreOffice 的时候最重要的就是教她保存文件．大多数用户仅仅看到第一个提示，只需要手指轻轻一点就可以以打开文件模式( Open Document Format )保存． + + +大约一年前或者更久，一个高中生说他没有通过期末考试，因为教授不能打开他写着论文的文件．这引来不能决定谁对谁错的读者的激烈评论．这个高中生和教授都不知道这件事该怪谁． + +我知道一些大学教授甚至每个人都能够打开一个 ODF 文件．见鬼，很少有像微软这样优秀的公司，我想 Microsoft Office 现在已经能打开 ODT 或者 ODF 文件了．我也不能确保，毕竟我最近一次用 Microsoft Office 是在 2005 年． + +甚至在困难时期,当 Microsoft 很受欢迎并且很热衷于为使用他们系统的厂商的企业桌面上安装他们自己的软件的时候，我和一些使用 Microsoft Office 的用户的产品生意和合作从来没有出现过问题，因为我会提前想到可能出现的问题并且不会有侥幸心理．我会发邮件给他们询问他们正在使用的 Office 版本．这样，我就可以确保以他们能够读写的格式保存文件． + +说到 Nicky ，她花了很多时间学习她的 Linux 系统．我很惊奇于她的热情． + +当人们意识到所有的使用 Windows 的习惯和工具都要被抛弃的时候，学习 Linux 系统也会很容易．甚至在我们谈论第一次用的系统时，我查看这些系统的桌面或者下载文件夹大多都找不到 some_dodgy_file.exe 这样的文件． + +在我们通常讨论这些文件的时候，我们也会提及关于更新的问题．很长时间我都不会在一台电脑上反复设置去完成多种程序的更新和安装．比如 Mint ，它没有带有 Synaptic ［译注:一个 Linux 管理图像程序包］的完整更新方法,这让我失去兴趣．但是我们的老成员 dpkg 和 apt 是我们的好朋友，聪明的领导者已经得到肯定并且认识到命令行看起来不是那么舒服，同时欢迎新的用户加入． + +我很生气，强烈反对机器对 Synaptic 的削弱，最后我放弃使用它．你记得你第一次使用的 Linux 发行版吗？记得你什么时候在 Synaptic 中详细查看大量的软件列表吗？记得你怎样开始检查并标记每个你发现的很酷的程序吗？你记得有多少这样的程序开始都是使用"lib"这样的文件吗？ + +是的，我也是。我安装并且查看了一些新的安装程序，直到我发现那些库文件是应用程序的螺母和螺栓，而不是应用程序本身．这就是为什么这些聪明的开发者在 Linux Mint 和 Ubuntu 之后创造了聪明、漂亮和易于使用的应用程序的安装程序．Synaptic 仍然是我们的老大，但是对于一些后来者，安装像 lib 文件这样的方式需要打开大量的文件夹，很多这样的事情都会导致他们放弃使用这个系统．在新的安装程序中，这些文件会被放在一个文件夹中甚至不会展示给用户．总之，这也是该有的解决方法． + +除非你要改变应该支持的需求． + +现在的 Linux 发行版中有很多有用的软件，我也很感谢这些开发者，因为他们，我的工作变得容易．不是每一个 Linux 新用户都像 Nicky 这样富有热情．她相当不错的完成了安装过程并且达到了忘我的状态．像她这样极具热情的毕竟是少数．大多数新的 Linux 用户也就是在需要的时候才这样用心． + +很不错，他们都是要教自己的孩子使用 Linux 的人． +-------------------------------------------------------------------------------- + +via: http://fossforce.com/2016/05/anatomy-linux-user/ + +作者：[Ken Starks][a] +译者：[vim-kakali](https://github.com/vim-kakali) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: http://linuxlock.blogspot.com/ diff --git a/translated/talk/20160531 Why Ubuntu-based Distros Are Leaders.md b/translated/talk/20160531 Why Ubuntu-based Distros Are Leaders.md deleted file mode 100644 index 9d9ce0f418..0000000000 --- a/translated/talk/20160531 Why Ubuntu-based Distros Are Leaders.md +++ /dev/null @@ -1,85 +0,0 @@ -为什么 Ubuntu 家族会占据 Linux 发行版的主导地位？ -========================================= - -在过去的数年中，我已经尝试了大量的优秀 Linux 发行版。我印象最深刻的是那些被强大的社区维护的发行版。但是这样的发行版却比他们s所属的社区更受人欢迎。流行的 Linux 发行版吸引着更多的人，通常由于这样的特点使得使用该发行版更加容易。这很明显毫无关系，但一般认为这种说法是正确的。 - - -我想到的一个发行版 [Ubuntu][1]。它属于健壮的 [Debian][2]分支,Ubuntu 不可思议的成为了受欢迎的 Linux 发行版，而且它也衍生出了其他的版本，比如 Linux Mint。在本文中，我会探讨我坚信 Ubuntu 会赢得 Linux 发行版战争的原因，以及它在整个 Linux 桌面领域有着怎样的影响力。 - - -### Ubuntu容易使用 - - -多年前我第一次尝试使用Ubuntu，在这之前我更喜欢使用 KED 桌面。在那个时期，我接触的大多是这种 KDE 桌面环境。主要原因还是 KDE 是大多数新手友好的 Linux 发行版中最受欢迎的。新手友好的发行版有 Knoppix，Simply Mepis, Xandros, Linspire等，另外一些发行版和这些发行版都指出他们的用户趋向于使用 KDE。 - - - -现在KDE能满足我的需求，也没有什么理由去折腾其他的桌面环境了。有一天我的 Debian 安装失败了（由于我个人的操作不当），我决定尝试开发代号为「整洁的公鸭(Ubuntu Dapper Drake)」的 Ubuntu 版本【译者注：ubuntu 6.06 - Dapper Drake(整洁的公鸭)，发布日期：2006年6月1日】。那个时候，我对于它的印象比一个屏幕截图还要少，但是我认为它很有趣并且毫无顾忌的使用它。 - - - -Ubuntu Dapper Drake 给我的最大的印象是它的操作很简单。记住，我是来自于 KDE 世界的用户，在 KDE 上要想改变菜单的设置就有15钟方法。Ubuntu 图形界面的安装启动极具极简主义。 - -时间来到2016年，最新的版本号是16.04：我们有多种可用的 Ubuntu 衍生版本，许多的都是基于 Ubuntu 的。所有的 Ubuntu 风格和公用发行版的核心都被设计的容易使用。并且发行版想要增大用户基数的时候，这就是最重要的原因。 - - -### Ubuntu LTS - -过去，我几乎一直坚持使用 LTS（Long Term Support）发行版作为我的主要桌面系统。10月份的发行版很适合我测试硬盘驱动器，甚至把它用在一个老旧的手提电脑上。我这样做的原因很简单——我没有兴趣在一个作为实验品的电脑上折腾短期发行版。我是个很忙的家伙，我觉得这样会浪费我的时间。 - - -对于我来说，我认为 Ubuntu 提供 LTS 发行版是 Ubuntu 能够变得流行的原因。这样说吧———提供一个大众的桌面 Linux 发行版，这个发行版能够得到长期的充分支持就是它的优势。事实上，Ubuntu 的优势不只这一点，其他的分支在这一点上也做的很好。长期支持版带有一个对新手的友好环境的策略，我认为这就为 Ubuntu 的普及带来了莫大的好处。 - - -### Ubuntu Snap 包 - - -以前，用户在他们的系统上使用很多 PPA（personal package archive个人软件包档案），他们总会抱怨它获得新的软件名称的能力。不好的是，这种技术也有缺点。它工作的时候带有任意的软件名称，而 PPA 却没有发现，这种情况很常见。 - - -现在有了[Snap 包][3] 。当然这不是一个全新的概念，过去已经进行了类似的尝试。用户不必要在最新的 Ubuntu 发行版上运行最新的软件，我认为这才是 Snap 将要长期提供给 Ubuntu 用户的东西。然而我仍然认为我们将会看到 Snap 淘汰的的那一天，我很期待看到一个在稳定的发行版上运行的优秀软件。 - - - -如果你要运行很多软件，那么 Snap 包实际使用的硬盘空间很明显存在问题。不仅如此，大多数 Ubuntu 软件也是通过由官方开发的 deb 包进行管理的。当后者需要花费一些时间的时候，这个问题可以通过 Snap 使用更大的硬盘驱动器空间得到解决。 - - - -### Ubuntu 社区 - -首先，我承认大多数主要的 Linux 发行版都有强大的社区。然而，我坚信 Ubuntu 社区的成员是最多样化的，他们来自各行各业。例如，我们有一个论坛来分类不同的苹果硬件对于游戏的支持程度。这些大量的专业讨论特别广泛。 - - -除过论坛，Ubuntu 也提供了一个很正式的社区组织。这个组织包括一个委员会，技术板块，[各地的团队LoCo teams][4](Ubuntu Local Community Teams)和开发人员板块。还有很多，但是这些都是我知道的社区组织部分。 - - -我们还有一个[Ubuntu 问答][5]板块。我认为，这种特色可以代替人们从论坛寻求帮助的方式，我发现在这个网站你得到有用信息的可能行更大。不仅如此，那些提供的解决方案中被选出的最精准的答案也会被写入到官方文档中。 - - -### Ubuntu 的未来 - - -我认为 Ubuntu 的 Unity 接口【译者注：Unity 是 Canonical 公司为 Ubuntu 操作系统的 GNOME 桌面环境开发的图形化 shell】在增加桌面舒适性上少有作为。我能理解其中的缘由，现在它主要做一些诸如可以使开发团队的工作更轻松的事情。但是最终，我还是希望 Unity 可以为 Ubuntu MATE 和 Linux Mint 的普及铺平道路。 - - -我最好奇的一点是 Ubuntu's IRC(Internet Relay Chat) 和邮件列表的发展【译者注：可以在 Ubuntu LoCo Teams IRC Chat上提问关于地方团队和计划的事件的问题，也可以和一些不同团队的成员进行交流】。事实是，他们都不能像 Ubuntu 问答板块那样为它们自己增添一些好的文档。至于邮件列表，我一直认为这对于合作是一种很痛苦的过时方法，但这仅仅是我的个人看法——其他人可能有不同的看法，也可能会认为它很好。 - -你说什么？你认为 Ubuntu 将来会剩下一点主要的使用者？也许你相信 Arch 和 Linux Mint 或者其他的发行版会在普及度上打败 Ubuntu 。 既然这样，那请大声说出你最喜爱的发行版。如果这个发行版是 Ubuntu 衍生版 ，说说你为什么更喜欢它而不是 Ubuntu 本身。如果不出意外，Ubuntu 会成为构建其他发行版的基础，我想很多人都是这样认为的。 - - --------------------------------------------------------------------------------- - -via: http://www.datamation.com/open-source/why-ubuntu-based-distros-are-leaders.html - -作者：[Matt Hartley][a] -译者：[vim-kakali](https://github.com/vim-kakali) -校对：[校对者ID](https://github.com/校对者ID) - -本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 - -[a]: http://www.datamation.com/author/Matt-Hartley-3080.html -[1]: http://www.ubuntu.com/ -[2]: https://www.debian.org/ -[3]: http://www.datamation.com/open-source/ubuntu-snap-packages-the-good-the-bad-the-ugly.html -[4]: http://loco.ubuntu.com/ -[5]: http://askubuntu.com/ diff --git a/translated/talk/20160614 ​Ubuntu Snap takes charge of Linux desktop and IoT software distribution.md b/translated/talk/20160614 ​Ubuntu Snap takes charge of Linux desktop and IoT software distribution.md new file mode 100644 index 0000000000..f7b3e5590c --- /dev/null +++ b/translated/talk/20160614 ​Ubuntu Snap takes charge of Linux desktop and IoT software distribution.md @@ -0,0 +1,121 @@ + + +Ubuntu Snap 软件包管理 Linux 桌面和 IoT 的软件安装 +=========================================================================== + + +[Canonical][28] 和 [Ubuntu][29] 创始人 Mark Shuttleworth 在一次采访中说他不计划宣布 Ubuntu 的新 [ Snap 程序包格式][30]。但是 +在之后几个月，各种 Linux 发行版的开发者和团队都宣布他们会把 Snap 作为通用 Linux 程序包格式。 +![](http://zdnet2.cbsistatic.com/hub/i/r/2016/06/14/a9b2a139-3cd4-41bf-8e10-180cb9450134/resize/770xauto/adc7d16a46167565399ecdb027dd1416/ubuntu-snap.jpg) +>Linux 供应商，独立软件开发商（ISV:Independent Software Vendor）和开发团队都采用 Ubuntu Snap 作为多种 Linux 系统的配置和更新程序包。 + +为什么呢？因为 Snap 能使一个二进制程序包可以完美、安全地在任何 Linux 台式机、服务器、云或设备上运行。Canonical 的 Ubuntu 客户端产品和版本负责人 Olli Ries 说： + + +>[ Snap 程序包的安全机制][1] 允许我们为 Snap 应用单独空出一些系统空间，这样我们就可以根据我们自身的情况更高效的进行循环开发。用户安装一个 Snap 的时候也不用担心是否会影响其他的应用程序和操作系统。 + + +当然了，早期的 Linux 内核开发者和 CoreOS 【译注：CoreOS是一种操作系统，于2013年十二月发布，它的设计旨在关注开源操作系统内核的新兴使用——用于大量基于云计算的虚拟服务器。】安全维护者 Matthew Garrett 指出：如果你 [使用带有不安全程序的 Snap 程序包比如 X11 ][2] 视窗系统【译注：X11也叫做 X Window 系统，X Window 系统 ( X11 或 X )是一种位图显示的视窗系统 。它是在 Unix 和类 Unix 操作系统 ，以及 OpenVMS 上建立图形用户界面的标准工具包和协议，并可用于几乎所有已有的现代操作系统。】，实际上你的系统一点也不安全。 + + +Shuttleworth 同意 Garrett 的观点，但是他也说你可以控制 Snap 应用使用多少的系统剩余空间。比如，一个 web 浏览器可以包含一个安全的 Snap 程序包，这个 Snap 使用 Ubuntu 的一个包 [openssl][3]【译注：OpenSSL 是一个强大的安全套接字层密码库，囊括主要的密码算法、常用的密钥和证书封装管理功能及 SSL 协议，并提供丰富的应用程序供测试或其它目的使用。】的安全传输层(TLS,Transport Layer Security)和安全套接字层(SSL,Secure Sockets Layer)二进制文件。除此之外，即使有程序攻破了浏览器的诉讼程序【译注：诉讼程序属于程序性法律程序中的公力救济型程序】，也不能进行底层的系统操作。 + +很多团队也这样认为。[戴尔][4]，[三星][5]，[Mozilla][6],[krita][7]【译注：Krita 是一个位图形编辑软件，KOffice 套装的一部份。包含一个绘画程式和照片编辑器，Krita 是自由软件，并根据GNU通用公共许可证发布。】，[麦考夫][8]【译注：Mycroft 是一个开源AI智能家居平台，配置 Raspberry Pi 2 和 Arduino 控制器，应该就是以夏洛克福尔摩斯的哥哥为名的。】，以及 [地平线计算][9] 【译注：地平线计算解决方案，为客户提供优质的硬件架构为其运行云平台。】都将使用 Snap。[Arch Linux][10],[Debain][11]，[Gentoo][12]，和 [OpenWrt][13] 【译注：OpenWrt 可以被描述为一个嵌入式的 Linux 发行版】开发团队也已经拥抱了 Snap，也会把 Snap 加入到他们各自开发的分支中。 + +Snap 包又叫做“ Snaps ”，现在在 Arch、Debian、Fedora、Kubuntu、Lubuntu、Ubuntu GNOME、Ubuntu Kylin、Ubuntu MATE、Ubuntu Unity 和 Xubuntu 上运行。 Snap 正在 CentOS、Elementary、Gentoo、Mint、OpenSUSE 和 Red Hat Enterprise Linux (RHEL) 上予以验证，并且在其他 Linux 发行版上运行也会很容易。 + +这些发行版都使用 Snaps，Shuttleworth 声称：“ Snaps 为每个 Linux 台式机、服务器、设备和云机器带来了很多应用程序，也给了用户更大的自由，用户可以选择任何带有最好应用程序的 Linux 发行版本。” + +把这些发行版放在一起代表了大多的主流 Linux 桌面、服务器和云系统分支。为什么他们切换到本地包来进行系统管理呢？ Arch Linux 的贡献者 +除过这些 Linux 分支，独立软件开发商（ISV,Independent Software Vendor）也将会因为 Snap 很好的简化了第三方 Linux 应用程序和安全维护问题而拥抱 Snap。例如，[文档基金会][14] 也将会开发出受欢迎的可用开源 office 套件 [LibreOffice][15] 作为一个 Snap 程序包。 + +文档基金会的联合创始人 Thorsten Behrens 这样说： + +>我们的目标是使 LibreOffice 能被大多数人更容易使用成为可能。Snap 使我们的用户能够在不同的桌面系统和分支上更快捷更容易的持续获取最新的 LibreOffice 版本。如上所述，它也会帮助我们的版本开发工程师最终从定期的自产的陈旧 Linux 开发解决方案中解放出来，总之很多东西会被共同维护。 + +Ｍozilla 的 [火狐][16] 副总裁（VP,Vice President）Nick Nguyen 在这段陈述中提到： + +>我们力求为用户提供良好的使用体验，并且使火狐浏览器能够在更多平台、设备和操作系统上运行。随着对 Snaps 的介绍，我们也会对火狐浏览器进行持续优化，使它可以为 Linux 用户提供最新特性。 + +基于 KDE 的图形程序的 [Krita Foundation][17] 项目领导 Boudewijn Rempt 说： + + +>正在维护的 DEB 包在一个私有仓库，这很复杂也很耗费时间。Snaps 更容易维护、打包和配置。把 Snap 放进软件商店也特别容易，我已经把软件发布在最合适的软件商店了。[Krita 3.0][18] 刚刚作为一个 snap 程序包发行，它作为最新的版本能够自动更新。 + +不仅 Linux 桌面系统程序使用 Snap。物联网(IoT)和嵌入式开发者也双手拥抱了 Snap。 + + +Snaps 彼此隔离开来，以确保安全性，它们还可以自动更新或回滚，这对于硬件设备是极好的。多种厂商都在他们的物联网设备上运行着 snappy【译注：Snap 基于 snappy进行构建。】，能够生产带有物联网应用程序商店的新的“智能边缘”设备。Snappy 设备能够自动接收系统更新，并且连同安装在设备上的应用程序也会得到更新。 + +戴尔公司根据最早的物联网厂商之一的创始人 Shuttleworth 看到的 Snap 的巨大潜力决定在他们的设备上使用 Snap。 + +戴尔公司的物联网战略和合作伙伴主管 Jason Shepherd 说：“我们认为，Snaps 能够报告安全风险，也能解决在单一物联网网关上部署和运行多个第三方应用程序所带来的安全风险和可管理性挑战。这种课信赖的通用的应用程序格式才是戴尔真正需要的，我们的物联网解决方案合作伙伴和产品客户都对物联网应用程序的充满活力的生态系统有极大的兴趣。” + + +OpenWrt 的开发者 Matteo Croce 说：“这很简单，在脱离无变化的核心操作系统的时候 Snaps 会为 OpenWrt 递送大量的软件...Snaps 是通过点和路由为 OpenWrt 提供大量软件的最快方式。” + +Shuttleworth 认为 Snaps 不会取代已经存在的 Linux 程序包比如 [RPM][19] 和 [DEB][20]。相反，他认为他们将会相辅相成。Snaps 将会与现有包共存。每个发行版都有为系统内核提供更新的相应机制，这种机制也在不断更新。Snap 为桌面系统带来的是通用的应用程序，这些应用程序不会影响基本的系统操作。 + +每个 Snap 使用大量的独立核心和安全机制时也会有所限制，这是 Snap 应用程序的特色，谨慎的重览过程确保 Snap 仅仅得到其完成请求操作的权限。用户在安装 Snap 的时候也不必考虑复杂的安全问题。 + +Snap实际上是独立式zip文件，能够非常迅速地在原地执行，很受欢迎的[中标麒麟][21]团队的负责人 Jack Yu 称：“Snaps 比传统的 Linux 包更容易构建，允许我们对这种基本的系统的操作的独立性产生依赖，所以我们可以为所有的分支用户开发更好的最新国产 Linux 应用程序。” + +Snap 程序包格式由 Canonical 设计，基于 [snapd][22] 。这是GitHub上的一个软件项目。大多 Linux 发行版的部分 snapd 已经被证明是容易理解的，社区里也加入了新的有大量 Linux 经验的贡献者。 + + +Snap 程序包使用 snapcraft 工具来构建。项目基地是 [snapcraft.io][24] 网站，附有构建 Snap 的预览和逐步指南，不包括项目开发者和使用者的文件。Snap可能基于现有的发行版程序包，但更常使用源代码来构建，为了优化和规模效率。 + +如果你不是 Ubuntu 的忠实粉丝或者一个偏执的 Linux 开发者你可能不知道 Snap。未来，在任何平台上需要用 Linux 完成工作的任何人都会知道这个软件。用它的方法完成工作会成为主流 -- 尤其在这些方面将更重要 -- Linux 应用程序的安装和更新机制。 + + +#### 相关内容： + + +- [Linux 专家 Matthew Garrett：Ubuntu 16.04 的新 Snap 程序包格式存在安全风险 ][25] +- [Ubuntu Linux 16.04 ] +- [Microsoft 和 Canonical 合作使 Ubuntu 可以在 Windows 10 上运行 ] + + +-------------------------------------------------------------------------------- + +via: http://www.zdnet.com/article/ubuntu-snap-takes-charge-of-linux-desktop-and-iot-software-distribution/ + +作者：[Steven J. Vaughan-Nichols][a] +译者：[vim-kakali](https://github.com/vim-kakali) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: http://www.zdnet.com/meet-the-team/us/steven-j-vaughan-nichols/ +[28]: http://www.canonical.com/ +[29]: http://www.ubuntu.com/ +[30]: https://insights.ubuntu.com/2016/04/13/snaps-for-classic-ubuntu/ +[1]: https://insights.ubuntu.com/2016/04/13/snaps-for-classic-ubuntu/ +[2]: http://www.zdnet.com/article/linux-expert-matthew-garrett-ubuntu-16-04s-new-snap-format-is-a-security-risk/ +[3]: https://www.openssl.org/ +[4]: http://www.dell.com/en-us/ +[5]: http://www.samsung.com/us/ +[6]: http://www.mozilla.com/ +[7]: https://krita.org/en/ +[8]: https://mycroft.ai/ +[9]: http://www.horizon-computing.com/ +[10]: https://www.archlinux.org/ +[11]: https://www.debian.org/ +[12]: https://www.gentoo.org/ +[13]: https://openwrt.org/ +[14]: https://www.documentfoundation.org/ +[15]: https://www.libreoffice.org/download/libreoffice-fresh/ +[16]: https://www.mozilla.org/en-US/firefox/new/ +[17]: https://krita.org/en/about/krita-foundation/ +[18]: https://krita.org/en/item/krita-3-0-released/ +[19]: http://rpm5.org/ +[20]: https://www.debian.org/doc/manuals/debian-faq/ch-pkg_basics.en.html +[21]: http://www.ubuntu.com/desktop/ubuntu-kylin +[22]: https://launchpad.net/ubuntu/+source/snapd +[23]: https://github.com/snapcore/snapd +[24]: http://snapcraft.io/ +[25]: http://www.zdnet.com/article/linux-expert-matthew-garrett-ubuntu-16-04s-new-snap-format-is-a-security-risk/ +[26]: http://www.zdnet.com/article/ubuntu-linux-16-04-is-here/ +[27]: http://www.zdnet.com/article/microsoft-and-canonical-partner-to-bring-ubuntu-to-windows-10/ + + diff --git a/translated/talk/20160615 Explanation of “Everything is a File” and Types of Files in Linux.md b/translated/talk/20160615 Explanation of “Everything is a File” and Types of Files in Linux.md new file mode 100755 index 0000000000..c9a1b243ff --- /dev/null +++ b/translated/talk/20160615 Explanation of “Everything is a File” and Types of Files in Linux.md @@ -0,0 +1,277 @@ +诠释 Linux 中“一切都是文件”概念和相应的文件类型 +==================================================================== + +![](http://www.tecmint.com/wp-content/uploads/2016/05/Everything-is-a-File-in-Linux.png) +>Linux 系统中一切都是文件并有相应的文件类型 + +在 Unix 和它衍生的比如 Linux 系统中，一切都可以看做文件。虽然它仅仅只是一个泛泛的概念，但这是事实。如果有不是文件的，那它一定是正运行的进程。 + +要理解这点，可以举个例子，您的根目录(/) 的空间是由不同类型的 Linux 文件所占据的。当您创建一个文件或向系统传一个文件时，它在物理磁盘上占据的一些空间，可以认为是一个特定的格式（文件类型）。 + +虽然 Linux 系统中文件和目录没有什么不同，但目录还有一个重要的功能，那就是有结构性的分组存储其它文件，以方便查找访问。所有的硬件部件都表示为文件，系统使用这些文件来与硬件通信。 + +这些思想是对伟大的 Linux 财产的重要阐述，因此像文档、目录（Mac OS X 和 Windows 系统下是文件夹）、键盘、监视器、硬盘、可移动媒体设备、打印机、调制解调器、虚拟终端，还有进程间通信（IPC）和网络通信等输入/输出资源都在定义在文件系统空间下的字节流。 + +一切都可看作是文件，其最显著的好处是对于上面所列出的输入/输出资源，只需要相同的一套 Linux 工具、实用程序和 API。 + +虽然在 Linux 中一切都可看作是文件，但也有一些特殊的文件，比如[套接字和命令管道][1]。 + +### Linux 文件类型的不同之处？ + +Linux 系统中有三种基本的文件类型： + +- 普通/常规文件 +- 特殊文件 +- 目录文件 + +#### 普通/常规文件 + +它们是包含文本、数据、程序指令等数据的文件，其在 Linux 系统中是最常见的一种。包括如下： + +- 只读文件 +- 二进制文件 +- 图像文件 +- 压缩文件等等 + +#### 特殊文件 + +特殊文件包括以下几种： + +块文件：设备文件，对访问系统硬件部件提供了缓存接口。他们提供了一种使用文件系统与设备驱动通信的方法。 + +有关于块文件一个重要的性能就是它们能在指定时间内传输大块的数据和信息。 + +列出某目录下的块文件： + +``` +# ls -l /dev | grep "^b" +``` + +输出例子 + +``` +brw-rw---- 1 root disk 7, 0 May 18 10:26 loop0 +brw-rw---- 1 root disk 7, 1 May 18 10:26 loop1 +brw-rw---- 1 root disk 7, 2 May 18 10:26 loop2 +brw-rw---- 1 root disk 7, 3 May 18 10:26 loop3 +brw-rw---- 1 root disk 7, 4 May 18 10:26 loop4 +brw-rw---- 1 root disk 7, 5 May 18 10:26 loop5 +brw-rw---- 1 root disk 7, 6 May 18 10:26 loop6 +brw-rw---- 1 root disk 7, 7 May 18 10:26 loop7 +brw-rw---- 1 root disk 1, 0 May 18 10:26 ram0 +brw-rw---- 1 root disk 1, 1 May 18 10:26 ram1 +brw-rw---- 1 root disk 1, 10 May 18 10:26 ram10 +brw-rw---- 1 root disk 1, 11 May 18 10:26 ram11 +brw-rw---- 1 root disk 1, 12 May 18 10:26 ram12 +brw-rw---- 1 root disk 1, 13 May 18 10:26 ram13 +brw-rw---- 1 root disk 1, 14 May 18 10:26 ram14 +brw-rw---- 1 root disk 1, 15 May 18 10:26 ram15 +brw-rw---- 1 root disk 1, 2 May 18 10:26 ram2 +brw-rw---- 1 root disk 1, 3 May 18 10:26 ram3 +brw-rw---- 1 root disk 1, 4 May 18 10:26 ram4 +brw-rw---- 1 root disk 1, 5 May 18 10:26 ram5 +... +``` + +字符文件： 也是设备文件，对访问系统硬件组件提供了非缓冲串行接口。它们与设备的通信工作方式是一次只传输一个字符的数据。 + +列出某目录下的字符文件： + +``` +# ls -l /dev | grep "^c" +``` + +输出例子 + +``` +crw------- 1 root root 10, 235 May 18 15:54 autofs +crw------- 1 root root 10, 234 May 18 15:54 btrfs-control +crw------- 1 root root 5, 1 May 18 10:26 console +crw------- 1 root root 10, 60 May 18 10:26 cpu_dma_latency +crw------- 1 root root 10, 203 May 18 15:54 cuse +crw------- 1 root root 10, 61 May 18 10:26 ecryptfs +crw-rw---- 1 root video 29, 0 May 18 10:26 fb0 +crw-rw-rw- 1 root root 1, 7 May 18 10:26 full +crw-rw-rw- 1 root root 10, 229 May 18 10:26 fuse +crw------- 1 root root 251, 0 May 18 10:27 hidraw0 +crw------- 1 root root 10, 228 May 18 10:26 hpet +crw-r--r-- 1 root root 1, 11 May 18 10:26 kmsg +crw-rw----+ 1 root root 10, 232 May 18 10:26 kvm +crw------- 1 root root 10, 237 May 18 10:26 loop-control +crw------- 1 root root 10, 227 May 18 10:26 mcelog +crw------- 1 root root 249, 0 May 18 10:27 media0 +crw------- 1 root root 250, 0 May 18 10:26 mei0 +crw-r----- 1 root kmem 1, 1 May 18 10:26 mem +crw------- 1 root root 10, 57 May 18 10:26 memory_bandwidth +crw------- 1 root root 10, 59 May 18 10:26 network_latency +crw------- 1 root root 10, 58 May 18 10:26 network_throughput +crw-rw-rw- 1 root root 1, 3 May 18 10:26 null +crw-r----- 1 root kmem 1, 4 May 18 10:26 port +crw------- 1 root root 108, 0 May 18 10:26 ppp +crw------- 1 root root 10, 1 May 18 10:26 psaux +crw-rw-rw- 1 root tty 5, 2 May 18 17:40 ptmx +crw-rw-rw- 1 root root 1, 8 May 18 10:26 random +``` + +符号链接文件 ： 符号链接是指向系统上其他文件的引用。因此，符号链接文件是指向其它文件的文件，也可以是目录或常规文件。 + +列出某目录下的符号链接文件： + +``` +# ls -l /dev/ | grep "^l" +``` + +输出例子 + +``` +lrwxrwxrwx 1 root root 3 May 18 10:26 cdrom -> sr0 +lrwxrwxrwx 1 root root 11 May 18 15:54 core -> /proc/kcore +lrwxrwxrwx 1 root root 13 May 18 15:54 fd -> /proc/self/fd +lrwxrwxrwx 1 root root 4 May 18 10:26 rtc -> rtc0 +lrwxrwxrwx 1 root root 8 May 18 10:26 shm -> /run/shm +lrwxrwxrwx 1 root root 15 May 18 15:54 stderr -> /proc/self/fd/2 +lrwxrwxrwx 1 root root 15 May 18 15:54 stdin -> /proc/self/fd/0 +lrwxrwxrwx 1 root root 15 May 18 15:54 stdout -> /proc/self/fd/1 +``` + +Linux 中使用 `ln` 工具就可以创建一个符号链接文件，如下所示： + +``` +# touch file1.txt +# ln -s file1.txt /home/tecmint/file1.txt [创建符号链接文件] +# ls -l /home/tecmint/ | grep "^l" [列出符号链接文件] +``` + +在上面的例子中，首先我们在 `/tmp` 目录创建了一个名叫 `file1.txt` 的文件，然后创建符号链接文件，所以 `/home/tecmint/file1.txt` 指向 `/tmp/file1.txt` 文件。 + +套接字和命令管道 : 连接一个进行的输出和另一个进程的输入，允许进程间通信的文件。 + +命名管道实际上是一个文件，用来使两个进程彼此通信，就像一个 Linux pipe(管道) 命令一样。 + +列出某目录下的管道文件： + +``` +# ls -l | grep "^p" +``` + +输出例子 + +``` +prw-rw-r-- 1 tecmint tecmint 0 May 18 17:47 pipe1 +prw-rw-r-- 1 tecmint tecmint 0 May 18 17:47 pipe2 +prw-rw-r-- 1 tecmint tecmint 0 May 18 17:47 pipe3 +prw-rw-r-- 1 tecmint tecmint 0 May 18 17:47 pipe4 +prw-rw-r-- 1 tecmint tecmint 0 May 18 17:47 pipe5 +``` + +在 Linux 中可以使用 `mkfifo` 工具来创建一个命名管道，如下所示： + +``` +# mkfifo pipe1 +# echo "This is named pipe1" > pipe1 +``` + +在上的例子中，我们创建了一个名叫 `pipe1` 的命名管道，然后使用 [echo 命令][2] 加入一些数据，在这操作后，要使用这些输入数据就要用非交互的 shell 了。 + + + +然后，我们打开另外的 shell 终端，运行另外的命令来打印出刚加入管道的数据。 + +``` +# while read line ;do echo "This was passed-'$line' "; done我们使用 Linux 是因为它比其他操作系统更实用，还是其他更高级的理由呢？ + +其中一件关于运行 Linux 的最伟大的事情之一就是它所提供的自由。凡出现在 Linux 社区之间的划分在于我们如何珍惜这种自由。 + +一些人认为，通过使用 Linux 所享有的自由是从供应商锁定或高软件成本的自由。大多数人会称这个是一个实际的考虑。而其他用户会告诉你，他们享受的是自由软件的自由。那就意味着拥抱支持 [开源软件运动][1] 的 Linux 发行版，完全避免专有软件和所有相关的东西。 + + +在这篇文章中，我将带你比较这两种自由的区别，以及他们如何影响 Linux 的使用。 + +### 专有的问题 + +大多数的用户有一个共同的一点是他们的喜欢避免专有软件。对于像我这样的实际的爱好者来说，这是一个我怎么样花我的钱，来控制我的软件和避免供应商锁定的问题。当然，我不是一个程序员……所以我调整我的安装软件是十分温柔的。但也有一些个别情况，一个应用程序的小调整可以意味着它的工作和不工作的区别。 + +还有就是选择避开专有软件的Linux爱好者，因为他们觉得这是不道德的使用。通常这里主要的问题是使用专有软件会带走或者干脆阻碍你的个人自由。像这些用户更喜欢使用的Linux发行版和软件来支持 [自由软件理念][2] 。虽然它类似于开源的概念并经常直接与之混淆，[这里有些差异][3] 。 + +因此，这里有个问题：像我这样的用户往往以其便利掩盖了其纯软件自由的理想化。不要误会我的意思，像我这样的人更喜欢使用符合自由软件背后的理想软件，但我们也更有可能做出让步，以完成特定的任务。 + +这两种类型的 Linux 爱好者都喜欢使用非专有的解决方案。但是，自由软件倡导者根本不会去使用所有权，在那里作为实际的用户将依靠具有最佳性能的最佳工具。这意味着，在有些情况下的实际用户愿意来运行他们的非专有操作系统上的专有应用或代码实例。 + +最终，这两种类型的用户都喜欢使用 Linux 所提供的。但是，我们这样做的原因往往会有所不同。有人认为那些不支持自由软件的人是无知的。我不同意，我认为它是实用方便性的问题。那些喜欢实用方便性的用户根本不关心他们软件的政治问题。 + +### 实用方便性 + +当你问起绝大多数的人为什么使用他们现在的操作系统，回答通常都集中于实用方便性。这种关于方便性的例子可能包括“它是我一直使用的东西”、“它运行的软件是我需要的”。 其他人可能进一步解释说，并没有那么多软件影响他们对操作系统的偏好和熟悉程度，最后，有“利基任务”或硬件兼容性问题也提供了很好的理由让我们用这个操作系统而不是另一个。 + +这可能会让你们中许多人很惊讶，但我今天运行的桌面 Linux 最大的一个原因是由于熟悉。即使我为别人提供对 Windows 和 OS X 的支持，但实际上我是相当沮丧地使用这些操作系统，因为它们根本就不是我记忆中的那样习惯用法。我相信这可以让我对那些 Linux 新手表示同情，因为我太懂得踏入陌生的领域是怎样的让人倒胃口了。我的观点是这样的 —— 熟悉具有价值。而且熟悉同样使得实用方便性变得有力量。 + +现在，如果我们把它和一个自由软件倡导者的需求来比较，你会发现那些人都愿意学习新的东西，甚至更具挑战性，去学习那些若转化成为他们所避免使用的非自由软件。这就是我经常赞美的那种用户，我认为他们愿意采取最少路径来遵循坚持他们的原则是十分值得赞赏的。 + +### 自由的价值 + +我不羡慕那些自由软件倡导者的一个地方，就是根据 [自由软件基金会][4] 所规定的标准需要确保他们可以一直使用 Linux 发行版和硬件，以便于尊重他们的数字自由。这意味着 Linux 内核需要摆脱专有的斑点的驱动支持和不需要任何专有代码的硬件。当然不是不可能的，但它很接近。 + +一个自由软件倡导者可以达到的最好的情况是硬件是“自由兼容”的。有些供应商，可以满足这一需求，但他们大多是提供依赖于 Linux 兼容专有固件的硬件。伟大的实际用户对自由软件倡导者来说是个搅局者。 + +那么这一切意味着的是，倡导者必须比实际的 Linux 爱好者，更加警惕。这本身并不一定是消极的，但如果是打算用自由软件的方法来计算的话那就值得考虑了。通过对比，实用的用户可以专心地使用与 Linux 兼容的任何软件或硬件。我不知道你是怎么想的，但在我眼中是更轻松一点的。 + +### 定义自由软件 + +这一部分可能会让一部分人失望，因为我不相信自由软件只有一种。从我的立场，我认为真正的自由是能够在一个给定的情况里沉浸在所有可用的数据里，然后用最适合这个人的生活方式的途径来达成协议。 + +所以对我来说，我更喜欢使用的 Linux 桌面，满足了我所有的需求，这包括使用非专有软件和专有软件。尽管这是公平的建议，专有的软件限制了我的个人自由，但我必须反驳这一点，因为我有选择用不用它，即选择的自由。 + +或许，这也就是为什么我发现自己更确定开源软件的理想，而不是坚持自由软件运动背后的理念的原因。我更愿意和那些不会花时间告诉我，我是怎么用错了的那些人群在一起。我的经验是，那些开源的人群仅仅是感兴趣去分享自由软件的优点，而不是因为自由软件的理想主义的激情。 + +我觉的自由软件的概念实在是太棒了。对那些需要活跃在软件政治，并指出使用专有软件的人的缺陷的人来说，那么我认为 Linux ( [GNU/Linux][5] ) 行动是一个不错的选择。在我们的介绍里，像我一样的实际用户更倾向于从自由软件的支持者改变方向。 + +当我介绍 Linux 的桌面时，我富有激情地分享它的实际优点。而且我成功地让他们享受这一经历，我允许用户自己去发现自由软件的观点。但我发现大多数人使用的 Linux 不是因为他们想拥抱自由软件，而是因为他们只是想要最好的用户体验。也许只有我是这样的，很难说。 + +嘿！说你呢？你是一个自由软件倡导者吗？也许你是个使用桌面 Linux 发行专有软件/代码的粉丝？那么评论和分享您的 Linux 桌面体验吧！ + + +-------------------------------------------------------------------------------- + +via: http://www.datamation.com/open-source/linux-practicality-vs-activism.html + +作者：[Matt Hartley][a] +译者：[joVoV](https://github.com/joVoV) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: http://www.datamation.com/author/Matt-Hartley-3080.html +[1]: https://en.wikipedia.org/wiki/Free_software_movement +[2]: https://www.gnu.org/philosophy/free-sw.en.html +[3]: https://www.gnu.org/philosophy/free-software-for-freedom.en.html +[4]: https://en.wikipedia.org/wiki/Free_Software_Foundation +[5]: https://en.wikipedia.org/wiki/GNU/Linux_naming_controversy \ No newline at end of file diff --git a/translated/talk/my-open-source-story/20160316 Growing a career alongside Linux.md b/translated/talk/my-open-source-story/20160316 Growing a career alongside Linux.md new file mode 100644 index 0000000000..f7ddefb92c --- /dev/null +++ b/translated/talk/my-open-source-story/20160316 Growing a career alongside Linux.md @@ -0,0 +1,49 @@ +培养一个 Linux 职业生涯 +================================== + +![](https://opensource.com/sites/default/files/styles/image-full-size/public/images/business/OPENHERE_blue.png?itok=3eqp-7gT) + +我与 Linux 的故事开始于 1998 年，一直延续到今天。 当时我在 Gap 公司工作，管理着成千台运行着 [OS/2][1] 系统的台式机 ( 并且在随后的几年里是 [Warp 3.0][2])。 作为一个 OS/2 的使用者，那时我非常高兴。 随着这些台式机的嗡鸣，我们使用 Gap 开发的工具轻而易举地就能支撑起对成千的用户的服务支持。 然而，一切都将改变了。 + +在 1998 年的 11 月， 我收到邀请加入一个新成立的公司，这家公司将专注于 Linux 上。 这就是后来非常出名的 [Linuxcare][2]. + +### 我在 Linuxcare 的时光 + +我曾经有接触过一些 Linux ， 但我从未想过要把它提供给企业客户。仅仅几个月后 ( 从这里开始成为了空间和时间上的转折点 )， 我就在管理一整条线的业务，让企业获得他们的软件，硬件，甚至是证书认证等不同风格且在当时非常盛行的的 Linux 服务。 + +我向我的客户提供像 IBM ，Dell ，HP 等产品以确保他们的硬件能够成功的运行 Linux 。 今天你们应该都听过许多关于在硬件上预载 Linux 的事， 但当时我被邀请到 Dell 去讨论有关于为即将到来的贸易展在笔记本电脑上运行 Linux 的相关事宜。 这是多么激动人心的时刻 ！同时我们也在有效期的几年内支持 IBM 和 HP 等多项认证工作。 + +Linux 变化得非常快，并且它总是这样。 它也获得了更多的关键设备的支持，比如声音，网络和图形。在这段时间， 我把个人使用的系统从基于 RPM 的系统换成了 [Debian][3] 。 + +### 使用 Linux 的这些年 + +几年前我在一些以 Linux 为硬设备，客户软件以及数据中心的公司工作。而在二十世纪中期的时候，那时我正在忙着做咨询，而那些在 Redmond 的大型软件公司正围绕着 Linux 做一些分析和验证以和自己的解决方案做对比。 我个人使用的系统一直改变,我仍会在任何能做到的时候运行 Debian 测试系统。 + +我真的非常欣赏其发行版本的灵活性和永久更新状态。 Debian 是我所使用过的最有趣且拥有良好支持的发行版本且拥有最好的社区的版本之一。 + +当我回首我使用 Linux 的这几年，我仍记得大约在二十世纪前期和中期的时候在圣何塞，旧金山，波士顿和纽约的那些 Linux 的展览会。在 Linuxcare 时我们总是会做一些有趣而且时髦的展览位，在那边逛的时候总会碰到一些老朋友。这一切工作都是需要付出代价的，所有的这一切都是在努力地强调使用 Linux 的乐趣。 + +同时，虚拟化和云的崛起也让 Linux 变得更加有趣。 当我在 Linuxcare 的时候， 我们常和 Palo Alto 的一个约 30 人左右的小公司在一块。我们会开车到他们的办公处然后准备一个展览并且他们也会参与进来。 谁会想得到这个小小的开端会成就后来的 VMware ？ + +我还有许多的故事，能认识这些人并和他们一起工作我感到很幸运。 Linux 在各方面都不断发展且变得尤为重要。 并且甚至随着它重要性的提升，它使用起来仍然非常有趣。 我认为它的开放性和可定制能力给它带来了大量的新用户，这也是让我感到非常震惊的一点。 + +### 现在 + +在过去的五年里我逐渐离开 Linux 的主流事物。 我所管理的大规模基础设施项目中包含着许多不同的操作系统 ( 包括非开源的和开源的 ), 但我的心一直以来都是和 Linux 在一起的。 + +在使用 Linux 过程中的乐趣和不断进步是在过去的 18 年里一直驱动我的动力。我从 Linux 2.0 内核开始看着它变成现在的这样。 Linux 是一个卓越，有机且非常酷的东西。 + +-------------------------------------------------------------------------------- + +via: https://opensource.com/life/16/3/my-linux-story-michael-perry + +作者：[Michael Perry][a] +译者：[译者ID](https://github.com/chenxinlong) +校对：[校对者ID](https://github.com/校对者ID) + +[a]: https://opensource.com/users/mpmilestogo +[1]: https://en.wikipedia.org/wiki/OS/2 +[2]: https://archive.org/details/IBMOS2Warp3Collection +[3]: https://en.wikipedia.org/wiki/Linuxcare +[4]: https://www.debian.org/ +[5]: diff --git a/translated/talk/yearbook2015/20151208 5 great Raspberry Pi projects for the classroom.md b/translated/talk/yearbook2015/20151208 5 great Raspberry Pi projects for the classroom.md deleted file mode 100644 index 06191d551c..0000000000 --- a/translated/talk/yearbook2015/20151208 5 great Raspberry Pi projects for the classroom.md +++ /dev/null @@ -1,98 +0,0 @@ -5 个适合课堂教学的树莓派项目 -================================================================================ -![](https://opensource.com/sites/default/files/styles/image-full-size/public/images/life/osdc-open-source-yearbook-lead3.png) - -图片来源 : opensource.com - -### 1. Minecraft Pi ### - -![](https://opensource.com/sites/default/files/lava.png) - -上图由树莓派基金会提供。遵循 [CC BY-SA 4.0.][1] 协议。 - -Minecraft（我的世界）几乎是世界上每个青少年都极其喜爱的游戏 —— 在吸引年轻人注意力方面，它也是最具创意的游戏之一。伴随着每一个树莓派的游戏版本不仅仅是一个关于创造性思维的建筑游戏，它还带有一个编程接口，允许使用者通过 Python 代码来与 Minecraft 世界进行互动。 - -对于教师来说，Minecraft: Pi 版本是一个鼓励学生们解决遇到的问题以及通过书写代码来执行特定任务的极好方式。你可以使用 Python API - 来建造一所房子，让它跟随你到任何地方；或在你所到之处修建一座桥梁；又或者是下一场岩溶雨；或在天空中显示温度；以及其他任何你能想像到的事物。 - -可在 "[Minecraft Pi 入门][2]" 中了解更多相关内容。 - -### 2. 反应游戏和交通指示灯 ### - -![](https://opensource.com/sites/default/files/pi_traffic_installed_yellow_led_on.jpg) - -上图由 [Low Voltage Labs][3] 提供。遵循 [CC BY-SA 4.0][1] 协议。 - -在树莓派上进行物理计算是非常容易的 —— 只需将 LED 灯 和按钮连接到 GPIO 针脚上，再加上少量的代码，你就可以点亮 LED 灯并通过按按钮来控制物体。一旦你知道来执行基本操作的代码，下一步就可以随你的想像那样去做了！ - -假如你知道如何让一盏灯闪烁，你就可以让三盏灯闪烁。选出三盏交通灯颜色的 LED 灯，你就可以编程出交通灯闪烁序列。假如你知道如何使用一个按钮来触发一个事件，然后你就有一个人行横道了！同时，你还可以找到诸如 [PI-TRAFFIC][4]、[PI-STOP][5]、[Traffic HAT][6] 等预先构建好的交通灯插件。 - -这不总是关于代码的 —— 它还可以被用来作为一个的练习，用以理解真实世界中的系统是如何被设计出来的。计算思维在生活中的各种情景中都是一个有用的技能。 - -![](https://opensource.com/sites/default/files/reaction-game.png) - -上图由树莓派基金会提供。遵循 [CC BY-SA 4.0][1] 协议。 - -下面尝试将两个按钮和一个 LED 灯连接起来，来制作一个二人制反应游戏 —— 让灯在一段随机的时间中点亮，然后看谁能够先按到按钮！ - -想了解更多的话，请查看 [GPIO 新手指南][7]。你所需要的尽在 [CamJam EduKit 1][8]。 - -### 3. Sense HAT 像素宠物 ### - -Astro Pi— 一个增强版的树莓派 —将于今年 12 月（注：应该是去年的事了。）问世，但你并没有错过让你的手玩弄硬件的机会。Sense HAT 是一个用在 Astro Pi 任务中的感应器主板插件，且任何人都可以买到。你可以用它来做数据收集、科学实验、游戏或者更多。 观看下面这个由树莓派的 Carrie Anne 带来的 Gurl Geek Diaries 录像来开始一段美妙的旅程吧 —— 通过在 Sense HAT 的显示器上展现出你自己设计的一个动物像素宠物： - -注：youtube 视频 - - -在 "[探索 Sense HAT][9]" 中可以学到更多。 - -### 4. 红外鸟箱 ### - -![](https://opensource.com/sites/default/files/ir-bird-box.png) -上图由 [Low Voltage Labs][3] 提供。遵循 [CC BY-SA 4.0][1] 协议。 - -让全班所有同学都能够参与进来的一个好的练习是 —— 在一个鸟箱中沿着某些红外线放置一个树莓派和 NoIR 照相模块，这样你就可以在黑暗中观看，然后通过网络或在网络中你可以从树莓派那里获取到视频流。等鸟进入笼子，然后你就可以在不打扰到它们的情况下观察它们。 - -在这期间，你可以学习到所有关于红外和光谱的知识，以及如何用软件来调整摄像头的焦距和控制它。 - -在 "[制作一个红外鸟箱][10]" 中你可以学到更多。 - -### 5. 机器人 ### - -![](https://opensource.com/sites/default/files/edukit3_1500-alex-eames-sm.jpg) - -上图由 Low Voltage Labs 提供。遵循 [CC BY-SA 4.0][1] 协议。 - -拥有一个树莓派，一些感应器和一个感应器控制电路板，你就可以构建你自己的机器人。你可以制作各种类型的机器人，从用透明胶带和自制底盘组合在一起的简易四驱车，一直到由游戏控制器驱动的具有自我意识，带有传感器和摄像头的金属马儿。 - -学习如何直接去控制单个的发动机，例如通过 RTK Motor Controller Board (£8/$12)，或者尝试新的 CamJam robotics kit (£17/$25) ，它带有发动机、轮胎和一系列的感应器 — 这些都很有价值并很有学习的潜力。 - -另外，如何你喜欢更为骨灰级别的东西，可以尝试 PiBorg 的 [4Borg][11] (£99/$150) 或 [DiddyBorg][12] (£180/$273) 或者一干到底，享受他们的 DoodleBorg 金属版 (£250/$380) — 并构建一个他们声名远扬的 [DoodleBorg tank][13]（很不幸的时，这个没有卖的） 的迷你版。 - -另外请参考 [CamJam robotics kit worksheets][14]。 - --------------------------------------------------------------------------------- - -via: https://opensource.com/education/15/12/5-great-raspberry-pi-projects-classroom - -作者：[Ben Nuttall][a] -译者：[译者ID](https://github.com/译者ID) -校对：[校对者ID](https://github.com/校对者ID) - -本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 - -[a]:https://opensource.com/users/bennuttall -[1]:https://creativecommons.org/licenses/by-sa/4.0/ -[2]:https://opensource.com/life/15/5/getting-started-minecraft-pi -[3]:http://lowvoltagelabs.com/ -[4]:http://lowvoltagelabs.com/products/pi-traffic/ -[5]:http://4tronix.co.uk/store/index.php?rt=product/product&product_id=390 -[6]:https://ryanteck.uk/hats/1-traffichat-0635648607122.html -[7]:http://pythonhosted.org/gpiozero/recipes/ -[8]:http://camjam.me/?page_id=236 -[9]:https://opensource.com/life/15/10/exploring-raspberry-pi-sense-hat -[10]:https://www.raspberrypi.org/learning/infrared-bird-box/ -[11]:https://www.piborg.org/4borg -[12]:https://www.piborg.org/diddyborg -[13]:https://www.piborg.org/doodleborg -[14]:http://camjam.me/?page_id=1035#worksheets diff --git a/translated/tech/20160218 How to Best Manage Encryption Keys on Linux.md b/translated/tech/20160218 How to Best Manage Encryption Keys on Linux.md deleted file mode 100644 index b833d94658..0000000000 --- a/translated/tech/20160218 How to Best Manage Encryption Keys on Linux.md +++ /dev/null @@ -1,110 +0,0 @@ -Linux 如何最好地管理加密密钥 -============================================= - -![](http://www.linux.com/images/stories/41373/key-management-diagram.png) - -存储 SSH 的加密秘钥以及记住密码一直是一个让人头疼的问题。但是不幸的是，在当前充满了恶意黑客和攻击的世界中，基本的安全预警是必不可少的。对于大量的普通用户，它相当于简单地记住密码，也可能寻找一个好程序去存储密码，正如我们提醒这些用户不要在每个网站都有相同的密码。但是对于在各个 IT 领域的我们，我们需要将这个提高一个层次。我们不得不处理加密秘钥，比如 SSH 密钥，而不只是密码。 - -设想一个场景：我有一个运行在云上的服务器，用于我的主 git 库。我有很多台工作电脑。所有电脑都需要登陆中央服务器去 push 与 pull。我设置 git 使用 SSH。当 git 使用 SSH, git 实际上以相同的方式登陆服务器，就好像你通过 SSH 命令打开一个服务器的命令行。为了配置所有内容，我在我的 .ssh 目录下创建一个配置文件，其中包含一个有服务器名字，主机名，登陆用户，密钥文件的路径的主机项。之后我可以通过输入命令来测试这个配置。 - ->ssh gitserver - -很快我得到了服务器的 bash shell。现在我可以配置 git 使用相同项与存储的密钥来登陆服务器。很简单，除了一个问题，对于每一个我用于登陆服务器的电脑，我需要有一个密钥文件。那意味着需要不止一个密钥文件。当前这台电脑和我的其他电脑都存储有这些密钥文件。同样的，用户每天有特大量的密码，对于我们 IT人员，很容易结束这特大量的密钥文件。怎么办呢？ - -## 清理 - -在开始使用程序去帮助你管理你的密钥之前，你不得不在你的密码应该怎么处理和我们问的问题是否有意义这两个方面打下一些基础。同时，这需要第一，也是最重要的，你明白你的公钥和私钥的使用位置。我将设想你知道： - -1. 公钥和私钥之间的差异； - -2. 为什么你不可以从公钥生成私钥，但是你可以逆向生成？ - -3. `authorized_keys` 文件的目的以及它的内容； - -4. 你如何使用私钥去登陆服务器，其中服务器上的 `authorized_keys` 文件中存有相应的公钥； - -这里有一个例子。当你在亚马逊的网络服务上创建一个云服务器，你必须提供一个 SSH 密码，用于连接你的服务器。每一个密钥有一个公开的部分，和私密的部分。因为你想保持你的服务器安全，乍看之下你可能要将你的私钥放到服务器上，同时你自己带着公钥。毕竟，你不想你的服务器被公开访问，对吗？但是实际上这是逆向的。 - -你把自己的公钥放到 AWS 服务器，同时你持有你自己的私钥用于登陆服务器。你保护私钥，同时保持私钥在自己一方，而不是在一些远程服务器上，正如上图中所示。 - -原因如下：如果公钥公之于众，他们不可以登陆服务器，因为他们没有私钥。进一步说，如果有人成功攻入你的服务器，他们所能找到的只是公钥。你不可以从公钥生成私钥。同时如果你在其他的服务器上使用相同的密钥，他们不可以使用它去登陆别的电脑。 - -这就是为什么你把你自己的公钥放到你的服务器上以便通过 SSH 登陆这些服务器。你持有这些私钥，不要让这些私钥脱离你的控制。 - -但是还有麻烦。试想一下我 git 服务器的例子。我要做一些决定。有时我登陆架设在别的地方的开发服务器。在开发服务器上，我需要连接我的 git 服务器。如何使我的开发服务器连接 git 服务器？通过使用私钥。同时这里面还有麻烦。这个场景需要我把私钥放置到一个架设在别的地方的服务器上。这相当危险。 - -一个进一步的场景：如果我要使用一个密钥去登陆许多的服务器，怎么办？如果一个入侵者得到这个私钥，他或她将拥有私钥，并且得到服务器的全部虚拟网络的权限，同时准备做一些严重的破坏。这一点也不好。 - -同时那当然会带来一个别的问题，我真的应该在这些其他服务器上使用相同的密钥？因为我刚才描述的，那会非常危险的。 - -最后，这听起来有些混乱，但是有一些简单的解决方案。让我们有条理地组织一下： - -（注意你有很多地方需要密钥登陆服务器，但是我提出这个作为一个场景去向你展示当你处理密钥的时候你面对的问题） - -## 关于口令句 - -当你创建你的密钥时，你可以选择是否包含一个口令字，这个口令字会在使用私钥的时候是必不可少的。有了这个口令字，私钥文件本身会被口令字加密。例如，如果你有一个公钥存储在服务器上，同时你使用私钥去登陆服务器的时候，你会被提示，输入口令字。没有口令字，这个密钥是无法使用的。或者，你可以配置你的密钥不需要口令字。然后所有你需要的只是用于登陆服务器的密钥文件。 - -普遍上，不使用口令字对于用户来说是更容易的，但是我强烈建议在很多情况下使用口令字，原因是，如果私钥文件被偷了，偷密钥的人仍然不可以使用它，除非他或者她可以找到口令字。在理论上，这个将节省你很多时间，因为你可以在攻击者发现口令字之前，从服务器上删除公钥文件，从而保护你的系统。还有一些别的原因去使用口令字，但是这个原因对我来说在很多场合更有价值。（举一个例子，我的 Android 平板上有 VNC 软件。平板上有我的密钥。如果我的平板被偷了之后，我会马上从服务器上删除公钥，使得它的私钥没有作用，无论有没有口令字。）但是在一些情况下我不使用口令字，是因为我正在登陆的服务器上没有什么有价值的数据。它取决于情境。 - -## 服务器基础设施 - -你如何设置自己服务器的基础设置将会影响到你如何管理你的密钥。例如，如果你有很多用户登陆，你将需要决定每个用户是否需要一个单独的密钥。（普遍来说，他们应该；你不会想要用户之间共享私钥。那样当一个用户离开组织或者失去信任时，你可以删除那个用户的公钥，而不需要必须给其他人生成新的密钥。相似地，通过共享密钥，他们能以其他人的身份登录，这就更坏了。）但是另外一个问题，你如何配置你的服务器。你是否使用工具，比如 Puppet，配置大量的服务器？同时你是否基于你自己的镜像创建大量的服务器？当你复制你的服务器，你是否需要为每个人设置相同的密钥？不同的云服务器软件允许你配置这个；你可以让这些服务器使用相同的密钥，或者给每一个生成一个新的密钥。 - -如果你在处理复制的服务器，它可能导致混淆如果用户需要使用不同的密钥登陆两个不同的系统。但是另一方面，服务器共享相同的密钥会有安全风险。或者，第三，如果你的密钥有除了登陆之外的需要（比如挂载加密的驱动），之后你会在很多地方需要相同的密钥。正如你所看到的，你是否需要在不同的服务器上使用相同的密钥不是我为你做的决定；这其中有权衡，而且你需要去决定什么是最好的。 - -最终，你可能会有： - -- 需要登录的多个服务器 - -- 多个用户登陆不同的服务器，每个都有自己的密钥 - -- 每个用户多个密钥当他们登陆不同的服务器的时候 - -（如果你正在别的情况下使用密钥，相同的普遍概念会应用于如何使用密钥，需要多少密钥，他们是否共享，你如何处理密钥的私密部分和公开部分。） - -## 安全方法 - -知道你的基础设施和独一无二的情况，你需要组合一个密钥管理方案，它会引导你去分发和存储你的密钥。比如，正如我之前提到的，如果我的平板被偷了，我会从我服务器上删除公钥，期望在平板在用于访问服务器。同样的，我会在我的整体计划中考虑以下内容： - -1. 移动设备上的私钥没有问题，但是必须包含口令字； - -2. 必须有一个方法可以快速地从服务器上删除公钥。 - -在你的情况中，你可能决定，你不想在自己经常登录的系统上使用口令字；比如，这个系统可能是一个开发者一天登录多次的测试机器。这没有问题，但是你需要调整你的规则。你可能添加一条规则，不可以通过移动设备登录机器。换句话说，你需要根据自己的状况构建你的协议，不要假设某个方案放之四海而皆准。 - -## 软件 - -至于软件，毫不意外，现实世界中并没有很多好的，可用的软件解决方案去存储和管理你的私钥。但是应该有吗？考虑到这个，如果你有一个程序存储你所有服务器的全部密钥，并且这个程序被一个核心密钥锁住，那么你的密钥就真的安全了吗？或者，同样的，如果你的密钥被放置在你的硬盘上，用于 SSH 程序快速访问，那样一个密钥管理软件是否真正提供了任何保护吗？ - -但是对于整体基础设施和创建，管理公钥，有许多的解决方案。我已经提到了 Puppet。在 Puppet 的世界中，你创建模块来以不同的方式管理你的服务器。这个想法是服务器是动态的，而且不必要准确地复制其他机器。[这里有一个聪明的途径](http://manuel.kiessling.net/2014/03/26/building-manageable-server-infrastructures-with-puppet-part-4/),它在不同的服务器上使用相同的密钥，但是对于每一个用户使用不同的 Puppet 模块。这个方案可能适合你，也可能不适合你。 - -或者，另一个选项就是完全换挡。在 Docker 的世界中，你可以采取一个不同的方式，正如[关于 SSH 和 Docker 博客](http://blog.docker.com/2014/06/why-you-dont-need-to-run-sshd-in-docker/)所描述的。 - -但是怎么样管理私钥？如果你搜索，你无法找到很多的软件选择，原因我之前提到过；密钥存放在你的硬盘上，一个管理软件可能无法提到很多额外的安全。但是我确实使用这种方法来管理我的密钥： - -首先，我的 `.ssh/config` 文件中有很多的主机项。我有一个我登陆的主机项，但是有时我对于一个单独的主机有不止一项。如果我有很多登陆，那种情况就会发生。对于架设我的 git 库的服务器，我有两个不同的登陆项；一个限制于 git，另一个为普遍目的的 bash 访问。这个为 git 设置的登陆选项在机器上有极大的限制。还记得我之前说的关于我存在于远程开发机器上的 git 密钥吗？好了。虽然这些密钥可以登陆到我其中一个服务器，但是使用的账号是被严格限制的。 - -其次，大部分的私钥都包含口令字。（对于处理不得不多次输入口令字的情况，考虑使用 [ssh-agent](http://blog.docker.com/2014/06/why-you-dont-need-to-run-sshd-in-docker/)。） - -再次，我确实有许多服务器，我想要更加小心地防御，并且在我 host 文件中并没有这样的项。这更加接近于社交工程方面，因为密钥文件还存在于那里，但是可能需要攻击者花费更长的时间去定位这个密钥文件，分析出来他们攻击的机器。在这些例子中，我只是手动打出来长的 SSH 命令。（这真不怎么坏。） - -同时你可以看出来我没有使用任何特别的软件去管理这些私钥。 - -## 无放之四海而皆准的方案 - -我们偶然间收到 linux.com 的问题，关于管理密钥的好软件的建议。但是让我们后退一步。这个问题事实上需要重新定制，因为没有一个普适的解决方案。你问的问题基于你自己的状况。你是否简单地尝试找到一个位置去存储你的密钥文件？你是否寻找一个方法去管理多用户问题，其中每个人都需要将他们自己的公钥插入到 `authorized_keys` 文件中？ - -通过这篇文章，我已经囊括了基础知识，希望到此你明白如何管理你的密钥，并且，只有当你问了正确的问题，无论你寻找任何软件（甚至你需要另外的软件），它都会出现。 - ------------------------------------------------------------------------------- - -via: http://www.linux.com/learn/tutorials/838235-how-to-best-manage-encryption-keys-on-linux - -作者：[Jeff Cogswell][a] -译者：[mudongliang](https://github.com/mudongliang) -校对：[校对者ID](https://github.com/校对者ID) - -本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创翻译，[Linux中国](https://linux.cn/) 荣誉推出 - -[a]:http://www.linux.com/community/forums/person/62256 diff --git a/translated/tech/20160219 How to Setup Lighttpd Web server on Ubuntu 15.04 or CentOS 7.md b/translated/tech/20160219 How to Setup Lighttpd Web server on Ubuntu 15.04 or CentOS 7.md deleted file mode 100644 index 8840e8b973..0000000000 --- a/translated/tech/20160219 How to Setup Lighttpd Web server on Ubuntu 15.04 or CentOS 7.md +++ /dev/null @@ -1,210 +0,0 @@ -[Translated] Haohong Wang -如何在Ubuntu 15.04/CentOS 7中安装Lighttpd Web server -================================================================================= -Lighttpd 是一款开源Web服务器软件。Lighttpd 安全快速，符合行业标准，适配性强并且针对高配置环境进行了优化。Lighttpd因其CPU、内存占用小，针对小型CPU加载的快速适配以及出色的效率和速度而从众多Web服务器中脱颖而出。 而Lighttpd诸如FastCGI，CGI，Auth，Out-Compression，URL-Rewriting等高级功能更是那些低配置的服务器的福音。 - -以下便是在我们运行Ubuntu 15.04 或CentOS 7 Linux发行版的机器上安装Lighttpd Web服务器的简要流程。 - -### 安装Lighttpd - -#### 使用包管理器安装 - -这里我们通过使用包管理器这种最简单的方法来安装Lighttpd。只需以sudo模式在终端或控制台中输入下面的指令即可。 - -**CentOS 7** - -由于CentOS 7.0官方repo中并没有提供Lighttpd，所以我们需要在系统中安装额外的软件源epel repo。使用下面的yum指令来安装epel。 - - # yum install epel-release - -然后，我们需要更新系统及进程为Lighttpd的安装做准备。 - - # yum update - # yum install lighttpd - -![Install Lighttpd Centos](http://blog.linoxide.com/wp-content/uploads/2016/02/install-lighttpd-centos.png) - -**Ubuntu 15.04** - -Ubuntu 15.04官方repo中包含了Lighttpd，所以只需更新本地repo并使用apt-get指令即可安装Lighttpd。 - - # apt-get update - # apt-get install lighttpd - -![Install lighttpd ubuntu](http://blog.linoxide.com/wp-content/uploads/2016/02/install-lighttpd-ubuntu.png) - -#### 从源代码安装Lighttpd - -如果想从Lighttpd源码安装最新版本(例如1.4.39)，我们需要在本地编译源码并进行安装。首先我们要安装编译源码所需的依赖包。 - - # cd /tmp/ - # wget http://download.lighttpd.net/lighttpd/releases-1.4.x/lighttpd-1.4.39.tar.gz - -下载完成后，执行下面的指令解压缩。 - - # tar -zxvf lighttpd-1.4.39.tar.gz - -然后使用下面的指令进行编译。 - - # cd lighttpd-1.4.39 - # ./configure - # make - -**注：**在这份教程中，我们安装的是默认配置的Lighttpd。其他诸如高级功能或拓展功能，如对SSL的支持，mod_rewrite，mod_redirect等，需自行配置。 - -当编译完成后，我们就可以把它安装到系统中了。 - - # make install - -### 设置Lighttpd - -如果有更高的需求，我们可以通过修改默认设置文件，如`/etc/lighttpd/lighttpd.conf`，来对Lighttpd进行进一步设置。 而在这份教程中我们将使用默认设置，不对设置文件进行修改。如果你曾做过修改并想检查设置文件是否出错，可以执行下面的指令。 - - # lighttpd -t -f /etc/lighttpd/lighttpd.conf - -#### 使用 CentOS 7 - -在CentOS 7中，我们需在Lighttpd默认设置中创设一个例如`/src/www/htdocs`的webroot文件夹。 - - # mkdir -p /srv/www/htdocs/ - -而后将默认欢迎页面从`/var/www/lighttpd`复制至刚刚新建的目录中： - - # cp -r /var/www/lighttpd/* /srv/www/htdocs/ - -### 开启服务 - -现在，通过执行systemctl指令来重启数据库服务。 - - # systemctl start lighttpd - -然后我们将它设置为伴随系统启动自动运行。 - - # systemctl enable lighttpd - -### 设置防火墙 - -如要让我们运行在Lighttpd上的网页和网站能在Internet或相似的网络上被访问，我们需要在防火墙程序中设置打开80端口。由于CentOS 7和Ubuntu15.04都附带Systemd作为默认初始化系统，所以我们安装firewalld作为解决方案。如果要打开80端口或http服务，我们只需执行下面的命令： - - # firewall-cmd --permanent --add-service=http - success - # firewall-cmd --reload - success - -### 连接至Web Server -在将80端口设置为默认端口后，我们就可以默认直接访问Lighttpd的欢迎页了。我们需要根据运行Lighttpd的设备来设置浏览器的IP地址和域名。在本教程中，我们令浏览器指向 [http://lighttpd.linoxide.com/](http://lighttpd.linoxide.com/) 同时将子域名指向它的IP地址。如此一来，我们就可以在浏览器中看到如下的欢迎页面了。 - -![Lighttpd Welcome Page](http://blog.linoxide.com/wp-content/uploads/2016/02/lighttpd-welcome-page.png) - -此外，我们可以将网站的文件添加到webroot目录下，并删除lighttpd的默认索引文件，使我们的静态网站链接至互联网上。 - -如果想在Lighttpd Web Server中运行PHP应用，请参考下面的步骤： - -### 安装PHP5模块 -在Lighttpd成功安装后，我们需要安装PHP及相关模块以在Lighttpd中运行PHP5脚本。 - -#### 使用 Ubuntu 15.04 - - # apt-get install php5 php5-cgi php5-fpm php5-mysql php5-curl php5-gd php5-intl php5-imagick php5-mcrypt php5-memcache php-pear - -#### 使用 CentOS 7 - - # yum install php php-cgi php-fpm php-mysql php-curl php-gd php-intl php-pecl-imagick php-mcrypt php-memcache php-pear lighttpd-fastcgi - -### 设置Lighttpd的PHP服务 - -如要让PHP与Lighttpd协同工作，我们只要根据所使用的发行版执行如下对应的指令即可。 - -#### 使用 CentOS 7 - -首先要做的便是使用文件编辑器编辑php设置文件(例如`/etc/php.ini`)并取消掉对**cgi.fix_pathinfo=1**的注释。 - - # nano /etc/php.ini - -完成上面的步骤之后，我们需要把PHP-FPM进程的所有权从Apache转移至Lighttpd。要完成这些，首先用文件编辑器打开`/etc/php-fpm.d/www.conf`文件。 - - # nano /etc/php-fpm.d/www.conf - -然后在文件中增加下面的语句： - - user = lighttpd - group = lighttpd - -做完这些，我们保存并退出文本编辑器。然后从`/etc/lighttpd/modules.conf`设置文件中添加FastCGI模块。 - - # nano /etc/lighttpd/modules.conf - -然后，去掉下面语句前面的`#`来取消对它的注释。 - - include "conf.d/fastcgi.conf" - -最后我们还需在文本编辑器设置FastCGI的设置文件。 - - # nano /etc/lighttpd/conf.d/fastcgi.conf - -在文件尾部添加以下代码： - - fastcgi.server += ( ".php" => - (( - "host" => "127.0.0.1", - "port" => "9000", - "broken-scriptfilename" => "enable" - )) - ) - -在编辑完成后保存并退出文本编辑器即可。 - -#### 使用 Ubuntu 15.04 - -如需启用Lighttpd的FastCGI，只需执行下列代码： - - # lighttpd-enable-mod fastcgi - - Enabling fastcgi: ok - Run /etc/init.d/lighttpd force-reload to enable changes - - # lighttpd-enable-mod fastcgi-php - - Enabling fastcgi-php: ok - Run `/etc/init.d/lighttpd` force-reload to enable changes - -然后，执行下列命令来重启Lighttpd。 - - # systemctl force-reload lighttpd - -### 检测PHP工作状态 - -如需检测PHP是否按预期工作，我们需在Lighttpd的webroot目录下新建一个php文件。本教程中，在Ubuntu下/var/www/html 目录，CentOS下/src/www/htdocs目录下使用文本编辑器创建并打开info.php。 - -**使用 CentOS 7** - - # nano /var/www/info.php - -**使用 Ubuntu 15.04** - - # nano /srv/www/htdocs/info.php - -然后只需将下面的语句添加到文件里即可。 - - - -在编辑完成后保存并推出文本编辑器即可。 - -现在，我们需根据路径 [http://lighttpd.linoxide.com/info.php](http://lighttpd.linoxide.com/info.php) 下的info.php文件的IP地址或域名，来让我们的网页浏览器指向系统上运行的Lighttpd。如果一切都按照以上说明进行，我们将看到如下图所示的PHP页面信息。 - -![phpinfo lighttpd](http://blog.linoxide.com/wp-content/uploads/2016/02/phpinfo-lighttpd.png) - -### 总结 - -至此，我们已经在CentOS 7和Ubuntu 15.04 Linux 发行版上成功安装了轻巧快捷并且安全的Lighttpd Web服务器。现在，我们已经可以利用Lighttpd Web服务器来实现上传网站文件到网站根目录，配置虚拟主机，启用SSL，连接数据库，运行Web应用等功能了。 如果你有任何疑问，建议或反馈请在下面的评论区中写下来以让我们更好的改良Lighttpd。谢谢！(译注：评论网址 http://linoxide.com/linux-how-to/setup-lighttpd-web-server-ubuntu-15-04-centos-7/ ) --------------------------------------------------------------------------------- - -via: http://linoxide.com/linux-how-to/setup-lighttpd-web-server-ubuntu-15-04-centos-7/ - -作者：[Arun Pyasi][a] -译者：[HaohongWANG](https://github.com/HaohongWANG) -校对：[校对者ID](https://github.com/校对者ID) - -本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 - -[a]:http://linoxide.com/author/arunp/ diff --git a/translated/tech/20160301 The Evolving Market for Commercial Software Built On Open Source.md b/translated/tech/20160301 The Evolving Market for Commercial Software Built On Open Source.md deleted file mode 100644 index c45b3eb760..0000000000 --- a/translated/tech/20160301 The Evolving Market for Commercial Software Built On Open Source.md +++ /dev/null @@ -1,36 +0,0 @@ -构建在开源之上的商业软件市场持续成长 -===================================================================== - -![](https://www.linux.com/images/stories/41373/Structure-event-photo.jpg) -> 与会者在 Structure 上听取演讲，Structure Data 2016 也将在 UCSF Mission Bay 会议中心举办。图片来源：Structure Events。 - -如今真的很难低估开源项目对于企业软件市场的影响；开源集成如此快速地形成了规范，我们没能捕捉到转折点也情有可原。 - -举个例子，Hadoop，改变的不止是数据分析的世界。它引领了新一代数据公司，它们围绕开源项目创造自己的软件，按需调整和支持那些代码，更像红帽在 90 年代和 21 世纪早期拥抱 Linux 那样。软件越来越多地通过公有云交付，而不是购买者自己的服务器，拥有了令人惊奇的操作灵活性，但同时也带来了一些关于授权，支持以及价格之类的新问题。 - -我们多年来持续追踪这个趋势，它们组成了我们的 Structure Data 会议，而 Structure Data 2016 也不例外。三家围绕 Hadoop 最重要的大数据公司——Hortonworks，Cloudera 和 MapR——的 CEO 将会共同讨论它们是如何销售他们围绕开源项目的企业软件和服务，获利的同时回报那个社区项目。 - -以前在企业软件上获利是很容易的事情。一个客户购买了之后，企业供应商的一系列大型软件就变成了它自己的收银机，从维护合同和阶段性升级中获得近乎终生的收入，软件也越来越难以被替代，因为它已经成为了客户的业务核心。客户抱怨这种绑定，但如果它们想提高工作队伍的生产力也确实没有多少选择。 - -而现在的情况不再是这样了。尽管无数的公司还陷于在他们的基础设施上运行至关重要的巨大软件包，新的项目被使用开源技术部署到云服务器上。这让升级功能不再需要去掉大量软件包再重新安装别的，同时也让公司按需付费，而不是为一堆永远用不到的特性买单。 - -有很多客户想要利用开源项目的优势，而又不想建立和支持一支工程师队伍来调整开源项目以满足自己的需求。这些客户愿意为开源项目和在这之上的专有特性之间的差异付费。 - -这对于基础设施相关的软件来说格外正确。当然，你的客户们可以安装他们自己对项目的调整，比如 Hadoop，Spark 或 Node.js，但付费可以帮助他们自定义包部署如今重要的开源技术而不用自己干这些活儿。只需看看 Structure Data 2016 的发言者就明白了，比如 Confluent（Kafka），Databricks（Spark），以及 Cloudera-Hortonworks-MapR（Hadoop）三人组。 - -当然还有一个值得提到的是在出错的时候有个供应商给你指责。如果你的工程师弄糟了开源项目的实现，那你只能怪你自己了。但是如果你和一个愿意保证在服务级别的特定性能和正常运行时间指标的公司签订了合同，你就是愿意为支持，指导，以及在突然出现不可避免的问题时朝你公司外的人发火的机会买单。 - -构建在开源之上的商业软件市场的持续成长是我们在 Structure Data 上追踪多年的内容，如果这个话题正合你意，我们鼓励你加入我们，在旧金山，3 月 9 日和 10 日。 - - --------------------------------------------------------------------------------- - -via: https://www.linux.com/news/enterprise/cloud-computing/889564-the-evolving-market-for-commercial-software-built-on-open-source- - -作者：[Tom Krazit ][a] -译者：[alim0x](https://github.com/alim0x) -校对：[校对者ID](https://github.com/校对者ID) - -本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 - -[a]: https://www.linux.com/community/forums/person/70513 diff --git a/translated/tech/20160303 Top 5 open source command shells for Linux.md b/translated/tech/20160303 Top 5 open source command shells for Linux.md deleted file mode 100644 index d40eb58b54..0000000000 --- a/translated/tech/20160303 Top 5 open source command shells for Linux.md +++ /dev/null @@ -1,86 +0,0 @@ -最牛的五个Linux开源command shell -=============================================== - -关键字: shell , Linux , bash , zsh , fish , ksh , tcsh , license - -![](https://opensource.com/sites/default/files/styles/image-full-size/public/images/business/terminal_blue_smoke_command_line_0.jpg?itok=u2mRRqOa) - -这个世界上有两种Linux用户：敢于冒险的和态度谨慎的。 - -其中一类用户总是本能的去尝试任何能够戳中其痛点的新选择。他们尝试过不计其数的窗口管理器、系统发行版和几乎所有能找到的桌面插件。 - -另一类用户找到他们喜欢的东西后，会一直使用下去。他们往往喜欢所使用的系统发行版的默认选项。最先熟练掌握的文本编辑器会成为他们最钟爱的那一个。 - -作为一个使用桌面版和服务器版十五年之久的Linux用户，比起第一类来，我无疑属于第二类用户。我更倾向于使用现成的东西，如此一来，很多时候我就可以通过文档和示例方便地找到我所需要的使用案例。如果我决定选择使用非费标准的东西，这个切换过程一定会基于细致的研究，并且前提是来自挚友的大力推荐。 - -但这并不意味着我不喜欢尝试新事物并且查漏补失。所以最近一段时间，在我不假思索的使用了bash shell多年之后，决定尝试一下另外四个shell工具：ksh, tcsh, zsh, 和 fish. 这四个shell都可以通过我所以用的Fedora系统的默认库轻松安装，并且他们可能已经内置在你所使用的系统发行版当中了。 - -这里对每个选择都稍作介绍，并且阐述下它适合做为你的下一个Linux命令行解释器的原因所在。 - -### bash - -首先，我们回顾一下最为熟悉的一个。 [GNU Bash][1]，又名 Bourne Again Shell，它是我这些年使用过的众多Linux发行版的默认选择。它最初发布于1989年，并且轻松成长为Linux世界中使用最广泛的shell，甚至常见于其他一些类Unix系统当中。 - -Bash是一个广受赞誉的shell，当你通过互联网寻找各种事情解决方法所需的文档时，总能够无一例外的发现这些文档都默认你使用的是bash shell。但Bash也有一些缺点存在，如果你写过Bash脚本就会发现我们写的代码总是得比真正所需要的多那么几行。这并不是说有什么事情是它做不到的，而是说它读写起来并不总是那么直观，至少是不够优雅。 - -如上所述，基于其巨大的安装量，并且考虑到各类专业和非专业系统管理员已经适应了它的使用方式和独特之处，至少在将来一段时间内，bash或许会一直存在。 - -### ksh - -[KornShell][4]，或许你对这个名字并不熟悉，但是你一定知道它的调用命令 ksh。这个替代性的shell于80年代起源于贝尔实验室，由David Korn所写。虽然最初是一个专有软件，但是后期版本是在[Eclipse Public 许可][5]下发布的。 - -ksh的拥趸们列出了他们觉得其优越的诸多理由，包括更好的循环语法，清晰的管道退出代码，更简单的方式来处理重复命令和关联数组。它能够模拟vi和emacs的许多行为，所以如果你是一个重度文本编辑器患者，它值得你一试。最后，我发现它虽然在高级脚本方面拥有不同的体验，但在基本输入方面与bash如出一辙。 - -### tcsh - -[Tcsh][6]衍生于csh（Berkely Unix C shell），并且可以追溯到早期的Unix和计算本身。 - -Tcsh最大的卖点在于它的脚本语言，对于熟悉C语言编程的人来说，看起来会非常亲切。Tcsh的脚本编写有人喜欢，有人憎恶。但是它也有其他的技术特色，包括可以为aliases添加参数，各种可能迎合你偏好的默认行为，包括tab自动完成和将tab完成的工作记录下来以备后查。 - -你可以在[BSD 许可][7]下找到tcsh。 - -### zsh - -[Zsh][8]是另外一个与bash和ksh有着相似之处的shell。产生于90年代初，zsh支持众多有用的新技术，包括拼写纠正，主题化，可命名的目录快捷键，在多个终端中分享命令历史信息和各种相对于original Bourne shell的轻微调整。 - -虽然部分需要遵照GPL许可，但zsh的代码和二进制文件可以在MIT-like许可下进行分发； 你可以在 [actual license][9] 中查看细节。 - -### fish - -之前我访问了[fish][10]的主页，当看到 “好了，这是一个为90年代而生的命令行shell” 这条略带调侃的介绍时（fish完成于2005年），我就意识到我会爱上这个交互友好的shell的。 - -Fish的作者提供了若干切换过来的理由，shell中所有的不太实用的调用都有点小幽默并且能戳中笑点。这些特性包括自动建议（"Watch out, Netscape Navigator 4.0"），支持“惊人”的256色VGA调色，不过也有真正有用的特性，包括根据机器的man页面自动补全命令，清除脚本和基于web的配置。 - -Fish的许可主要基于第二版GPL，但有些部分是在其他许可下的。你可以查看资源库来了解[完整信息][11] - -*** - -如果你想要寻找关于每个选择确切不同之处的详尽纲要，[这个网站][12]应该可以帮到你。 - -我的立场到底是怎样的呢？