oracular (3) sem_unlink.3posix.gz

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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


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 function 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.

       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.


EXAMPLES
       None.


APPLICATION USAGE
       None.


RATIONALE
       None.


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


SEE ALSO
       semctl(), semget(), semop(), sem_close(), sem_open()

       The Base Definitions volume of POSIX.1‐2017, <semaphore.h>


       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 http://www.opengroup.org/unix/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 .