(PHP 4, PHP 5, PHP 7) Find out whether an extension is loaded

(PHP 4 >= 4.3.0, PHP 5, PHP 7) Gets options from the command line argument list

(PHP 4, PHP 5, PHP 7) Gets the inode of the current script

(PHP 4, PHP 5) Alias of

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

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

(PHP 4 >= 4.0.2, PHP 5, PHP 7) Returns information about the operating system PHP is running on

(PHP 4 >= 4.1.0, PHP 5, PHP 7) Get PHP script owner's GID

(PHP 4 >= 4.1.0, PHP 5, PHP 7) Compares two "PHP-standardized" version number strings

(PHP 4, PHP 5, PHP 7) Limits the maximum execution time