(PHP 4, PHP 5, PHP 7) Gets the current PHP version

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

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

(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, PHP 5) Sets the current active configuration setting of magic_quotes_runtime

(PHP 4, PHP 5, PHP 7) Sets the value of a configuration option

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