title: Why does execve() does not return on success?
body: <p>I have read the man pages.</p>
  
  <p>All I understood from this link <a href="http://support.sas.com/documentation/onlinedoc/sasc/doc750/html/lr2/zid-7281.htm" rel="nofollow">http://support.sas.com/documentation/onlinedoc/sasc/doc750/html/lr2/zid-7281.htm</a> is that 
  <code>A successful call to execve does not have a return value because the new process image overlays the calling process image</code></p>
  
  <p>I am not very clear as to why this will happen ? And if the new process overlays the calling process, why does it return on failure only and not on success ?</p>