mq_setattr(3p) — Linux manual page

MQ_SETATTR(3P)          POSIX Programmer's Manual         MQ_SETATTR(3P)

PROLOG

       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.

NAME

       mq_setattr — set message queue attributes (REALTIME)

SYNOPSIS

       #include <mqueue.h>

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

DESCRIPTION

       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.

RETURN VALUE

       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.

ERRORS

       The mq_setattr() function shall fail if:

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

       The following sections are informative.

EXAMPLES

       None.

APPLICATION USAGE

       None.

RATIONALE

       None.

FUTURE DIRECTIONS

       None.

SEE ALSO

       mq_open(3p), mq_send(3p), msgctl(3p), msgget(3p), msgrcv(3p),
       msgsnd(3p)

       The Base Definitions volume of POSIX.1‐2017, mqueue.h(0p)

COPYRIGHT

       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(3P)

Pages that refer to this page: mqueue.h(0p), mq_getattr(3p), mq_open(3p), mq_send(3p), msgctl(3p), msgget(3p), msgrcv(3p), msgsnd(3p)

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