好吧，最终我应该还是会重新投入bash的怀抱，因为对于大多数时间都在使用命令行交互的人来说，切换过程对于高级脚本能带来的好处微乎其微，并且我已经习惯于使用bash了。 - -但是我很庆幸做出了敞开大门并且尝试新选择的决定。我知道门外还有许许多多其他的东西。你尝试过哪些shell，更中意哪一个？请在评论里告诉我们。 - -本文来源: https://opensource.com/business/16/3/top-linux-shells - -作者：[Jason Baker][a] -译者：[mr-ping](https://github.com/mr-ping) -校对：[校对者ID](https://github.com/校对者ID) - -本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 - -[a]:https://opensource.com/users/jason-baker - -[1]: https://www.gnu.org/software/bash/ -[2]: http://mywiki.wooledge.org/BashPitfalls -[3]: http://www.gnu.org/licenses/gpl.html -[4]: http://www.kornshell.org/ -[5]: https://www.eclipse.org/legal/epl-v10.html -[6]: http://www.tcsh.org/Welcome -[7]: https://en.wikipedia.org/wiki/BSD_licenses -[8]: http://www.zsh.org/ -[9]: https://sourceforge.net/p/zsh/code/ci/master/tree/LICENCE -[10]: https://fishshell.com/ -[11]: https://github.com/fish-shell/fish-shell/blob/master/COPYING -[12]: http://hyperpolyglot.org/unix-shells - diff --git a/translated/tech/20160416 A newcomer's guide to navigating OpenStack Infrastructure.md b/translated/tech/20160416 A newcomer's guide to navigating OpenStack Infrastructure.md new file mode 100644 index 0000000000..25353ef462 --- /dev/null +++ b/translated/tech/20160416 A newcomer's guide to navigating OpenStack Infrastructure.md @@ -0,0 +1,64 @@ +给学习OpenStack基础设施的新手的入门指南 +=========================================================== + +任何一个为OpenStack贡献源码的人会受到社区的欢迎，但是，对于一个发展趋近成熟并且快速迭代的开源社区而言，能够拥有一个新手指南并不是 +件坏事。在奥斯汀举办的OpenStack峰会上，[Paul Belanger][1] (红帽公司), [Elizabeth K. Joseph][2] (HPE公司),和[Christopher Aedo][3] (IBM公司)将会就针对新人的OpenStack基础设施作一场专门的会谈。在这次采访中，他们将会提供一些建议和资源来帮助新人成为OpenStack贡献者中的一员。 +![](https://opensource.com/sites/default/files/images/life/Interview%20banner%20Q%26A.png) + +**你在谈话中表示你将“投入全部身心于基础设施并解释你需要知道的有关于维持OpenStack正常工作的系统的每一件事情”。这是一个持续了40分钟的的艰巨任务。那么，对于学习OpenStack基础设施的新手来说最需要知道那些事情呢?** +**Elizabeth K. Joseph (EKJ)**: 我们没有为OpenStack使用GitHub这种提交补丁的方式，这是因为这样做会对新手造成巨大的困扰，尽管由于历史原因我们还是保留了所有原先就在GitHub上的所有库的镜像。相反，我们使用了一种完全开源的复查形式，并通过OpenStack基础设施团队来持续的维持系统集成(CI)。相关的，自从我们使用了CI系统，每一个提交给OpenStack的改变都会在被合并之前进行测试。 +**Paul Belanger (PB)**: 这个项目中的大多数都是富有激情的人，因此当你提交的补丁被某个人否定时不要感到沮丧。 +**Christopher Aedo (CA)**:社区很想帮助你取得成功，因此不要害怕提问或者寻求更多的那些能够促进你理解某些事物的引导者。 + +### 在你的讲话中，对于一些你无法涉及到的方面，你会向新手推荐哪些在线资源来让他们更加容易入门？ +**PB**:当然是我们的[OpenStack项目基础设施文档][5]。我们已经花了足够大的努力来尽可能让这些文档能够随时保持最新状态。我们对每个运行OpenStack项目并投入使用的系统都有制作专门的页面来进行说明。甚至于连OpenStack云基础设施团队也即将上线。 + +**EKJ**:我对于将基础设施文档作为新手入门教程这件事上的观点和Paul是一致的，另外，我们十分乐意看到来自那些folk了我们项目的学习者提交上来的补丁。我们通常不会意识到我们忽略了文档中的某些内容，除非它们恰好被人问起。因此，阅读，学习，然后帮助我们修补这些知识上的漏洞。你可以在[OpenStack基础设施邮件清单]提出你的问题，或者在我们位于FreeNode上的#OpenStack-infra的IRC专栏发起你的提问。 +**CA**:我喜欢[这个详细的发布][7]，它是由Ian Wienand写的一篇关于构建图片的文章。 +### "gotchas" 会是OpenStack新的代码贡献者苦苦寻找的吗？ +**EKJ**:向项目作出贡献并不仅仅是提交新的代码和新的特性；OpenStack社区高度重视代码复查。如果你想要别人查看你的补丁，那你最好先看看其他人是如何做的，然后参考他们的风格，最后一步布做到你也能够向其他人一样提交清晰且结构分明的代码补丁。你越是能让你的同伴了解你的工作并知道你正在做的复查，那他们也就更有可能形成及时复查你的代码的风格。 +**CA**:我看到过大量的新手在面对Gerrit时受挫，阅读开发者引导中的[开发者工作步骤][9]时，可能只是将他通读了一遍。如果你没有经常使用Gerrit，那你最初对它的感觉可能是困惑和无力的。但是，如果你随后做了一些代码复查的工作，那么你马上就能轻松应对它。同样，我是IRC的忠实粉丝。它可能是一个获得帮助的好地方，但是，你最好保持一个长期保留的状态，这样，尽管你在某个时候没有出现，人们也可以回答你的问题。（阅读[IRC,开源界的成功秘诀][10]。）你不必总是在线，但是你最好能够轻松的在一个通道中进行回滚操作，以此来跟上最新的动态，这种能力非常重要。 +**PB**:我同意Elizabeth和Chris—Gerrit关于寻求何种方式来学习的观点。每个开发人员所作出的努力都将让社区变得更加美好。你不仅仅要提交代码给别人去复查，同时，你也要能够复查其他人的代码。留意Gerrit的用户接口，你可能一时会变的很疑惑。我推荐新手去尝试[Gertty][11]，它是一个基于控制台的终端接口，用于Gerrit代码复查系统，而它恰好也是OpenStack基础设施所驱动的一个项目。 +### 你对于OpenStack新手如何通过网络与其他贡献者交流方面有什么好的建议？ +**PB**:对我来说，是通过IRC以及在Freenode上参加#OpenStack-infra专栏([IRC logs][12]).这专栏上面有很多对新手来说很有价值的资源。你可以看到OpenStack项目日复一日的运作情况，同时，一旦你知道了OpenStack项目的工作原理，你将更好的知道如何为OpenStack的未来发展作出贡献。 +**CA**:我想要为IRC再次说明一点，在IRC上保持一整天的在线记录对我来说有非常重大的意义，因为我会感觉到被重视并且时刻保持连接。这也是一种非常好的获得帮助的方式，特别是当你卡在了项目中出现的某一个难题的时候，而在专栏中，总会有一些人很乐意为你解决问题。 +**EKJ**:[OpenStack开发邮件列表][13]对于能够时刻查看到你所致力于的OpenStack项目的最新情况是非常重要的。因此，我推荐一定要订阅它。邮件列表使用课题标签来区分项目，因此你可以设置你的邮件客户端来使用它，并且集中精力于你所关心的项目。除了在线资源之外，全世界范围内也成立了一些OpenStack小组，他们被用来为OpenStack的用户和贡献者提供服务。这些小组可能会定期举行座谈和针对OpenStack主要贡献者的一些活动。你可以在MeetUp.com上搜素你所在地域的贡献者活动聚会，或者在[groups.openstack.org]上查看你所在的地域是否存在OpenStack小组。最后，还有一个每六个月举办一次的OpenStack峰会，这个峰会上会作一些关于基础设施的演说。当前状态下，这个峰会包含了用户会议和开发者会议，会议内容都是和OpenStack相关的东西，包括它的过去，现在和未来。 +### OpenStack需要在那些方面得到提升来让新手更加容易学会并掌握？ +**PB**: 我认为我们的[account-setup][16]过程对于新的贡献者已经做的比较容易了，特别是教他们如何提交他们的第一个补丁。真正参与到OpenStack开发者模式的过程是需要花费很大的努力的，可能对于开发者来说已经显得非常多了；然而，一旦融入进去了，这个模式将会运转的十分高效和令人满意。 +**CA**: 我们拥有一个由专业开发者组成的社区，而且我们的关注点都是发展OpenStack本身，同时，我们致力于让用户付出更小的代价去使用OpenStack云基础设施平台。我们需要发掘更多的应用开发者，并且鼓励更多的人去开发能在OpenStack云上完美运行的云应用程序，我们还鼓励他们在[社区App目录]上去贡献那些由他们开发的app。我们可以通过提升我们的API标准和保证我们不同的库（比如libcloud，phpopencloud已经其他一些库），并让他们持续的为开发者提供可信赖的支持来实现这一目标。还有一点就是通过倡导更多的OpenStack黑客加入进来。所有的这些事情都可以降低新人的学习门槛，这样也能引导他们与这个社区之间的关系更加紧密。y. +**EKJ**: 我已经致力于开源软件很多年了。但是，对于大量的OpenStack开发者而言，这是一个他们每个人都在从事的第一个开源项目。我发现他们之前使用私有软件的背景并没有为他们塑造开源的观念和方法论，还有在开源项目中需要具备的合作技巧。我乐于看到我们能够让那些曾经一直在使用私有软件工作的人能够真正的明白他们在开源如软件社区所从事的事情的巨大价值。 +### 我认为2016年对于开源Haiku的进一步增长是具有重大意义的一年。通过Haiku来向新手解释OpenStack。 +**PB**: 如果你喜欢自由软件，你可以向OpenStack提交你的第一个补丁。 +**CA**: 在不久的未来，OpenStack将以统治世界的姿态让这个世界变得更好。 +**EKJ**: OpenStack是一个可以免费部署在你的服务器上面并且运行你自己的云的一个软件。 +*Paul,Elizabeth和Christopher将会在4月25号星期一上午11：15于奥斯汀举办的OpenStack峰会上进行演说。 + +------------------------------------------------------------------------------ + +via: https://opensource.com/business/16/4/interview-openstack-infrastructure-beginners + +作者：[linux.com][a] +译者：[kylepeng93](https://github.com/kylepeng93) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创翻译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: http://rikkiendsley.com/ +[1]: https://twitter.com/pabelanger +[2]: https://twitter.com/pleia2 +[3]: https://twitter.com/docaedo +[4]: https://www.openstack.org/summit/austin-2016/summit-schedule/events/7337 +[5]: http://docs.openstack.org/infra/system-config/ +[6]: http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-infra +[7]: https://www.technovelty.org/openstack/image-building-in-openstack-ci.html +[8]: https://code.google.com/p/gerrit/ +[9]: http://docs.openstack.org/infra/manual/developers.html#development-workflow +[10]: https://developer.ibm.com/opentech/2015/12/20/irc-the-secret-to-success-in-open-source/ +[11]: https://pypi.python.org/pypi/gertty +[12]: http://eavesdrop.openstack.org/irclogs/%23openstack-infra/ +[13]: http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev +[14]: https://groups.openstack.org/ +[15]: https://www.openstack.org/summit/ +[16]: http://docs.openstack.org/infra/manual/developers.html#account-setup +[17]: https://apps.openstack.org/ +[18]: https://www.openstack.org/summit/austin-2016/summit-schedule/events/7337 diff --git a/translated/tech/20160425 How to Use Awk to Print Fields and Columns in File.md b/translated/tech/20160425 How to Use Awk to Print Fields and Columns in File.md deleted file mode 100644 index 127cc061c1..0000000000 --- a/translated/tech/20160425 How to Use Awk to Print Fields and Columns in File.md +++ /dev/null @@ -1,109 +0,0 @@ -ictlyh Translating -How to Use Awk to Print Fields and Columns in File -=================================================== - -In this part of our [Linux Awk command series][1], we shall have a look at one of the most important features of Awk, which is field editing. - -It is good to know that Awk automatically divides input lines provided to it into fields, and a field can be defined as a set of characters that are separated from other fields by an internal field separator. - -![](http://www.tecmint.com/wp-content/uploads/2016/04/Awk-Print-Fields-and-Columns.png) ->Awk Print Fields and Columns - -If you are familiar with the Unix/Linux or do [bash shell programming][2], then you should know what internal field separator (IFS) variable is. The default IFS in Awk are tab and space. - -This is how the idea of field separation works in Awk: when it encounters an input line, according to the IFS defined, the first set of characters is field one, which is accessed using $1, the second set of characters is field two, which is accessed using $2, the third set of characters is field three, which is accessed using $3 and so forth till the last set of character(s). - -To understand this Awk field editing better, let us take a look at the examples below: - -**Example 1**: I have created a text file called tecmintinfo.txt. - -``` -# vi tecmintinfo.txt -# cat tecmintinfo.txt -``` - -![](http://www.tecmint.com/wp-content/uploads/2016/04/Create-File-in-Linux.png) ->Create File in Linux - -Then from the command line, I try to print the first, second and third fields from the file tecmintinfo.txt using the command below: - -``` -$ awk '//{print $1 $2 $3 }' tecmintinfo.txt -TecMint.comisthe -``` - -From the output above, you can see that the characters from the first three fields are printed based on the IFS defined which is space: - -- Field one which is “TecMint.com” is accessed using $1. -- Field two which is “is” is accessed using $2. -- Field three which is “the” is accessed using $3. - -If you have noticed in the printed output, the field values are not separated and this is how print behaves by default. - -To view the output clearly with space between the field values, you need to add (,) operator as follows: - -``` -$ awk '//{print $1, $2, $3; }' tecmintinfo.txt - -TecMint.com is the -``` - -One important thing to note and always remember is that the use of ($) in Awk is different from its use in shell scripting. - -Under shell scripting ($) is used to access the value of variables while in Awk ($) it is used only when accessing the contents of a field but not for accessing the value of variables. - -**Example 2**: Let us take a look at one other example using a file which contains multiple lines called my_shoping.list. - -``` -No Item_Name Unit_Price Quantity Price -1 Mouse #20,000 1 #20,000 -2 Monitor #500,000 1 #500,000 -3 RAM_Chips #150,000 2 #300,000 -4 Ethernet_Cables #30,000 4 #120,000 -``` - -Say you wanted to only print Unit_Price of each item on the shopping list, you will need to run the command below: - -``` -$ awk '//{print $2, $3 }' my_shopping.txt - -Item_Name Unit_Price -Mouse #20,000 -Monitor #500,000 -RAM_Chips #150,000 -Ethernet_Cables #30,000 -``` - -Awk also has a printf command that helps you to format your output is a nice way as you can see the above output is not clear enough. - -Using printf to format output of the Item_Name and Unit_Price: - -``` -$ awk '//{printf "%-10s %s\n",$2, $3 }' my_shopping.txt - -Item_Name Unit_Price -Mouse #20,000 -Monitor #500,000 -RAM_Chips #150,000 -Ethernet_Cables #30,000 -``` - -### Summary - -Field editing is very important when using Awk to filter text or strings, it helps you get particular data in columns in a list. And always remember that the use of ($) operator in Awk is different from that in shell scripting. - -I hope the article was helpful to you and for any additional information required or questions, you can post a comment in the comment section. - --------------------------------------------------------------------------------- - -via: http://www.tecmint.com/awk-print-fields-columns-with-space-separator/?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+tecmint+%28Tecmint%3A+Linux+Howto%27s+Guide%29 - -作者：[Aaron Kili][a] -译者：[译者ID](https://github.com/译者ID) -校对：[校对者ID](https://github.com/校对者ID) - -本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 - -[a]: http://www.tecmint.com/author/aaronkili/ -[1]: http://www.tecmint.com/tag/awk-command/ -[2]: http://www.tecmint.com/category/bash-shell/ diff --git a/translated/tech/20160511 An introduction to data processing with Cassandra and Spark.md b/translated/tech/20160511 An introduction to data processing with Cassandra and Spark.md deleted file mode 100644 index 0786996e39..0000000000 --- a/translated/tech/20160511 An introduction to data processing with Cassandra and Spark.md +++ /dev/null @@ -1,49 +0,0 @@ -Cassandra 和 Spark 数据处理入门 -============================================================== - -![](https://opensource.com/sites/default/files/styles/image-full-size/public/images/life/osdc_520x292_opendata_0613mm.png?itok=mzC0Tb28) - -Apache Cassandra 数据库近来引起了很多的兴趣，这主要源于现代云端软件对于可用性及性能方面的要求。 - -那么，Apache Cassandra 是什么？它是一种为高可用性及线性可扩展性优化的分布式的联机交易处理 (OLTP) 数据库。当人们想知道 Cassandra 的用途时，可以想想你想要的离客户近的系统。这j最终是我们的用户进行交互的系统。需要保证实时可用的程序：产品目录，IoT，医疗系统，以及移动应用。对这些程序而言，下线时间意味着利润降低甚至导致其他更坏的结果。Netfilix 是这个于2008年开源的项目的早期使用者，他们对此项目的贡献以及带来的成功让这个项目名声大噪。 - -Cassandra 于2010年成为了 Apache 软件基金会的顶级项目，在这之后就开始变得流行。现在，只要你有 Cassadra 的相关知识，找工作时就能轻松不少。光是想想一个 NoSQL 语言和开源技术能达到如此企业级 SQL 的高度就觉得这是十分疯狂而又不可思议的。这引出了一个问题。是什么让它如此的流行？ - -因为采用了首先在[亚马逊发表的 Dynamo 论文][1]提出的设计，Cassandra 有能力在大规模的硬件及网络故障时保持实时在线。由于采用了点对点模式，在没有单点故障的情况下，我们能幸免于机架故障甚至完全网络分区。我们能在不影响用户体验的前提下处理数据中心故障。一个能考虑到故障的分布式系统才是一个没有后顾之忧的分布式系统，因为老实说，故障是迟早会发生的。有了 Cassandra， 我们可疑直面残酷的生活并将之融入数据库的结构和功能中。 - - - -我们能猜到你现在在想什么，“但我只有关系数据库相关背景，难道这样的转变不会很困难吗？"这问题的答案介于是和不是之间。使用 Cassandra 建立数据模型对有关系数据库背景的开发者而言是轻车熟路。我们使用表格来建立数据模型，并使用 CQL 或者 Cassandra 查询语言来查询数据库。然而，与 SQL 不同的是，Cassandra 支持更加复杂的数据结构，例如多重和用户自定义类型。举个例子，当要储存对一个小猫照片的点赞数目时，我们可以将整个数据储存在一个包含照片本身的集合之中从而获得更快的顺序查找而不是建立一个独立的表。这样的表述在 CQL 中十分的自然。在我们照片表中，我们需要记录名字，URL以及给此照片点赞过的人。 - -![](https://opensource.com/sites/default/files/resize/screen_shot_2016-05-06_at_7.17.33_am-350x198.png) - -在一个高性能系统中，毫秒对用户体验和客户保留都能产生影响。昂贵的 JOIN 制约了我们通过增加不可预见的网络调用而扩容的能力。当我们将数据反规范化使其能在尽可能少的请求中被获取到时，我们即可从磁盘空间花费的降低中获益并获得可预测的，高性能应用。我们将反规范化同 Cassandra 一同介绍是因为它提供了很有吸引力的的折衷方案。 - -很明显，我们不会局限于对于小猫照片的点赞数量。Canssandra 是一款个为并发高写入优化的方案。这使其成为需要时常吞吐数据的大数据应用的理想解决方案。市场上的时序和 IoT 的使用场景正在以稳定的速度在需求和亮相方面增加，我们也在不断探寻优化我们所收集到的数据以求提升我们的技术应用（注：这句翻的非常别扭，求校队） - - -这就引出了我们的下一步，我们已经提到了如何以一种现代的，性价比高的方式储存数据，但我们应该如何获得更多的马力呢？具体而言，当我们收集到了所需的数据，我们应该怎样处理呢？如何才能有效的分析几百 TB 的数据呢？如何才能在实时的对我们所收集到的信息进行反馈并在几秒而不是几小时的时间利作出决策呢？Apache Spark 将给我们答案。 - - -Spark 是大数据变革中的下一步。 Hadoop 和 MapReduce 都是革命性的产品，他们让大数据界获得了分析所有我们所取得的数据的机会。Spark 对性能的大幅提升及对代码复杂度的大幅降低则将大数据分析提升到了另一个高度。通过 Spark，我们能大批量的处理计算，对流处理进行快速反映，通过机器学习作出决策并理解通过对图的遍历理解复杂的递归关系。这并非只是为你的客户提供与快捷可靠的应用程序连接（Cassandra 已经提供了这样的功能），这更是能一探 Canssandra 所储存的数据并作出更加合理的商业决策同时更好地满足客户需求。 - -你可以看看 [Spark-Cassandra Connector][2] (open source) 并动手试试。若想了解更多关于这两种技术的信息，我们强烈推荐名为 [DataStax Academy][3] 的自学课程 - --------------------------------------------------------------------------------- - -via: https://opensource.com/life/16/5/basics-cassandra-and-spark-data-processing - -作者：[Jon Haddad][a],[Dani Traphagen][b] -译者：[KevinSJ](https://github.com/KevinSJ) -校对：[校对者ID](https://github.com/校对者ID) - -本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 - -[a]: https://twitter.com/rustyrazorblade -[b]: https://opensource.com/users/dtrapezoid -[1]: http://www.allthingsdistributed.com/files/amazon-dynamo-sosp2007.pdf -[2]: https://github.com/datastax/spark-cassandra-connector -[3]: https://academy.datastax.com/ -[4]: http://conferences.oreilly.com/oscon/open-source-us/public/schedule/detail/49162 -[5]: https://twitter.com/dtrapezoid -[6]: https://twitter.com/rustyrazorblade diff --git a/translated/tech/20160512 Bitmap in Linux Kernel.md b/translated/tech/20160512 Bitmap in Linux Kernel.md new file mode 100644 index 0000000000..6475b9260e --- /dev/null +++ b/translated/tech/20160512 Bitmap in Linux Kernel.md @@ -0,0 +1,405 @@ +--- +date: 2016-07-09 14:42 +status: public +title: 20160512 Bitmap in Linux Kernel +--- + +Linux 内核里的数据结构 +================================================================================ + +Linux 内核中的位数组和位操作 +-------------------------------------------------------------------------------- + +除了不同的基于[链式](https://en.wikipedia.org/wiki/Linked_data_structure)和[树](https://en.wikipedia.org/wiki/Tree_%28data_structure%29)的数据结构以外，Linux 内核也为[位数组](https://en.wikipedia.org/wiki/Bit_array)或`位图`提供了 [API](https://en.wikipedia.org/wiki/Application_programming_interface)。位数组在 Linux 内核里被广泛使用，并且在以下的源代码文件中包含了与这样的结构搭配使用的通用 `API`： + +* [lib/bitmap.c](https://github.com/torvalds/linux/blob/master/lib/bitmap.c) +* [include/linux/bitmap.h](https://github.com/torvalds/linux/blob/master/include/linux/bitmap.h) + +除了这两个文件之外，还有体系结构特定的头文件，它们为特定的体系结构提供优化的位操作。我们将探讨 [x86_64](https://en.wikipedia.org/wiki/X86-64) 体系结构，因此在我们的例子里，它会是 + +* [arch/x86/include/asm/bitops.h](https://github.com/torvalds/linux/blob/master/arch/x86/include/asm/bitops.h) + +头文件。正如我上面所写的，`位图`在 Linux 内核中被广泛地使用。例如，`位数组`常常用于保存一组在线/离线处理器，以便系统支持[热插拔](https://www.kernel.org/doc/Documentation/cpu-hotplug.txt)的 CPU（你可以在 [cpumasks](https://0xax.gitbooks.io/linux-insides/content/Concepts/cpumask.html) 部分阅读更多相关知识 ），一个`位数组`可以在 Linux 内核初始化等期间保存一组已分配的中断处理。 + +因此，本部分的主要目的是了解位数组是如何在 Linux 内核中实现的。让我们现在开始吧。 + +位数组声明 +================================================================================ + +在我们开始查看位图操作的 `API` 之前，我们必须知道如何在 Linux 内核中声明它。有两中通用的方法声明位数组。第一种简单的声明一个位数组的方法是，定义一个 unsigned long 的数组，例如： + +```C +unsigned long my_bitmap[8] +``` + +第二种方法，是使用 `DECLARE_BITMAP` 宏，它定义于 [include/linux/types.h](https://github.com/torvalds/linux/blob/master/include/linux/types.h) 头文件： + +```C +#define DECLARE_BITMAP(name,bits) \ + unsigned long name[BITS_TO_LONGS(bits)] +``` + +我们可以看到 `DECLARE_BITMAP` 宏使用两个参数： + +* `name` - 位图名称; +* `bits` - 位图中位数; + +并且只是使用 `BITS_TO_LONGS(bits)` 元素展开 `unsigned long` 数组的定义。 `BITS_TO_LONGS` 宏将一个给定的位数转换为 `longs` 的个数，换言之，就是计算 `bits` 中有多少个 `8` 字节元素： + +```C +#define BITS_PER_BYTE 8 +#define DIV_ROUND_UP(n,d) (((n) + (d) - 1) / (d)) +#define BITS_TO_LONGS(nr) DIV_ROUND_UP(nr, BITS_PER_BYTE * sizeof(long)) +``` + +因此，例如 `DECLARE_BITMAP(my_bitmap, 64)` 将产生： + +```python +>>> (((64) + (64) - 1) / (64)) +1 +``` + +与： + +```C +unsigned long my_bitmap[1]; +``` + +在能够声明一个位数组之后，我们便可以使用它了。 + +体系结构特定的位操作 +================================================================================ + +我们已经看了以上一对源文件和头文件，它们提供了位数组操作的 [API](https://en.wikipedia.org/wiki/Application_programming_interface)。其中重要且广泛使用的位数组 API 是体系结构特定的且位于已提及的头文件中 [arch/x86/include/asm/bitops.h](https://github.com/torvalds/linux/blob/master/arch/x86/include/asm/bitops.h)。 + +首先让我们查看两个最重要的函数： + +* `set_bit`; +* `clear_bit`. + +我认为没有必要解释这些函数的作用。从它们的名字来看，这已经很清楚了。让我们直接查看它们的实现。如果你浏览 [arch/x86/include/asm/bitops.h](https://github.com/torvalds/linux/blob/master/arch/x86/include/asm/bitops.h) 头文件，你将会注意到这些函数中的每一个都有[原子性](https://en.wikipedia.org/wiki/Linearizability)和非原子性两种变体。在我们开始深入这些函数的实现之前，首先，我们必须了解一些有关原子操作的知识。 + +简而言之，原子操作保证两个或以上的操作不会并发地执行同一数据。`x86` 体系结构提供了一系列原子指令，例如， [xchg](http://x86.renejeschke.de/html/file_module_x86_id_328.html)、[cmpxchg](http://x86.renejeschke.de/html/file_module_x86_id_41.html) 等指令。除了原子指令，一些非原子指令可以在 [lock](http://x86.renejeschke.de/html/file_module_x86_id_159.html) 指令的帮助下具有原子性。目前已经对原子操作有了充分的理解，我们可以接着探讨 `set_bit` 和 `clear_bit` 函数的实现。 + +我们先考虑函数的非原子性变体。非原子性的 `set_bit` 和 `clear_bit` 的名字以双下划线开始。正如我们所知道的，所有这些函数都定义于 [arch/x86/include/asm/bitops.h](https://github.com/torvalds/linux/blob/master/arch/x86/include/asm/bitops.h) 头文件，并且第一个函数就是 `__set_bit`: + +```C +static inline void __set_bit(long nr, volatile unsigned long *addr) +{ + asm volatile("bts %1,%0" : ADDR : "Ir" (nr) : "memory"); +} +``` + +正如我们所看到的，它使用了两个参数： + +* `nr` - 位数组中的位号（从0开始，译者注） +* `addr` - 我们需要置位的位数组地址 + +注意，`addr` 参数使用 `volatile` 关键字定义，以告诉编译器给定地址指向的变量可能会被修改。 `__set_bit` 的实现相当简单。正如我们所看到的，它仅包含一行[内联汇编代码](https://en.wikipedia.org/wiki/Inline_assembler)。在我们的例子中，我们使用 [bts](http://x86.renejeschke.de/html/file_module_x86_id_25.html) 指令，从位数组中选出一个第一操作数（我们的例子中的 `nr`）,存储选出的位的值到 [CF](https://en.wikipedia.org/wiki/FLAGS_register) 标志寄存器并设置该位（即 `nr` 指定的位置为1，译者注）。 + +注意，我们了解了 `nr` 的用法，但这里还有一个参数 `addr` 呢！你或许已经猜到秘密就在 `ADDR`。 `ADDR` 是一个定义在同一头文件的宏，它展开为一个包含给定地址和 `+m` 约束的字符串： + +```C +#define ADDR BITOP_ADDR(addr) +#define BITOP_ADDR(x) "+m" (*(volatile long *) (x)) +``` + +除了 `+m` 之外，在 `__set_bit` 函数中我们可以看到其他约束。让我们查看并试图理解它们所表示的意义： + +* `+m` - 表示内存操作数，这里的 `+` 表明给定的操作数为输入输出操作数; +* `I` - 表示整型常量; +* `r` - 表示寄存器操作数 + +除了这些约束之外，我们也能看到 `memory` 关键字，其告诉编译器这段代码会修改内存中的变量。到此为止，现在我们看看相同的原子性变体函数。它看起来比非原子性变体更加复杂： + +```C +static __always_inline void +set_bit(long nr, volatile unsigned long *addr) +{ + if (IS_IMMEDIATE(nr)) { + asm volatile(LOCK_PREFIX "orb %1,%0" + : CONST_MASK_ADDR(nr, addr) + : "iq" ((u8)CONST_MASK(nr)) + : "memory"); + } else { + asm volatile(LOCK_PREFIX "bts %1,%0" + : BITOP_ADDR(addr) : "Ir" (nr) : "memory"); + } +} +``` + +（BITOP_ADDR 的定义为：`#define BITOP_ADDR(x) "=m" (*(volatile long *) (x))`，ORB 为字节按位或，译者注） + +首先注意，这个函数使用了与 `__set_bit` 相同的参数集合，但额外地使用了 `__always_inline` 属性标记。 `__always_inline` 是一个定义于 [include/linux/compiler-gcc.h](https://github.com/torvalds/linux/blob/master/include/linux/compiler-gcc.h) 的宏，并且只是展开为 `always_inline` 属性： + +```C +#define __always_inline inline __attribute__((always_inline)) +``` + +其意味着这个函数总是内联的，以减少 Linux 内核映像的大小。现在我们试着了解 `set_bit` 函数的实现。首先我们在 `set_bit` 函数的开头检查给定的位数量。`IS_IMMEDIATE` 宏定义于相同[头文件](https://github.com/torvalds/linux/blob/master/arch/x86/include/asm/bitops.h)，并展开为 gcc 内置函数的调用： + +```C +#define IS_IMMEDIATE(nr) (__builtin_constant_p(nr)) +``` + +如果给定的参数是编译期已知的常量，`__builtin_constant_p` 内置函数则返回 `1`，其他情况返回 `0`。假若给定的位数是编译期已知的常量，我们便无须使用效率低下的 `bts` 指令去设置位。我们可以只需在给定地址指向的字节和和掩码上执行 [按位或](https://en.wikipedia.org/wiki/Bitwise_operation#OR) 操作，其字节包含给定的位，而掩码为位号高位 `1`，其他位为 0。在其他情况下，如果给定的位号不是编译期已知常量，我们便做和 `__set_bit` 函数一样的事。`CONST_MASK_ADDR` 宏： + +```C +#define CONST_MASK_ADDR(nr, addr) BITOP_ADDR((void *)(addr) + ((nr)>>3)) +``` + +展开为带有到包含给定位的字节偏移的给定地址，例如，我们拥有地址 `0x1000` 和 位号是 `0x9`。因为 `0x9` 是 `一个字节 + 一位`，所以我们的地址是 `addr + 1`: + +```python +>>> hex(0x1000 + (0x9 >> 3)) +'0x1001' +``` + +`CONST_MASK` 宏将我们给定的位号表示为字节，位号对应位为高位 `1`，其他位为 `0`： + +```C +#define CONST_MASK(nr) (1 << ((nr) & 7)) +``` + +```python +>>> bin(1 << (0x9 & 7)) +'0b10' +``` + +最后，我们应用 `按位或` 运算到这些变量上面，因此，假如我们的地址是 `0x4097` ，并且我们需要置位号为 `9` 的位 为 1： + +```python +>>> bin(0x4097) +'0b100000010010111' +>>> bin((0x4097 >> 0x9) | (1 << (0x9 & 7))) +'0b100010' +``` + +`第 9 位` 将会被置位。（这里的 9 是从 0 开始计数的，比如0010，按照作者的意思，其中的 1 是第 1 位，译者注） + +注意，所有这些操作使用 `LOCK_PREFIX` 标记，其展开为 [lock](http://x86.renejeschke.de/html/file_module_x86_id_159.html) 指令，保证该操作的原子性。 + +正如我们所知，除了 `set_bit` 和 `__set_bit` 操作之外，Linux 内核还提供了两个功能相反的函数，在原子性和非原子性的上下文中清位。它们为 `clear_bit` 和 `__clear_bit`。这两个函数都定义于同一个[头文件](https://github.com/torvalds/linux/blob/master/arch/x86/include/asm/bitops.h) 并且使用相同的参数集合。不仅参数相似，一般而言，这些函数与 `set_bit` 和 `__set_bit` 也非常相似。让我们查看非原子性 `__clear_bit` 的实现吧： + +```C +static inline void __clear_bit(long nr, volatile unsigned long *addr) +{ + asm volatile("btr %1,%0" : ADDR : "Ir" (nr)); +} +``` + +没错，正如我们所见，`__clear_bit` 使用相同的参数集合，并包含极其相似的内联汇编代码块。它仅仅使用 [btr](http://x86.renejeschke.de/html/file_module_x86_id_24.html) 指令替换 `bts`。