(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, 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) 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 >= 4.0.1, PHP 5, PHP 7) Create an anonymous (lambda-style) function