title: What does os.execl do exactly? Why am I getting this error?
body: <p>I'm running into some trouble with deploying Django on the passenger_wsgi module with virtualenv. The Python code in the passenger_wsgi.py file, which should fix my problem is:</p>
  
  <pre><code>import os, sys
  INTERP = '/home/login/.virtualenvs/env_name/bin/python'
  if sys.executable != INTERP:
      os.execl(INTERP, INTERP, *sys.argv)
  </code></pre>
  
  <p>The first three lines I understand, but I only have a very vague idea about the fourth one and that's the one that happens to be giving me an error:</p>
  
  <blockquote>
    <p><code>/home/login/.virtualenvs/env_name/bin/python: can't find '__main__.py' in ''</code></p>
  </blockquote>
  
  <p>So what is os.execl doing here exactly? And what does that error message mean?</p>