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 sem_close(2)							sem_close(2)




 NAME
      sem_close - close a named POSIX semaphore

 SYNOPSIS
      #include <&lt&lt&lt;sys/semaphore.h>&gt&gt&gt;

      int sem_close(sem_t *sem);

 DESCRIPTION
      sem_close() is used to close a named semaphore.  A successful call to
      sem_close() will do the following: Remove the process's descriptor for
      the semaphore referenced by the specified sem_t structure sem.  Remove
      the semaphore referenced by the specified sem_t structure sem, if the
      semaphore is marked for removal by a call to sem_unlink() and there
      are no other descriptors referencing this semaphore.

      When the process's descriptor for the semaphore referenced by sem is
      removed, subsequent use of this semaphore by this process will fail.
      Descriptors for named semaphores are also removed by processes on
      exit.  Calling sem_close() does not affect other processes referencing
      the same semaphore.

      To use this function, link in the realtime library by specifying -lrt
      on the compiler or linker command line.

 EXAMPLES
      The following call to sem_close() will close a named semaphore
      referred to by sem by removing the process's descriptor to the
      semaphore and removing the semaphore if it is marked for removal by a
      previous sem_unlink() and there are no descriptors referencing it.

	   sem_close(sem);

 RETURN VALUE
      If the semaphore was closed and the descriptors referencing it were
      removed, sem_close() returns 0 to the caller.

      If the semaphore could not be closed, the call returns -1 and sets
      errno to indicate the error.

 ERRORS
      sem_close() fails and does not perform the requested operation if the
      following condition is encountered:

	   [EINVAL]	  The argument sem is not a valid named semaphore.

 SEE ALSO
      sem_init(2), sem_open(2), sem_unlink(2), <semaphore.h>.

 STANDARDS CONFORMANCE
      sem_close(): POSIX



 Hewlett-Packard Company	    - 1 -   HP-UX Release 11i: November 2000