SEM_UNLINK(P) POSIX Programmer's Manual SEM_UNLINK(P)NAMEsem_unlink - remove a named semaphore (REALTIME)
SYNOPSIS
#include <semaphore.h>
int sem_unlink(const char *name);
DESCRIPTION
The sem_unlink() function shall remove the semaphore named by the
string name. If the semaphore named by name is currently referenced by
other processes, then sem_unlink() shall have 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(), _exit(), or exec. Calls to sem_open() to recreate or
reconnect to the semaphore refer to a new semaphore after sem_unlink()
is called. The sem_unlink() call shall not block until all references
have been destroyed; it shall return immediately.
RETURN VALUE
Upon successful completion, the sem_unlink() function shall return a
value of 0. Otherwise, the semaphore shall not be changed and the func‐
tion shall return a value of -1 and set errno to indicate the error.
ERRORS
The sem_unlink() function shall fail if:
EACCES Permission is denied to unlink the named semaphore.
ENAMETOOLONG
The length of the name argument exceeds {PATH_MAX} or a pathname
component is longer than {NAME_MAX}.
ENOENT The named semaphore does not exist.
The following sections are informative.
EXAMPLES
None.
APPLICATION USAGE
The sem_unlink() function is part of the Semaphores option and need not
be available on all implementations.
RATIONALE
None.
FUTURE DIRECTIONS
None.
SEE ALSOsemctl() , semget() , semop() , sem_close() , sem_open() , the Base
Definitions volume of IEEE Std 1003.1-2001, <semaphore.h>
COPYRIGHT
Portions of this text are reprinted and reproduced in electronic form
from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
-- Portable Operating System Interface (POSIX), The Open Group Base
Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of
Electrical and Electronics Engineers, Inc and The Open Group. In the
event of any discrepancy between this version and the original IEEE and
The Open Group Standard, the original IEEE and The Open Group Standard
is the referee document. The original Standard can be obtained online
at http://www.opengroup.org/unix/online.html .
IEEE/The Open Group 2003 SEM_UNLINK(P)
