(PHP 4, PHP 5, PHP 7) Set/get the various assert flags

(PHP 4, PHP 5, PHP 7) Gets the version of the current Zend engine

(PHP 4 >= 4.3.0, PHP 5, PHP 7) Gets the current include_path configuration option

(PHP 5 >= 5.2.0, PHP 7) Returns the peak of memory allocated by PHP

(PHP 4, PHP 5, PHP 7) Gets the value of an environment variable

(PHP 4 >= 4.1.0, PHP 5, PHP 7) Returns an associative array with the names of all the constants and their

(PHP 5 >= 5.3.0, PHP 7) Activates the circular reference collector

(PHP 5, PHP 7 >= 5.5.0, PHP 7) Sets the process title

(PHP 4, PHP 5, PHP 7) Returns an array with the names of included or required files

(PHP 4, PHP 5, PHP 7) Returns an array with the names of all modules compiled and loaded