title: Where is the source code for understanding linux commands?
body: <p>I'd like to know where the source code for the commands are in the linux tree. </p>
  
  <p>Some commands:</p>
  
  <ul>
  <li>mkdir</li>
  <li>ls</li>
  <li>dir</li>
  <li>chmod</li>
  <li>etc</li>
  </ul>
  
  <p>Right now I'd just like to read the code and understand it, I know there are many more steps in understanding how linux works, but right now I really want to understand how the OS receives the command and how it calls the correct command</p>