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SEM_UNLINK(3P) POSIX Programmer's Manual SEM_UNLINK(3P)
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.
sem_unlink — remove a named semaphore
#include <semaphore.h>
int sem_unlink(const char *name);
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.
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.
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:
ENAMETOOLONG
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.
None.
None.
None.
A future version might require the sem_open() and sem_unlink()
functions to have semantics similar to normal file system operations.
semctl(3p), semget(3p), semop(3p), sem_close(3p), sem_open(3p)
The Base Definitions volume of POSIX.1‐2008, semaphore.h(0p)
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 http://www.unix.org/online.html .
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
https://www.kernel.org/doc/man-pages/reporting_bugs.html .
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)