NAME

sem_unlink − remove a named semaphore

SYNOPSIS

cc [ flag ... ] file ... −lposix4 [ library ... ]

#include <semaphore.h>

int sem_unlink(const char ∗name);

MT-LEVEL

MT-Safe

DESCRIPTION

sem_unlink() removes the semaphore named by the string name.  If the semaphore, name, is currently referenced by other processes, then sem_unlink() has 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(3R), exit(2), or exec(2).  Calls to sem_open(3R) to re-create or re-connect to the semaphore will refer to a new semaphore after sem_unlink() is called.  sem_unlink() does not block until all references have been destroyed; rather, it returns immediately. 

RETURN VALUES

If successful, sem_unlink() returns 0; otherwise, the function returns -1, sets errno to indicate the error condition, and the semaphore is left unchanged. 

ERRORS

EACCES Permission is denied to unlink the named semaphore. 

ENAMETOOLONG
The string-length of name exceeds {PATH_MAX}, or a pathname component is longer than {NAME_MAX} while _POSIX_NO_TRUNC is in effect. 

ENOENT The named semaphore does not exist. 

ENOSYS sem_unlink() is not supported by this implementation. 

SEE ALSO

exec(2), exit(2), sem_close(3R), sem_open(3R)

Sun Microsystems  —  Last change: 12 Aug 1993