NAME

sem_unlink − Removes the specified named semaphore (P1003.1b)

SYNOPSIS

#include <semaphore.h>
 
int sem_unlink (
const char ∗name) ;

LIBRARY

Realtime Library (librt.so, librt.a)

PARAMETERS

∗name
Specifies the name of the semaphore to remove.

DESCRIPTION

The sem_unlink function removes a semaphore named by the string name. If the semaphore is referenced by other processes, sem_unlink does not change the state of the semaphore. 

If other processes have the semaphore open when sem_unlink is called, the semaphore is not destroyed until all references to the semaphore have been destroyed by calls to sem_close.  The sem_unlink function returns immediately; it does not wait until all references have been destroyed. 

Calls to sem_open to recreate or reconnect to the semaphore refer to a new semaphore after sem_unlink is called. 

RETURN VALUES

On a successful call, a value of 0 (zero) is returned. Otherwise, a value of −1 is returned and errno is set to indicate that an error occurred. 

ERRORS

The sem_unlink function fails under the following conditions:

[EACCES]
Permission is denied to unlink the named semaphore.

[ENAMETOOLONG]
The length of the name string exceeds {NAME_MAX} while {_POSIX_NO_TRUNC} is in effect. 

[ENOENT]
The named semaphore does not exist.

SEE ALSO

Functions: sem_close(3), sem_open(3)

Guide to Realtime Programming