title: Asynchronous shell exec in PHP
body: <p>I've got a PHP script that needs to invoke a shell script but doesn't care at all about the output. The shell script makes a number of SOAP calls and is slow to complete, so I don't want to slow down the PHP request while it waits for a reply. In fact, the PHP request should be able to exit without terminating the shell process.</p>
  
  <p>I've looked into the various <code>exec()</code>, <code>shell_exec()</code>, <code>pcntl_fork()</code>, etc. functions, but none of them seem to offer exactly what I want. (Or, if they do, it's not clear to me how.) Any suggestions?</p>