(PHP 5 >= 5.3.0, PHP 7) Check whether a message queue exists

(PHP 4 >= 4.3.0, PHP 5, PHP 7) Returns information from the message queue data structure

(PHP 4 >= 4.2.0, PHP 5, PHP 7) Convert a pathname and a project identifier to a System V IPC key

(PHP 4, PHP 5, PHP 7) Release a semaphore bool

(PHP 4 >= 4.3.0, PHP 5, PHP 7) Set information in the message queue data structure

(PHP 4, PHP 5, PHP 7) Removes a variable from shared memory

(PHP 4, PHP 5, PHP 7) Disconnects from shared memory segment

(PHP 4, PHP 5, PHP 7) Returns a variable from shared memory

(PHP 4 >= 4.3.0, PHP 5, PHP 7) Send a message to a message queue

(PHP 4 >= 4.3.0, PHP 5, PHP 7) Receive a message from a message queue