(PHP 4 >= 4.0.3, PHP 5, PHP 7) Register a function for execution on each tick

(PHP 4, PHP 5, PHP 7) Register a function for execution on shutdown

(PHP 4, PHP 5, PHP 7) Returns an array comprising a function's argument list

(PHP 4, PHP 5, PHP 7) Return an item from the argument list

(PHP 4, PHP 5, PHP 7) Returns the number of arguments passed to the function

(PHP 4, PHP 5, PHP 7) Call the callback given by the first parameter

(PHP 4 >= 4.0.4, PHP 5, PHP 7) Call a callback with an array of parameters

(PHP 4 >= 4.0.4, PHP 5, PHP 7) Returns an array of all defined functions

(PHP 4 >= 4.0.3, PHP 5, PHP 7) De-register a function for execution on each tick

(PHP 4, PHP 5, PHP 7) Return TRUE if the given function has been defined