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 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.

       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 Definitions 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 .