shm_unlink Subroutine

Purpose

Removes a shared memory object.

Library

Standard C Library (libc.a)

Syntax

#include <sys/mman.h>

int shm_unlink (name)
const char *name;

Description

The shm_unlink subroutine removes the name of the shared memory object named by the string pointed to by the name parameter.

If one or more references to the shared memory object exist when the object is unlinked, the name is removed before the shm_unlink subroutine returns, but the removal of the memory object contents is postponed until all open and map references to the shared memory object have been removed.

Even if the object continues to exist after the last shm_unlink call, reuse of the name subsequently causes the shm_open subroutine to behave as if no shared memory object of this name exists. In other words, the shm_open subroutine will fail if O_CREAT is not set, or will create a new shared memory object if O_CREAT is set.

Parameters

Return Values

Upon successful completion, zero is returned. Otherwise, -1 is returned and errno is set to indicate the error. If -1 is returned, the named shared memory object is not changed by the subroutine call.

Error Codes