title: What is a good Linux exit error code strategy?
body: <p>I have several independent executable Perl, PHP CLI scripts and C++ programs for which I need to develop an exit error code strategy.  These programs are called by other programs using a wrapper class I created to use <code>exec()</code> in PHP.  So, I will be able to get an error code back.  Based on that error code, the calling script will need to do something.  </p>
  
  <p>I have done a little bit of research and it seems like anything in the 1-254 (or maybe just 1-127) range could be fair game to user-defined error codes.  </p>
  
  <p>I was just wondering how other people have approached error handling in this situation.</p>