sys/semaphore.h

int sem_close(sem_t *)

sem_close(2) — close a named semaphore

sem_t * sem_open(const char *, int, ...)

sem_open(2) — initialize and open a named semaphore

int sem_post(sem_t *)

sem_post(2) — unlock a semaphore

int sem_unlink(const char *)

sem_unlink(2) — remove a named semaphore