Remove a queue


#include <mqueue.h>

int mq_unlink( const char* name );


The name of the message queue that you want to unlink.



The mq_unlink() function removes the queue with the given name.

Note: The message queue manager needs to be running. QNX Neutrino supports two implementations of message queues: a traditional implementation, and an alternate one that uses the mq server and a queue in kernel space. For more information, see the entries for mq and mqueue in the Utilities Reference, as well as the Managing POSIX Message Queues technote.

If some process has the queue open when the call to mq_unlink() is made, then the actual deletion of the queue is postponed until it has been closed. If a queue exists in the netherworld between unlinking and the actual removal of the queue, then all calls to open a queue with the given name fail (even if O_CREAT is present in oflag). Once the queue is deleted, all elements currently on it are freed. Due to the lazy deletion of queues, it's impossible for any process to be blocked on the message queue when it's deleted.

Calling unlink() with a name that resolves to the message queue server's namespace (e.g., /dev/mqueue/my_queue) is analogous to calling mq_unlink() with name set to the last elements of the pathname (e.g., my_queue).


-1 if the queue wasn't successfully unlinked (errno is set). Any other value indicates that the queue was successfully unlinked.


You don't have permission to unlink the specified queue.
Too many levels of symbolic links or prefixes.
The length of name exceeds PATH_MAX.
The queue name doesn't exist.
The mq_unlink() function isn't implemented for the filesystem specified in name, or the message queue manager (mq or mqueue) isn't running.


POSIX 1003.1 MSG

Cancellation point No
Interrupt handler No
Signal handler No
Thread Yes