From 618f5ca9d1c2ddd6813e7a024c75ea1aa20448d5 Mon Sep 17 00:00:00 2001 From: xllc <392137944@qq.com> Date: Wed, 14 Jun 2017 22:31:03 +0800 Subject: [PATCH] Delete 20170515 How I got started with bash scripting.md --- ...5 How I got started with bash scripting.md | 138 ------------------ 1 file changed, 138 deletions(-) delete mode 100644 sources/talk/20170515 How I got started with bash scripting.md diff --git a/sources/talk/20170515 How I got started with bash scripting.md b/sources/talk/20170515 How I got started with bash scripting.md deleted file mode 100644 index 67c10ae521..0000000000 --- a/sources/talk/20170515 How I got started with bash scripting.md +++ /dev/null @@ -1,138 +0,0 @@ -【xllc翻译中】 - -How I got started with bash scripting -============================================================ - -### With a few simple Google searches, a programming novice learned to write code that automates a previously tedious and time-consuming task. - - - -![How Google helped me learn bash scripting](https://opensource.com/sites/default/files/styles/image-full-size/public/images/life/computer_happy_sad_developer_programming.png?itok=5E3k_t_r "How Google helped me learn bash scripting") ->Image by : opensource.com - -I wrote a script the other day. For some of you, that sentence sounds like no big deal. For others, and I know you're out there, that sentence is significant. You see, I'm not a programmer. I'm a writer. - -### What I needed to solve - -My problem was fairly simple: I had to juggle files from engineering into our documentation. The files were available in a .zip format from a web URL. I was copying them to my desktop manually, then moving them into a different directory structure to match my documentation needs. A fellow writer gave me this advice:  _"Why don't you just write a script to do this for you?"_ - -Programming and development - -* [New Python content][1] - -* [Our latest JavaScript articles][2] - -* [Recent Perl posts][3] - -* [Red Hat Developers Blog][4] - -​ - -I thought  _"just write a script?!?"_ —as if it was the easiest thing in the world to do. - -### How Google came to the rescue - -My colleague's question got me thinking, and as I thought, I googled. - -**What scripting languages are on Linux?** - -This was my first Google search criteria, and many of you are probably thinking, "She's pretty clueless." Well, I was, but it did set me on a path to solving my problem. The most common result was Bash. Hmm, I've seen Bash. Heck, one of the files I had to document had Bash in it, that ubiquitous line **#!/bin/bash**. I took another look at that file, and I knew what it was doing because I had to document it. - -So that led me to my next Google search request. - -**How to download a zip file from a URL?** - -That was my basic task really. I had a URL with a .zip file containing all the files I needed to include in my documentation, so I asked the All Powerful Google to help me out. That search gem, and a few more, led me to Curl. But here's the best part: Not only did I find Curl, one of the top search hits showed me a Bash script that used Curl to download a .zip file and extract it. That was more than I asked for, but that's when I realized being specific in my Google search requests could give me the information I needed to write this script. So, momentum in my favor, I wrote the simplest of scripts: - -``` -#!/bin/sh - -curl http://rather.long.url | tar -xz -C my_directory --strip-components=1 -``` - -What a moment to see that thing run! But then I realized one gotcha: The URL can change, depending on which set of files I'm trying to access. I had another problem to solve, which led me to my next search. - -**How to pass parameters into a Bash script?** - -I needed to be able to run this script with different URLs and different end directories. Google showed me how to put in **$1**, **$2**, etc., to replace what I typed on the command line with my script. For example: - -``` -bash myscript.sh http://rather.long.url my_directory -``` - -That was much better. Everything was working as I needed it to, I had flexibility, I had a working script, and most of all, I had a short command to type and save myself 30 minutes of copy-paste grunt work. That was a morning well spent. - -Then I realized I had one more problem. You see, my memory is short, and I knew I'd run this script only every couple of months. That left me with two issues: - -* How would I remember what to type for my script (URL first? directory first?)? - -* How would another writer know how to run my script if I got hit by a truck? - -I needed a usage message—something the script would display if I didn't use it correctly. For example: - -``` -usage: bash yaml-fetch.sh <'snapshot_url'> -``` - -Otherwise, run the script. My next search was: - -**How to write "if/then/else" in a Bash script?** - -Fortunately I already knew **if/then/else** existed in programming. I just had to find out how to do that. Along the way, I also learned to print from a Bash script using **echo**. What I ended up with was something like this: - -``` -#!/bin/sh - -URL=$1 -DIRECTORY=$2 - -if [ $# -eq 0 ]; - then - echo "usage: bash yaml-fetch.sh <'snapshot_url'> ". - else - - # make the directory if it doesn't already exist - echo 'create directory' - - mkdir $DIRECTORY - - # fetch and untar the yaml files - echo 'fetch and untar the yaml files' - - curl $URL | tar -xz -C $DIRECTORY --strip-components=1 -fi -``` - -### How Google and scripting rocked my world - -Okay, slight exaggeration there, but this being the 21st century, learning new things (especially somewhat simple things) is a whole lot easier than it used to be. What I learned (besides how to write a short, self-documented Bash script) is that if I have a question, there's a good chance someone else had the same or a similar question before. When I get stumped, I can ask the next question, and the next question. And in the end, not only do I have a script, I have the start of a new skill that I can hold onto and use to simplify other tasks I've been avoiding. - -Don't let that first script (or programming step) get the best of you. It's a skill, like any other, and there's a wealth of information out there to help you along the way. You don't need to read a massive book or take a month-long course. You can do it a simpler way with baby steps and baby scripts that get you started, then build on that skill and your confidence. There will always be a need for folks to write those thousands-of-lines-of-code programs with all the branching and merging and bug-fixing. - -But there is also a strong need for simple scripts and other ways to automate/simplify tasks. And that's where a little script and a little confidence can give you a kickstart. - --------------------------------------------------------------------------------- - -作者简介： - -Sandra McCann - Sandra McCann is a Linux and open source advocate. She's worked as a software developer, content architect for learning resources, and content creator. Sandra is currently a content creator for Red Hat in Westford, MA focusing on OpenStack and NFV techology. - ----- - -via: https://opensource.com/article/17/5/how-i-learned-bash-scripting - -作者：[ Sandra McCann ][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/sandra-mccann -[1]:https://opensource.com/tags/python?src=programming_resource_menu -[2]:https://opensource.com/tags/javascript?src=programming_resource_menu -[3]:https://opensource.com/tags/perl?src=programming_resource_menu -[4]:https://developers.redhat.com/?intcmp=7016000000127cYAAQ&src=programming_resource_menu -[5]:https://opensource.com/article/17/5/how-i-learned-bash-scripting?rate=s_R-jmOxcMvs9bi41yRwenl7GINDvbIFYrUMIJ8OBYk -[6]:https://opensource.com/user/39771/feed -[7]:https://opensource.com/article/17/5/how-i-learned-bash-scripting#comments -[8]:https://opensource.com/users/sandra-mccann