正如我们从函数名所理解的一样，通过给定地址，它清除了给定的位。`btr` 指令表现得像 `bts`（原文这里为 btr，可能为笔误，修正为 bts，译者注）。该指令选出第一操作数指定的位，存储它的值到 `CF` 标志寄存器，并且清楚第二操作数指定的位数组中的对应位。 + +`__clear_bit` 的原子性变体为 `clear_bit`： + +```C +static __always_inline void +clear_bit(long nr, volatile unsigned long *addr) +{ + if (IS_IMMEDIATE(nr)) { + asm volatile(LOCK_PREFIX "andb %1,%0" + : CONST_MASK_ADDR(nr, addr) + : "iq" ((u8)~CONST_MASK(nr))); + } else { + asm volatile(LOCK_PREFIX "btr %1,%0" + : BITOP_ADDR(addr) + : "Ir" (nr)); + } +} +``` + +并且正如我们所看到的，它与 `set_bit` 非常相似，同时只包含了两处差异。第一处差异为 `clear_bit` 使用 `btr` 指令来清位，而 `set_bit` 使用 `bts` 指令来置位。第二处差异为 `clear_bit` 使用否定的位掩码和 `按位与` 在给定的字节上置位，而 `set_bit` 使用 `按位或` 指令。 + +到此为止，我们可以在任何位数组置位和清位了，并且能够转到位掩码上的其他操作。 + +在 Linux 内核位数组上最广泛使用的操作是设置和清除位，但是除了这两个操作外，位数组上其他操作也是非常有用的。Linux 内核里另一种广泛使用的操作是知晓位数组中一个给定的位是否被置位。我们能够通过 `test_bit` 宏的帮助实现这一功能。这个宏定义于 [arch/x86/include/asm/bitops.h](https://github.com/torvalds/linux/blob/master/arch/x86/include/asm/bitops.h) 头文件，并展开为 `constant_test_bit` 或 `variable_test_bit` 的调用，这要取决于位号。 + +```C +#define test_bit(nr, addr) \ + (__builtin_constant_p((nr)) \ + ? constant_test_bit((nr), (addr)) \ + : variable_test_bit((nr), (addr))) +``` + +因此，如果 `nr` 是编译期已知常量，`test_bit` 将展开为 `constant_test_bit` 函数的调用，而其他情况则为 `variable_test_bit`。现在让我们看看这些函数的实现，我们从 `variable_test_bit` 开始看起： + +```C +static inline int variable_test_bit(long nr, volatile const unsigned long *addr) +{ + int oldbit; + + asm volatile("bt %2,%1\n\t" + "sbb %0,%0" + : "=r" (oldbit) + : "m" (*(unsigned long *)addr), "Ir" (nr)); + + return oldbit; +} +``` + +`variable_test_bit` 函数调用了与 `set_bit` 及其他函数使用的相似的参数集合。我们也可以看到执行 [bt](http://x86.renejeschke.de/html/file_module_x86_id_22.html) 和 [sbb](http://x86.renejeschke.de/html/file_module_x86_id_286.html) 指令的内联汇编代码。`bt` 或 `bit test` 指令从第二操作数指定的位数组选出第一操作数指定的一个指定位，并且将该位的值存进标志寄存器的 [CF](https://en.wikipedia.org/wiki/FLAGS_register) 位。第二个指令 `sbb` 从第二操作数中减去第一操作数，再减去 `CF` 的值。因此，这里将一个从给定位数组中的给定位号的值写进标志寄存器的 `CF` 位，并且执行 `sbb` 指令计算： `00000000 - CF`，并将结果写进 `oldbit` 变量。 + +`constant_test_bit` 函数做了和我们在 `set_bit` 所看到的一样的事： + +```C +static __always_inline int constant_test_bit(long nr, const volatile unsigned long *addr) +{ + return ((1UL << (nr & (BITS_PER_LONG-1))) & + (addr[nr >> _BITOPS_LONG_SHIFT])) != 0; +} +``` + +它生成了一个位号对应位为高位 `1`，而其他位为 `0` 的字节（正如我们在 `CONST_MASK` 所看到的），并将 [按位与](https://en.wikipedia.org/wiki/Bitwise_operation#AND) 应用于包含给定位号的字节。 + +下一广泛使用的位数组相关操作是改变一个位数组中的位。为此，Linux 内核提供了两个辅助函数： + +* `__change_bit`; +* `change_bit`. + +你可能已经猜测到，就拿 `set_bit` 和 `__set_bit` 例子说，这两个变体分别是原子和非原子版本。首先，让我们看看 `__change_bit` 函数的实现： + +```C +static inline void __change_bit(long nr, volatile unsigned long *addr) +{ + asm volatile("btc %1,%0" : ADDR : "Ir" (nr)); +} +``` + +相当简单，不是吗？ `__change_bit` 的实现和 `__set_bit` 一样，只是我们使用 [btc](http://x86.renejeschke.de/html/file_module_x86_id_23.html) 替换 `bts` 指令而已。 该指令从一个给定位数组中选出一个给定位，将该为位的值存进 `CF` 并使用求反操作改变它的值，因此值为 `1` 的位将变为 `0`，反之亦然： + +```python +>>> int(not 1) +0 +>>> int(not 0) +1 +``` + + `__change_bit` 的原子版本为 `change_bit` 函数： + +```C +static inline void change_bit(long nr, volatile unsigned long *addr) +{ + if (IS_IMMEDIATE(nr)) { + asm volatile(LOCK_PREFIX "xorb %1,%0" + : CONST_MASK_ADDR(nr, addr) + : "iq" ((u8)CONST_MASK(nr))); + } else { + asm volatile(LOCK_PREFIX "btc %1,%0" + : BITOP_ADDR(addr) + : "Ir" (nr)); + } +} +``` + +它和 `set_bit` 函数很相似，但也存在两点差异。第一处差异为 `xor` 操作而不是 `or`。第二处差异为 `btc`（原文为 `bts`，为作者笔误，译者注） 而不是 `bts`。 + +目前，我们了解了最重要的体系特定的位数组操作，是时候看看一般的位图 API 了。 + +通用位操作 +================================================================================ + +除了 [arch/x86/include/asm/bitops.h](https://github.com/torvalds/linux/blob/master/arch/x86/include/asm/bitops.h) 中体系特定的 API 外，Linux 内核提供了操作位数组的通用 API。正如我们本部分开头所了解的一样，我们可以在 [include/linux/bitmap.h](https://github.com/torvalds/linux/blob/master/include/linux/bitmap.h) 头文件和* [lib/bitmap.c](https://github.com/torvalds/linux/blob/master/lib/bitmap.c) 源文件中找到它。但在查看这些源文件之前，我们先看看 [include/linux/bitops.h](https://github.com/torvalds/linux/blob/master/include/linux/bitops.h) 头文件，其提供了一系列有用的宏，让我们看看它们当中一部分。 + +首先我们看看以下 4 个 宏： + +* `for_each_set_bit` +* `for_each_set_bit_from` +* `for_each_clear_bit` +* `for_each_clear_bit_from` + +所有这些宏都提供了遍历位数组中某些位集合的迭代器。第一个红迭代那些被置位的位。第二个宏也是一样，但它是从某一确定位开始。最后两个宏做的一样，但是迭代那些被清位的位。让我们看看 `for_each_set_bit` 宏： + +```C +#define for_each_set_bit(bit, addr, size) \ + for ((bit) = find_first_bit((addr), (size)); \ + (bit) < (size); \ + (bit) = find_next_bit((addr), (size), (bit) + 1)) +``` + +正如我们所看到的，它使用了三个参数，并展开为一个循环，该循环从作为 `find_first_bit` 函数返回结果的第一个置位开始到最后一个置位且小于给定大小为止。 + +除了这四个宏， [arch/x86/include/asm/bitops.h](https://github.com/torvalds/linux/blob/master/arch/x86/include/asm/bitops.h) 也提供了 `64-bit` 或 `32-bit` 变量循环的 API 等等。 + +下一个 [头文件](https://github.com/torvalds/linux/blob/master/include/linux/bitmap.h) 提供了操作位数组的 API。例如，它提供了以下两个函数： + +* `bitmap_zero`; +* `bitmap_fill`. + +它们分别可以清除一个位数组和用 `1` 填充位数组。让我们看看 `bitmap_zero` 函数的实现： + +```C +static inline void bitmap_zero(unsigned long *dst, unsigned int nbits) +{ + if (small_const_nbits(nbits)) + *dst = 0UL; + else { + unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long); + memset(dst, 0, len); + } +} +``` + +首先我们可以看到对 `nbits` 的检查。 `small_const_nbits` 是一个定义在同一[头文件](https://github.com/torvalds/linux/blob/master/include/linux/bitmap.h) 的宏： + +```C +#define small_const_nbits(nbits) \ + (__builtin_constant_p(nbits) && (nbits) <= BITS_PER_LONG) +``` + +正如我们可以看到的，它检查 `nbits` 是否为编译期已知常量，并且其值不超过 `BITS_PER_LONG` 或 `64`。如果位数目没有超过一个 `long` 变量的位数，我们可以仅仅设置为 0。在其他情况，我们需要计算有多少个需要填充位数组的 `long` 变量并且使用 [memset](http://man7.org/linux/man-pages/man3/memset.3.html) 进行填充。 + +`bitmap_fill` 函数的实现和 `biramp_zero` 函数很相似，除了我们需要在给定的位数组中填写 `0xff` 或 `0b11111111`： + +```C +static inline void bitmap_fill(unsigned long *dst, unsigned int nbits) +{ + unsigned int nlongs = BITS_TO_LONGS(nbits); + if (!small_const_nbits(nbits)) { + unsigned int len = (nlongs - 1) * sizeof(unsigned long); + memset(dst, 0xff, len); + } + dst[nlongs - 1] = BITMAP_LAST_WORD_MASK(nbits); +} +``` + +除了 `bitmap_fill` 和 `bitmap_zero`，[include/linux/bitmap.h](https://github.com/torvalds/linux/blob/master/include/linux/bitmap.h) 头文件也提供了和 `bitmap_zero` 很相似的 `bitmap_copy`，只是仅仅使用 [memcpy](http://man7.org/linux/man-pages/man3/memcpy.3.html) 而不是 [memset](http://man7.org/linux/man-pages/man3/memset.3.html) 这点差异而已。它也提供了位数组的按位操作，像 `bitmap_and`, `bitmap_or`, `bitamp_xor`等等。我们不会探讨这些函数的实现了，因为如果你理解了本部分的所有内容，这些函数的实现是很容易理解的。无论如何，如果你对这些函数是如何实现的感兴趣，你可以打开并研究 [include/linux/bitmap.h](https://github.com/torvalds/linux/blob/master/include/linux/bitmap.h) 头文件。 + +本部分到此为止。 + +链接 +================================================================================ + +* [bitmap](https://en.wikipedia.org/wiki/Bit_array) +* [linked data structures](https://en.wikipedia.org/wiki/Linked_data_structure) +* [tree data structures](https://en.wikipedia.org/wiki/Tree_%28data_structure%29) +* [hot-plug](https://www.kernel.org/doc/Documentation/cpu-hotplug.txt) +* [cpumasks](https://0xax.gitbooks.io/linux-insides/content/Concepts/cpumask.html) +* [IRQs](https://en.wikipedia.org/wiki/Interrupt_request_%28PC_architecture%29) +* [API](https://en.wikipedia.org/wiki/Application_programming_interface) +* [atomic operations](https://en.wikipedia.org/wiki/Linearizability) +* [xchg instruction](http://x86.renejeschke.de/html/file_module_x86_id_328.html) +* [cmpxchg instruction](http://x86.renejeschke.de/html/file_module_x86_id_41.html) +* [lock instruction](http://x86.renejeschke.de/html/file_module_x86_id_159.html) +* [bts instruction](http://x86.renejeschke.de/html/file_module_x86_id_25.html) +* [btr instruction](http://x86.renejeschke.de/html/file_module_x86_id_24.html) +* [bt instruction](http://x86.renejeschke.de/html/file_module_x86_id_22.html) +* [sbb instruction](http://x86.renejeschke.de/html/file_module_x86_id_286.html) +* [btc instruction](http://x86.renejeschke.de/html/file_module_x86_id_23.html) +* [man memcpy](http://man7.org/linux/man-pages/man3/memcpy.3.html) +* [man memset](http://man7.org/linux/man-pages/man3/memset.3.html) +* [CF](https://en.wikipedia.org/wiki/FLAGS_register) +* [inline assembler](https://en.wikipedia.org/wiki/Inline_assembler) +* [gcc](https://en.wikipedia.org/wiki/GNU_Compiler_Collection) + + +------------------------------------------------------------------------------ + +via: https://github.com/0xAX/linux-insides/blob/master/DataStructures/bitmap.md + +作者：[0xAX][a] +译者：[cposture](https://github.com/cposture) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创翻译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://twitter.com/0xAX \ No newline at end of file diff --git a/translated/tech/20160518 Python 3 - An Intro to Encryption.md b/translated/tech/20160518 Python 3 - An Intro to Encryption.md new file mode 100644 index 0000000000..5c57264aa7 --- /dev/null +++ b/translated/tech/20160518 Python 3 - An Intro to Encryption.md @@ -0,0 +1,280 @@ +Python 3: 加密简介 +=================================== + +Python 3 的标准库中没什么用来解决加密的，不过却有用于处理哈希的库。在这里我们会对其进行一个简单的介绍，但重点会放在两个第三方的软件包： PyCrypto 和 cryptography 上。我们将学习如何使用这两个库，来加密和解密字符串。 + +--- + +### 哈希 + +如果需要用到安全哈希算法或是消息摘要算法，那么你可以使用标准库中的 **hashlib** 模块。这个模块包含了标准的安全哈希算法，包括 SHA1，SHA224，SHA256，SHA384，SHA512 以及 RSA 的 MD5 算法。Python 的 **zlib** 模块也提供 adler32 以及 crc32 哈希函数。 + +一个哈希最常见的用法是，存储密码的哈希值而非密码本身。当然了，使用的哈希函数需要稳健一点，否则容易被破解。另一个常见的用法是，计算一个文件的哈希值，然后将这个文件和它的哈希值分别发送。接受到文件的人可以计算文件的哈希值，检验是否与接受到的哈希值相符。如果两者相符，就说明文件在传送的过程中未经篡改。 + +让我们试着创建一个 md5 哈希： + +``` +>>> import hashlib +>>> md5 = hashlib.md5() +>>> md5.update('Python rocks!') +Traceback (most recent call last): + File "", line 1, in + md5.update('Python rocks!') +TypeError: Unicode-objects must be encoded before hashing +>>> md5.update(b'Python rocks!') +>>> md5.digest() +b'\x14\x82\xec\x1b#d\xf6N}\x16*+[\x16\xf4w' +``` + +Let’s take a moment to break this down a bit. First off, we import **hashlib** and then we create an instance of an md5 HASH object. Next we add some text to the hash object and we get a traceback. It turns out that to use the md5 hash, you have to pass it a byte string instead of a regular string. So we try that and then call it’s **digest** method to get our hash. If you prefer the hex digest, we can do that too: + +让我们花点时间一行一行来讲解。首先，我们导入 **hashlib** ，然后创建一个 md5 哈希对象的实例。接着，我们向这个实例中添加一个字符串后，却得到了报错信息。原来，计算 md5 哈希时，需要使用字节形式的字符串而非普通字符串。正确添加字符串后，我们调用它的 **digest** 函数来得到哈希值。如果你想要十六进制的哈希值，也可以用以下方法： + +``` +>>> md5.hexdigest() +'1482ec1b2364f64e7d162a2b5b16f477' +``` + +实际上，有一种精简的方法来创建哈希，下面我们看一下用这种方法创建一个 sha512 哈希： + +``` +>>> sha = hashlib.sha1(b'Hello Python').hexdigest() +>>> sha +'422fbfbc67fe17c86642c5eaaa48f8b670cbed1b' +``` + +可以看到，我们可以同时创建一个哈希实例并且调用其 digest 函数。然后，我们打印出这个哈希值看一下。这里我使用 sha1 哈希函数作为例子，但它不是特别安全，读者可以随意尝试其他的哈希函数。 + + +--- + +### 密钥导出 + +Python 的标准库对密钥导出支持较弱。实际上，hashlib 函数库提供的唯一方法就是 **pbkdf2_hmac** 函数。它是基于口令的密钥导出函数 PKCS#5 ，并使用 HMAC 作为伪随机函数。因为它支持加盐和迭代操作，你可以使用类似的方法来哈希你的密码。例如，如果你打算使用 SHA-256 加密方法，你将需要至少 16 个字节的盐，以及最少 100000 次的迭代操作。 + +简单来说，盐就是随机的数据，被用来加入到哈希的过程中，以加大破解的难度。这基本可以保护你的密码免受字典和彩虹表的攻击。 + +让我们看一个简单的例子： + +``` +>>> import binascii +>>> dk = hashlib.pbkdf2_hmac(hash_name='sha256', + password=b'bad_password34', + salt=b'bad_salt', + iterations=100000) +>>> binascii.hexlify(dk) +b'6e97bad21f6200f9087036a71e7ca9fa01a59e1d697f7e0284cd7f9b897d7c02' +``` + +这里，我们用 SHA256 对一个密码进行哈希，使用了一个糟糕的盐，但经过了 100000 次迭代操作。当然，SHA 实际上并不被推荐用来创建密码的密钥。你应该使用类似 **scrypt** 的算法来替代。另一个不错的选择是使用一个叫 **bcrypt** 的第三方库。它是被专门设计出来哈希密码的。 + +--- + +### PyCryptodome + +PyCrypto 可能是 Python 中密码学方面最有名的第三方软件包。可惜的是，它的开发工作于 2012 年就已停止。其他人还在继续发布最新版本的 PyCrypto，如果你不介意使用第三方的二进制包，仍可以取得 Python 3.5 的相应版本。比如，我在 Github (https://github.com/sfbahr/PyCrypto-Wheels) 上找到了对应 Python 3.5 的 PyCrypto 二进制包。 + +幸运的是，有一个该项目的分支 PyCrytodome 取代了 PyCrypto 。为了在 Linux 上安装它，你可以使用以下 pip 命令： + +``` +pip install pycryptodome +``` + +在 Windows 系统上安装则稍有不同： + +``` +pip install pycryptodomex +``` + +如果你遇到了问题，可能是因为你没有安装正确的依赖包（译者注：如 python-devel），或者你的 Windows 系统需要一个编译器。如果你需要安装上的帮助或技术支持，可以访问 PyCryptodome 的[网站][1]。 + +还值得注意的是，PyCryptodome 在 PyCrypto 最后版本的基础上有很多改进。非常值得去访问它们的主页，看看有什么新的特性。 + +### 加密字符串 + +访问了他们的主页之后，我们可以看一些例子。在第一个例子中，我们将使用 DES 算法来加密一个字符串： + +``` +>>> from Crypto.Cipher import DES +>>> key = 'abcdefgh' +>>> def pad(text): + while len(text) % 8 != 0: + text += ' ' + return text +>>> des = DES.new(key, DES.MODE_ECB) +>>> text = 'Python rocks!' +>>> padded_text = pad(text) +>>> encrypted_text = des.encrypt(text) +Traceback (most recent call last): + File "", line 1, in + encrypted_text = des.encrypt(text) + File "C:\Programs\Python\Python35-32\lib\site-packages\Crypto\Cipher\blockalgo.py", line 244, in encrypt + return self._cipher.encrypt(plaintext) +ValueError: Input strings must be a multiple of 8 in length +>>> encrypted_text = des.encrypt(padded_text) +>>> encrypted_text +b'>\xfc\x1f\x16x\x87\xb2\x93\x0e\xfcH\x02\xd59VQ' +``` + +这段代码稍有些复杂，让我们一点点来看。首先需要注意的是，DES 加密使用的密钥长度为 8 个字节，这也是我们将密钥变量设置为 8 个字符的原因。而我们需要加密的字符串的长度必须是 8 的倍数，所以我们创建了一个名为 **pad** 的函数，来给一个字符串末尾添加空格，直到它的长度是 8 的倍数。然后，我们创建了一个 DES 的实例，以及我们需要加密的文本。我们还创建了一个经过填充处理的文本。我们尝试这对未经填充处理的文本进行加密，啊欧，报错了！我们需要对经过填充处理的文本进行加密，然后得到加密的字符串。 +（译者注：encrypt 函数的参数应为 byte 类型字符串，代码为：`encrypted_text = des.encrypt(padded_textpadded_text.encode('uf-8'))`） + +知道了如何加密，还要知道如何解密： + +``` +>>> des.decrypt(encrypted_text) +b'Python rocks! ' +``` + +幸运的是，解密非常容易，我们只需要调用 des 对象的 **decrypt** 方法就可以得到我们原来的 byte 类型字符串了。下一个任务是学习如何用 RSA 算法加密和解密一个文件。首先，我们需要创建一些 RSA 密钥。 + +### 创建 RSA 密钥 + +如果你希望使用 RSA 算法加密数据，那么你需要拥有访问 RAS 公钥和私钥的权限，否则你需要生成一组自己的密钥对。在这个例子中，我们将生成自己的密钥对。创建 RSA 密钥非常容易，所以我们将在 Python 解释器中完成。 + +``` +>>> from Crypto.PublicKey import RSA +>>> code = 'nooneknows' +>>> key = RSA.generate(2048) +>>> encrypted_key = key.exportKey(passphrase=code, pkcs=8, + protection="scryptAndAES128-CBC") +>>> with open('/path_to_private_key/my_private_rsa_key.bin', 'wb') as f: + f.write(encrypted_key) +>>> with open('/path_to_public_key/my_rsa_public.pem', 'wb') as f: + f.write(key.publickey().exportKey()) +``` + +首先我们从 **Crypto.PublicKey** 包中导入 **RSA**，然后创建一个傻傻的密码。接着我们生成 2048 位的 RSA 密钥。现在我们到了关键的部分。为了生成私钥，我们需要调用 RSA 密钥实例的 **exportKey** 方法，然后传入密码，使用的 PKCS 标准，以及加密方案这三个参数。之后，我们把私钥写入磁盘的文件中。 + +接下来，我们通过 RSA 密钥实例的 **publickey** 方法创建我们的公钥。我们使用方法链调用 publickey 和 exportKey 方法生成公钥，同样将它写入磁盘上的文件。 + +### 加密文件 + +有了私钥和公钥之后，我们就可以加密一些数据，并写入文件了。这儿有个比较标准的例子： + +``` +from Crypto.PublicKey import RSA +from Crypto.Random import get_random_bytes +from Crypto.Cipher import AES, PKCS1_OAEP + +with open('/path/to/encrypted_data.bin', 'wb') as out_file: + recipient_key = RSA.import_key( + open('/path_to_public_key/my_rsa_public.pem').read()) + session_key = get_random_bytes(16) + + cipher_rsa = PKCS1_OAEP.new(recipient_key) + out_file.write(cipher_rsa.encrypt(session_key)) + + cipher_aes = AES.new(session_key, AES.MODE_EAX) + data = b'blah blah blah Python blah blah' + ciphertext, tag = cipher_aes.encrypt_and_digest(data) + + out_file.write(cipher_aes.nonce) + out_file.write(tag) + out_file.write(ciphertext) +``` + +代码的前三行导入 PyCryptodome 包。然后我们打开一个文件用于写入数据。接着我们导入公钥赋给一个变量，创建一个 16 字节的会话密钥。在这个例子中，我们将使用混合加密方法，即 PKCS#1 OAEP ，也就是最优非对称加密填充。这允许我们向文件中写入任意长度的数据。接着我们创建 AES 加密，要加密的数据，然后加密数据。我们将得到加密的文本和消息认证码。最后，我们将随机数，消息认证码和加密的文本写入文件。 + +顺便提一下，随机数通常是真随机或伪随机数，只是用来进行密码通信的。对于 AES 加密，其密钥长度最少是 16 个字节。随意用一个你喜欢的编辑器试着打开这个被加密的文件，你应该只能看到乱码。 + +现在让我们学习如何解密我们的数据。 + +``` +from Crypto.PublicKey import RSA +from Crypto.Cipher import AES, PKCS1_OAEP + +code = 'nooneknows' + +with open('/path/to/encrypted_data.bin', 'rb') as fobj: + private_key = RSA.import_key( + open('/path_to_private_key/my_rsa_key.pem').read(), + passphrase=code) + + enc_session_key, nonce, tag, ciphertext = [ fobj.read(x) + for x in (private_key.size_in_bytes(), + 16, 16, -1) ] + + cipher_rsa = PKCS1_OAEP.new(private_key) + session_key = cipher_rsa.decrypt(enc_session_key) + + cipher_aes = AES.new(session_key, AES.MODE_EAX, nonce) + data = cipher_aes.decrypt_and_verify(ciphertext, tag) + +print(data) +``` + +如果你认真看了上一个例子，这段代码应该很容易解析。在这里，我们先读取二进制的加密文件，然后导入私钥。注意，当你导入私钥时，需要提供一个密码，否则会出现错误。然后，我们文件中读取数据，首先是加密的会话密钥，然后是 16 字节的随机数和 16 字节的消息认证码，最后是剩下的加密的数据。 + +接下来我们需要解密出会话密钥，重新创建 AES 密钥，然后解密出数据。 + +你还可以用 PyCryptodome 库做更多的事。不过我们要接着讨论在 Python 中还可以用什么来满足我们加密解密的需求。 + +--- + +### cryptography 包 + +**cryptography** 的目标是成为人类易于使用的密码学包，就像 **requests** 是人类易于使用的 HTTP 库一样。这个想法使你能够创建简单安全，易于使用的加密方案。如果有需要的话，你也可以使用一些底层的密码学基元，但这也需要你知道更多的细节，否则创建的东西将是不安全的。 + +如果你使用的 Python 版本是 3.5, 你可以使用 pip 安装，如下： + +``` +pip install cryptography +``` + +你会看到 cryptography 包还安装了一些依赖包（译者注：如 libopenssl-devel）。如果安装都顺利，我们就可以试着加密一些文本了。让我们使用 **Fernet** 对称加密算法，它保证了你加密的任何信息在不知道密码的情况下不能被篡改或读取。Fernet 还通过 **MultiFernet** 支持密钥轮换。下面让我们看一个简单的例子： + +``` +>>> from cryptography.fernet import Fernet +>>> cipher_key = Fernet.generate_key() +>>> cipher_key +b'APM1JDVgT8WDGOWBgQv6EIhvxl4vDYvUnVdg-Vjdt0o=' +>>> cipher = Fernet(cipher_key) +>>> text = b'My super secret message' +>>> encrypted_text = cipher.encrypt(text) +>>> encrypted_text +(b'gAAAAABXOnV86aeUGADA6mTe9xEL92y_m0_TlC9vcqaF6NzHqRKkjEqh4d21PInEP3C9HuiUkS9f' + b'6bdHsSlRiCNWbSkPuRd_62zfEv3eaZjJvLAm3omnya8=') +>>> decrypted_text = cipher.decrypt(encrypted_text) +>>> decrypted_text +b'My super secret message' +``` + +首先我们需要导入 Fernet，然后生成一个密钥。我们输出密钥看看它是什么样儿。如你所见，它是一个随机的字节串。如果你愿意的话，可以试着多运行 **generate_key** 方法几次，生成的密钥会是不同的。然后我们使用这个密钥生成 Fernet 密码实例。 + +现在我们有了用来加密和解密消息的密码。下一步是创建一个需要加密的消息，然后使用 **encrypt** 方法对它加密。我打印出加密的文本，然后你可以看到你不再能够读懂它。为了**解密**出我们的秘密消息，我们只需调用 decrypt 方法，并传入加密的文本作为参数。结果就是我们得到了消息字节串形式的纯文本。 + +--- + +### 小结 + +这一章仅仅浅显地介绍了 PyCryptodome 和 cryptography 这两个包的使用。不过这也确实给了你一个关于如何加密解密字符串和文件的简述。请务必阅读文档，做做实验，看看还能做些什么！ + +--- + +### 相关阅读 + +[Github][2] 上 Python 3 的 PyCrypto Wheels + +PyCryptodome 的 [文档][3] + +Python’s 加密 [服务][4] + +Cryptography 包的 [官网][5] + +------------------------------------------------------------------------------ + +via: http://www.blog.pythonlibrary.org/2016/05/18/python-3-an-intro-to-encryption/ + +作者：[Mike][a] +译者：[Cathon](https://github.com/Cathon) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创翻译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]:http://www.blog.pythonlibrary.org/author/mld/ +[1]: http://pycryptodome.readthedocs.io/en/latest/ +[2]: https://github.com/sfbahr/PyCrypto-Wheels +[3]: http://pycryptodome.readthedocs.io/en/latest/src/introduction.html +[4]: https://docs.python.org/3/library/crypto.html +[5]: https://cryptography.io/en/latest/ diff --git a/translated/tech/20160519 The future of sharing integrating Pydio and ownCloud.md b/translated/tech/20160519 The future of sharing integrating Pydio and ownCloud.md deleted file mode 100644 index bf5a25c77e..0000000000 --- a/translated/tech/20160519 The future of sharing integrating Pydio and ownCloud.md +++ /dev/null @@ -1,65 +0,0 @@ -分享的未来：整合 Pydio 与 ownCloud -========================================================= - -![](https://opensource.com/sites/default/files/styles/image-full-size/public/images/business/BIZ_darwincloud_520x292_0311LL.png?itok=5yWIaEDe) ->图片来源 : -opensource.com - -开源共享生态圈内容纳了许多各异的项目，他们每一个都能提供出自己的解决方案，且每一个都不按套路来。有很多原因导致你选择开源的解决方案，而非 Dropbox、Google Drive、iCloud 或 OneDrive 这些商业的解决方案。这些商业的解决方案虽然能让你不必为如何管理数据担心，但也理所应当的带着种种限制，其中就包含对于原有基础结构的控制和整合不足。 - -对于用户而言仍有相当一部分文件分享和同步的替代品可供选择，其中就包括了 Pydio 和 ownCloud。 - -### Pydio - -Pydio （Put your data in orbit 把你的数据放上轨道） 项目由一位作曲家 Charles du Jeu 发起，起初他也只是需要一种与乐队成员分享大型音频文件的方法。[Pydio][1] 是一种文件分享与同步的解决方案，综合了多存储后端，设计时还同时考虑了开发者和系统管理员两方面。在世界各地有逾百万的下载量，已被翻译成 27 种语言。 - -项目在很开始的时候便开源了，先是在 [SourceForge][2] 上茁壮的成长，现在已在 [GitHub][3] 上安了家.。 - -用户界面基于 Google 的 [Material 设计][4]。用户可以使用现有的传统的文件基础结构或是本地部署 Pydio，并通过 web、桌面和移动端应用随时随地地管理自己的东西。对于管理员来说，细粒度的访问权限绝对是配置访问时的利器。 - -在 [Pydio 社区][5]，你可以找到许多让你增速的资源。Pydio 网站 [对于如何为 Pydio GitHub 仓库贡献][6] 给出了明确的指导方案。[论坛][7]中也包含了开发者板块和社区。 - -### ownCloud - -[ownCloud][8] 在世界各地拥有逾 8 百万的用户，并且开源，支持自托管文件同步，且共享技术。同步客户端支持所有主流平台并支持 WebDAV 通过 web 界面实现。ownCloud 拥有简单的使用界面，强大的管理工具，和大规模的共享及协作功能——以满足用户管理数据时的需求。 - -ownCloud 的开放式架构是通过 API 和为应用提供平台来实现可扩展性的。迄今已有逾 300 款应用，功能包括处理像日历、联系人、邮件、音乐、密码、笔记等诸多数据类型。ownCloud 由一个数百位贡献者的国际化的社区开发，安全，并且能做到为小到一个树莓派大到好几百万用户的 PB 级存储集群量身定制。 - -### 联合共享 （Federated sharing） - -文件共享开始转向团队合作时代，而标准化为合作提供了坚实的土壤。 - -联合共享——一个由 [OpenCloudMesh][9] 项目提供的新开放标准，就是在这个方向迈出的一步。先不说别的，在支持该标准的服务端上，可以像 Pydio 和 ownCloud 那样分享文件和文件夹。 - -ownCloud 7 率先引入，这种服务端到服务端的分享方式可以让你挂载远程服务端上共享的文件，实际上就是创建你所有云的云。你可以直接创建共享链接，让用户在其他支持联合云共享的服务端上使用。 - -实现这个新的 API 允许存储解决方案之间更深层次的集成，同时保留了原有平台的安全，控制和属性。 - -“交换和共享文件是当下和未来不可或缺的东西。”ownCloud 的创始人 Frank Karlitschek 说道：“正因如此，采用联合和分布的方式而非集中的数据孤岛就显得至关重要。[联合共享]的设计初衷便是在保证安全和用户隐私的同时追求分享的无缝、至简之道。” - -### 下一步是什么呢？ - -正如 OpenCloudMesh 做的那样，将会通过像 Pydio 和 ownCloud 这样的机构和公司，合作推广这一文件共享的新开放标准。ownCloud 9 已经引入联合服务端间交换用户列表的功能，让你的用户在你的服务器上享有和你同样的无缝体验。将来，一个中央地址簿服务(联合!)集合，用以检索其他联合云 ID 的想法可能会把云间合作推向一个新的高度。 - -这一举措无疑有助于日益开放的技术社区中的那些成员方便地讨论，开发，并推动“OCM 分享 API”作为一个厂商中立协议。所有领导 OCM 项目的合作伙伴都全心致力于开放 API 的设计原理，并欢迎其他开源的文件分享和同步社区参与并加入其中。 - --------------------------------------------------------------------------------- - -via: https://opensource.com/business/16/5/sharing-files-pydio-owncloud - -作者：[ben van 't ende][a] -译者：[martin2011qi](https://github.com/martin2011qi) -校对：[校对者ID](https://github.com/校对者ID) - -本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 - -[a]: https://opensource.com/users/benvantende -[1]: https://pydio.com/ -[2]: https://sourceforge.net/projects/ajaxplorer/ -[3]: https://github.com/pydio/ -[4]: https://www.google.com/design/spec/material-design/introduction.html -[5]: https://pydio.com/en/community -[6]: https://pydio.com/en/community/contribute -[7]: https://pydio.com/forum/f -[8]: https://owncloud.org/ -[9]: https://wiki.geant.org/display/OCM/Open+Cloud+Mesh diff --git a/translated/tech/20160524 Writing online multiplayer game with python and asyncio - part 1.md b/translated/tech/20160524 Writing online multiplayer game with python and asyncio - part 1.md new file mode 100644 index 0000000000..26ddea6b1e --- /dev/null +++ b/translated/tech/20160524 Writing online multiplayer game with python and asyncio - part 1.md @@ -0,0 +1,71 @@ +使用python 和asyncio编写在线多人游戏 - 第1部分 +=================================================================== + +你曾经把async和python关联起来过吗？在这里我将告诉你怎样做，而且在[working example][1]这个例子里面展示-一个流行的贪吃蛇游戏，这是为多人游戏而设计的。 +[Play game][2] + +###1.简介 + +在技术和文化领域，大量的多人在线游戏毋庸置疑是我们这个世界的主流之一。同时，为一个MMO游戏写一个服务器一般和大量的预算与低水平的编程技术相关，在最近这几年，事情发生了很大的变化。基于动态语言的现代框架允许在稳健的硬件上面处理大量并发的用户连接。同时，HTML5 和 WebSockets 标准允许基于实时的图形游戏直接在web浏览器上创建客户端，而不需要任何的扩展。 + +对于创建可扩展非堵塞的服务器，Python可能不是最受欢迎的工具，尤其是和在这个领域最受欢迎的node.js相比。但是最近版本的python打算改变这种现状。