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 (con-
       sult 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 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.


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 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(),  mq_send(),  mq_setattr(), mq_timedsend(), msgctl(), msgget(), msgrcv(), msgsnd(), the Base Definitions volume
       of IEEE Std 1003.1-2001, <mqueue.h>

COPYRIGHT
       Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2003  Edition,  Standard  for
       Information  Technology -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 6, Copy-
       right (C) 2001-2003 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.open-
       group.org/unix/online.html .



IEEE/The Open Group                                           2003                                                MQ_GETATTR(3P)