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

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

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

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

(PHP 5 >= 5.3.0, PHP 7) Call a static method