sem_unlink(3p) — Linux manual page


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

PROLOG         top

       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         top

       sem_unlink — remove a named semaphore

SYNOPSIS         top

       #include <semaphore.h>

       int sem_unlink(const char *name);

DESCRIPTION         top

       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         top

       Upon successful completion, the sem_unlink() function shall return a
       value of 0. Otherwise, the semaphore shall not be changed and the
       function shall return a value of −1 and set errno to indicate the

ERRORS         top

       The sem_unlink() function shall fail if:

       EACCES Permission is denied to unlink the named semaphore.

       ENOENT The named semaphore does not exist.

       The sem_unlink() function may fail if:

              The length of the name argument exceeds {_POSIX_PATH_MAX} on
              systems that do not support the XSI option or exceeds
              {_XOPEN_PATH_MAX} on XSI systems, or has a pathname component
              that is longer than {_POSIX_NAME_MAX} on systems that do not
              support the XSI option or longer than {_XOPEN_NAME_MAX} on XSI
              systems.  A call to sem_unlink() with a name argument that
              contains the same semaphore name as was previously used in a
              successful sem_open() call shall not give an [ENAMETOOLONG]

       The following sections are informative.

EXAMPLES         top




RATIONALE         top



       A future version might require the sem_open() and sem_unlink()
       functions to have semantics similar to normal file system operations.

SEE ALSO         top

       semctl(3p), semget(3p), semop(3p), sem_close(3p), sem_open(3p)

       The Base Definitions volume of POSIX.1‐2008, semaphore.h(0p)

COPYRIGHT         top

       Portions of this text are reprinted and reproduced in electronic form
       from IEEE Std 1003.1, 2013 Edition, Standard for Information
       Technology -- Portable Operating System Interface (POSIX), The Open
       Group Base Specifications Issue 7, Copyright (C) 2013 by the
       Institute of Electrical and Electronics Engineers, Inc and The Open
       Group.  (This is POSIX.1-2008 with the 2013 Technical Corrigendum 1
       applied.) 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 .

       Any typographical or formatting errors that appear in this page are
       most likely to have been introduced during the conversion of the
       source files to man page format. To report such errors, see .

IEEE/The Open Group                 2013                      SEM_UNLINK(3P)

Pages that refer to this page: semaphore.h(0p)sem_close(3p)semctl(3p)semget(3p)semop(3p)sem_open(3p)