sem_close(3)		    Library Functions Manual		    sem_close(3)

NAME
     sem_close - close a named semaphore

LIBRARY
     POSIX threads library (libpthread, -lpthread)

SYNOPSIS
     #include <semaphore.h>

     int sem_close(sem_t *sem);

DESCRIPTION
     sem_close() closes the named semaphore referred to by sem, allowing any re-
     sources that the system has allocated to the calling process for this sema-
     phore to be freed.

RETURN VALUE
     On	 success sem_close() returns 0; on error, -1 is returned, with errno set
     to indicate the error.

ERRORS
     EINVAL
	    sem is not a valid semaphore.

ATTRIBUTES
     For an explanation of the terms used in this  section,  see  attributes(7).
     allbox; lbx lb lb l l l.  Interface Attribute Value T{ sem_close()
     T}	  Thread safety	  MT-Safe

STANDARDS
     POSIX.1-2008.

HISTORY
     POSIX.1-2001.

NOTES
     All  open named semaphores are automatically closed on process termination,
     or upon execve(2).

SEE ALSO
     sem_getvalue(3),  sem_open(3),  sem_post(3),  sem_unlink(3),   sem_wait(3),
     sem_overview(7)

Linux man-pages 6.18		   2026-02-08			    sem_close(3)