diff --git a/sources/tech/20150115 20 Unix Command Line Tricks--Part I.md b/sources/tech/20150115 20 Unix Command Line Tricks--Part I.md new file mode 100644 index 0000000000..af1218d6df --- /dev/null +++ b/sources/tech/20150115 20 Unix Command Line Tricks--Part I.md @@ -0,0 +1,303 @@ +20 Unix Command Line Tricks – Part I +================================================================================ +Let us start new year with **these Unix command line tricks** to increase productivity at the Terminal. I have found them over the years and I'm now going to share with you. + +![](http://s0.cyberciti.org/uploads/cms/2015/01/unix-command-line-tricks.001.jpg) + +### Deleting a HUGE file ### + +I had a huge log file 200GB I need to delete on a production web server. My rm and ls command was crashed and I was afraid that the system to a crawl with huge disk I/O load. To remove a HUGE file, enter: + + > /path/to/file.log + # or use the following syntax + : > /path/to/file.log + + # finally delete it + rm /path/to/file.log + +### Want to cache console output? ### + +Try the script command line utility to create a typescript of everything printed on your terminal. + + script my.terminal.sessio + +Type commands: + + ls + date + sudo service foo stop + +To exit (to end script session) type *exit* or *logout* or press *control-D* + + exit + +To view type: + + more my.terminal.session + less my.terminal.session + cat my.terminal.session + +### Restoring deleted /tmp folder ### + +As my journey continues with [Linux and Unix shell, I made a few mistakes][1]. I accidentally deleted /tmp folder. To restore it all you have to do is: + + mkdir /tmp + chmod 1777 /tmp + chown root:root /tmp + ls -ld /tmp + +### Locking a directory ### + +For privacy of my data I wanted to lock down /downloads on my file server. So I ran: + + chmod 0000 /downloads + +The root user can still has access and ls and cd commands will not work. To go back: + + chmod 0755 /downloads + +### Password protecting file in vim text editor ### + +Afraid that root user or someone may snoop into your personal text files? Try password protection to a file in vim, type: + + vim +X filename + +Or, before quitting in vim use :X vim command to encrypt your file and vim will prompt for a password. + +### Clear gibberish all over the screen ### + +Just type: + + reset + +### Becoming human ### + +Pass the *-h* or *-H* (and other options) command line option to GNU or BSD utilities to get output of command commands like ls, df, du, in human-understandable formats: + + ls -lh + # print sizes in human readable format (e.g., 1K 234M 2G) + df -h + df -k + # show output in bytes, KB, MB, or GB + free -b + free -k + free -m + free -g + # print sizes in human readable format (e.g., 1K 234M 2G) + du -h + # get file system perms in human readable format + stat -c %A /boot + # compare human readable numbers + sort -h -a file + # display the CPU information in human readable format on a Linux + lscpu + lscpu -e + lscpu -e=cpu,node + # Show the size of each file but in a more human readable way + tree -h + tree -h /boot + +### Show information about known users in the Linux based system ### + +Just type: + + ## linux version ## + lslogins + + ## BSD version ## + logins + +Sample outputs: + + UID USER PWD-LOCK PWD-DENY LAST-LOGIN GECOS + 0 root 0 0 22:37:59 root + 1 bin 0 1 bin + 2 daemon 0 1 daemon + 3 adm 0 1 adm + 4 lp 0 1 lp + 5 sync 0 1 sync + 6 shutdown 0 1 2014-Dec17 shutdown + 7 halt 0 1 halt + 8 mail 0 1 mail + 10 uucp 0 1 uucp + 11 operator 0 1 operator + 12 games 0 1 games + 13 gopher 0 1 gopher + 14 ftp 0 1 FTP User + 27 mysql 0 1 MySQL Server + 38 ntp 0 1 + 48 apache 0 1 Apache + 68 haldaemon 0 1 HAL daemon + 69 vcsa 0 1 virtual console memory owner + 72 tcpdump 0 1 + 74 sshd 0 1 Privilege-separated SSH + 81 dbus 0 1 System message bus + 89 postfix 0 1 + 99 nobody 0 1 Nobody + 173 abrt 0 1 + 497 vnstat 0 1 vnStat user + 498 nginx 0 1 nginx user + 499 saslauth 0 1 "Saslauthd user" + +### How do I fix mess created by accidentally untarred files in the current dir? ### + +So I accidentally untar a tarball in /var/www/html/ directory instead of /home/projects/www/current. It created mess in /var/www/html/. The easiest way to fix this mess: + + cd /var/www/html/ + /bin/rm -f "$(tar ztf /path/to/file.tar.gz)" + +### Confused on a top command output? ### + +Seriously, you need to try out htop instead of top: + + sudo htop + +### Want to run the same command again? ### + +Just type !!. For example: + + /myhome/dir/script/name arg1 arg2 + + # To run the same command again + !! + + ## To run the last command again as root user + sudo !! + +The !! repeats the most recent command. To run the most recent command beginning with "foo": + + !foo + # Run the most recent command beginning with "service" as root + sudo !service + +The !$ use to run command with the last argument of the most recent command: + + # Edit nginx.conf + sudo vi /etc/nginx/nginx.conf + + # Test nginx.conf for errors + /sbin/nginx -t -c /etc/nginx/nginx.conf + + # After testing a file with "/sbin/nginx -t -c /etc/nginx/nginx.conf", you + # can edit file again with vi + sudo vi !