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shm_remove	SysvMessageQueue

Semaphore Functions	Last updated: Mon, 26 Oct 2026

shm_remove_var

(PHP 4, PHP 5, PHP 7, PHP 8)

shm_remove_var — Removes a variable from shared memory

Description

function shm_remove_var(SysvSharedMemory $shm, int $key): bool

Removes a variable with a given key and frees the occupied memory.

Parameters

shm: A shared memory segment obtained from shm_attach().
key: The variable key.

Return Values

Returns true on success or false on failure.

Errors/Exceptions

Throws an Error if shm has already been detached with shm_detach().

Changelog

Version	Description
8.0.0	`shm` expects a SysvSharedMemory instance now; previously, a resource was expected.

See Also

shm_remove() - Removes shared memory from Unix systems

shm_remove	SysvMessageQueue

Semaphore Functions	Last updated: Mon, 26 Oct 2026