[asyncio][3]的介绍和一个特别的[async/await][4] 语法使得异步代码看起来像常规的阻塞代码，这使得python成为一个值得信赖的异步编程语言。所以我将尝试利用这些新特点来创建一个多人在线游戏。 + +###2.异步 +一个游戏服务器应该处理最大数量的用户的并发连接和实时处理这些连接。一个典型的解决方案----创建线程，然而在这种情况下并不能解决这个问题。运行上千的线程需要CPU在它们之间不停的切换（这叫做上下文切换），这将开销非常大，效率很低下。更糟糕的是，因为，此外，它们会占用大量的内存。在python中，还有一个问题，python的解释器（CPython）并不是针对多线程设计的，它主要针对于单线程实现最大数量的行为。这就是为什么它使用GIL（global interpreter lock）,一个不允许同时运行多线程python代码的架构，来防止共享物体的不可控用法。正常情况下当当前线程正在等待的时候，解释器转换到另一个线程，通常是一个I/O的响应（像一个服务器的响应一样）。这允许在你的应用中有非阻塞I/O，因为每一个操作仅仅堵塞一个线程而不是堵塞整个服务器。然而，这也使得通常的多线程变得无用，因为它不允许你并发执行python代码，即使是在多核心的cpu上。同时在单线程中拥有非阻塞IO是完全有可能的，因而消除了经常切换上下文的需要。 + +实际上，你可以用纯python代码来实现一个单线程的非阻塞IO。你所需要的只是标准的[select][5]模块，这个模块可以让你写一个事件循环来等待未阻塞的socket的io。然而，这个方法需要你在一个地方定义所有app的逻辑，不久之后，你的app就会变成非常复杂的状态机。有一些框架可以简化这个任务，比较流行的是[tornade][6] 和 [twisted][7]。他们被用来使用回调方法实现复杂的协议（这和node.js比较相似）。这个框架运行在他自己的事件循环中，这个事件在定义的事件上调用你的回调。并且，这或许是一些情况的解决方案，但是它仍然需要使用回调的方式编程，这使你的代码碎片化。和写同步代码并且并发执行多个副本相比，就像我们会在普通的线程上做一样。这为什么在单个线程上是不可能的呢？ + +这就是为什么microthread出现的原因。这个想法是为了在一个线程上并发执行任务。当你在一个任务中调用阻塞的方法时，有一个叫做"manager" (或者“scheduler”)的东西在执行事件循环。当有一些事件准备处理的时候，一个manager会让等这个事件的“任务”单元去执行，直到自己停了下来。然后执行完之后就返回那个管理器（manager）。 + +>Microthreads are also called lightweight threads or green threads (a term which came from Java world). Tasks which are running concurrently in pseudo-threads are called tasklets, greenlets or coroutines.（Microthreads 也会被称为lightweight threads 或者 green threads（java中的一个术语）。在伪线程中并发执行的任务叫做tasklets，greenlets或者coroutines）. + +microthreads的其中一种实现在python中叫做[Stackless Python][8]。这个被用在了一个叫[EVE online][9]的非常有名的在线游戏中，所以它变得非常有名。这个MMO游戏自称说在一个持久的宇宙中，有上千个玩家在做不同的活动，这些都是实时发生的。Stackless 是一个单独的python解释器，它代替了标准的栈调用并且直接控制流来减少上下文切换的开销。尽管这非常有效，这个解决方案不如使用标准解释器的“soft”库有名。像[eventlet][10]和[gevent][11] 的方式配备了标准的I / O库的补丁的I / O功能在内部事件循环执行。这使得将正常的阻塞代码转变成非阻塞的代码变得简单。这种方法的一个缺点是从代码看这并不明显，这被称为非阻塞。Python的新的版本介绍了本地协同程序作为生成器的高级形式。在Python 的3.4版本中，引入了asyncio库，这个库依赖于本地协同程序来提供单线程并发。但是在Python 3.5 协同程序变成了Python语言的一部分，使用新的关键字 async 和 await 来描述。这是一个简单的例子，这表明了使用asyncio来运行 并发任务。 + +``` +import asyncio + +async def my_task(seconds): + print("start sleeping for {} seconds".format(seconds)) + await asyncio.sleep(seconds) + print("end sleeping for {} seconds".format(seconds)) + +all_tasks = asyncio.gather(my_task(1), my_task(2)) +loop = asyncio.get_event_loop() +loop.run_until_complete(all_tasks) +loop.close() +``` + +我们启动了两个任务，一个睡眠1秒钟，另一个睡眠2秒钟，输出如下： + +``` +start sleeping for 1 seconds +start sleeping for 2 seconds +end sleeping for 1 seconds +end sleeping for 2 seconds +``` + +正如你所看到的，协同程序不会阻塞彼此-----第二个任务在第一个结束之前启动。这发生的原因是asyncio.sleep是协同程序，它会返回一个调度器的执行直到时间过去。在下一节中， +我们将会使用coroutine-based的任务来创建一个游戏循环。 + +-------------------------------------------------------------------------------- + +via: https://7webpages.com/blog/writing-online-multiplayer-game-with-python-asyncio-getting-asynchronous/ + +作者：[Kyrylo Subbotin][a] +译者：[xinglianfly](https://github.com/xinglianfly) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://7webpages.com/blog/writing-online-multiplayer-game-with-python-asyncio-getting-asynchronous/ +[1]: http://snakepit-game.com/ +[2]: http://snakepit-game.com/ +[3]: https://docs.python.org/3/library/asyncio.html +[4]: https://docs.python.org/3/whatsnew/3.5.html#whatsnew-pep-492 +[5]: https://docs.python.org/2/library/select.html +[6]: http://www.tornadoweb.org/ +[7]: http://twistedmatrix.com/ +[8]: http://www.stackless.com/ +[9]: http://www.eveonline.com/ +[10]: http://eventlet.net/ +[11]: http://www.gevent.org/ diff --git a/translated/tech/20160601 Learn Python Control Flow and Loops to Write and Tune Shell Scripts – Part 2.md b/translated/tech/20160601 Learn Python Control Flow and Loops to Write and Tune Shell Scripts – Part 2.md new file mode 100644 index 0000000000..d7b6bf6c2e --- /dev/null +++ b/translated/tech/20160601 Learn Python Control Flow and Loops to Write and Tune Shell Scripts – Part 2.md @@ -0,0 +1,285 @@ +学习使用 python 控制流和循环来编写和执行 Shell 脚本 —— Part 2 +====================================================================================== + +在[Python series][1]之前的文章里，我们分享了 Python的一个简介，它的命令行 shell 和 IDLE（译者注：python 自带的一个IDE）。我们也演示了如何进行数值运算，如何用变量存储值，还有如何打印那些值到屏幕上。最后，我们通过一个练习示例讲解了面向对象编程中方法和属性概念。 + +![](http://www.tecmint.com/wp-content/uploads/2016/06/Write-Shell-Scripts-in-Python-Programming.png) +>在 Python 编程中写 Linux Shell 脚本 + +本篇中，我嫩会讨论控制流（根据用户输入的信息，计算的结果，或者一个变量的当前值选择不同的动作行为）和循环（自动重复执行任务），接着应用到我们目前所学东西中，编写一个简单的 shell 脚本，这个脚本会显示操作系统类型，主机名，内核发行版，版本号和机器硬件名字。 + +这个例子尽管很基础，但是会帮助我们证明，比起使用一些 bash 工具写 shell 脚本，我们可以使得用 Python OOP 的兼容特性来编写 shell 脚本会更简单些。 + +换句话说，我们想从这里出发 + +``` +# uname -snrvm +``` + +![](http://www.tecmint.com/wp-content/uploads/2016/05/Check-Hostname-of-Linux.png) +> 检查 Linux 的主机号 + +到 + +![](http://www.tecmint.com/wp-content/uploads/2016/05/Check-Linux-Hostname-Using-Python-Script.png) +> 用 Python 脚本来检查 Linux 的主机号 + +或者 + +![](http://www.tecmint.com/wp-content/uploads/2016/05/Script-to-Check-Linux-System-Information.png) +> 用脚本检查 Linux 系统信息 + +看着不错，不是吗？那我们就挽起袖子，开干吧。 + +### Python 中的控制流 + +如我们刚说那样，控制流允许我们根据一个给定的条件，选择不同的输出结果。在 Python 中最简单的实现就是一个 if/else 语句。 + +基本语法是这样的： + +``` +if condition: + # action 1 +else: + # action 2 +``` + +当 condition 求值为真（true），下面的代码块就会被执行（`# action 1`代表的部分）。否则，else 下面的代码就会运行。 +condition 可以是任何表达式，只要可以求得值为真或者假。 + +举个例子： + +1. 1 < 3 # 真 + +2. firstName == "Gabriel" # 对 firstName 为 Gabriel 的人是真，对其他不叫 Gabriel 的人为假 + + - 在第一个例子中，我们比较了两个值，判断 1 是否小于 3。 + - 在第二个例子中，我们比较了 firstName（一个变量）与字符串 “Gabriel”，看在当前执行的位置，firstName 的值是否等于该字符串。 + - 条件和 else 表达式都必须带着一个冒号（：）。 + - 缩进在 Python 非常重要。同样缩进下的行被认为是相同的代码块。 + +请注意，if/else 表达式只是 Python 中许多控制流工具的一个而已。我们先在这里了解以下，后面会用在我们的脚本中。你可以在[官方文档][2]中学到更多工具。 + +### Python 中的循环 + +简单来说，一个循环就是一组指令或者表达式序列，可以按顺序一直执行，只要一个条件为真，或者在一个列表里一次执行一个条目。 + +Python 中最简单的循环，就是 for 循环迭代一个给定列表的元素，或者一个字符串从第一个字符开始到最后一个字符结束。 + +基本语句： + +``` +for x in example: + # do this +``` + +这里的 example 可以是一个列表或者一个字符串。如果是列表，变量 x 就代表列表中每个元素；如果是字符串，x 就代表字符串中每个字符。 + +``` +>>> rockBands = [] +>>> rockBands.append("Roxette") +>>> rockBands.append("Guns N' Roses") +>>> rockBands.append("U2") +>>> for x in rockBands: + print(x) +or +>>> firstName = "Gabriel" +>>> for x in firstName: + print(x) +``` + +上面例子的输出如下图所示： + +![](http://www.tecmint.com/wp-content/uploads/2016/05/Learn-Loops-in-Python.png) +>学习 Python 中的循环 + +### Python 模块 + +很明显，必须有个途径可以保存一系列的 Python 指令和表达式到文件里，然后需要的时候再取出来。 + +准确来说模块就是这样的。特别地，os 模块提供了一个接口到操作系统的底层，允许我们做许多通常在命令行下的操作。 + +没错，os 模块包含了许多方法和属性，可以用来调用，就如我们之前文章里讲解的那样。尽管如此，我们需要使用 import 关键词导入（或者叫包含）模块到开发环境里来： + +``` +>>> import os +``` + +我们来打印出当前的工作目录： + +``` +>>> os.getcwd() +``` + +![](http://www.tecmint.com/wp-content/uploads/2016/05/Learn-Python-Modules.png) +>学习 Python 模块 + +现在，让我们把所有结合在一起（包括之前文章里讨论的概念），编写需要的脚本。 + +### Python 脚本 + +以一个声明开始一个脚本是个不错的想法，表明脚本的目的，发行所依据的证书，和一个修订历史列出所做的修改。尽管这主要是个人喜好，但这会让我们的工作看起来比较专业。 + +这里有个脚本，可以输出这篇文章最前面展示的那样。脚本做了大量的注释，为了让大家可以理解发生了什么。 + +在进行下一步之前，花点时间来理解它。注意，我们是如何使用一个 if/else 结构，判断每个字段标题的长度是否比字段本身的值还大。 + +基于这个结果，我们用空字符去填充一个字段标题和下一个之间的空格。同时，我们使用一定数量的短线作为字段标题与其值之间的分割符。 + +``` +#!/usr/bin/python3 +# Change the above line to #!/usr/bin/python if you don't have Python 3 installed + +# Script name: uname.py +# Purpose: Illustrate Python's OOP capabilities to write shell scripts more easily +# License: GPL v3 (http://www.gnu.org/licenses/gpl.html) + +# Copyright (C) 2016 Gabriel Alejandro Cánepa +# ​Facebook / Skype / G+ / Twitter / Github: gacanepa +# Email: gacanepa (at) gmail (dot) com + +# This program is free software: you can redistribute it and/or modify +# it under the terms of the GNU General Public License as published by +# the Free Software Foundation, either version 3 of the License, or +# (at your option) any later version. + +# This program is distributed in the hope that it will be useful, +# but WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +# GNU General Public License for more details. + +# You should have received a copy of the GNU General Public License +# along with this program. If not, see . + +# REVISION HISTORY +# DATE VERSION AUTHOR CHANGE DESCRIPTION +# ---------- ------- -------------- +# 2016-05-28 1.0 Gabriel Cánepa Initial version + +# Import the os module +import os + +# Assign the output of os.uname() to the the systemInfo variable +# os.uname() returns a 5-string tuple (sysname, nodename, release, version, machine) +# Documentation: https://docs.python.org/3.2/library/os.html#module-os +systemInfo = os.uname() + +# This is a fixed array with the desired captions in the script output +headers = ["Operating system","Hostname","Release","Version","Machine"] + +# Initial value of the index variable. It is used to define the +# index of both systemInfo and headers in each step of the iteration. +index = 0 + +# Initial value of the caption variable. +caption = "" + +# Initial value of the values variable +values = "" + +# Initial value of the separators variable +separators = "" + +# Start of the loop +for item in systemInfo: + if len(item) < len(headers[index]): + # A string containing dashes to the length of item[index] or headers[index] + # To repeat a character(s), enclose it within quotes followed + # by the star sign (*) and the desired number of times. + separators = separators + "-" * len(headers[index]) + " " + caption = caption + headers[index] + " " + values = values + systemInfo[index] + " " * (len(headers[index]) - len(item)) + " " + else: + separators = separators + "-" * len(item) + " " + caption = caption + headers[index] + " " * (len(item) - len(headers[index]) + 1) + values = values + item + " " + # Increment the value of index by 1 + index = index + 1 +# End of the loop + +# Print the variable named caption converted to uppercase +print(caption.upper()) + +# Print separators +print(separators) + +# Print values (items in systemInfo) +print(values) + +# INSTRUCTIONS: +# 1) Save the script as uname.py (or another name of your choosing) and give it execute permissions: +# chmod +x uname.py +# 2) Execute it: +# ./uname.py +``` + +如果你已经保存上面的脚本到一个文件里，给文件执行权限，并且运行它，像代码底部描述的那样： + +``` +# chmod +x uname.py +# ./uname.py +``` + +如果试图运行脚本时，你得到了如下的错误： + +``` +-bash: ./uname.py: /usr/bin/python3: bad interpreter: No such file or directory +``` + +这意味着你没有安装 Python3。如果那样的话，你要么安装 Python3 的包，要么替换解释器那行（如果你跟着下面的步骤去更新 Python 执行文件的软连接，如之前文章里概述的那样，要特别注意并且非常小心）： + +``` +#!/usr/bin/python3 +``` + +为 + +``` +#!/usr/bin/python +``` + +这样会导致使用安装好的 Python 2 版本去执行该脚本。 + +**注意**: 该脚本在 Python 2.x 与 Pyton 3.x 上都测试成功过了。 + +尽管比较粗糙，你可以认为该脚本就是一个 Python 模块。这意味着你可以在 IDLE 中打开它（File → Open… → Select file): + +![](http://www.tecmint.com/wp-content/uploads/2016/05/Open-Python-in-IDLE.png) +>在 IDLE 中打开 Python + +一个包含有文件内容的新窗口就会打开。然后执行 Run → Run module（或者按 F5）。脚本的输出就会在原 Shell 里显示出来： + +![](http://www.tecmint.com/wp-content/uploads/2016/05/Run-Python-Script.png) +>执行 Python 脚本 + +如果你想纯粹用 bash 写一个脚本，也获得同样的结果，你可能需要结合使用 [awk][3]，[sed][4]，并且借助复杂的方法来存储与获得列表中的元素（忘了提醒使用 tr 命令将小写字母转为大写） + +另外，Python 在所有的 Linux 系统版本中集成了至少一个 Python 版本（2.x 或者 3.x，或者两者都有）。你还需要依赖 shell 去完成同样的目标吗，那样你可能会为不同的 shell 编写不同的版本。 + +这里演示了面向对象编程的特性，会成为一个系统管理员得力的助手。 + +**注意**：你可以在我的 Github 仓库里获得 [这个 python 脚本][5]（或者其他的）。 + +### 总结 + +这篇文章里，我们讲解了 Python 中控制流，循环/迭代，和模块的概念。我们也演示了如何利用 Python 中 OOP 的方法和属性，来简化复杂的 shell 脚本。 + +你有任何其他希望去验证的想法吗？开始吧，写出自己的 Python 脚本，如果有任何问题可以咨询我们。不必犹豫，在分割线下面留下评论，我们会尽快回复你。 + +-------------------------------------------------------------------------------- + +via: http://www.tecmint.com/learn-python-programming-to-write-linux-shell-scripts/?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+tecmint+%28Tecmint%3A+Linux+Howto%27s+Guide%29 + +作者：[Gabriel Cánepa][a] +译者：[wi-cuckoo](https://github.com/wi-cuckoo) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: http://www.tecmint.com/author/gacanepa/ +[1]: http://www.tecmint.com/learn-python-programming-and-scripting-in-linux/ +[2]: http://please%20note%20that%20the%20if%20/%20else%20statement%20is%20only%20one%20of%20the%20many%20control%20flow%20tools%20available%20in%20Python.%20We%20reviewed%20it%20here%20since%20we%20will%20use%20it%20in%20our%20script%20later.%20You%20can%20learn%20more%20about%20the%20rest%20of%20the%20tools%20in%20the%20official%20docs. +[3]: http://www.tecmint.com/use-linux-awk-command-to-filter-text-string-in-files/ +[4]: http://www.tecmint.com/sed-command-to-create-edit-and-manipulate-files-in-linux/ +[5]: https://github.com/gacanepa/scripts/blob/master/python/uname.py + diff --git a/translated/tech/20160602 How to mount your Google Drive on Linux with google-drive-ocamlfuse.md b/translated/tech/20160602 How to mount your Google Drive on Linux with google-drive-ocamlfuse.md deleted file mode 100644 index b64fa51ab0..0000000000 --- a/translated/tech/20160602 How to mount your Google Drive on Linux with google-drive-ocamlfuse.md +++ /dev/null @@ -1,68 +0,0 @@ -教你用 google-drive-ocamlfuse 在 Linux 上挂载 Google Drive -===================== - ->如果你在找一个方便的方式在 Linux 机器上挂载你的 Google Drive 文件夹， Jack Wallen 将教你怎么使用 google-drive-ocamlfuse 来挂载 Google Drive。 - -![](http://tr4.cbsistatic.com/hub/i/2016/05/18/ee5d7b81-e5be-4b24-843d-d3ca99230a63/651be96ac8714698f8100afa6883e64d/linuxcloudhero.jpg) ->图片来源: Jack Wallen - -Google 还没有发行 Linux 版本的 Google Drive 应用，尽管现在有很多方法从 Linux 中访问你的 Drive 文件。 -（注：不清楚 app 需不需要翻译成应用，这里翻译了） - -如果你喜欢界面化的工具，你可以选择 Insync。如果你喜欢用命令行，这有很多工具，像 Grive2 和用 Ocaml 语言编写的、非常容易使用的、基于 FUSE 的系统（注：there are tools such as Grive2 and the incredibly easy to use FUSE-based system written in Ocaml. 这一句感觉翻译不出来）。我将会用后面这种方式演示如何在 Linux 桌面上挂载你的 Google Drive。尽管这是通过命令行完成的，但是它的用法会简单到让你吃惊。它太简单了以至于谁都能做到。 - -系统特点： - -- 对普通文件/文件夹有完全的读写权限 -- 对于 Google Docs，sheets，slides 这三个应用只读 -- 能够访问 Drive 回收站（.trash） -- 处理重复文件功能 -- 支持多个帐号 - -接下来完成 google-drive-ocamlfuse 在 Ubuntu 16.04 桌面的安装，然后你就能够访问云盘上的文件了。 - -### 安装 - -1. 打开终端。 -2. 用`sudo add-apt-repository ppa:alessandro-strada/ppa`命令添加必要的 PPA -3. 出现提示的时候，输入密码并按下回车。 -4. 用`sudo apt-get update`命令更新应用。 -5. 输入`sudo apt-get install google-drive-ocamlfuse`命令安装软件。 -（注：这里，我把所有的命令加上着重标记了） - -### 授权 - -接下来就是授权 google-drive-ocamlfuse，让它有权限访问你的 Google 账户。先回到终端窗口敲下命令 google-drive-ocamlfuse，这个命令将会打开一个浏览器窗口，它会提示你登陆你的 Google 帐号或者如果你已经登陆了 Google 帐号，它会询问是否允许 google-drive-ocamlfuse 访问 Google 账户。如果你还没有登陆，先登陆然后点击允许。接下来的窗口（在 Ubuntu 16.04 桌面上会出现，但不会出现在基本系统 Freya 桌面上）将会询问你是否授给 gdfuse 和 OAuth2 Endpoint访问你的 Google 账户的权限，再次点击允许。然后出现的窗口就会告诉你等待授权令牌下载完成，这个时候就能最小化浏览器了。当你的终端提示像图 A 一样的内容，你就能知道令牌下载完了，并且你已经可以挂载 Google Drive 了。 - -**图 A** - -![](http://tr4.cbsistatic.com/hub/i/r/2016/05/18/a493122b-445f-4aca-8974-5ec41192eede/resize/620x/6ae5907ad2c08dc7620b7afaaa9e389c/googledriveocamlfuse3.png) ->图片来源: Jack Wallen - -**应用已经得到授权，你可以进行后面的工作。** - -### 挂载 Google Drive - -在挂载 Google Drive 之前，你得先创建一个文件夹，作为挂载点。在终端里，敲下`mkdir ~/google-drive`命令在你的家目录下创建一个新的文件夹。最后敲下命令`google-drive-ocamlfuse ~/google-drive`将你的 Google Drive 挂载到 google-drive 文件夹中。 - -这时你可以查看本地 google-drive 文件夹中包含的 Google Drive 文件/文件夹。你能够把 Google Drive 当作本地文件系统来进行工作。 - -当你想 卸载 google-drive 文件夹，输入命令 `fusermount -u ~/google-drive`。 - -### 没有 GUI，但它特别好用 - -我发现这个特别的系统非常容易使用，在同步 Google Drive 时它出奇的快，并且这可以作为一种巧妙的方式备份你的 Google Drive 账户。 - -试试 google-drive-ocamlfuse，看看你能用它做出什么有趣的事。 - --------------------------------------------------------------------------------- - -via: http://www.techrepublic.com/article/how-to-mount-your-google-drive-on-linux-with-google-drive-ocamlfuse/ - -作者：[Jack Wallen ][a] -译者：[GitFuture](https://github.com/GitFuture) -校对：[校对者ID](https://github.com/校对者ID) - -本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 - -[a]: http://www.techrepublic.com/search/?a=jack+wallen diff --git a/translated/tech/20160605 How to Add Cron Jobs in Linux and Unix.md b/translated/tech/20160605 How to Add Cron Jobs in Linux and Unix.md deleted file mode 100644 index d445be5b51..0000000000 --- a/translated/tech/20160605 How to Add Cron Jobs in Linux and Unix.md +++ /dev/null @@ -1,173 +0,0 @@ -如何在 Linux 及 Unix 系统中添加 cron 任务 -====================================== - -![](https://www.unixmen.com/wp-content/uploads/2016/05/HOW-TO-ADD-CRON-JOBS-IN-LINUX-AND-UNIX-696x334.png) - -### 导言 - -![](http://www.unixmen.com/wp-content/uploads/2016/05/cronjob.gif) - -定时任务 (Cron job) 被用于安排那些需要被周期性执行的命令。利用它，你可以配置某些命令或者脚本，让它们在某个设定的时间周期性地运行。`Cron` 是 Linux 或者类 Unix 系统中最为实用的工具之一。cron 服务（守护进程）在系统后台运行，并且会持续地检查 `/etc/crontab` 文件和 `/etc/cron.*/ `目录。它同样也会检测 `/var/spool/cron/` 目录。 - -### crontab 命令 - -`crontab` 是用来安装、卸载或者列出 cron 配置文件列表的命令。cron 配置文件则用于驱动 `Vixie Cron` 的 [cron(8)][1] 守护进程。每个用户都可以拥有自己的 crontab 文件，虽然这些文件都位于 `/var/spool/cron/crontabs` 目录中，但并不意味着你可以直接编辑它们。你需要通过 `crontab` 命令来编辑或者配置你自己的定时任务。 - -### 定时配置文件的类型 - -配置文件分为以下不同的类型： - -- **UNIX 或 Linux 系统的 crontab** : 此类型通常由那些需要 root 或类似权限的系统服务和重要任务使用。第六个字段（见下方的字段介绍）为用户名，用来指定此命令以哪个用户身份来执行。如此一来，系统的 `crontab` 就能够以任意用户的身份来执行操作。 - -- **用户的 crontabs**: 用户可以使用 `corntab` 命令来安装属于他们自己的定时任务。 第六个字段为需要运行的命令, 所有的命令都会以创建该 crontab 任务的用户的身份运行。 - -**注意**: 这种问答形式的 `Cron` 实现由 Paul Vixie 所写，并且被包含在许多 [Linux][2] 发行版和类 Unix 系统（如广受欢迎的第四版 BSD）中。它的语法被各种 crond 的实现所[兼容][3]。 - -那么我该如何安装、创建或者编辑我自己的定时任务呢？ - -要编辑你的 crontab 文件，需要在 Linux 或 Unix 的 shell 提示符后键入以下命令： - -``` -$ crontab -e -``` - -`crontab` 语法（字段介绍） - -语法为： - -``` -1 2 3 4 5 /path/to/command arg1 arg2 -``` - -或者 - -``` -1 2 3 4 5 /root/ntp_sync.sh -``` - -其中： - -- 1: 分钟 (0-59) -- 2: 小时 (0-23) -- 3: 日期 (0-31) -- 4: 月份 (0-12 [12 代表 December]) -- 5: 一周当中的某天 (0-7 [7 或 0 代表星期天]) -- /path/to/command – 计划执行的脚本或命令的名称 - -便于记忆的格式： - -``` -* * * * * command to be executed -– – – – – -| | | | | -| | | | —– 一周当中的某天 (0 – 7) (周日为 0 或 7) -| | | ——- 月份 (1 – 12) -| | ——— 一月当中的某天 (1 – 31) -| ———– 小时 (0 – 23) -————- 分钟 (0 – 59) -``` - -简单的 `crontab` 示例： - -```` -## 每隔 5 分钟运行一次 backupscript 脚本 ## -*/5 * * * * /root/backupscript.sh - -## 每天的凌晨 1 点运行 backupscript 脚本 ## - -0 1 * * * /root/backupscript.sh - -## 每月的第一个凌晨 3:15 运行 backupscript 脚本 ## - -15 3 1 * * /root/backupscript.sh -``` - -### 如何使用操作符 - -操作符允许你为一个字段指定多个值，这里有三个操作符可供使用： - -- **星号 (*)** : 此操作符为字段指定所有可用的值。举个例子，在小时字段中，一个星号等同于每个小时；在月份字段中，一个星号则等同于每月。 - -- **逗号 (,)** : 这个操作符指定了一个包含多个值的列表，例如：`1,5,10,15,20,25`. - -- **横杠 (–)** : 此操作符指定了一个值的范围，例如：`5-15` ，等同于使用逗号操作符键入的 `5,6,7,8,9,….,13,14,15`。 - -- **分隔符 (/)** : 此操作符指定了一个步进值，例如： `0-23/` 可以用于小时字段来指定某个命令每小时被执行一次。步进值也可以跟在星号操作符后边，如果你希望命令行每 2 小时执行一次，则可以使用 `*/2`。 - -### 使用特殊字符节省时间 - -你可以使用以下 8 个特殊字符中的其中一个替代头五个字段，这样不但可以节省你的时间，还可以提高可读性。 - -特殊字符 | 含义 -|:-- |:-- -@reboot | 在每次启动时运行一次 -@yearly | 每年运行一次, “0 0 1 1 *”. -@annually | (同 @yearly) -@monthly | 每月运行一次, “0 0 1 * *”. -@weekly | 每周运行一次, “0 0 * * 0”. -@daily | 每天运行一次, “0 0 * * *”. -@midnight | (同 @daily) -@hourly | 每小时运行一次, “0 * * * *”. - -示例： - -#### 每小时运行一次 ntpdate 命令 #### - -``` -@hourly /path/to/ntpdate -``` - -### 关于 `/etc/crontab` 文件和 `/etc/cron.d/*` 目录的更多内容 - -** /etc/crontab ** 是系统的 corntabs 文件。通常只被 root 用户或守护进程用于配置系统级别的任务。每个独立的用户必须像上面介绍的那样使用 `corntab` 命令来安装和编辑自己的任务。`/var/spool/cron/` 或者 `/var/cron/tabs/` 目录存放了个人用户的 corntab 文件，它必定会备份在用户的家目录当中。 - -###　理解默认的 `/etc/crontab` - -典型的 `/etc/crontab` 文件内容是这样的： - -``` -SHELL=/bin/bash -PATH=/sbin:/bin:/usr/sbin:/usr/bin -MAILTO=root -HOME=/ -# run-parts -01 * * * * root run-parts /etc/cron.hourly -02 4 * * * root run-parts /etc/cron.daily -22 4 * * 0 root run-parts /etc/cron.weekly -42 4 1 * * root run-parts /etc/cron.monthly -``` - -首先，环境变量必须被定义。如果 shell 行被忽略，corn 会使用默认的 sh shell。如果 PATH 变量被忽略，就没有默认路径会被使用，所有的文件都需要使用绝对路径来定位。如果 HOME 变量被忽略，corn 会使用调用者（用户）的家目录。 - -另外，corn 会读取 `/etc/cron.d/`目录中的文件。通常情况下，像 sa-update 或者 sysstat 这样的系统守护进程会将他们的定时任务存放在此处。作为 root 用户或者超级用户，你可以使用以下目录来配置你的定时任务。你可以直接将脚本放到这里。`run-parts`命令会通过 `/etc/crontab` 文件来运行位于某个目录中的脚本或者程序。 - -目录 |描述 -|:-- |:-- -/etc/cron.d/ | 将所有的脚本文件放在此处，并从 /etc/crontab 文件中调用它们。 -/etc/cron.daily/ | 运行需要每天运行一次的脚本 -/etc/cron.hourly/ | 运行需要每小时运行一次的脚本 -/etc/cron.monthly/ | 运行需要每月运行一次的脚本 -/etc/cron.weekly/ | 运行需要每周运行一次的脚本 - -### 备份定时任务 - -``` -# crontab -l > /path/to/file - -# crontab -u user -l > /path/to/file -``` - --------------------------------------------------------------------------------- - -via: https://www.unixmen.com/add-cron-jobs-linux-unix/?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+unixmenhowtos+%28Unixmen+Howtos+%26+Tutorials%29 - -作者：[Duy NguyenViet][a] -译者：[mr-ping](https://github.com/mr-ping) -校对：[FSSlc](https://github.com/FSSlc) - -本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 - -[a]: https://www.unixmen.com/author/duynv/ -[1]: http://www.manpager.com/linux/man8/cron.8.html -[2]: http://www.linuxsecrets.com/ -[3]: http://www.linuxsecrets.com/linux-hardware/ diff --git a/translated/tech/20160611 vlock – A Smart Way to Lock User Virtual Console or Terminal in Linux.md b/translated/tech/20160611 vlock – A Smart Way to Lock User Virtual Console or Terminal in Linux.md deleted file mode 100644 index 26c74b019e..0000000000 --- a/translated/tech/20160611 vlock – A Smart Way to Lock User Virtual Console or Terminal in Linux.md +++ /dev/null @@ -1,99 +0,0 @@ -vlock – 一个锁定 Linux 用户虚拟控制台或终端的好方法 -======================================================================= - -虚拟控制台是 Linux 非常重要的功能，他们为使用系统的用户提供了 shell 提示符，以保证用户在登录和远程登录一个未安装图形界面的系统时仍能使用。 - -一个用户可以同时操作多个虚拟控制台会话，只需在虚拟控制台间来回切换即可。 - -![](http://www.tecmint.com/wp-content/uploads/2016/05/vlock-Lock-User-Terminal-in-Linux.png) ->用 vlock 锁定 Linux 用户控制台或终端 - -这篇使用指导，旨在教会大家如何使用 vlock 来锁定用户虚拟控制台和终端。 - -### vlock 是什么？ - -vlock 是一个用于锁定一个或多个用户虚拟控制台用户会话的工具。在多用户系统中 vlock 是扮演着重要的角色，他让用户可以在锁住自己会话的同时不影响其他用户通过其他虚拟控制台操作同一个系统。必要时，还可以锁定所有的控制台，同时禁止在虚拟控制台间切换。 - -vlock 的主要功能面向控制台会话方面，同时也支持非控制台会话的锁定，但该功能的测试还不完全。 - -### 在 Linux 上安装 vlock - -根据你的 Linux 系统选择 vlock 安装指令： - -``` -# yum install vlock [On RHEL / CentOS / Fedora] -$ sudo apt-get install vlock [On Ubuntu / Debian / Mint] -``` - -### 在 Linux 上使用 vlock - -vlock 操作选项的常规语法： - -``` -# vlock option -# vlock option plugin -# vlock option -t plugin -``` - -#### vlock 常用选项及用法： - -1. 锁定用户的当前虚拟控制台或终端会话，如下： - - ``` - # vlock --current - ``` - - ![](http://www.tecmint.com/wp-content/uploads/2016/05/Lock-User-Terminal-Session-in-Linux.png) - >锁定 Linux 用户终端会话 - - 选项 -c 或 --current，锁定当前的会话，该参数为运行 vlock 时的默认行为。 - -2. 锁定所有你的虚拟控制台会话，并禁用虚拟控制台间切换，命令如下： - - ``` - # vlock --all - ``` - - ![](http://www.tecmint.com/wp-content/uploads/2016/05/Lock-All-Linux-Terminal-Sessions.png) - >锁定所有 Linux 终端会话 - - 选项 -a 或 --all，锁定所有用户的控制台会话，并禁用虚拟控制台间切换。 - - 其他的选项只有在编译 vlock 时编入了相关插件支持及其引用后，才能发挥作用： - -3. 选项 -n 或 --new，调用时后，会在锁定用户的控制台会话前切换到一个新的虚拟控制台。 - - ``` - # vlock --new - ``` - -4. 选项 -s 或 --disable-sysrq，在禁用虚拟控制台的同时禁用 SysRq 功能，只有在与 -a 或 --all 同时使用时才起作用。 - - ``` - # vlock -sa - ``` - -5. 选项 -t 或 --timeout ，用以设定屏幕保护插件的 timeout 值。 - - ``` - # vlock --timeout 5 - ``` - -你可以使用 `-h` 或 `--help` 和 `-v` 或 `--version` 分别查看帮助消息和版本信息。 - -我们的介绍就到这了，提示一点，你可以将 vlock 的 `~/.vlockrc` 文件包含到系统启动中并参考入门手册[添加环境变量][1]，特别是 Debian 系的用户。 - -想要找到更多或是补充一些这里没有提及的信息，可以直接在写在下方评论区。 - --------------------------------------------------------------------------------- - -via: http://www.tecmint.com/vlock-lock-user-virtual-console-terminal-linux/?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+tecmint+%28Tecmint%3A+Linux+Howto%27s+Guide%29 - -作者：[Aaron Kili][a] -译者：[martin2011qi](https://github.com/martin2011qi) -校对：[校对者ID](https://github.com/校对者ID) - -本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 - -[a]: http://www.tecmint.com/author/aaronkili/ -[1]: http://www.tecmint.com/set-path-variable-linux-permanently/ diff --git a/translated/tech/20160616 10 Basic Linux Commands That Every Linux Newbies Should Remember.md b/translated/tech/20160616 10 Basic Linux Commands That Every Linux Newbies Should Remember.md deleted file mode 100644 index c69b7a6e54..0000000000 --- a/translated/tech/20160616 10 Basic Linux Commands That Every Linux Newbies Should Remember.md +++ /dev/null @@ -1,141 +0,0 @@ -Linux新手必知必会的10条Linux基本命令 -===================================================================== - -![](http://www.linuxandubuntu.com/uploads/2/1/1/5/21152474/4225072_orig.png) - - -[Linux][1]对我们的生活产生了巨大的冲击。至少你的安卓手机使用的就是Linux核心。尽管如此，在第一次开始使用Linux时你还是会感到难以下手。因为在Linux中，通常需要使用终端命令来取代Windows系统中的点击启动图标操作。但是不必担心，这里我们会介绍10个Linux基本命令来帮助你开启Linux神秘之旅。 - - -### 帮助新手走出第一步的10个Linux基本命令 - -当我们谈论Linux命令时，实质上是在谈论Linux系统本身。这短短的10个Linux基本命令不会让你变成天才或者Linux专家，但是能帮助你轻松开始Linux之旅。使用这些基本命令会帮助新手们完成Linux的日常任务，由于它们的使用频率如此至高，所以我更乐意称他们为Linux命令之王！ - -让我们开始学习这10条Linux基本命令吧。 - - -#### 1. sudo - -这条命令的意思是“以超级用户的身份执行”，是 SuperUserDo 的简写，它是新手将要用到的最重要的一条Linux命令。当一条单行命令需要root权限的时候，`sudo`命令就派上用场了。你可以在每一条需要root权限的命令前都加上`sudo`。 - -``` -$ sudo su -``` - - -#### 2. ls (list) - - -跟其他人一样，你肯定也经常想看看目录下都有些什么东西。使用列表命令，终端会把当前工作目录下所有的文件以及文件夹展示给你。比如说，我当前处在 /home 文件夹中，我想看看 /home文件夹中都有哪些文件和目录。 - -``` -/home$ ls -``` - - -在/home中执行`ls`命令将会返回以下内容 - -``` -imad lost+found -``` - - -#### 3. cd - -变更目录命令（cd）是终端中总会被用到的主要命令。他是最常用到的Linux基本命令之一。此命令使用非常简单，当你打算从当前目录跳转至某个文件夹时，只需要将文件夹键入此命令之后即可。如果你想跳转至上层目录，只需要在此命令之后键入两个点(..)就可以了。 -​ -举个例子，我现在处在/home目录中，我想移动到/home目录中的usr文件夹下，可以通过以下命令来完成操作。 - -``` -/home $ cd usr - -/home/usr $ -``` - - -#### 4. mkdir - -只是可以切换目录还是不够完美。有时候你会想要新建一个文件夹或子文件夹。此时可以使用mkdir命令来完成操作。使用方法很简单，只需要把新的文件夹名跟在mkdir命令之后就好了。 - -``` -~$ mkdir folderName -``` - - -#### 5. cp - -拷贝-粘贴（copy-and-paste）是我们组织文件需要用到的重要命令。使用 `cp` 命令可以帮助你在终端当中完成拷贝-粘贴操作。首先确定你想要拷贝的文件，然后键入打算粘贴此文件的目标位置。 - -``` -$ cp src des -``` - -注意：如果目标目录对新建文件需要root权限时，你可以使用`sudo`命令来完成文件拷贝操作。 - - -#### 6. rm - -rm命令可以帮助你移除文件甚至目录。如果文件需要root权限才能移除，可以用`-f`参数来强制执行。也可以使用`-r`参数来递归的移除文件夹。 - -``` -$ rm myfile.txt -``` - - -#### 7. apt-get - -这个命令会依据发行版的不同而有所区别。在基于Debian的发行版中，我们拥有Advanced Packaging Tool（APT）包管理工具来安装、移除和升级包。apt-get命令会帮助你安装需要在Linux系统中运行的软件。它是一个功能强大的命令行，可以用来帮助你对软件执行安装、升级和移除操作。 - -在其他发行版中，例如Fedora、Centos，都各自不同的包管理工具。Fedora之前使用的是yum，不过现在dnf成了它默认的包管理工具。 - -``` -$ sudo apt-get update - -$ sudo dnf update -``` - - -#### 8. grep - -当你需要查找一个文件，但是又忘记了它具体的位置和路径时，`grep`命令会帮助你解决这个难题。你可以提供文件的关键字，使用`grep`命令来查找到它。 - -``` -$ grep user /etc/passwd -``` - - -#### 9. cat - -作为一个用户，你应该会经常需要浏览脚本内的文本或者代码。`cat`命令是Linux系统的基本命令之一，它的用途就是将文件的内容展示给你。 - -``` -$ cat CMakeLists.txt -``` - - -#### 10. poweroff - -最后一个命令是 `poweroff`。有时你需要直接在终端中执行关机操作。此命令可以完成这个任务。由于关机操作需要root权限，所以别忘了在此命令之前添加`sudo`。 - -``` -$ sudo poweroff -``` - - -### 总结 - -如我在文章开始所言，这10条命令并不会让你立即成为一个Linux大拿。它们会让你在初期快速上手Linux。以这些命令为基础，给自己设置一个目标，每天学习一到三条命令，这就是此文的目的所在。在下方评论区分享有趣并且有用的命令。别忘了跟你的朋友分享此文。 - - --------------------------------------------------------------------------------- - -via: http://www.linuxandubuntu.com/home/10-basic-linux-commands-that-every-linux-newbies-should-remember - -作者：[Commenti][a] -译者：[mr-ping](https://github.com/mr-ping) -校对：[校对者ID](https://github.com/校对者ID) - -本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 - -[a]: http://www.linuxandubuntu.com/home/10-basic-linux-commands-that-every-linux-newbies-should-remember#comments -[1]: http://linuxandubuntu.com/home/category/linux diff --git a/translated/tech/20160620 PowerPC gains an Android 4.4 port with Big Endian support.md b/translated/tech/20160620 PowerPC gains an Android 4.4 port with Big Endian support.md deleted file mode 100644 index 3b450cb603..0000000000 --- a/translated/tech/20160620 PowerPC gains an Android 4.4 port with Big Endian support.md +++ /dev/null @@ -1,103 +0,0 @@ -PowerPC 获得大端 Android 4.4 系统的移植 -=========================================================== - -eInfochips（一家软件厂商） 已将将 Android 4.4 系统移植到 PowerPC 架构，它将作为一家航空电子客户的人机界面（HMI:Human Machine Interface）用来监视引擎的建康状况。 - -eInfochips 已经开发了第一个面向 PowerPC 架构的 CPU 的 Android 移植版本，它使用较新的大端 Android 系统。此移植基于 Android 开源项目[Android Open Source Project (AOSP)] 中 Android 4.4 (KitKat) 的代码，其功能内核的版本号为 3.12.19。 - -Android 开始兴起的时候，PowerPC正在快速失去和 ARM 架构共通角逐的市场。高端的网络客户和以市场为导向的嵌入式工具大多运行在诸如飞思卡尔（Freescale）的 PowerQUICC 和 QorIQ 上，而不取决于 Linux 系统。一些 Android 的移植计划最终失败，然而在 2009 年，飞思卡尔和 Embedded Alley（一家软件厂商，当前是 Mentor Graphics 的 Linux 团队的一部分）[宣布了针对 PowerQUICC 和 QorIQ 芯片的移植版本][15]，当前由 NXP 公司构建。另一个名为[Android-PowerPC][16] 的项目也作出了相似的工作。 - -这些努力来的都并不容易，然而，当航空公司找到 eInfochips，希望能够为他们那些基于 PowerPC 的引擎监控系统添加 Android 应用程序以改善人机界面。此公司找出了这些早期的移植版本，然而，他们都很难达到标准。所以，他们不得不从头开始新的移植。 - -最主要的问题是这些移植的 Android 版本实在是太老了，且 very different。Embedded Alley 移植的版本为 Android 1.5 (Cupcake)，它于 2009 年发布，Linux 内核版本为 2.6.28。最后一版的移植为 Android-PowerPC 项目的 Android 2.2 (Froyo)它于 2010 年发布，内核版本为 2.6.32。此外，航空公司还有一些额外的技术诉求，例如对大端的支持. 现有的存储器接入方案仍旧应用于网络通信和电信行业。然而那些早期的移植版本仅能够支持小端的存储器访问。 - -### 来自 eInfochips 的全新 PowerPC 架构移植 - -eInfochips, 它最为出名的应该是那些基于 ARM/骁龙处理器的模块计算机板卡，例如 [Eragon 600][17]。 它已经完成了基于 QorIQ 的 Android 4.4 系统移植，且发布了白皮书描述了此项目。采用该项目的航空电子设备客户仍旧不愿透露姓名，目前仍旧不清楚什么时候会公开此该移植版本。 - - -![](http://hackerboards.com/files/einfochips_porting_android_on_powerpc-sm.jpg) ->图片来自 eInfochips 的博客日志 - -- 全新的 PowerPC Android 项目包括： -- 基于 PowerPC [e5500][1] 深度定制（bionic 定制不知道什么鬼，校对的时候也可以想想怎么处理） -- 基于 Android KitKat 的大端序支持 -- 开发工具链为 Gcc 5.2 -- Android 4.4 框架的 PowerPC 支持 -- PowerPC e5500 的 Android 内核版本为 3.12.19 - -根据 eInfochips 的销售经理 Sooryanarayanan Balasubramanian 描述，航空电子客户想要使用 Android 主要是因为熟悉的界面能够缩减培训的时间，并且让程序更新和提供新的程序变得更加容易。他继续解释说：“这次成功的移植了 Android，使得今后的工作仅仅需要在应用层作出修修改改，而不再向以前一样需要在所有层之间作相互的校验。”“这是第一次在航空航天工业作出这些尝试，这需要在设计时作出尽职的调查。” - -通过白皮书，可以知道将 Android 移植到 PowerPC 上需要对框架，核心库，开发工具链，运行时链接器，对象链接器和开源编译工具作出大量的修改。在字节码生成阶段，移植团队决定使用便携模式而不是快速的解释模式。这是因为，还没有 PowerPC 可用的快速解释模式，而使用 [libffi][18] 的便携模式能够支持 PowerPC。 - -同时，团队还面临在 Android 运行时 (ART) 环境和 Dalvik 虚拟机 (DVM) 环境之间的选择。他们发现，ART 环境下的便携模式还未经测试且缺乏良好的文档支持，所以最终选择了 DVM 环境下的便携模式。 - -白皮书中还提及了其它的一些在移植过程中遇到的困难，包括重新开发工具链，重写脚本以解决 AOSP “非标准”的使用编译器标志的问题。最终，移植提供了 37 个服务，and features a headless Android deployment along with an emulated UI in user space. - - -### 目标硬件 - -感谢来自 [eInfochips 博客日志][2] 的图片（如下图所示），我们能够确认此 PowerPC 的 Android 移植项目的硬件平台。这个板卡为 [X-ES Xpedite 6101][3]，它是固实的 XMC/PrPMC 夹层模组。 - -![](http://hackerboards.com/files/xes_xpedite6101-sm.jpg) ->X-ES Xpedite 6101 照片和框图 - -X-ES Xpedite 6101 板卡拥有可选择的 NXP 公司基于 QorIQ T系列通信处理器 T2081, T1042, 和 T1022，他们分别拥有 8 个，4 个和 2 个 e6500 核心，稍有不同的是，T2081 的处理器主频为 1.8GHz，T1042/22 的处理器主频为 1.4GHz。所有的核心都集成了 AltiVec SIMD 引擎，这也就意味着它能够提供 DSP 级别的浮点运算性能。所有以上 3 款 X-ES 板卡都能够支持最高 8GB 的 DDR3-1600 ECC SDRAM 内存。外加 512MB NOR 和 32GB 的 NAND 闪存。 - -![](http://hackerboards.com/files/nxp_qoriq_t2081_block-sm.jpg) ->NXP T2081 框图 - -板卡的 I/O 包括一个 x4 PCI Express Gen2 通到，along with dual helpings of Gigabit Ethernet, RS232/422/485 串口和 SATA 3.0 接口。此外，它可选 3 款 QorIQ 处理器，Xpedite 6101 提供了三种[X-ES 加固等级][19]，分别是额定工作温度 0 ~ 55°C, -40 ~ 70°C, 或者是 -40 ~ 85°C，且包含 3 类冲击和抗振类别。 - -此外，我们已经介绍过的基于 X-ES QorIQ 的 XMC/PrPMC 板卡包括[XPedite6401 和 XPedite6370][20]，它们支持已有的板卡级 Linux Linux，Wind River VxWorks（一种实时操作系统） 和 Green Hills Integrity（也是一种操作系统）。 - - -### 更多信息 - -eInfochips Android PowerPC 移植白皮书可以[在此[4]下载(需要先免费注册)。 - -### Related posts: - -- [Commercial embedded Linux distro boosts virtualization][5] -- [Freescale unveils first ARM-based QorIQ SoCs][6] -- [High-end boards run Linux on 64-bit ARM QorIQ SoCs][7] -- [Free, Open Enea Linux taps Yocto Project and Linaro code][8] -- [LynuxWorks reverts to its LynxOS roots, changes name][9] -- [First quad- and octa-core QorIQ SoCs unveiled][10] -- [Free white paper shows how Linux won embedded][11] -- [Quad-core Snapdragon COM offers three dev kit options][12] -- [Tiny COM runs Linux on quad-core 64-bit Snapdragon 410][13] -- [PowerPC based IoT gateway COM ships with Linux BSP][14] - - --------------------------------------------------------------------------------- - -via: http://hackerboards.com/powerpc-gains-android-4-4-port-with-big-endian-support/ - -作者：[Eric Brown][a] -译者：[dongfengweixiao](https://github.com/dongfengweixiao) -校对：[校对者ID](https://github.com/校对者ID) - -本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 - -[a]: http://hackerboards.com/powerpc-gains-android-4-4-port-with-big-endian-support/ -[1]: http://linuxdevices.linuxgizmos.com/low-cost-powerquicc-chips-offer-flexible-interconnect-options/ -[2]: https://www.einfochips.com/blog/k2-categories/aerospace/presenting-a-case-for-porting-android-on-powerpc-architecture.html -[3]: http://www.xes-inc.com/products/processor-mezzanines/xpedite6101/ -[4]: http://biz.einfochips.com/portingandroidonpowerpc -[5]: http://hackerboards.com/commercial-embedded-linux-distro-boosts-virtualization/ -[6]: http://hackerboards.com/freescale-unveils-first-arm-based-qoriq-socs/ -[7]: http://hackerboards.com/high-end-boards-run-linux-on-64-bit-arm-qoriq-socs/ -[8]: http://hackerboards.com/free-open-enea-linux-taps-yocto-and-linaro-code/ -[9]: http://hackerboards.com/lynuxworks-reverts-to-its-lynxos-roots-changes-name/ -[10]: http://hackerboards.com/first-quad-and-octa-core-qoriq-socs-unveiled/ -[11]: http://hackerboards.com/free-white-paper-shows-how-linux-won-embedded/ -[12]: http://hackerboards.com/quad-core-snapdragon-com-offers-three-dev-kit-options/ -[13]: http://hackerboards.com/tiny-com-runs-linux-and-android-on-quad-core-64-bit-snapdragon-410/ -[14]: http://hackerboards.com/powerpc-based-iot-gateway-com-ships-with-linux-bsp/ -[15]: http://linuxdevices.linuxgizmos.com/android-ported-to-powerpc/ -[16]: http://www.androidppc.com/ -[17]: http://hackerboards.com/quad-core-snapdragon-com-offers-three-dev-kit-options/ -[18]: https://sourceware.org/libffi/ -[19]: http://www.xes-inc.com/capabilities/ruggedization/ -[20]: http://hackerboards.com/high-end-boards-run-linux-on-64-bit-arm-qoriq-socs/ diff --git a/translated/tech/20160623 Advanced Image Processing with Python.md b/translated/tech/20160623 Advanced Image Processing with Python.md new file mode 100644 index 0000000000..73f8751225 --- /dev/null +++ b/translated/tech/20160623 Advanced Image Processing with Python.md @@ -0,0 +1,124 @@ +Python高级图像处理 +====================================== + +![](http://www.cuelogic.com/blog/wp-content/uploads/2016/06/Image-Search-Engine.png) + +构建图像搜索引擎并不是一件容易的任务。这里有几个概念、工具、想法和技术需要实现。主要的图像处理概念之一是逆图像查询(RIQ)或者说逆图像搜索。Google、Cloudera、Sumo Logic 和 Birst等公司在使用逆图像搜索中名列前茅。通过分析图像和使用数据挖掘RIQ提供了很好的洞察分析能力。 + +### 顶级公司与逆图像搜索 + +有很多顶级的技术公司使用RIQ来产生最好的收益。例如：在2014年Pinterest第一次带来了视觉搜索。随后在2015年发布了一份白皮书，揭示了其架构。逆图像搜索让Pinterest获得对时尚对象的视觉特征和显示类似的产品建议的能力。 + +众所周知，谷歌图片使用逆图像搜索允许用户上传一张图片然后搜索相关联的图片。通过使用先进的算法对提交的图片进行分析和数学建模。然后和谷歌数据库中无数的其他图片进行比较得到相似的结果。 + +**这是opencv 2.4.9特征比较报告一个图表：** + +![](http://www.cuelogic.com/blog/wp-content/uploads/2016/06/search-engine-graph.jpg) + +### 算法 & Python库 + +在我们使用它工作之前，让我们过一遍构建图像搜索引擎的Python库的主要元素： + +### 专利算法 + +#### 尺度不变特征变换算法（SIFT - Scale-Invariant Feature Transform） + +1. 非自由功能的一个专利技术，利用图像识别符，以识别相似图像，甚至那些从不同的角度，大小，深度和规模点击，它们被包括在搜索结果中。[点击这里][4]查看SIFT详细视频。 +2. SIFT能与从许多图片中提取的特征的大型数据库正确的匹配搜索条件。 +3. 从不同的方面来匹配相同的图像和匹配不变特征来获得搜索结果是SIFT的另一个特征。了解更多关于尺度不变[关键点][5] + +#### 加速鲁棒特征(SURF - Speeded Up Robust Features)算法 + +1. [SURF][1] 也是一种非自由功能的专利技术而且还是一种“加速”的SIFT版本。不像SIFT， + +2. SURF依赖于Hessian矩阵行列式的位置和尺度。 + +3. 在许多应用中，旋转不变性是不是一个必要条件。所以找不到这个方向的速度加快了这个过程。 + +4. SURF包括几种特性，在每一步的速度提高。比SIFT快三倍的速度，SIFT擅长旋转和模糊化。然而它不擅长处理照明和变换视角。 + +5. Open CV，一个程序功能库提供SURF相似的功能，SURF.compute()和SURF.Detect()可以用来找到描述符和要点。阅读更多关于SURF[点击这里][2] + +### 开源算法 + +#### KAZE 算法 + +1. KAZE是一个开源的非线性尺度空间的二维多尺度和新的特征检测和描述算法。在加性算子分裂的有效技术（AOS）和可变电导扩散是用来建立非线性尺度空间。 + +2. 多尺度图像处理基础是简单的创建一个图像的尺度空间，同时用正确的函数过滤原始图像，提高时间或规模。 + +#### AKAZE (Accelerated-KAZE) 算法 + +1. 顾名思义，这是一个更快的图像搜索方式，找到匹配的关键点在两幅图像之间。AKAZE 使用二进制描述符和非线性尺度空间来平衡精度和速度。 + +#### BRISK (Binary Robust Invariant Scalable Keypoints) 算法 + +1. BRISK 非常适合描述关键点的检测与匹配。 + +2. 是一种高度自适应的算法，基于尺度空间的快速检测器和一个位字符串描述符，有助于加快搜索显着。 + +3. 尺度空间关键点检测与关键点描述帮助优化手头相关任务的性能 + +#### FREAK (Fast Retina Keypoint) + +1. 这个新的关键点描述的灵感来自人的眼睛。通过图像强度比能有效地计算一个二进制串级联。FREAK算法相比BRISK，SURF和SIFT算法有更快的计算与较低的内存负载。 + +#### ORB (Oriented FAST and Rotated BRIEF) + +1. 快速的二进制描述符，ORB具有抗噪声和旋转不变性。ORB建立在FAST关键点检测器和BRIEF描述符之上，有成本低、性能好的元素属性。 + +2. 除了快速和精确的定位元件，有效地计算定向的BRIEF，分析变动和面向BRIEF特点相关，是另一个ORB的特征。 + +### Python库 + +#### Open CV + +1. Open CV提供学术和商业用途。一个开源的机器学习和计算机视觉库，OpenCV便于组织利用和修改代码。 + +2. 超过2500个优化算法，包括国家最先进的机器学习和计算机视觉算法服务与各种图像搜索--人脸检测、目标识别、摄像机目标跟踪，从图像数据库中寻找类似图像、眼球运动跟随、风景识别等。 + +3. 像谷歌，IBM，雅虎，IBM，索尼，本田，微软和英特尔这样的大公司广泛的使用OpenCV。 + +4. OpenCV拥有python，java，C，C++和MATLAB接口，同时支持Windows，Linux，Mac OS和Android。 + +#### Python图像库 （PIL） + +1. Python图像库（PIL）支持多种文件格式，同时提供图像处理和图形解决方案。开源的PIL为你的Python解释器添加图像处理能力。 +2. 标准的图像处理能力包括图像增强、透明和屏蔽作用、图像过滤、像素操作等。 + +详细的数据和图表，请看OpenCV 2.4.9 特征比较报告。[这里][3] + +### 构建图像搜索引擎 + +图像搜索引擎可以从预置集图像库选择相似的图像。其中最受欢迎的是谷歌的著名的图像搜索引擎。对于初学者来说，有不同的方法来建立这样的系统。提几个如下： + +1. 采用图像提取、图像描述提取、元数据提取和搜索结果提取，建立图像搜索引擎。 +2. 定义你的图像描述符，数据集索引，定义你的相似性度量，然后搜索和排名。 +3. 选择要搜索的图像，选择用于进行搜索的目录，所有图片的搜索目录，创建图片特征索引，评估相同的搜索图片的功能，在搜索中匹配图片，并获得匹配的图片。 + +我们的方法基本上就比较grayscaled版本的图像，逐渐移动到复杂的特征匹配算法如SIFT和SURF，最后沉淀下来的是开源的解决方案称为BRISK。所有这些算法提供了有效的结果，在性能和延迟的细微变化。建立在这些算法上的引擎有许多应用，如分析流行统计的图形数据，在图形内容中识别对象，以及更多。 + +**例如**：一个图像搜索引擎需要由一个IT公司作为客户机来建立。因此，如果一个品牌的标志图像被提交在搜索中，所有相关的品牌形象搜索显示结果。所得到的结果也可以通过客户端分析，使他们能够根据地理位置估计品牌知名度。但它还比较年轻，RIQ或反向图像搜索尚未被完全挖掘利用。 + +这就结束了我们的文章，使用Python构建图像搜索引擎。浏览我们的博客部分来查看最新的编程技术。 + +数据来源：OpenCV 2.4.9 特征比较报告(computer-vision-talks.com) + +(Ananthu Nair 的指导与补充) + +-------------------------------------------------------------------------------- + +via: http://www.cuelogic.com/blog/advanced-image-processing-with-python/ + +作者：[Snehith Kumbla][a] +译者：[Johnny-Liao](https://github.com/Johnny-Liao) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: http://www.cuelogic.com/blog/author/snehith-kumbla/ +[1]: http://docs.opencv.org/3.0-beta/doc/py_tutorials/py_feature2d/py_surf_intro/py_surf_intro.html +[2]: http://www.vision.ee.ethz.ch/~surf/eccv06.pdf +[3]: https://docs.google.com/spreadsheets/d/1gYJsy2ROtqvIVvOKretfxQG_0OsaiFvb7uFRDu5P8hw/edit#gid=10 +[4]: https://www.youtube.com/watch?v=NPcMS49V5hg +[5]: https://www.cs.ubc.ca/~lowe/papers/ijcv04.pdf diff --git a/translated/tech/20160628 Python 101 An Intro to urllib.md b/translated/tech/20160628 Python 101 An Intro to urllib.md new file mode 100644 index 0000000000..641ac2baf1 --- /dev/null +++ b/translated/tech/20160628 Python 101 An Intro to urllib.md @@ -0,0 +1,193 @@ +Python 101: urllib 简介 +================================= + +Python 3 的 urllib 模块是一堆可以处理 URL 的组件集合。如果你有 Python 2 背景，那么你就会注意到 Python 2 中有 urllib 和 urllib2 两个版本的模块。这些现在都是 Python 3 的 urllib 包的一部分。当前版本的 urllib 包括下面几部分： + +- urllib.request +- urllib.error +- urllib.parse +- urllib.rebotparser + +接下来我们会分开讨论除了 urllib.error 以外的几部分。官方文档实际推荐你尝试第三方库， requests，一个高级的 HTTP 客户端接口。然而我依然认为知道如何不依赖第三方库打开 URL 并与之进行交互是很有用的，而且这也可以帮助你理解为什么 requests 包是如此的流行。 + +--- + +### urllib.request + +urllib.request 模块期初是用来打开和获取 URL 的。让我们看看你可以用函数 urlopen可以做的事： + + +``` +>>> import urllib.request +>>> url = urllib.request.urlopen('https://www.google.com/') +>>> url.geturl() +'https://www.google.com/' +>>> url.info() + +>>> header = url.info() +>>> header.as_string() +('Date: Fri, 24 Jun 2016 18:21:19 GMT\n' + 'Expires: -1\n' + 'Cache-Control: private, max-age=0\n' + 'Content-Type: text/html; charset=ISO-8859-1\n' + 'P3P: CP="This is not a P3P policy! See ' + 'https://www.google.com/support/accounts/answer/151657?hl=en for more info."\n' + 'Server: gws\n' + 'X-XSS-Protection: 1; mode=block\n' + 'X-Frame-Options: SAMEORIGIN\n' + 'Set-Cookie: ' + 'NID=80=tYjmy0JY6flsSVj7DPSSZNOuqdvqKfKHDcHsPIGu3xFv41LvH_Jg6LrUsDgkPrtM2hmZ3j9V76pS4K_cBg7pdwueMQfr0DFzw33SwpGex5qzLkXUvUVPfe9g699Qz4cx9ipcbU3HKwrRYA; ' + 'expires=Sat, 24-Dec-2016 18:21:19 GMT; path=/; domain=.google.com; HttpOnly\n' + 'Alternate-Protocol: 443:quic\n' + 'Alt-Svc: quic=":443"; ma=2592000; v="34,33,32,31,30,29,28,27,26,25"\n' + 'Accept-Ranges: none\n' + 'Vary: Accept-Encoding\n' + 'Connection: close\n' + '\n') +>>> url.getcode() +200 +``` + +在这里我们包含了需要的模块，然后告诉它打开 Google 的 URL。现在我们就有了一个可以交互的 HTTPResponse 对象。我们要做的第一件事是调用方法 geturl ，它会返回根据 URL 获取的资源。这可以让我们发现 URL 是否进行了重定向。 + +接下来调用 info ，它会返回网页的元数据，比如头信息。因此，我们可以将结果赋给我们的 headers 变量，然后调用它的方法 as_string 。就可以打印出我们从 Google 收到的头信息。你也可以通过 getcode 得到网页的 HTTP 响应码，当前情况下就是 200，意思是正常工作。 + +如果你想看看网页的 HTML 代码，你可以调用变量 url 的方法 read。我不准备再现这个过程，因为输出结果太长了。 + +请注意 request 对象默认是 GET 请求，除非你指定它的 data 参数。你应该给它传递 data 参数，这样 request 对象才会变成 POST 请求。 + +--- + +### 下载文件 + +urllib 一个典型的应用场景是下载文件。让我们看看几种可以完成这个任务的方法： + +``` +>>> import urllib.request +>>> url = 'http://www.blog.pythonlibrary.org/wp-content/uploads/2012/06/wxDbViewer.zip' +>>> response = urllib.request.urlopen(url) +>>> data = response.read() +>>> with open('/home/mike/Desktop/test.zip', 'wb') as fobj: +... fobj.write(data) +... +``` + +这个例子中我们打开一个保存在我的博客上的 zip 压缩文件的 URL。然后我们读出数据并将数据写到磁盘。一个替代方法是使用 urlretrieve ： + +``` +>>> import urllib.request +>>> url = 'http://www.blog.pythonlibrary.org/wp-content/uploads/2012/06/wxDbViewer.zip' +>>> tmp_file, header = urllib.request.urlretrieve(url) +>>> with open('/home/mike/Desktop/test.zip', 'wb') as fobj: +... with open(tmp_file, 'rb') as tmp: +... fobj.write(tmp.read()) +``` + +方法 urlretrieve 会把网络对象拷贝到本地文件。除非你在使用 urlretrieve 的第二个参数指定你要保存文件的路径，否则这个文件在本地是随机命名的并且是保存在临时文件夹。这个可以为你节省一步操作，并且使代码开起来更简单： + +``` +>>> import urllib.request +>>> url = 'http://www.blog.pythonlibrary.org/wp-content/uploads/2012/06/wxDbViewer.zip' +>>> urllib.request.urlretrieve(url, '/home/mike/Desktop/blog.zip') +('/home/mike/Desktop/blog.zip', + ) +``` + +如你所见，它返回了文件保存的路径，以及从请求得来的头信息。 + +### 设置你的用户代理 + +当你使用浏览器访问网页时，浏览器会告诉网站它是谁。这就是所谓的 user-agent 字段。Python 的 urllib 会表示他自己为 Python-urllib/x.y ， 其中 x 和 y 是你使用的 Python 的主、次版本号。有一些网站不认识这个用户代理字段，然后网站的可能会有奇怪的表现或者根本不能正常工作。辛运的是你可以很轻松的设置你自己的 user-agent 字段。 + +``` +>>> import urllib.request +>>> user_agent = ' Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:47.0) Gecko/20100101 Firefox/47.0' +>>> url = 'http://www.whatsmyua.com/' +>>> headers = {'User-Agent': user_agent} +>>> request = urllib.request.Request(url, headers=headers) +>>> with urllib.request.urlopen(request) as response: +... with open('/home/mdriscoll/Desktop/user_agent.html', 'wb') as out: +... out.write(response.read()) +``` + +这里设置我们的用户代理为 Mozilla FireFox ，然后我们访问 ， 它会告诉我们它识别出的我们的 user-agent 字段。之后我们将 url 和我们的头信息传给 urlopen 创建一个 Request 实例。最后我们保存这个结果。如果你打开这个结果，你会看到我们成功的修改了自己的 user-agent 字段。使用这段代码尽情的尝试不同的值来看看它是如何改变的。 + +--- + +### urllib.parse + +urllib.parse 库是用来拆分和组合 URL 字符串的标准接口。比如，你可以使用它来转换一个相对的 URL 为绝对的 URL。让我们试试用它来转换一个包含查询的 URL ： + + +``` +>>> from urllib.parse import urlparse +>>> result = urlparse('https://duckduckgo.com/?q=python+stubbing&t=canonical&ia=qa') +>>> result +ParseResult(scheme='https', netloc='duckduckgo.com', path='/', params='', query='q=python+stubbing&t=canonical&ia=qa', fragment='') +>>> result.netloc +'duckduckgo.com' +>>> result.geturl() +'https://duckduckgo.com/?q=python+stubbing&t=canonical&ia=qa' +>>> result.port +None +``` + +这里我们导入了函数 urlparse ， 并且把一个包含搜索查询 duckduckgo 的 URL 作为参数传给它。我的查询的关于 “python stubbing” 的文章。如你所见，它返回了一个 ParseResult 对象，你可以用这个对象了解更多关于 URL 的信息。举个例子，你可以获取到短信息（此处的没有端口信息），网络位置，路径和很多其他东西。 + +### 提交一个 Web 表单 + +这个模块还有一个方法 urlencode 可以向 URL 传输数据。 urllib.parse 的一个典型使用场景是提交 Web 表单。让我们通过搜索引擎 duckduckgo 搜索 Python 来看看这个功能是怎么工作的。 + +``` +>>> import urllib.request +>>> import urllib.parse +>>> data = urllib.parse.urlencode({'q': 'Python'}) +>>> data +'q=Python' +>>> url = 'http://duckduckgo.com/html/' +>>> full_url = url + '?' + data +>>> response = urllib.request.urlopen(full_url) +>>> with open('/home/mike/Desktop/results.html', 'wb') as f: +... f.write(response.read()) +``` + +这个例子很直接。基本上我们想使用 Python 而不是浏览器向 duckduckgo 提交一个查询。要完成这个我们需要使用 urlencode 构建我们的查询字符串。然后我们把这个字符串和网址拼接成一个完整的正确 URL ，然后使用 urllib.request 提交这个表单。最后我们就获取到了结果然后保存到磁盘上。 + +--- + +### urllib.robotparser + +robotparser 模块是由一个单独的类 —— RobotFileParser —— 构成的。这个类会回答诸如一个特定的用户代理可以获取已经设置 robot.txt 的网站。 robot.txt 文件会告诉网络爬虫或者机器人当前网站的那些部分是不允许被访问的。让我们看一个简单的例子： + +``` +>>> import urllib.robotparser +>>> robot = urllib.robotparser.RobotFileParser() +>>> robot.set_url('http://arstechnica.com/robots.txt') +None +>>> robot.read() +None +>>> robot.can_fetch('*', 'http://arstechnica.com/') +True +>>> robot.can_fetch('*', 'http://arstechnica.com/cgi-bin/') +False +``` + +这里我们导入了 robot 分析器类，然后创建一个实例。然后我们给它传递一个表明网站 robots.txt 位置的 URL 。接下来我们告诉分析器来读取这个文件。现在就完成了，我们给它了一组不同的 URL 让它找出那些我们可以爬取而那些不能爬取。我们很快就看到我们可以访问主站但是不包括 cgi-bin 路径。 + +--- + +### 总结一下 + +现在你就有能力使用 Python 的 urllib 包了。在这一节里，我们学习了如何下载文件，提交 Web 表单，修改自己的用户代理以及访问 robots.txt。 urllib 还有一大堆附加功能没有在这里提及，比如网站授权。然后你可能会考虑在使用 urllib 进行认证之前切换到 requests 库，因为 requests 已经以更易用和易调试的方式实现了这些功能。我同时也希望提醒你 Python 已经通过 http.cookies 模块支持 Cookies 了，虽然在 request 包里也很好的封装了这个功能。你应该可能考虑同时试试两个来决定那个最适合你。 + +-------------------------------------------------------------------------------- + +via: http://www.blog.pythonlibrary.org/2016/06/28/python-101-an-intro-to-urllib/ + +作者：[Mike][a] +译者：[Ezio](https://github.com/oska874) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创翻译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: http://www.blog.pythonlibrary.org/author/mld/ diff --git a/translated/tech/20160706 Create Your Own Shell in Python - Part II.md b/translated/tech/20160706 Create Your Own Shell in Python - Part II.md new file mode 100644 index 0000000000..88f6a0fba8 --- /dev/null +++ b/translated/tech/20160706 Create Your Own Shell in Python - Part II.md @@ -0,0 +1,216 @@ +使用 Python 创建你自己的 Shell:Part II +=========================================== + +在 [part 1][1] 中，我们已经创建了一个主要的 shell 循环、切分了的命令输入，以及通过 `fork` 和 `exec` 执行命令。在这部分，我们将会解决剩下的问题。首先，`cd test_dir2` 命令无法修改我们的当前目录。其次，我们仍无法优雅地从 shell 中退出。 + +### 步骤 4：内置命令 + +“cd test_dir2 无法修改我们的当前目录” 这句话是对的，但在某种意义上也是错的。在执行完该命令之后，我们仍然处在同一目录，从这个意义上讲，它是对的。