This manual page is part of the POSIX Programmer's Manual. The Linux implementation of this interface

       None.

       Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1-2017, Standard
       for  Information  Technology  --  Portable  Operating  System  Interface  (POSIX),  The  Open  Group Base
       Specifications Issue 7, 2018 Edition, Copyright (C) 2018 by the Institute of Electrical  and  Electronics
       Engineers, Inc and The Open Group.  In the event of any discrepancy between this version and the original
       IEEE  and The Open Group Standard, the original IEEE and The Open Group Standard is the referee document.
       The original Standard can be obtained online at http://www.opengroup.org/unix/online.html .

       Any typographical or formatting errors that appear in this page are most likely to have  been  introduced
       during   the   conversion  of  the  source  files  to  man  page  format.  To  report  such  errors,  see
       https://www.kernel.org/doc/man-pages/reporting_bugs.html .

IEEE/The Open Group                                   2017                                    MQ_SETATTR(3POSIX)

       The  mq_setattr()  function  shall  set  attributes  associated  with  the open message queue description
       referenced by the message queue descriptor specified by mqdes.

       The message queue attributes corresponding to the following members  defined  in  the  mq_attr  structure
       shall be set to the specified values upon successful completion of mq_setattr():

       mq_flags    The  value  of  this  member  is the bitwise-logical OR of zero or more of O_NONBLOCK and any
                   implementation-defined flags.

       The values of the mq_maxmsg, mq_msgsize, and mq_curmsgs members of the mq_attr structure shall be ignored
       by mq_setattr().

       If omqstat is non-NULL, the mq_setattr() function shall store, in the location referenced by omqstat, the
       previous message queue attributes and the current queue status.  These values shall be the same as  would
       be returned by a call to mq_getattr() at that point.

       The mq_setattr() function shall fail if:

       EBADF  The mqdes argument is not a valid message queue descriptor.

       Thefollowingsectionsareinformative.

       None.

       None.

       mq_setattr — set message queue attributes (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.

       None.

       Upon  successful  completion, the function shall return a value of zero and the attributes of the message
       queue shall have been changed as specified.

       Otherwise, the message queue attributes shall be unchanged, and the function shall return a value  of  -1
       and set errno to indicate the error.

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

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

       #include <mqueue.h>

       int mq_setattr(mqd_t mqdes, const struct mq_attr *restrict mqstat,
           struct mq_attr *restrict omqstat);