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PROLOG | NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | ERRORS | EXAMPLES | APPLICATION USAGE | RATIONALE | FUTURE DIRECTIONS | SEE ALSO | COPYRIGHT |
MQ_GETATTR(3P) POSIX Programmer's Manual MQ_GETATTR(3P)
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.
mq_getattr — get message queue attributes (REALTIME)
#include <mqueue.h>
int mq_getattr(mqd_t mqdes, struct mq_attr *mqstat);
The mq_getattr() function shall obtain status information and
attributes of the message queue and the open message queue
description associated with the message queue descriptor.
The mqdes argument specifies a message queue descriptor.
The results shall be returned in the mq_attr structure referenced by
the mqstat argument.
Upon return, the following members shall have the values associated
with the open message queue description as set when the message queue
was opened and as modified by subsequent mq_setattr() calls:
mq_flags.
The following attributes of the message queue shall be returned as
set at message queue creation: mq_maxmsg, mq_msgsize.
Upon return, the following members within the mq_attr structure
referenced by the mqstat argument shall be set to the current state
of the message queue:
mq_curmsgs
The number of messages currently on the queue.
Upon successful completion, the mq_getattr() function shall return
zero. Otherwise, the function shall return −1 and set errno to
indicate the error.
The mq_getattr() function may fail if:
EBADF The mqdes argument is not a valid message queue descriptor.
The following sections are informative.
See mq_notify(3p).
None.
None.
None.
mq_notify(3p), mq_open(3p), mq_send(3p), mq_setattr(3p), msgctl(3p),
msgget(3p), msgrcv(3p), msgsnd(3p)
The Base Definitions volume of POSIX.1‐2008, mqueue.h(0p)
Portions of this text are reprinted and reproduced in electronic form
from IEEE Std 1003.1, 2013 Edition, Standard for Information
Technology -- Portable Operating System Interface (POSIX), The Open
Group Base Specifications Issue 7, Copyright (C) 2013 by the
Institute of Electrical and Electronics Engineers, Inc and The Open
Group. (This is POSIX.1-2008 with the 2013 Technical Corrigendum 1
applied.) 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.unix.org/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 2013 MQ_GETATTR(3P)
Pages that refer to this page: mqueue.h(0p), mq_open(3p), msgctl(3p), msgget(3p), msgrcv(3p), msgsnd(3p)