I'm trying to write a website in PHP that allows the user to enter PHP code, and then be able to run it on my server. However, I want to be able to disable certain features (file access, database access, etc.). Basically, I want the code to run without any risk to my server, and if the code does attempt to do something dangerous, I just want the code to stop running (I don't mind if it just stops, produces an error, or carries on while ignoring the dangerous code).
Is this possible, and if so, how could I achieve this? Thanks :)
It is possible using libraries that do some simple checking or limiting.
Take a look at a PECL (PHP Extensions) extension called RunKit_Sandbox http://php.net/manual/en/runkit.sandbox.php or PHPSandbox.
The key to look for on Google is PHP Sandbox, it will find you similar libraries.