$ + +### ###Get a reminder you when you have to leave + +If you need a reminder to leave your terminal, type the following command: + + leave +hhmm + +Where, + +- **hhmm** - The time of day is in the form hhmm where hh is a time in hours (on a 12 or 24 hour clock), and mm are minutes. All times are converted to a 12 hour clock, and assumed to be in the next 12 hours. + +### Home sweet home ### + +Want to go the directory you were just in? Run: + + cd - + +Need to quickly return to your home directory? Enter: + + cd + +The variable *CDPATH* defines the search path for the directory containing directories: + + export CDPATH=/var/www:/nas10 + +Now, instead of typing cd */var/www/html/* I can simply type the following to cd into /var/www/html path: + + cd html + +### Editing a file being viewed with less pager ### + +To edit a file being viewed with less pager, press v. You will have the file for edit under $EDITOR: + + less *.c + less foo.html + ## Press v to edit file ## + ## Quit from editor and you would return to the less pager again ## + +### List all files or directories on your system ### + +To see all of the directories on your system, run: + + find / -type d | less + + # List all directories in your $HOME + find $HOME -type d -ls | less + +To see all of the files, run: + + find / -type f | less + + # List all files in your $HOME + find $HOME -type f -ls | less + +### Build directory trees in a single command ### + +You can create directory trees one at a time using mkdir command by passing the -p option: + + mkdir -p /jail/{dev,bin,sbin,etc,usr,lib,lib64} + ls -l /jail/ + +### Copy file into multiple directories ### + +Instead of running: + + cp /path/to/file /usr/dir1 + cp /path/to/file /var/dir2 + cp /path/to/file /nas/dir3 + +Run the following command to copy file into multiple dirs: + + echo /usr/dir1 /var/dir2 /nas/dir3 | xargs -n 1 cp -v /path/to/file + +[Creating a shell function][2] is left as an exercise for the reader + +### Quickly find differences between two directories ### + +The diff command compare files line by line. It can also compare two directories: + + ls -l /tmp/r + ls -l /tmp/s + # Compare two folders using diff ## + diff /tmp/r/ /tmp/s/ + +[![Fig. : Finding differences between folders](http://s0.cyberciti.org/uploads/cms/2015/01/differences-between-folders.jpg)][3] + +Fig. : Finding differences between folders + +### Text formatting ### + +You can reformat each paragraph with fmt command. In this example, I'm going to reformat file by wrapping overlong lines and filling short lines: + + fmt file.txt + +You can also split long lines, but do not refill i.e. wrap overlong lines, but do not fill short lines: + + fmt -s file.txt + +### See the output and write it to a file ### + +Use the tee command as follows to see the output on screen and also write to a log file named my.log: + + mycoolapp arg1 arg2 input.file | tee my.log + +The tee command ensures that you will see mycoolapp output on on the screen and to a file same time. + +-------------------------------------------------------------------------------- + +via: http://www.cyberciti.biz/open-source/command-line-hacks/20-unix-command-line-tricks-part-i/ + +作者：[nixCraft][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](http://linux.cn/) 荣誉推出 + +[a]:http://www.cyberciti.biz/tips/about-us +[1]:http://www.cyberciti.biz/tips/my-10-unix-command-line-mistakes.html +[2]:http://bash.cyberciti.biz/guide/Writing_your_first_shell_function +[3]:http://www.cyberciti.biz/open-source/command-line-hacks/20-unix-command-line-tricks-part-i/attachment/differences-between-folders/ \ No newline at end of file diff --git a/sources/tech/20150115 How To Extract a Tar Files To a Different Directory on a Linux or Unix-like Systems.md b/sources/tech/20150115 How To Extract a Tar Files To a Different Directory on a Linux or Unix-like Systems.md new file mode 100644 index 0000000000..bae3c66664 --- /dev/null +++ b/sources/tech/20150115 How To Extract a Tar Files To a Different Directory on a Linux or Unix-like Systems.md @@ -0,0 +1,63 @@ +How To Extract a Tar Files To a Different Directory on a Linux/Unix-like Systems +================================================================================ +I want to extract tar file to specific directory called /tmp/data. How can I extract a tar archive to a different directory using tar command on a Linux or Unix-like systems? + +You do not need to change the directory using cd command and extract files. Untarring a file can be done using the following syntax: + +### Syntax ### + +Typical Unix tar syntax: + + tar -xf file.name.tar -C /path/to/directory + +GNU/tar syntax: + + tar xf file.tar -C /path/to/directory + + tar xf file.tar --directory /path/to/directory + +### Example: Extract files to another directory ### + +In this example, I'm extracting $HOME/etc.backup.tar file to a directory called /tmp/data. First, you have to create the directory manually, enter: + + mkdir /tmp/data + +To extract a tar archive $HOME/etc.backup.tar into a /tmp/data, enter: + + tar -xf $HOME/etc.backup.tar -C /tmp/data + +To see a progress pass the -v option: + + tar -xvf $HOME/etc.backup.tar -C /tmp/data + +Sample outputs: + +![Gif 01: tar Command Extract Archive To Different Directory Command](http://s0.cyberciti.org/uploads/faq/2015/01/tar-extract-archive-to-dir.gif) + +Gif 01: tar Command Extract Archive To Different Directory Command + +You can extract specific files too use: + + tar -xvf $HOME/etc.backup.tar file1 file2 file3 dir1 -C /tmp/data + +To extract a foo.tar.gz (.tgz extension file) tarball to /tmp/bar, enter: + + mkdir /tmp/bar + tar -zxvf foo.tar.gz -C /tmp/bar + +To extract a foo.tar.bz2 (.tbz, .tbz2 & .tb2 extension file) tarball to /tmp/bar, enter: + + mkdir /tmp/bar + tar -jxvf foo.tar.bz2 -C /tmp/bar + +-------------------------------------------------------------------------------- + +via: http://www.cyberciti.biz/faq/howto-extract-tar-file-to-specific-directory-on-unixlinux/ + +作者：[nixCraft][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](http://linux.cn/) 荣誉推出 + +[a]:http://www.cyberciti.biz/tips/about-us \ No newline at end of file