NAME
mq_unlink — remove
a message queue (REALTIME)
SYNOPSIS
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(3) 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(3) 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(3) , mq_open(3) , msgctl(3) , msgget(3) , msgrcv(3) , msgsnd(3) , the Base Definitions volume of IEEE Std 1003.1-2001 (“POSIX.1”), <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.
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