title: How do I read the source code of shell commands?
body: <p>I would like to read the actual source code which the linux commands are written with. I've gained some experience using them and now I think it's time to interact with my machine at a deeper level. </p>
  
  <p>I've found some commands here <a href="http://directory.fsf.org/wiki/GNU" rel="noreferrer">http://directory.fsf.org/wiki/GNU</a>. Unfortunately I wasn't able to find basic commands such as 'ls' which seems to me easy enough to begin. </p>
  
  <p>How exactly do I read the source code of the simple shell commands like 'ls'? 
  I'm running on Ubuntu 12.04</p>