PHP 4, PHP 5, PHP 7, PHP 8
shm_put_var - Inserts or updates a variable in shared memory

shm_put_var( SysvSharedMemory$shm, int$key, mixed$value ): bool

shm_put_var inserts or updates the value with the given key.

Warnings (E_WARNING level) will be issued if shm is not a valid SysV shared memory index or if there was not enough shared memory remaining to complete your request.



A shared memory segment obtained from shm_attach.


The variable key.


The variable. All variable types that serialize supports may be used: generally this means all types except for resources and some internal objects that cannot be serialized.

Return Values

Returns true on success or false on failure.


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

Related Functions

Function shm_put_var:

  • Manual

Semaphore, Shared Memory and IPC Functions

Most used PHP functions