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 error.

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] error.

       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

SEE ALSO         top

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

       The Base Definitions volume of POSIX.1‐2017, semaphore.h(0p)

COPYRIGHT         top

       Portions of this text are reprinted and reproduced in electronic
       form from IEEE Std 1003.1-2017, Standard for Information
       Technology -- Portable Operating System Interface (POSIX), The
       Open Group Base Specifications Issue 7, 2018 Edition, Copyright
       (C) 2018 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 .

       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               2017                    SEM_UNLINK(3P)

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