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MQ_GETATTR(3P)             POSIX Programmer's Manual            MQ_GETATTR(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_getattr -- get message queue attributes (REALTIME)
SYNOPSIS
       #include <mqueue.h>
       int mq_getattr(mqd_t mqdes, struct mq_attr *mqstat);
DESCRIPTION
       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  refer-
       enced  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.
RETURN VALUE
       Upon successful completion,  the  mq_getattr()  function  shall  return
       zero. Otherwise, the function shall return -1 and set errno to indicate
       the error.
ERRORS
       The mq_getattr() function may fail if:
       EBADF  The mqdes argument is not a valid message queue descriptor.
       The following sections are informative.
EXAMPLES
       See mq_notify().
APPLICATION USAGE
       None.
RATIONALE
       None.
FUTURE DIRECTIONS
       None.
SEE ALSO
       mq_notify(), mq_open(), mq_send(),  mq_setattr(),  msgctl(),  msgget(),
       msgrcv(), msgsnd()
       The Base Definitions volume of POSIX.1-2008, <mqueue.h>
COPYRIGHT
       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 Electri-
       cal  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.ker-
       nel.org/doc/man-pages/reporting_bugs.html .
IEEE/The Open Group                  2013                       MQ_GETATTR(3P)