shm_attach Creates or open a shared memory segment &reftitle.description; intshm_attach intkey intmemsize intperm 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 memsize and the optional perm-bits perm. A second call to shm_attach for the same key will return a different shared memory identifier, but both identifiers access the same underlying shared memory. memsize and perm will be ignored. &reftitle.parameters; key memsize The memory size. If not provided, default to the sysvshm.init_mem in the &php.ini;, otherwise 10000 bytes. perm The optional permission bits. Default to 0666. &reftitle.returnvalues; Returns a shared memory segment identifier. &reftitle.seealso; sem_detach ftok