title: How to lookup the meaning of exit codes for Linux command line utilities?
body: <p>I have my prompt (bash) configured to print out the exit code from the last command, if it wasn't successful (aka not zero). Therefore I'm seeing a lot of exit codes, even when a program seems to encounter no problems. <strong>Is there a way to lookup the meaning of these exit codes?</strong></p>
  
  <p>I always try the man pages, info pages or the "--help" option, but to no avail.</p>
  
  <p>To clarify, I'm asking about the utilities that come with Linux, like <code>cd</code>, <code>ls</code>, <code>du</code>, ...</p>