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.

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.