The Open Group Base Specifications Issue 6
IEEE Std 1003.1, 2004 Edition
Copyright © 2001-2004 The IEEE and The Open Group, All Rights reserved.

#### NAME

> mq_unlink - remove a message queue (REALTIME)

#### SYNOPSIS

> ``[MSG] #include <mqueue.h>
> int mq_unlink(const char *`name`);``
> `
> `

#### DESCRIPTION

> The mq_unlink() function shall remove the message queue named by the pathname name. After a successful call to mq_unlink() with name, a call to mq_open() with name shall fail if the flag O_CREAT is not set in flags. If one or more processes have the message queue open when mq_unlink() is called, destruction of the message queue shall be postponed until all references to the message queue have been closed.

> Calls to mq_open() to recreate the message queue may fail until the message queue is actually removed. However, the mq_unlink() call need not block until all references have been closed; it may return immediately.

#### RETURN VALUE

> Upon successful completion, the function shall return a value of zero. Otherwise, the named message queue shall be unchanged by this function call, and the function shall return a value of -1 and set errno to indicate the error.

#### ERRORS

> The mq_unlink() function shall fail if:

> [EACCES]
>   Permission is denied to unlink the named message queue.
> [ENAMETOOLONG]
>   The length of the name argument exceeds {PATH_MAX} or a pathname component is longer than {NAME_MAX}.
> [ENOENT]
>   The named message queue does not exist.

The following sections are informative.

#### EXAMPLES

> None.

#### APPLICATION USAGE

> None.

#### RATIONALE

> None.

#### FUTURE DIRECTIONS

> None.

#### SEE ALSO

> mq_close(), mq_open(), msgctl(), msgget(), msgrcv(), msgsnd(), the Base Definitions volume of IEEE Std 1003.1-2001, <mqueue.h>

#### CHANGE HISTORY

> First released in Issue 5. Included for alignment with the POSIX Realtime Extension.

#### Issue 6

> The mq_unlink() function is marked as part of the Message Passing option.

> The Open Group Corrigendum U021/5 is applied, clarifying that upon unsuccessful completion, the named message queue is unchanged by this function.

> The [ENOSYS] error condition has been removed as stubs need not be provided if an implementation does not support the Message Passing option.

End of informative text.

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