SEM_UNLINK(3C) Standard C Library Functions SEM_UNLINK(3C)

NAME

sem_unlink - remove a named semaphore

SYNOPSIS

#include <semaphore.h>

int sem_unlink(const char *name);

DESCRIPTION

The sem_unlink() function removes the semaphore named by the string name.
If the semaphore named by 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(3C), _Exit(2), or
one of the exec functions (see exec(2)) . Calls to sem_open(3C) to re-
create or re-connect to the semaphore refer to a new semaphore after
sem_unlink() is called. The sem_unlink() call does not block until all
references have been destroyed; it returns immediately.

RETURN VALUES

Upon successful completion, sem_unlink() returns 0. Otherwise, the
semaphore is not changed and the function returns a value of -1 and sets
errno to indicate the error.

ERRORS

The sem_unlink() function will fail if:

EACCES
Permission is denied to unlink the named semaphore.


ENAMETOOLONG
The length of name string 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
The sem_unlink() function is not supported by the
system.

ATTRIBUTES

See attributes(7) for descriptions of the following attributes:


+--------------------+-------------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+--------------------+-------------------+
|Interface Stability | Committed |
+--------------------+-------------------+
|MT-Level | MT-Safe |
+--------------------+-------------------+
|Standard | See standards(7). |
+--------------------+-------------------+

SEE ALSO

exec(2), exit(2), sem_close(3C), sem_open(3C), attributes(7),
standards(7)

NOTES

Solaris 2.6 was the first release to support the Asynchronous Input and
Output option. Prior to this release, this function always returned -1
and set errno to ENOSYS.


February 5, 2008 SEM_UNLINK(3C)