然而，目录实际上已经被修改，只不过它是在子进程中被修改。 + +还记得我们 fork 了一个子进程，然后执行命令，执行命令的过程没有发生在父进程上。结果是我们只是改变了子进程的当前目录，而不是父进程的目录。 + +然后子进程退出，而父进程在原封不动的目录下继续运行。 + +因此，这类与 shell 自己相关的命令必须是内置命令。它必须在 shell 进程中执行而没有分叉（forking）。 + +#### cd + +让我们从 `cd` 命令开始。 + +我们首先创建一个 `builtins` 目录。每一个内置命令都会被放进这个目录中。 + +```shell +yosh_project +|-- yosh + |-- builtins + | |-- __init__.py + | |-- cd.py + |-- __init__.py + |-- shell.py +``` + +在 `cd.py` 中，我们通过使用系统调用 `os.chdir` 实现自己的 `cd` 命令。 + +```python +import os +from yosh.constants import * + + +def cd(args): + os.chdir(args[0]) + + return SHELL_STATUS_RUN +``` + +注意，我们会从内置函数返回 shell 的运行状态。所以，为了能够在项目中继续使用常量，我们将它们移至 `yosh/constants.py`。 + +```shell +yosh_project +|-- yosh + |-- builtins + | |-- __init__.py + | |-- cd.py + |-- __init__.py + |-- constants.py + |-- shell.py +``` + +在 `constants.py` 中，我们将状态常量都放在这里。 + +```python +SHELL_STATUS_STOP = 0 +SHELL_STATUS_RUN = 1 +``` + +现在，我们的内置 `cd` 已经准备好了。让我们修改 `shell.py` 来处理这些内置函数。 + +```python +... +# Import constants +from yosh.constants import * + +# Hash map to store built-in function name and reference as key and value +built_in_cmds = {} + + +def tokenize(string): + return shlex.split(string) + + +def execute(cmd_tokens): + # Extract command name and arguments from tokens + cmd_name = cmd_tokens[0] + cmd_args = cmd_tokens[1:] + + # If the command is a built-in command, invoke its function with arguments + if cmd_name in built_in_cmds: + return built_in_cmds[cmd_name](cmd_args) + + ... +``` + +我们使用一个 python 字典变量 `built_in_cmds` 作为哈希映射（hash map），以存储我们的内置函数。我们在 `execute` 函数中提取命令的名字和参数。如果该命令在我们的哈希映射中，则调用对应的内置函数。 + +（提示：`built_in_cmds[cmd_name]` 返回能直接使用参数调用的函数引用的。) + +我们差不多准备好使用内置的 `cd` 函数了。最后一步是将 `cd` 函数添加到 `built_in_cmds` 映射中。 + +``` +... +# Import all built-in function references +from yosh.builtins import * + +... + +# Register a built-in function to built-in command hash map +def register_command(name, func): + built_in_cmds[name] = func + + +# Register all built-in commands here +def init(): + register_command("cd", cd) + + +def main(): + # Init shell before starting the main loop + init() + shell_loop() +``` + +我们定义了 `register_command` 函数，以添加一个内置函数到我们内置的命令哈希映射。接着，我们定义 `init` 函数并且在这里注册内置的 `cd` 函数。 + +注意这行 `register_command("cd", cd)` 。第一个参数为命令的名字。第二个参数为一个函数引用。为了能够让第二个参数 `cd` 引用到 `yosh/builtins/cd.py` 中的 `cd` 函数引用，我们必须将以下这行代码放在 `yosh/builtins/__init__.py` 文件中。 + +``` +from yosh.builtins.cd import * +``` + +因此，在 `yosh/shell.py` 中，当我们从 `yosh.builtins` 导入 `*` 时，我们可以得到已经通过 `yosh.builtins` 导入的 `cd` 函数引用。 + +我们已经准备好了代码。让我们尝试在 `yosh` 同级目录下以模块形式运行我们的 shell，`python -m yosh.shell`。 + +现在，`cd` 命令可以正确修改我们的 shell 目录了，同时非内置命令仍然可以工作。非常好！ + +#### exit + +最后一块终于来了：优雅地退出。 + +我们需要一个可以修改 shell 状态为 `SHELL_STATUS_STOP` 的函数。这样，shell 循环可以自然地结束，shell 将到达终点而退出。 + +和 `cd` 一样，如果我们在子进程中 fork 和执行 `exit` 函数，其对父进程是不起作用的。因此，`exit` 函数需要成为一个 shell 内置函数。 + +让我们从这开始：在 `builtins` 目录下创建一个名为 `exit.py` 的新文件。 + +``` +yosh_project +|-- yosh + |-- builtins + | |-- __init__.py + | |-- cd.py + | |-- exit.py + |-- __init__.py + |-- constants.py + |-- shell.py +``` + +`exit.py` 定义了一个 `exit` 函数，该函数仅仅返回一个可以退出主循环的状态。 + +``` +from yosh.constants import * + + +def exit(args): + return SHELL_STATUS_STOP +``` + +然后，我们导入位于 `yosh/builtins/__init__.py` 文件的 `exit` 函数引用。 + +``` +from yosh.builtins.cd import * +from yosh.builtins.exit import * +``` + +最后，我们在 `shell.py` 中的 `init()` 函数注册 `exit` 命令。 + + +``` +... + +# Register all built-in commands here +def init(): + register_command("cd", cd) + register_command("exit", exit) + +... +``` + +到此为止！ + +尝试执行 `python -m yosh.shell`。现在你可以输入 `exit` 优雅地退出程序了。 + +### 最后的想法 + +我希望你能像我一样享受创建 `yosh` （**y**our **o**wn **sh**ell）的过程。但我的 `yosh` 版本仍处于早期阶段。我没有处理一些会使 shell 崩溃的极端状况。还有很多我没有覆盖的内置命令。为了提高性能，一些非内置命令也可以实现为内置命令（避免新进程创建时间）。同时，大量的功能还没有实现（请看 [公共特性](http://tldp.org/LDP/Bash-Beginners-Guide/html/x7243.html) 和 [不同特性](http://www.tldp.org/LDP/intro-linux/html/x12249.html)） + +我已经在 github.com/supasate/yosh 中提供了源代码。请随意 fork 和尝试。 + +现在该是创建你真正自己拥有的 Shell 的时候了。 + +Happy Coding! + +-------------------------------------------------------------------------------- + +via: https://hackercollider.com/articles/2016/07/06/create-your-own-shell-in-python-part-2/ + +作者：[Supasate Choochaisri][a] +译者：[cposture](https://github.com/cposture) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://disqus.com/by/supasate_choochaisri/ +[1]: https://hackercollider.com/articles/2016/07/05/create-your-own-shell-in-python-part-1/ +[2]: http://tldp.org/LDP/Bash-Beginners-Guide/html/x7243.html +[3]: http://www.tldp.org/LDP/intro-linux/html/x12249.html +[4]: https://github.com/supasate/yosh diff --git a/translated/tech/20160706 Doing for User Space What We Did for Kernel Space.md b/translated/tech/20160706 Doing for User Space What We Did for Kernel Space.md new file mode 100644 index 0000000000..a62f9ad09f --- /dev/null +++ b/translated/tech/20160706 Doing for User Space What We Did for Kernel Space.md @@ -0,0 +1,95 @@ +在用户空间做我们会在内核空间做的事情 +======================================================= + +我相信，Linux 最好也是最坏的事情，就是内核空间和用户空间之间的巨大差别。 + +但是如果没有这个区别，Linux 可能也不会成为世界上影响力最大的操作系统。如今，Linux 的使用范围在世界上是最大的，而这些应用又有着世界上最大的用户群——尽管大多数用户并不知道，当他们进行谷歌搜索或者触摸安卓手机的时候，他们其实正在使用 Linux。如果不是 Linux 的巨大成功，Apple 公司也可能并不会成为现在这样（即在他们的电脑产品中使用 BSD 的技术）（注：Linux 获得成功后，Apple 曾与 Linus 协商使用 Linux 核心作为 Apple 电脑的操作系统并帮助开发的事宜，但遭到拒绝。因此，Apple 转向使用许可证更为宽松的 BSD 。）。 + +不(需要)关注用户空间是 Linux 内核开发中的一个特点而非缺陷。正如 Linus 在 2003 的极客巡航中提到的那样，“我只做内核相关技术……我并不知道内核之外发生的事情，而且我并不关心。我只关注内核部分发生的事情。” 多年之后的另一个极客巡航上， Andrew Morton 给我上了另外的一课，这之后我写道： + +> Linux 存在于内核空间，而在用户空间中被使用，和其他的自然的建筑材料一样。内核空间和用户空间的区别，和自然材料与人类从中生产的人造材料的区别很类似。 + +这个区别的自然而然的结果，就是尽管外面的世界一刻也离不开 Linux， 但是 Linux 社区还是保持相对较小。所以，为了增加哪怕一点我们社区团体的规模，我希望指出两件事情。第一件已经非常火了，另外一件可能会火起来。 + +第一件事情就是 [blockchain][1]，出自著名的分布式货币——比特币之手。当你正在阅读这篇文章的同时，人们对 blockchain 的[关注度正在直线上升][2]。 + +![](http://www.linuxjournal.com/files/linuxjournal.com/ufiles/imagecache/large-550px-centered/u1000009/12042f1.png) +> 图1. Blockchain 的谷歌搜索趋势 + +第二件事就是自主身份。为了解释这个概念，让我先来问你：你是谁，你来自哪里？ + +如果你从你的雇员、你的医生或者车管所，Facebook、Twitter 或者谷歌上得到答案，你就会发现它们都是行政身份——机构完全以自己的便利为原因设置这些身份和职位。正如 [Evernym][3] 的 Timothy Ruff 所说，“你并不因组织而存在，但你的身份却因此存在。”身份是个因变量。自变量——即控制着身份的变量——是（你所在的）组织。 + +如果你的答案出自你自己，我们就有一个广大空间来发展一个新的领域，在这个领域中，我们完全自由。 + +据我所知，第一个解释这个的人是 [Devon Loffreto][4]。在 2012 年 2 月，他在博客[Moxy Tongue][5] 中写道：“什么是'Sovereign Source Authority'？”。在发表于 2016 年 2 月的 "[Self-Sovereign Identity][6]" 中，他写道： + +> 自主身份必须是独立个人提出的，并且不包含社会因素……自主身份源于每个个体对其自身本源的认识。 一个自主身份可以为个体带来新的社会面貌。每个个体都可能为自己生成一个自主身份，并且这并不会改变固有的人权。使用自主身份机制是所有参与者参与的基石，并且依旧可以同各种形式的人类社会保持联系。 + +将这个概念放在 Linux 领域中，只有个人才能为他或她设定一个自己的开源社区身份。这在现实实践中，这只是一个非常正从的事件。举个例子，我自己的身份包括： + +- David Allen Searls，我父母会这样叫我。 +- David Searls，正式场合下我会这么称呼自己。 +- Dave，我的亲戚和好朋友会这么叫我。 +- Doc，大多数人会这么叫我。 + +作为承认以上称呼的自主身份来源，我可以在不同的情景中轻易的转换。但是，这只是在现实世界中。在虚拟世界中，这就变得非常困难。除了上述的身份之外，我还可以是 @dsearls(我的 twitter 账号) 和 dsearls (其他的网络账号)。然而为了记住成百上千的不同账号的登录名和密码，我已经不堪重负。 + +你可以在你的浏览器上感受到这个糟糕的体验。在火狐上，我有成百上千个用户名密码。很多已经废弃(很多都是从 Netscape 时代遗留下来的)，但是我想会有大量的工作账号需要处理。对于这些，我只是被动接受者。没有其他的解决方法。甚至一些安全较低的用户认证，已经成为了现实世界中不可缺少的一环。 + +现在，最简单的方式来联系账号，就是通过 "Log in with Facebook" 或者 "Login in with Twitter" 来进行身份认证。在这种情况下，我们中的每一个甚至并不是真正意义上的自己，甚至（如果我们希望被其他人认识的话）缺乏对其他实体如何认识我们的控制。 + +我们从一开始就需要的是一个可以实体化我们的自主身份和交流时选择如何保护和展示自身的个人系统。因为缺少这个能力，我们现在陷入混乱。Shoshana Zuboff 称之为 "监视资本主义"，她如此说道： + +>...难以想象，在见证了互联网和获得了的巨大成功的谷歌背后。世界因 Apple 和 FBI 的对决而紧密联系在一起。讲道理，热衷于监视的资本家开发的监视系统是每一个国家安全机构都渴望的。 + +然后，她问道，”我们怎样才能保护自己远离他人的影响？“ + +我建议使用自主身份。我相信这是我们唯一的既可以保证我们从监视中逃脱、又可以使我们有一个有序的世界的办法。以此为基础，我们才可以完全无顾忌地和社会，政治，商业上的人交流。 + +我在五月联合国举行的 [ID2020][7] 会议中总结了这个临时的结论。很高兴，Devon Loffreto 也在那，他于 2013 年推动了自主身份的创立。这是[我那时写的一些文章][8]，引用了 Devon 的早期博客(比如上面的原文)。 + +这有三篇这个领域的准则: + +- "[Self-Sovereign Identity][9]" - Devon Loffreto. +- "[System or Human First][10]" - Devon Loffreto. +- "[The Path to Self-Sovereign Identity][11]" - Christopher Allen. + +从Evernym 的简要说明中，[digi.me][12], [iRespond][13] 和 [Respect Network][14] 也被包括在内。自主身份和社会身份 (也被称为“current model”） 的对比结果，显示在图二中。 + +![](http://www.linuxjournal.com/files/linuxjournal.com/ufiles/imagecache/large-550px-centered/u1000009/12042f2.jpg) +> 图 2. Current Model 身份 vs. 自主身份 + +Sovrin 就是为此而生的[平台][15]，它阐述自己为一个“依托于先进、专用、经授权、分布式平台的，完全开源、基于标识的身份声明图平台”。同时，这也有一本[白皮书][16]。它的代码名为 [plenum][17]，并且公开在 Github 上。 + +在这里——或者其他类似的地方——我们就可以在用户空间中重现我们在过去 25 年中在内核空间做过的事情。 + + +-------------------------------------------------------------------------------- + +via: https://www.linuxjournal.com/content/doing-user-space-what-we-did-kernel-space + +作者：[Doc Searls][a] +译者：[MikeCoder](https://github.com/MikeCoder) +校对：[PurlingNayuki](https://github.com/PurlingNayuki) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://www.linuxjournal.com/users/doc-searls +[1]: https://en.wikipedia.org/wiki/Block_chain_%28database%29 +[2]: https://www.google.com/trends/explore#q=blockchain +[3]: http://evernym.com/ +[4]: https://twitter.com/nzn +[5]: http://www.moxytongue.com/2012/02/what-is-sovereign-source-authority.html +[6]: http://www.moxytongue.com/2016/02/self-sovereign-identity.html +[7]: http://www.id2020.org/ +[8]: http://blogs.harvard.edu/doc/2013/10/14/iiw-challenge-1-sovereign-identity-in-the-great-silo-forest +[9]: http://www.moxytongue.com/2016/02/self-sovereign-identity.html +[10]: http://www.moxytongue.com/2016/05/system-or-human.html +[11]: http://www.lifewithalacrity.com/2016/04/the-path-to-self-soverereign-identity.html +[12]: https://get.digi.me/ +[13]: http://irespond.com/ +[14]: https://www.respectnetwork.com/ +[15]: http://evernym.com/technology +[16]: http://evernym.com/assets/doc/Identity-System-Essentials.pdf?v=167284fd65 +[17]: https://github.com/evernym/plenum diff --git a/translated/tech/20160706 Getting started with Docker Swarm and deploying a replicated Python 3 Application.md b/translated/tech/20160706 Getting started with Docker Swarm and deploying a replicated Python 3 Application.md new file mode 100644 index 0000000000..b06c56b46e --- /dev/null +++ b/translated/tech/20160706 Getting started with Docker Swarm and deploying a replicated Python 3 Application.md @@ -0,0 +1,282 @@ +教程:开始学习如何使用 Docker Swarm 部署可扩展的 Python3 应用 +============== + +[Ben Firshman][2]最近在[Dockercon][1]做了一个关于使用 Docker 构建无服务应用的演讲，你可以在[这查看详情][3](可以和视频一起)。之后，我写了[一篇文章][4]关于如何使用[AWS Lambda][5]构建微服务系统。 + +今天，我想展示给你的就是如何使用[Docker Swarm][6]然后部署一个简单的 Python Falcon REST 应用。尽管，我不会使用[dockerrun][7]或者是其他无服务特性。你可能会惊讶，使用 Docker Swarm 部署(替换)一个 Python(Java, Go 都一样) 应用是如此的简单。 + +注意：这展示的部分步骤是截取自[Swarm Tutorial][8]。我已经修改了部分章节，并且[在 Vagrant 的帮助文档][9]中添加了构建本地测试环境的文档。请确保，你使用的是1.12或以上版本的 Docker 引擎。我写这篇文章的时候，使用的是1.12RC2版本的 Docker。注意的是，这只是一个测试版本，只会可能还会有修改。 + +你要做的第一件事，就是你要保证你正确的安装了[Vagrant][10]，如果你想本地运行的话。你也可以按如下步骤使用你最喜欢的云服务提供商部署 Docker Swarm 虚拟机系统。 + +我们将会使用这三台 VM:一个简单的 Docker Swarm 管理平台和两台 worker。 + +安全注意事项:Vagrantfile 代码中包含了部分位于 Docker 测试服务器上的 shell 脚本。这是一个隐藏的安全问题。如果你没有权限的话。请确保你会在运行代码之前[审查这部分的脚本][11]。 + +``` +$ git clone https://github.com/chadlung/vagrant-docker-swarm +$ cd vagrant-docker-swarm +$ vagrant plugin install vagrant-vbguest +$ vagrant up +``` + +Vagrant up 命令可能会花很长的时间来执行。 + +SSH 登陆进入 manager1 虚拟机: + +``` +$ vagrant ssh manager1 +``` + +在 manager1 的终端中执行如下命令: + +``` +$ sudo docker swarm init --listen-addr 192.168.99.100:2377 +``` + +现在还没有 worker 注册上来: + +``` +$ sudo docker node ls +``` + +Let’s register the two workers. Use two new terminal sessions (leave the manager1 session running): +通过两个新的终端会话(退出 manager1 的登陆后)，我们注册两个 worker。 + +``` +$ vagrant ssh worker1 +``` + +在 worker1 上执行如下命令: + +``` +$ sudo docker swarm join 192.168.99.100:2377 +``` + +在 worker2 上重复这些命令。 + +在 manager1 上执行这个命令: + +``` +$ docker node ls +``` + +你将会看到： + +![](http://www.giantflyingsaucer.com/blog/wp-content/uploads/2016/06/Screen-Shot-2016-06-28-at-3.15.25-PM.png) + +开始在 manager1 的终端里，部署一个简单的服务。 + +``` +sudo docker service create --replicas 1 --name pinger alpine ping google.com +``` + +这个命令将会部署一个服务，他会从 worker 机器中的一台 ping google.com。(manager 也可以运行服务，不过[这也可以被禁止][12])如果你只是想 worker 运行容器的话)。可以使用如下命令，查看哪些节点正在执行服务: + +``` +$ sudo docker service tasks pinger +``` + +结果回合这个比较类似: + +![](http://www.giantflyingsaucer.com/blog/wp-content/uploads/2016/06/Screen-Shot-2016-06-28-at-5.23.05-PM.png) + +所以，我们知道了服务正跑在 worker1 上。我们可以回到 worker1 的会话里，然后进入正在运行的容器: + +``` +$ sudo docker ps +``` + +![](http://www.giantflyingsaucer.com/blog/wp-content/uploads/2016/06/Screen-Shot-2016-06-28-at-5.25.02-PM.png) + +你可以看到容器的 id 是: ae56769b9d4d + +在我的例子中，我运行的是如下的代码: + +``` +$ sudo docker attach ae56769b9d4d +``` + +![](http://www.giantflyingsaucer.com/blog/wp-content/uploads/2016/06/Screen-Shot-2016-06-28-at-5.26.49-PM.png) + +你可以仅仅只用 CTRL-C 来停止服务。 + +回到 manager1，并且移除 pinger 服务。 + +``` +$ sudo docker service rm pinger +``` + +现在，我们将会部署可复制的 Python 应用。请记住，为了保持文章的简洁，而且容易复制，所以部署的是一个简单的应用。 + +你需要做的第一件事就是将镜像放到[Docker Hub][13]上，或者使用我[已经上传的一个][14]。这是一个简单的 Python 3 Falcon REST 应用。他有一个简单的入口: /hello 带一个 value 参数。 + +[chadlung/hello-app][15]的 Python 代码看起来像这样: + +``` +import json +from wsgiref import simple_server + +import falcon + + +class HelloResource(object): + def on_get(self, req, resp): + try: + value = req.get_param('value') + + resp.content_type = 'application/json' + resp.status = falcon.HTTP_200 + resp.body = json.dumps({'message': str(value)}) + except Exception as ex: + resp.status = falcon.HTTP_500 + resp.body = str(ex) + + +if __name__ == '__main__': + app = falcon.API() + hello_resource = HelloResource() + app.add_route('/hello', hello_resource) + httpd = simple_server.make_server('0.0.0.0', 8080, app) + httpd.serve_forever() +``` + +Dockerfile 很简单: + +``` +FROM python:3.4.4 + +RUN pip install -U pip +RUN pip install -U falcon + +EXPOSE 8080 + +COPY . /hello-app +WORKDIR /hello-app + +CMD ["python", "app.py"] +``` + +再一次说明，这是非常详细的奖惩，如果你想，你也可以在本地访问这个入口: + +这将返回如下结果: + +``` +{"message": "Fred"} +``` + +在 Docker Hub 上构建和部署这个 hello-app（修改成你自己的 Docker Hub 仓库或者[这个][15]）: + +``` +$ sudo docker build . -t chadlung/hello-app:2 +$ sudo docker push chadlung/hello-app:2 +``` + +现在，我们可以将应用部署到之前的 Docker Swarm 了。登陆 manager1 终端，并且执行: + +``` +$ sudo docker service create -p 8080:8080 --replicas 2 --name hello-app chadlung/hello-app:2 +$ sudo docker service inspect --pretty hello-app +$ sudo docker service tasks hello-app +``` + +现在，我们已经可以测试了。使用任何一个节点 Swarm 的 IP，来访问/hello 的入口，在本例中，我在 Manager1 的终端里使用 curl 命令: + +注意,在 Swarm 中的所有 IP 都可以工作，即使这个服务只运行在一台或者更多的节点上。 + +``` +$ curl -v -X GET "http://192.168.99.100:8080/hello?value=Chad" +$ curl -v -X GET "http://192.168.99.101:8080/hello?value=Test" +$ curl -v -X GET "http://192.168.99.102:8080/hello?value=Docker" +``` + +结果就是: + +``` +* Hostname was NOT found in DNS cache +* Trying 192.168.99.101... +* Connected to 192.168.99.101 (192.168.99.101) port 8080 (#0) +> GET /hello?value=Chad HTTP/1.1 +> User-Agent: curl/7.35.0 +> Host: 192.168.99.101:8080 +> Accept: */* +> +* HTTP 1.0, assume close after body +< HTTP/1.0 200 OK +< Date: Tue, 28 Jun 2016 23:52:55 GMT +< Server: WSGIServer/0.2 CPython/3.4.4 +< content-type: application/json +< content-length: 19 +< +{"message": "Chad"} +``` + +从浏览器中访问其他节点: + +![](http://www.giantflyingsaucer.com/blog/wp-content/uploads/2016/06/Screen-Shot-2016-06-28-at-6.54.31-PM.png) + +如果你想看运行的所有服务，你可以在 manager1 节点上运行如下代码: + +``` +$ sudo docker service ls +``` + +如果你想添加可视化控制平台，你可以安装[Docker Swarm Visualizer][16](这非常简单上手)。在 manager1 的终端中执行如下代码: + +![]($ sudo docker run -it -d -p 5000:5000 -e HOST=192.168.99.100 -e PORT=5000 -v /var/run/docker.sock:/var/run/docker.sock manomarks/visualizer) + +打开你的浏览器，并且访问: + +结果(假设已经运行了两个 Docker Swarm 服务): + +![](http://www.giantflyingsaucer.com/blog/wp-content/uploads/2016/06/Screen-Shot-2016-06-30-at-2.37.28-PM.png) + +停止运行 hello-app(已经在两个节点上运行了)，可以在 manager1 上执行这个代码: + +``` +$ sudo docker service rm hello-app +``` + +如果想停止， 那么在 manager1 的终端中执行： + +``` +$ sudo docker ps +``` + +获得容器的 ID,这里是: f71fec0d3ce1 + +从 manager1 的终端会话中执行这个代码: + +``` +$ sudo docker stop f71fec0d3ce1 +``` + +祝你使用 Docker Swarm。这篇文章主要是以1.12版本来进行描述的。 + +-------------------------------------------------------------------------------- + +via: http://www.giantflyingsaucer.com/blog/?p=5923 + +作者：[Chad Lung][a] +译者：[译者ID](https://github.com/MikeCoder) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: http://www.giantflyingsaucer.com/blog/?author=2 +[1]: http://dockercon.com/ +[2]: https://blog.docker.com/author/bfirshman/ +[3]: https://blog.docker.com/author/bfirshman/ +[4]: http://www.giantflyingsaucer.com/blog/?p=5730 +[5]: https://aws.amazon.com/lambda/ +[6]: https://docs.docker.com/swarm/ +[7]: https://github.com/bfirsh/dockerrun +[8]: https://docs.docker.com/engine/swarm/swarm-tutorial/ +[9]: https://github.com/chadlung/vagrant-docker-swarm +[10]: https://www.vagrantup.com/ +[11]: https://test.docker.com/ +[12]: https://docs.docker.com/engine/reference/commandline/swarm_init/ +[13]: https://hub.docker.com/ +[14]: https://hub.docker.com/r/chadlung/hello-app/ +[15]: https://hub.docker.com/r/chadlung/hello-app/ +[16]: https://github.com/ManoMarks/docker-swarm-visualizer diff --git a/translated/tech/20160715 bc - Command line calculator.md b/translated/tech/20160715 bc - Command line calculator.md new file mode 100644 index 0000000000..d5dc711909 --- /dev/null +++ b/translated/tech/20160715 bc - Command line calculator.md @@ -0,0 +1,129 @@ +bc : 一个命令行计算器 +============================ + +![](https://cdn.fedoramagazine.org/wp-content/uploads/2016/07/bc-calculator-945x400.jpg) + +假如你运行在一个图形桌面环境中，当你需要一个计算器时，你可能只需要一路进行点击便可以找到一个计算器。例如，Fedora 工作站中就已经包含了一个名为 `Calculator` 的工具。它有着几种不同的操作模式，例如，你可以进行复杂的数学运算或者金融运算。但是，你知道吗，命令行也提供了一个与之相似的名为 `bc` 的工具？ + +`bc` 工具可以为你提供你期望一个科学计算器、金融计算器或者是简单的计算器所能提供的所有功能。另外，假如需要的话，它还可以从命令行中被脚本化。这使得当你需要做复杂的数学运算时，你可以在 shell 脚本中使用它。 + +因为 bc 被其他的系统软件所使用，例如 CUPS 打印服务，它可能已经在你的 Fedora 系统中被安装了。你可以使用下面这个命令来进行检查： + +``` +dnf list installed bc +``` + +假如因为某些原因你没有在上面命令的输出中看到它，你可以使用下面的这个命令来安装它： + +``` +sudo dnf install bc +``` + +### 用 bc 做一些简单的数学运算 + +使用 bc 的一种方式是进入它自己的 shell。在那里你可以在一行中做许多次计算。但在你键入 bc 后，首先出现的是有关这个程序的警告： + +``` +$ bc +bc 1.06.95 +Copyright 1991-1994, 1997, 1998, 2000, 2004, 2006 Free Software Foundation, Inc. +This is free software with ABSOLUTELY NO WARRANTY. +For details type `warranty'. +``` + +现在你可以按照每行一个输入运算式或者命令了： + +``` +1+1 +``` + +bc 会回答上面计算式的答案是： + +``` +2 +``` + +在这里你还可以执行其他的命令。你可以使用 加（+）、减（-）、乘（*）、除（/）、圆括号、指数符号（^） 等等。请注意 bc 同样也遵循所有约定俗成的运算规定，例如运算的先后顺序。你可以试试下面的例子： + +``` +(4+7)*2 +4+7*2 +``` + +若要离开 bc 可以通过按键组合 `Ctrl+D` 来发送 “输入结束”信号给 bc 。 + +使用 bc 的另一种方式是使用 `echo` 命令来传递运算式或命令。下面这个示例类似于计算器中的 "Hello, world" 例子，使用 shell 的管道函数（|） 来将 `echo` 的输出传入 `bc` 中： + +``` +echo '1+1' | bc +``` + +使用 shell 的管道，你可以发送不止一个运算操作，你需要使用分号来分隔不同的运算。结果将在不同的行中返回。 + +``` +echo '1+1; 2+2' | bc +``` + +### 精度 + +在某些计算中，bc 会使用精度的概念，即小数点后面的数字位数。默认的精度是 0。除法操作总是使用精度的设定。所以，如果你没有设置精度，有可能会带来意想不到的答案： + +``` +echo '3/2' | bc +echo 'scale=3; 3/2' | bc +``` + +乘法使用一个更复杂的精度选择机制： + +``` +echo '3*2' | bc +echo '3*2.0' | bc +``` + +同时，加法和减法的相关运算则与之相似： + +``` +echo '7-4.15' | bc +``` + +### 其他进制系统 + +bc 的另一个有用的功能是可以使用除 十进制以外的其他计数系统。例如，你可以轻松地做十六进制或二进制的数学运算。可以使用 `ibase` 和 `obase` 命令来分别设定输入和输出的进制系统。需要记住的是一旦你使用了 `ibase`，之后你输入的任何数字都将被认为是在新定义的进制系统中。 + +要做十六进制数到十进制数的转换或运算，你可以使用类似下面的命令。请注意大于 9 的十六进制数必须是大写的（A-F）： + +``` +echo 'ibase=16; A42F' | bc +echo 'ibase=16; 5F72+C39B' | bc +``` + +若要使得结果是十六进制数，则需要设定 `obase` ： + +``` +echo 'obase=16; ibase=16; 5F72+C39B' | bc +``` + +下面是一个小技巧。假如你在 shell 中做这些运算，怎样才能使得输入重新为十进制数呢？答案是使用 `ibase` 命令，但你必须设定它为在当前进制中与十进制中的 10 等价的值。例如，假如 `ibase` 被设定为十六进制，你需要输入： + +``` +ibase=A +``` + +一旦你执行了上面的命令，所有输入的数字都将是十进制的了，接着你便可以输入 `obase=10` 来重置输出的进制系统。 + +### 结论 + +上面所提到的只是 bc 所能做到的基础。它还允许你为某些复杂的运算和程序定义函数、变量和循环结构。你可以在你的系统中将这些程序保存为文本文件以便你在需要的时候使用。你还可以在网上找到更多的资源，它们提供了更多的例子以及额外的函数库。快乐地计算吧！ + +-------------------------------------------------------------------------------- + +via: http://www.tecmint.com/mandatory-access-control-with-selinux-or-apparmor-linux/ + +作者：[Paul W. Frields][a] +译者：[FSSlc](https://github.com/FSSlc) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://fedoramagazine.org/author/pfrields/ +[1]: http://phodd.net/gnu-bc/ diff --git a/translated/tech/20160722 Keeweb A Linux Password Manager.md b/translated/tech/20160722 Keeweb A Linux Password Manager.md new file mode 100644 index 0000000000..3e32d1001c --- /dev/null +++ b/translated/tech/20160722 Keeweb A Linux Password Manager.md @@ -0,0 +1,62 @@ +Linux 密码管理器：Keeweb +================================ + +![](http://www.linuxandubuntu.com/uploads/2/1/1/5/21152474/keeweb_1.png?608) + +如今，我们依赖于越来越多的线上服务。我们每注册一个线上服务，就要设置一个密码；如此，我们就不得不记住数以百计的密码。这样对于每个人来说，都很容易忘记密码。我将在本文中介绍 Keeweb，它是一款 Linux 密码管理器，可以将你所有的密码安全地存储在线上或线下。 + +当谈及 Linux 密码管理器时，我们会发现有很多这样的软件。我们已经在 LinuxAndUbuntu 上讨论过像 [Keepass][1] 和 [Encryptr，一个基于零知识系统的密码管理器][2] 这样的密码管理器。Keeweb 则是另外一款我们将在本文讲解的 Linux 密码管理器。 + +### Keeweb 可以在线下或线上存储密码 + +Keeweb 是一款跨平台的密码管理器。它可以在线下存储你所有的密码，并且能够同步到你自己的云存储服务上，例如 OneDrive, Google Drive, Dropbox 等。Keeweb 并没有它自己的用于同步你密码的在线数据库。 + +要使用 Keeweb 连接你的线上存储服务，只需要点击更多，然后再点击你想要使用的服务即可。 + +![](http://www.linuxandubuntu.com/uploads/2/1/1/5/21152474/keeweb.png?685) + +现在，Keeweb 会提示你登录到你的云盘。登录成功后，给 Keeweb 授权使用你的账户。 + +![](http://www.linuxandubuntu.com/uploads/2/1/1/5/21152474/authenticate-dropbox-with-keeweb_orig.jpg?649) + +### 使用 Keeweb 存储密码 + +使用 Keeweb 存储你的密码是非常容易的。你可以使用一个复杂的密码加密你的密码文件。Keeweb 也允许你使用一个秘钥文件来锁定密码文件，但是我并不推荐这种方式。如果某个家伙拿到了你的秘钥文件，他只需要简单点击一下就可以解锁你的密码文件。 + +#### 创建密码 + +想要创建一个新的密码，你只需要简单地点击 `+` 号，然后你就会看到所有需要填充的输入框。如果你想的话，可以创建更多的输入框。 + +#### 搜索密码 + +![](http://www.linuxandubuntu.com/uploads/2/1/1/5/21152474/search-passwords_orig.png) + +Keeweb 拥有一个图标库，这样你就可以轻松地找到任何特定的密码入口。你可以改变图标的颜色、下载更多的图标，甚至可以直接从你的电脑中导入图标。这对于密码搜索来说，异常好使。 + +相似服务的密码可以分组，这样你就可以在一个文件夹的一个地方同时找到它们。你也可以给密码打上标签并把它们存放在不同分类中。 + +![](http://www.linuxandubuntu.com/uploads/2/1/1/5/21152474/tags-passwords-in-keeweb.png?283) + +### 主题 + +![](http://www.linuxandubuntu.com/uploads/2/1/1/5/21152474/themes.png?304) + +如果你喜欢类似于白色或者高对比度的亮色主题，你可以在“设置 > 通用 > 主题”中修改。（Keeweb）有四款可供选择的主题，其中两款为暗色，另外两款为亮色。 + +### 不喜欢 Linux 密码管理器？没问题！ + +我已经发表过文章介绍了另外两款 Linux 密码管理器，它们分别是 Keepass 和 Encryptr，在 Reddit 和其它社交媒体上有些关于它们的争论。有些人反对使用任何密码管理器，反之亦然。在本文中，我想要澄清的是，存放密码文件是我们自己的责任。我认为像 keepass 和 Keeweb 这样的密码管理器是非常好用的，因为它们并没有自己的云来存放你的密码。这些密码管理器会创建一个文件，然后你可以将它存放在你的硬盘上，或者使用像 VeraCrypt 这样的应用给它加密。我个人不使用也不推荐使用那些将密码存储在它们自己数据库的服务。 + +-------------------------------------------------------------------------------- + +via: http://www.linuxandubuntu.com/home/keeweb-a-linux-password-manager + +作者：[author][a] +译者：[ChrisLeeGit](https://github.com/chrisleegit) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: http://www.linuxandubuntu.com/home/keeweb-a-linux-password-manager +[1]: http://www.linuxandubuntu.com/home/keepass-password-management-tool-creates-strong-passwords-and-keeps-them-secure +[2]: http://www.linuxandubuntu.com/home/encryptr-zero-knowledge-system-based-password-manager-for-linux diff --git a/translated/tech/20160727-How-to-use-multiple-connections-to-speed-up-apt-get on Ubuntu Linux 16.04 LTS server.md b/translated/tech/20160727-How-to-use-multiple-connections-to-speed-up-apt-get on Ubuntu Linux 16.04 LTS server.md new file mode 100644 index 0000000000..e36813cdc9 --- /dev/null +++ b/translated/tech/20160727-How-to-use-multiple-connections-to-speed-up-apt-get on Ubuntu Linux 16.04 LTS server.md @@ -0,0 +1,218 @@ +如何在Ubuntu Linux 16.04 LTS中使用多条连接加速apt-get/apt +========================================================================================= + +我该如何在Ubuntu Linux 16.04或者14.04 LTS中从多个仓库中下载包来加速apt-get或者apt命令？ + +你需要使用到apt-fast这个shell封装器。它会通过多个连接同时下载一个包来加速apt-get/apt和aptitude命令。所有的包都会同时下载。它使用aria2c作为默认的下载加速。 + +### 安装 apt-fast 工具 + +在Ubuntu Linux 14.04或者之后的版本尝试下面的命令： + +``` +$ sudo add-apt-repository ppa:saiarcot895/myppa +``` + +示例输出： + +![](http://s0.cyberciti.org/uploads/faq/2016/07/install-apt-fast-repo.jpg) + +更新你的仓库： + +``` +$ sudo apt-get update +``` + +或者 + +``` +$ sudo apt update +``` + +![](http://s0.cyberciti.org/uploads/faq/2016/07/install-apt-fast-command.jpg) + +安装 apt-fast： + +``` +$ sudo apt-get -y install apt-fast +``` + +或者 + +``` +$ sudo apt -y install apt-fast +``` + +示例输出： + + +``` +Reading package lists... Done +Building dependency tree +Reading state information... Done +The following additional packages will be installed: + aria2 libc-ares2 libssh2-1 +Suggested packages: + aptitude +The following NEW packages will be installed: + apt-fast aria2 libc-ares2 libssh2-1 +0 upgraded, 4 newly installed, 0 to remove and 0 not upgraded. +Need to get 1,282 kB of archives. +After this operation, 4,786 kB of additional disk space will be used. +Do you want to continue? [Y/n] y +Get:1 http://01.archive.ubuntu.com/ubuntu xenial/universe amd64 libssh2-1 amd64 1.5.0-2 [70.3 kB] +Get:2 http://ppa.launchpad.net/saiarcot895/myppa/ubuntu xenial/main amd64 apt-fast all 1.8.3~137+git7b72bb7-0ubuntu1~ppa3~xenial1 [34.4 kB] +Get:3 http://01.archive.ubuntu.com/ubuntu xenial/main amd64 libc-ares2 amd64 1.10.0-3 [33.9 kB] +Get:4 http://01.archive.ubuntu.com/ubuntu xenial/universe amd64 aria2 amd64 1.19.0-1build1 [1,143 kB] +54% [4 aria2 486 kB/1,143 kB 42%] 20.4 kB/s 32s +``` + +### 配置 apt-fast + +你将会得到下面的提示（必须输入一个5到16的数值）： + +![](http://s0.cyberciti.org/uploads/faq/2016/07/max-connection-10.jpg) + +并且 + +![](http://s0.cyberciti.org/uploads/faq/2016/07/apt-fast-confirmation-box.jpg) + +你可以直接编辑设置： + +``` +$ sudo vi /etc/apt-fast.conf +``` + +>**请注意这个工具并不是给慢速网络连接的，它是给快速网络连接的。如果你的网速慢，那么你将无法从这个工具中得到好处。** + +### 我该怎么使用 apt-fast 命令？ + +语法是： + +``` +apt-fast command +apt-fast [options] command +``` + +#### 使用apt-fast取回新的包列表 + +``` +sudo apt-fast update +``` + +#### 使用apt-fast执行升级 + +``` +sudo apt-fast upgrade +``` + + +#### 执行发行版升级（发布或者强制内核升级），输入： + +``` +$ sudo apt-fast dist-upgrade +``` + +#### 安装新的包 + +语法是： + +``` +sudo apt-fast install pkg +``` + +比如要安装nginx，输入： + +``` +$ sudo apt-fast install nginx +``` + +示例输出： + +![](http://s0.cyberciti.org/uploads/faq/2016/07/sudo-apt-fast-install.jpg) + +#### 删除包 + +``` +$ sudo apt-fast remove pkg +$ sudo apt-fast remove nginx +``` + +#### 删除包和它的配置文件 + +``` +$ sudo apt-fast purge pkg +$ sudo apt-fast purge nginx +``` + +#### 删除所有未使用的包 + +``` +$ sudo apt-fast autoremove +``` + +#### 下载源码包 + +``` +$ sudo apt-fast source pkgNameHere +``` + +#### 清理下载的文件 + +``` +$ sudo apt-fast clean +``` + +#### 清理旧的下载文件 + +``` +$ sudo apt-fast autoclean +``` + +#### 验证没有破坏的依赖 + +``` +$ sudo apt-fast check +``` + +#### 下载二进制包到当前目录 + +``` +$ sudo apt-fast download pkgNameHere +$ sudo apt-fast download nginx +``` + +示例输出： + +``` +[#7bee0c 0B/0B CN:1 DL:0B] +07/26 15:35:42 [NOTICE] Verification finished successfully. file=/home/vivek/nginx_1.10.0-0ubuntu0.16.04.2_all.deb +07/26 15:35:42 [NOTICE] Download complete: /home/vivek/nginx_1.10.0-0ubuntu0.16.04.2_all.deb +Download Results: +gid |stat|avg speed |path/URI +======+====+===========+======================================================= +7bee0c|OK | n/a|/home/vivek/nginx_1.10.0-0ubuntu0.16.04.2_all.deb +Status Legend: +(OK):download completed. +``` + +#### 下载并显示指定包的changelog + +``` +$ sudo apt-fast changelog pkgNameHere +$ sudo apt-fast changelog nginx +``` + + + +-------------------------------------------------------------------------------- + +via: https://fedoramagazine.org/introducing-flatpak/ + +作者：[VIVEK GITE][a] +译者：[geekpi](https://github.com/geekpi) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: http://www.cyberciti.biz/tips/about-us diff --git a/translated/tech/LFCS/Part 13 - How to Configure and Troubleshoot Grand Unified Bootloader (GRUB).md b/translated/tech/LFCS/Part 13 - How to Configure and Troubleshoot Grand Unified Bootloader (GRUB).md new file mode 100644 index 0000000000..d8b7b294e2 --- /dev/null +++ b/translated/tech/LFCS/Part 13 - How to Configure and Troubleshoot Grand Unified Bootloader (GRUB).md @@ -0,0 +1,184 @@ +LFCS 系列第十三讲：如何配置并排除 GNU 引导加载程序（GRUB）故障 +===================================================================================== + +由于 LFCS 考试需求的变动已于 2016 年 2 月 2 日生效，因此我们向 [LFCS 系列][1] 添加了一些必要的话题。为了准备认证考试，我们也强烈推荐你去看 [LFCE 系列][2]。 + +![](http://www.tecmint.com/wp-content/uploads/2016/03/Configure-Troubleshoot-Grub-Boot-Loader.png) +>LFCS 系列第十三讲：配置并排除 Grub 引导加载程序故障。 + +本文将会向你介绍 GRUB 的知识，并会说明你为什么需要一个引导加载程序，以及它是如何增强系统通用性的。 + +[Linux 引导过程][3] 是从你按下你的电脑电源键开始，直到你拥有一个全功能的系统为止，整个过程遵循着这样的高层次顺序： + +* 1. 一个叫做 **POST**（**上电自检**）的过程会对你的电脑硬件组件做全面的检查。 +* 2. 当 **POST** 完成后，它会把控制权转交给引导加载程序，接下来引导加载程序会将 Linux 内核（以及 **initramfs**）加载到内存中并执行。 +* 3. 内核首先检查并访问硬件，然后运行初始进程（主要以它的通用名 **init** 而为人熟知），接下来初始进程会启动一些服务，最后完成系统启动过程。 + +在该系列的第七讲（“[SysVinit, Upstart, 和 Systemd][4]”）中，我们介绍了现代 Linux 发行版使用的一些服务管理系统和工具。在继续学习之前，你可能想要回顾一下那一讲的知识。 + +### GRUB 引导装载程序介绍 + +在现代系统中，你会发现有两种主要的 **GRUB** 版本（一种是偶尔被成为 **GRUB Legacy** 的 **v1** 版本，另一种则是 **v2** 版本），虽说多数最新版本的发行版系统都默认使用了 **v2** 版本。如今，只有 **红帽企业版 Linux 6** 及其衍生系统仍在使用 **v1** 版本。 + +因此，在本指南中，我们将着重关注 **v2** 版本的功能。 + +不管 **GRUB** 的版本是什么，一个引导加载程序都允许用户： + +* 1). 通过指定使用不同的内核来修改系统的表现方式； +* 2). 从多个操作系统中选择一个启动； +* 3). 添加或编辑配置节点来改变启动选项等。 + +如今，**GNU** 项目负责维护 **GRUB**，并在它们的网站上提供了丰富的文档。当你在阅读这篇指南时，我们强烈建议你看下 [GNU 官方文档][6]。 + +当系统引导时，你会在主控制台看到如下的 **GRUB** 画面。最开始，你可以根据提示在多个内核版本中选择一个内核（默认情况下，系统将会使用最新的内核启动），并且可以进入 **GRUB** 命令行模式（使用 `c` 键），或者编辑启动项（按下 `e` 键）。 + +![](http://www.tecmint.com/wp-content/uploads/2016/03/GRUB-Boot-Screen.png) +> GRUB 启动画面 + +你会考虑使用一个旧版内核启动的原因之一是之前工作正常的某个硬件设备在一次升级后出现了“怪毛病（acting up）”（例如，你可以参考 AskUbuntu 论坛中的 [这条链接][7]）。 + +**GRUB v2** 的配置文件会在启动时从 `/boot/grub/grub.cfg` 或 `/boot/grub2/grub.cfg` 文件中读取，而 **GRUB v1** 使用的配置文件则来自 `/boot/grub/grub.conf` 或 `/boot/grub/menu.lst`。这些文件不能直接手动编辑，而是根据 `/etc/default/grub` 的内容和 `/etc/grub.d` 目录中的文件来修改的。 + +在 **CentOS 7** 上，当系统最初完成安装后，会生成如下的配置文件： + +``` +GRUB_TIMEOUT=5 +GRUB_DISTRIBUTOR="$(sed 's, release .*$,,g' /etc/system-release)" +GRUB_DEFAULT=saved +GRUB_DISABLE_SUBMENU=true +GRUB_TERMINAL_OUTPUT="console" +GRUB_CMDLINE_LINUX="vconsole.keymap=la-latin1 rd.lvm.lv=centos_centos7-2/swap crashkernel=auto vconsole.font=latarcyrheb-sun16 rd.lvm.lv=centos_centos7-2/root rhgb quiet" +GRUB_DISABLE_RECOVERY="true" +``` + +除了在线文档外，你也可以使用下面的命令查阅 GNU GRUB 手册： + +``` +# info grub +``` + +如果你对 `/etc/default/grub` 文件中的可用选项特别感兴趣的话，你可以直接查阅配置一节的帮助文档： + +``` +# info -f grub -n 'Simple configuration' +``` + +使用上述命令，你会发现 `GRUB_TIMEOUT` 用于设置启动画面出现和系统自动开始启动（除非被用户中断）之间的时间。当该变量值为 `-1` 时，除非用户主动做出选择，否则不会开始启动。 + +当同一台机器上安装了多个操作系统或内核后，`GRUB_DEFAULT` 就需要用一个整数来指定 GRUB 启动画面默认选择启动的操作系统或内核条目。我们既可以通过上述启动画查看启动条目列表，也可以使用下面的命令： + +### 在 CentOS 和 openSUSE 系统上 + +``` +# awk -F\' '$1=="menuentry " {print $2}' /boot/grub2/grub.cfg +``` + +### 在 Ubuntu 系统上 + +``` +# awk -F\' '$1=="menuentry " {print $2}' /boot/grub/grub.cfg +``` + +如下图所示的例子中，如果我们想要使用版本为 `3.10.0-123.el7.x86_64` 的内核（第四个条目），我们需要将 `GRUB_DEFAULT` 设置为 `3`（条目从零开始编号），如下所示： + +``` +GRUB_DEFAULT=3 +``` + +![](http://www.tecmint.com/wp-content/uploads/2016/03/Boot-System-with-Old-Kernel-Version.png) +> 使用旧版内核启动系统 + +最后一个需要特别关注的 GRUB 配置变量是 `GRUB_CMDLINE_LINUX`，它是用来给内核传递选项的。我们可以在 [内核变量文件][8] 和 [man 7 bootparam][9] 中找到能够通过 GRUB 传递给内核的选项的详细文档。 + +我的 **CentOS 7** 服务器上当前的选项是： + +``` +GRUB_CMDLINE_LINUX="vconsole.keymap=la-latin1 rd.lvm.lv=centos_centos7-2/swap crashkernel=auto vconsole.font=latarcyrheb-sun16 rd.lvm.lv=centos_centos7-2/root rhgb quiet" +``` +为什么你希望修改默认的内核参数或者传递额外的选项呢？简单来说，在很多情况下，你需要告诉内核某些由内核自身无法判断的硬件参数，或者是覆盖一些内核会检测的值。 + +不久之前，就在我身上发生过这样的事情，当时我在自己已用了 10 年的老笔记本上尝试衍生自 **Slackware** 的 **Vector Linux**。完成安装后，内核并没有检测出我的显卡的正确配置，所以我不得不通过 GRUB 传递修改过的内核选项来让它工作。 + +另外一个例子是当你需要将系统切换到单用户模式以执行维护工作时。为此，你可以直接在 `GRUB_CMDLINE_LINUX` 变量中直接追加 `single` 并重启即可： + +``` +GRUB_CMDLINE_LINUX="vconsole.keymap=la-latin1 rd.lvm.lv=centos_centos7-2/swap crashkernel=auto vconsole.font=latarcyrheb-sun16 rd.lvm.lv=centos_centos7-2/root rhgb quiet single" +``` + +编辑完 `/etc/default/grub` 之后，你需要运行 `update-grub` （在 Ubuntu 上）或者 `grub2-mkconfig -o /boot/grub2/grub.cfg` （在 **CentOS** 和 **openSUSE** 上）命令来更新 `grub.cfg` 文件（否则，改动会在系统启动时丢失）。 + +这条命令会处理早先提到的一些启动配置文件来更新 `grub.cfg` 文件。这种方法可以确保改动持久化，而在启动时刻通过 GRUB 传递的选项仅在当前会话期间有效。 + +### 修复 Linux GRUB 问题 + +如果你安装了第二个操作系统，或者由于人为失误而导致你的 GRUB 配置文件损坏了，依然有一些方法可以让你恢复并能够再次启动系统。 + +在启动画面中按下 `c` 键进入 GRUB 命令行模式（记住，你也可以按下 `e` 键编辑默认启动选项），并可以在 GRUB 提示中输入 `help` 命令获得可用命令： + +![](http://www.tecmint.com/wp-content/uploads/2016/03/Fix-Grub-Issues-in-Linux.png) +> 修复 Linux 的 Grub 配置问题 + +我们将会着重关注 **ls** 命令，它会列出已安装的设备和文件系统，并且我们将会看看它可以查找什么。在下面的图片中，我们可以看到有 4 块硬盘（`hd0` 到 `hd3`）。 + +貌似只有 `hd0` 已经分区了（msdos1 和 msdos2 可以证明，这里的 1 和 2 是分区号，msdos 则是分区方案）。 + +现在我们来看看能否在第一个分区 `hd0`（**msdos1**）上找到 GRUB。这种方法允许我们启动 Linux，并且使用高级工具修复配置文件或者如果有必要的话，干脆重新安装 GRUB： + +``` +# ls (hd0,msdos1)/ +``` + +从高亮区域可以发现，`grub2` 目录就在这个分区： + +![](http://www.tecmint.com/wp-content/uploads/2016/03/Find-Grub-Configuration.png) +> 查找 Grub 配置 + +一旦我们确信了 GRUB 位于 (**hd0, msdos1**)，那就让我们告诉 GRUB 该去哪儿查找它的配置文件并指示它去尝试启动它的菜单： + +``` +set prefix=(hd0,msdos1)/grub2 +set root=(hd0,msdos1) +insmod normal +normal +``` + +![](http://www.tecmint.com/wp-content/uploads/2016/03/Find-and-Launch-Grub-Menu.png) +> 查找并启动 Grub 菜单 + +然后，在 GRUB 菜单中，选择一个条目并按下 **Enter** 键以使用它启动。一旦系统成功启动后，你就可以运行 `grub2-install /dev/sdX` 命令修复问题了（将 `sdX` 改成你想要安装 GRUB 的设备）。然后启动信息将会更新，并且所有相关文件都会得到恢复。 + +``` +# grub2-install /dev/sdX +``` + +其它更加复杂的情景及其修复建议都记录在 [Ubuntu GRUB2 故障排除指南][10] 中。该指南中阐述的概念对于其它发行版也是有效的。 + +### 总结 + +本文向你介绍了 GRUB，并指导你可以在何处找到线上和线下的文档，同时说明了如何面对由于引导加载相关的问题而导致系统无法正常启动的情况。 + +幸运的是，GRUB 是文档支持非常丰富的工具之一，你可以使用我们在文中分享的资源非常轻松地获取已安装的文档或在线文档。 + +你有什么问题或建议吗？请不要犹豫，使用下面的评论框告诉我们吧。我们期待着来自你的回复！ + +-------------------------------------------------------------------------------- + +via: http://www.tecmint.com/configure-and-troubleshoot-grub-boot-loader-linux/ + +作者：[Gabriel Cánepa][a] +译者：[ChrisLeeGit](https://github.com/chrisleegit) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创翻译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: http://www.tecmint.com/author/gacanepa/ +[1]: http://www.tecmint.com/sed-command-to-create-edit-and-manipulate-files-in-linux/ +[2]: http://www.tecmint.com/installing-network-services-and-configuring-services-at-system-boot/ +[3]: http://www.tecmint.com/linux-boot-process/ +[4]: http://www.tecmint.com/linux-boot-process-and-manage-services/ +[5]: http://www.tecmint.com/best-linux-log-monitoring-and-management-tools/ +[6]: http://www.gnu.org/software/grub/manual/ +[7]: http://askubuntu.com/questions/82140/how-can-i-boot-with-an-older-kernel-version +[8]: https://www.kernel.org/doc/Documentation/kernel-parameters.txt +[9]: http://man7.org/linux/man-pages/man7/bootparam.7.html +[10]: https://help.ubuntu.com/community/Grub2/Troubleshooting diff --git a/translated/tech/awk/20160714 Part 8 - Learn How to Use Awk Variables, Numeric Expressions and Assignment Operators.md b/translated/tech/awk/20160714 Part 8 - Learn How to Use Awk Variables, Numeric Expressions and Assignment Operators.md new file mode 100644 index 0000000000..a5eb6b6df4 --- /dev/null +++ b/translated/tech/awk/20160714 Part 8 - Learn How to Use Awk Variables, Numeric Expressions and Assignment Operators.md @@ -0,0 +1,275 @@ + + +第 8 节－－学习怎样使用 Awk 变量，数值表达式以及赋值运算符 + +======================================================================================= + + +我相信 [Awk 命令系列][1] 将会令人兴奋不已，在系列的前几节我们讨论了在 Linux 中处理文件和筛选字符串需要的基本 Awk 命令。 + + +在这一部分，我们会对处理更复杂的文件和筛选字符串操作需要的更高级的命令进行讨论。因此，我们将会看到关于 Awk 的一些特性诸如变量，数值表达式和赋值运算符。 +![](http://www.tecmint.com/wp-content/uploads/2016/07/Learn-Awk-Variables-Numeric-Expressions-Assignment-Operators.png) +>学习 Awk 变量，数值表达式和赋值运算符 + +你可能已经在很多编程语言中接触过它们，比如 shell，C，Python等；这些概念在理解上和这些语言没有什么不同，所以在这一小节中你不用担心很难理解，我们将会简短的提及常用的一些 Awk 特性。 + +这一小节可能是 Awk 命令里最容易理解的部分，所以放松点，我们开始吧。 +### 1. Awk 变量 + + +在任何编程语言中，当你在程序中新建一个变量的时候这个变量就是一个存储了值的占位符，程序一运行就占用了一些内存空间，你为变量赋的值会存储在这些内存空间上。 + + +你可以像下面这样定义 shell 变量一样定义 Awk 变量： +``` +variable_name=value +``` + +上面的语法： + +- `variable_name`: 为定义的变量的名字 +- `value`: 为变量赋的值 + +再看下面的一些例子: +``` +computer_name=”tecmint.com” +port_no=”22” +email=”admin@tecmint.com” +server=”computer_name” +``` + +观察上面的简单的例子，在定义第一个变量的时候，值 'tecmint.com' 被赋给了 'computer_name' 变量。 + + +此外，值 22 也被赋给了 port_no 变量，把一个变量的值赋给另一个变量也是可以的，在最后的例子中我们把变量 computer_name 的值赋给了变量 server。 + +你可以看看 [本系列的第 2 节][2] 中提到的字段编辑，我们讨论了 Awk 怎样将输入的行分隔为若干字段并且使用标准的字段进行输入操作 ，$ 访问不同的被分配的字段。我们也可以像下面这样使用变量为字段赋值。 + +``` +first_name=$2 +second_name=$3 +``` + +在上面的例子中，变量 first_name 的值设置为第二个字段，second_name 的值设置为第三个字段。 + + +再举个例子，有一个名为 names.txt 的文件，这个文件包含了一个应用程序的用户列表，这个用户列表显示了用户的名字和曾用名以及性别。可以使用 [cat 命令][3] 查看文件内容： +``` +$ cat names.txt +``` + +![](http://www.tecmint.com/wp-content/uploads/2016/07/List-File-Content-Using-cat-Command.png) +>使用 cat 命令查看列表文件内容 + + +然后，我们也可以使用下面的 Awk 命令把列表中第一个用户的第一个和第二个名字分别存储到变量 first_name 和 second_name 上： +``` +$ awk '/Aaron/{ first_name=$2 ; second_name=$3 ; print first_name, second_name ; }' names.txt +``` + +![](http://www.tecmint.com/wp-content/uploads/2016/07/Store-Variables-Using-Awk-Command.png) +>使用 Awk 命令为变量赋值 + + +再看一个例子，当你在终端运行 'uname -a' 时，它可以打印出所有的系统信息。 + +第二个字段包含了你的 'hostname'，因此，我们可以像下面这样把它赋给一个叫做 hostname 的变量并且用 Awk 打印出来。 +``` +$ uname -a +$ uname -a | awk '{hostname=$2 ; print hostname ; }' +``` + +![](http://www.tecmint.com/wp-content/uploads/2016/07/Store-Command-Output-to-Variable-Using-Awk.png) +>使用 Awk 把命令的输出赋给变量 + +### 2. 数值表达式 + +在 Awk 中，数值表达式使用下面的数值运算符组成： + +- `*` : 乘法运算符 +- `+` : 加法运算符 +- `/` : 除法运算符 +- `-` : 减法运算符 +- `%` : 取模运算符 +- `^` : 指数运算符 + + +数值表达式的语法是： +``` +$ operand1 operator operand2 +``` + +上面的 operand1 和 operand2 可以是数值和变量，运算符可以是上面列出的任意一种。 + +下面是一些展示怎样使用数值表达式的例子： +``` +counter=0 +num1=5 +num2=10 +num3=num2-num1 +counter=counter+1 +``` + + +理解了 Awk 中数值表达式的用法，我们就可以看下面的例子了，文件 domians.txt 里包括了所有属于 Tecmint 的域名。 +``` +news.tecmint.com +tecmint.com +linuxsay.com +windows.tecmint.com +tecmint.com +news.tecmint.com +tecmint.com +linuxsay.com +tecmint.com +news.tecmint.com +tecmint.com +linuxsay.com +windows.tecmint.com +tecmint.com +``` + +可以使用下面的命令查看文件的内容; +``` +$ cat domains.txt +``` + +![](http://www.tecmint.com/wp-content/uploads/2016/07/View-Contents-of-File.png) +>查看文件内容 + + +如果想要计算出域名 tecmint.com 在文件中出现的次数，我们就可以通过写一个简单的脚本实现这个功能： +``` +#!/bin/bash +for file in $@; do +if [ -f $file ] ; then +#print out filename +echo "File is: $file" +#print a number incrementally for every line containing tecmint.com +awk '/^tecmint.com/ { counter=counter+1 ; printf "%s\n", counter ; }' $file +else +#print error info incase input is not a file +echo "$file is not a file, please specify a file." >&2 && exit 1 +fi +done +#terminate script with exit code 0 in case of successful execution +exit 0 +``` + +![](http://www.tecmint.com/wp-content/uploads/2016/07/Shell-Script-to-Count-a-String-in-File.png) +>计算一个字符串或文本在文件中出现次数的 shell 脚本 + + +写完脚本后保存并赋予执行权限，当我们使用文件运行脚本的时候，文件 domains.txt 作为脚本的输入，我们会得到下面的输出： + +``` +$ ./script.sh ~/domains.txt +``` + +![](http://www.tecmint.com/wp-content/uploads/2016/07/Script-To-Count-String.png) +>计算字符串或文本出现次数的脚本 + + +从脚本执行后的输出中，可以看到在文件 domains.txt 中包含域名 tecmint.com 的地方有 6 行，你可以自己计算进行验证。 + +### 3. 赋值操作符 + +我们要说的最后的 Awk 特性是赋值运算符，下面列出的只是 Awk 中的部分赋值运算符： + +- `*=` : 乘法赋值运算符 +- `+=` : 加法赋值运算符 +- `/=` : 除法赋值运算符 +- `-=` : 减法赋值运算符 +- `%=` : 取模赋值运算符 +- `^=` : 指数赋值运算符 + +下面是 Awk 中最简单的一个赋值操作的语法： +``` +$ variable_name=variable_name operator operand +``` + + +例子： + +``` +counter=0 +counter=counter+1 +num=20 +num=num-1 +``` + + +你可以使用在 Awk 中使用上面的赋值操作符使命令更简短，从先前的例子中，我们可以使用下面这种格式进行赋值操作： +``` +variable_name operator=operand +counter=0 +counter+=1 +num=20 +num-=1 +``` + + +因此，我们可以在 shell 脚本中改变 Awk 命令，使用上面提到的 += 操作符: +``` +#!/bin/bash +for file in $@; do +if [ -f $file ] ; then +#print out filename +echo "File is: $file" +#print a number incrementally for every line containing tecmint.com +awk '/^tecmint.com/ { counter+=1 ; printf "%s\n", counter ; }' $file +else +#print error info incase input is not a file +echo "$file is not a file, please specify a file." >&2 && exit 1 +fi +done +#terminate script with exit code 0 in case of successful execution +exit 0 +``` + + +![](http://www.tecmint.com/wp-content/uploads/2016/07/Alter-Shell-Script.png) +>改变了的 shell 脚本 + + +在 [Awk 系列][4] 的这一部分，我们讨论了一些有用的 Awk 特性，有变量，使用数值表达式和赋值运算符，还有一些使用他们的实例。 + +这些概念和其他的编程语言没有任何不同，但是可能在 Awk 中有一些意义上的区别。 + +在本系列的第 9 节，我们会学习更多的 Awk 特性，比如特殊格式： BEGIN 和 END。这也会与 Tecmit 有联系。 + +-------------------------------------------------------------------------------- + +via: http://www.tecmint.com/learn-awk-variables-numeric-expressions-and-assignment-operators/ + +作者：[Aaron Kili][a] +译者：[vim-kakali](https://github.com/vim-kakali) +校对：[校对ID](https://github.com/校对ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: http://www.tecmint.com/author/aaronkili/ + + + + + + + + + + + + + + + + + + + +[1]: http://www.tecmint.com/category/awk-command/ +[2]: http://www.tecmint.com/awk-print-fields-columns-with-space-separator/ +[3]: http://www.tecmint.com/13-basic-cat-command-examples-in-linux/ +[4]: http://www.tecmint.com/category/awk-command/ diff --git a/translated/tech/awk/20160719 Part 9 - Learn How to Use Awk Special Patterns begin and end.md b/translated/tech/awk/20160719 Part 9 - Learn How to Use Awk Special Patterns begin and end.md new file mode 100644 index 0000000000..378811776a --- /dev/null +++ b/translated/tech/awk/20160719 Part 9 - Learn How to Use Awk Special Patterns begin and end.md @@ -0,0 +1,166 @@ +awk 系列：如何使用 awk 的特殊模式 BEGIN 和 END +=============================================================== +在 awk 系列的第八节，我们介绍了一些强大的 awk 命令功能，它们是变量、数字表达式和赋值运算符。 + +本节我们将学习更多的 awk 功能，即 awk 的特殊模式：`BEGIN` 和 `END`。 + +![](http://www.tecmint.com/wp-content/uploads/2016/07/Learn-Awk-Patterns-BEGIN-and-END.png) +> 学习 awk 的模式 BEGIN 和 END + +随着我们逐渐展开，并探索出更多构建复杂 awk 操作的方法，将会证明 awk 的这些特殊功能的是多么强大。 + +开始前，先让我们回顾一下 awk 系列的介绍，记得当我们开始这个系列时，我就指出 awk 指令的通用语法是这样的： + +``` +# awk 'script' filenames +``` + +在上述语法中，awk 脚本拥有这样的形式： + +``` +/pattern/ { actions } +``` + +当你看脚本中的模式（`/pattern`）时，你会发现它通常是一个正则表达式，此外，你也可以将模式（`/pattern`）当成特殊模式 `BEGIN` 和 `END`。 +因此，我们也能按照下面的形式编写一条 awk 命令： + +``` +awk ' +BEGIN { actions } +/pattern/ { actions } +/pattern/ { actions } +………. +END { actions } +' filenames +``` + +假如你在 awk 脚本中使用了特殊模式：`BEGIN` 和 `END`，以下则是它们对应的含义： + +- `BEGIN` 模式：是指 awk 将在读取任何输入行之前立即执行 `BEGIN` 中指定的动作。 +- `END` 模式：是指 awk 将在它正式退出前执行 `END` 中指定的动作。 + +含有这些特殊模式的 awk 命令脚本的执行流程如下： + +- 当在脚本中使用了 `BEGIN` 模式，则 `BEGIN` 中所有的动作都会在读取任何输入行之前执行。 +- 然后，读入一个输入行并解析成不同的段。 +- 接下来，每一条指定的非特殊模式都会和输入行进行比较匹配，当匹配成功后，就会执行模式对应的动作。对所有你指定的模式重复此执行该步骤。 +- 再接下来，对于所有输入行重复执行步骤 2 和 步骤 3。 +- 当读取并处理完所有输入行后，假如你指定了 `END` 模式，那么将会执行相应的动作。 + +当你使用特殊模式时，想要在 awk 操作中获得最好的结果，你应当记住上面的执行顺序。 + +为了便于理解，让我们使用第八节的例子进行演示，那个例子是关于 Tecmint 拥有的域名列表，并保存在一个叫做 domains.txt 的文件中。 + +``` +news.tecmint.com +tecmint.com +linuxsay.com +windows.tecmint.com +tecmint.com +news.tecmint.com +tecmint.com +linuxsay.com +tecmint.com +news.tecmint.com +tecmint.com +linuxsay.com +windows.tecmint.com +tecmint.com +``` + +``` +$ cat ~/domains.txt +``` + +![](http://www.tecmint.com/wp-content/uploads/2016/07/View-Contents-of-File.png) +> 查看文件内容 + +在这个例子中，我们希望统计出 domains.txt 文件中域名 `tecmint.com` 出现的次数。所以，我们编写了一个简单的 shell 脚本帮助我们完成任务，它使用了变量、数学表达式和赋值运算符的思想，脚本内容如下： + +``` +#!/bin/bash +for file in $@; do +if [ -f $file ] ; then +# 输出文件名 +echo "File is: $file" +# 输出一个递增的数字记录包含 tecmint.com 的行数 +awk '/^tecmint.com/ { counter+=1 ; printf "%s\n", counter ; }' $file +else +# 若输入不是文件，则输出错误信息 +echo "$file 不是一个文件，请指定一个文件。" >&2 && exit 1 +fi +done +# 成功执行后使用退出代码 0 终止脚本 +exit 0 +``` + +现在让我们像下面这样在上述脚本的 awk 命令中应用这两个特殊模式：`BEGIN` 和 `END`： + +我们应当把脚本： + +``` +awk '/^tecmint.com/ { counter+=1 ; printf "%s\n", counter ; }' $file +``` + +改成： + +``` +awk ' BEGIN { print "文件中出现 tecmint.com 的次数是：" ; } +/^tecmint.com/ { counter+=1 ; } +END { printf "%s\n", counter ; } +' $file +``` + +在修改了 awk 命令之后，现在完整的 shell 脚本就像下面这样： + +``` +#!/bin/bash +for file in $@; do +if [ -f $file ] ; then +# 输出文件名 +echo "File is: $file" +# 输出文件中 tecmint.com 出现的总次数 +awk ' BEGIN { print "文件中出现 tecmint.com 的次数是：" ; } +/^tecmint.com/ { counter+=1 ; } +END { printf "%s\n", counter ; } +' $file +else +# 若输入不是文件，则输出错误信息 +echo "$file 不是一个文件，请指定一个文件。" >&2 && exit 1 +fi +done +# 成功执行后使用退出代码 0 终止脚本 +exit 0 +``` + +![](http://www.tecmint.com/wp-content/uploads/2016/07/Awk-BEGIN-and-END-Patterns.png) +> awk 模式 BEGIN 和 END + +当我们运行上面的脚本时，它会首先输出 domains.txt 文件的位置，然后执行 awk 命令脚本，该命令脚本中的特殊模式 `BEGIN` 将会在从文件读取任何行之前帮助我们输出这样的消息“`文件中出现 tecmint.com 的次数是：`”。 + +接下来，我们的模式 `/^tecmint.com/` 会在每个输入行中进行比较，对应的动作 `{ counter+=1 ; }` 会在每个匹配成功的行上执行，它会统计出 `tecmint.com` 在文件中出现的次数。 + +最终，`END` 模式将会输出域名 `tecmint.com` 在文件中出现的总次数。 + +``` +$ ./script.sh ~/domains.txt +``` +![](http://www.tecmint.com/wp-content/uploads/2016/07/Script-to-Count-Number-of-Times-String-Appears.png) +> 用于统计字符串出现次数的脚本 + +最后总结一下，我们在本节中演示了更多的 awk 功能，并学习了特殊模式 `BEGIN` 和 `END` 的概念。 + +正如我之前所言，这些 awk 功能将会帮助我们构建出更复杂的文本过滤操作。第十节将会给出更多的 awk 功能，我们将会学习 awk 内置变量的思想，所以，请继续保持关注。 + + +-------------------------------------------------------------------------------- + +via: http://www.tecmint.com/learn-use-awk-special-patterns-begin-and-end/ + +作者：[Aaron Kili][a] +译者：[ChrisLeeGit](https://github.com/chrisleegit) +校对：[校对ID](https://github.com/校对ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: http://www.tecmint.com/author/aaronkili/