mq_close - Man Page

close a message queue (REALTIME)


This manual page is part of the POSIX Programmer's Manual. The Linux implementation of this interface may differ (consult the corresponding Linux manual page for details of Linux behavior), or the interface may not be implemented on Linux.


#include <mqueue.h>

int mq_close(mqd_t mqdes);


The mq_close() function shall remove the association between the message queue descriptor, mqdes, and its message queue. The results of using this message queue descriptor after successful return from this mq_close(), and until the return of this message queue descriptor from a subsequent mq_open(), are undefined.

If the process has successfully attached a notification request to the message queue via this mqdes, this attachment shall be removed, and the message queue is available for another process to attach for notification.

Return Value

Upon successful completion, the mq_close() function shall return a value of zero; otherwise, the function shall return a value of -1 and set errno to indicate the error.


The mq_close() function shall fail if:


The mqdes argument is not a valid message queue descriptor.

The following sections are informative.



Application Usage




Future Directions


See Also

mq_open(), mq_unlink(), msgctl(), msgget(), msgrcv(), msgsnd()

The Base Definitions volume of POSIX.1-2017, <mqueue.h>

Referenced By

_Exit(3p), mq_open(3p), mqueue.h(0p), mq_unlink(3p), msgctl(3p), msgget(3p), msgrcv(3p), msgsnd(3p).

2017 IEEE/The Open Group POSIX Programmer's Manual