SEM_UNLINK(3) Library Functions Manual SEM_UNLINK(3)

sem_unlink — remove a named semaphore (REALTIME)

#include <semaphore.h>

int sem_unlink(const char *name);

The sem_unlink() function removes the semaphore named by the string name . If the semaphore named by name is currently referenced by other processes, then sem_unlink() has no effect on the state of the semaphore. If one or more processes have the semaphore open when sem_unlink() is called, destruction of the semaphore is postponed until all references to the semaphore have been destroyed by calls to sem_close(3) , _exit(3) , or exec . Calls to sem_open(3) to re-create or re-connect to the semaphore refer to a new semaphore after sem_unlink() is called. The sem_unlink() call does not block until all references have been destroyed; it returns immediately.

Upon successful completion, the function returns a value of 0. Otherwise, the semaphore is not changed and the function returns a value of -1 and sets errno to indicate the error.

The sem_unlink() function will fail if:

Permission is denied to unlink the named semaphore.
The length of the name string exceeds {NAME_MAX} while {POSIX_NO_TRUNC} is in effect.
The named semaphore does not exist.
The function sem_unlink() is not supported by this implementation.

None.

None.

None.

semctl(3) , semget(3) , semop(3) , sem_close(3) , sem_open(3) , <semaphore.h> .

Derived from the POSIX Realtime Extension (1003.1b-1993/1003.1i-1995)

February 1997 posix.fail