shm_attach
shm_attach returns an id that can be used to access the System V shared memory with the given key, the first call creates the shared memory segment with size and the optional perm-bits permissions.
A second call to shm_attach for the same key will return a different SysvSharedMemory instance, but both instances access the same underlying shared memory. size and permissions will be ignored.
Parameters
- key
-
A numeric shared memory segment ID
- size
-
The memory size. If not provided, default to the sysvshm.init_mem in the php.ini, otherwise 10000 bytes.
- permissions
-
The optional permission bits. Default to 0666.
Return Values
Returns a SysvSharedMemory instance on success, or false on failure.
Changelog
| Version | Description |
| 8.0.0 | On success, this function returns an SysvSharedMemory instance now; previously, a resource was returned. |
| 8.0.0 | size is nullable now. |