(PHP 4, PHP 5, PHP 7) Tells what the user's browser is capable of

(PHP 5 >= 5.1.3, PHP 7) Gets system load average

(PHP 4, PHP 5, PHP 7) Equivalent to exit

(PHP 4, PHP 5, PHP 7) Returns connection status bitfield

(PHP 4, PHP 5, PHP 7) Alias of

(PHP 5 >= 5.1.0, PHP 7) Make the script sleep until the specified time

(PHP 5, PHP 7) Return source with stripped comments and whitespace

(PHP 4, PHP 5, PHP 7) Output a message and terminate the current script

(PHP 4, PHP 5, PHP 7) Defines a named constant

(PHP 4 >= 4.0.4, PHP 5, PHP 7) Returns the value of a constant