How can I allow only specified functions to be executed and disable all others?
<p>I am planning on allowing certain (registered &amp; vetted) users to post php code and/or upload a php file that I will execute in a sandbox environment.</p>

<p>I am aware of how much a bad idea this sounds and the possible security holes I could open.</p>

<p>I'm also going to be doing things like setting strict, short execution times, max runs of a script per day, running the webserver user as unprivileged, et cetera.</p>

<p>I'm aware that I can disallow usage of certain functions in php.ini, but I want to know if it's possible to disable all functions (without putting every single one in php.ini) but allow the use of certain functions that I have vetted and think are safe to allow?</p>
