sem_get Get a semaphore id &reftitle.description; resourcesem_get intkey intmax_acquire1 intperm0666 intauto_release1 sem_get returns an id that can be used to access the System V semaphore with the given key. A second call to sem_get for the same key will return a different semaphore identifier, but both identifiers access the same underlying semaphore. &reftitle.parameters; key max_acquire The number of processes that can acquire the semaphore simultaneously is set to max_acquire. perm The semaphore permissions. Actually this value is set only if the process finds it is the only process currently attached to the semaphore. auto_release Specifies if the semaphore should be automatically released on request shutdown. &reftitle.returnvalues; Returns a positive semaphore identifier on success, or &false; on error. &reftitle.notes; When using sem_get to access a semaphore created outside PHP, note that the semaphore must have been created as a set of 3 semaphores (for example, by specifying 3 as the nsems parameter when calling the C semget() function), otherwise PHP will be unable to access the semaphore. &reftitle.seealso; sem_acquire sem_release ftok