(PECL uopz >= 2.0.2) Get or set flags on function or class

(PHP 5 >= 5.2.0, PHP 7) Get the last occurred error

(PECL runkit >= 0.8.0) Determines if the current functions return value will be used

(PECL apc >= 3.1.4) Checks if APC key exists

(PECL wincache >= 1.0.0) Retrieves information about opcode cache memory usage

(PECL wincache >= 1.1.0) Retrieves information about session cache memory usage

(PHP 4, PHP 5, PHP 7) Prints out the credits for PHP

(PHP 5, PHP 7) Returns a unique identifier for the current thread

(PECL apd 0.2-0.4) Return all persistent resources as an array

(PECL uopz >= 1.0.0) Rename a function at runtime