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SEM_UNLINK(3P)             POSIX Programmer's Manual            SEM_UNLINK(3P)

PROLOG
       This  manual  page is part of the POSIX Programmer's Manual.  The Linux
       implementation of this interface may differ (consult the  corresponding
       Linux  manual page for details of Linux behavior), or the interface may
       not be implemented on Linux.
NAME
       sem_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 ALSO
       semctl(),  semget(), semop(), sem_close(), sem_open(), the Base Defini-
       tions 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(3P)