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MQ_GETATTR(2)		    BSD	System Calls Manual		 MQ_GETATTR(2)

NAME
     mq_getattr	-- get message queue attributes	(REALTIME)

LIBRARY
     POSIX Real-time Library (librt, -lrt)

SYNOPSIS
     #include <mqueue.h>

     int
     mq_getattr(mqd_t mqdes, struct mq_attr *mqstat);

DESCRIPTION
     The mq_getattr() system call obtains 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 are returned in the mq_attr structure referenced by the
     mqstat argument.

     Upon return, the following	members	will 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 will	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 will be set to the current state of the mes-
     sage queue:

     mq_curmsgs	 The number of messages	currently on the queue.

RETURN VALUES
     Upon successful completion, the value 0 is	returned; otherwise the
     value -1 is returned and the global variable errno	is set to indicate the
     error.

ERRORS
     The mq_getattr() system call will fail if:

     [EBADF]		The mqdes argument is not a valid message queue	de-
			scriptor.

SEE ALSO
     mq_open(2), mq_send(2), mq_setattr(2), mq_timedsend(2)

STANDARDS
     The mq_getattr() system call conforms to IEEE Std 1003.1-2004
     ("POSIX.1").

HISTORY
     Support for POSIX message queues first appeared in	FreeBSD	7.0.

COPYRIGHT
     Portions of this text are reprinted and reproduced	in electronic form
     from IEEE Std 1003.1, 2004	Edition, Standard for Information Technology
     --	Portable Operating System Interface (POSIX), The Open Group Base Spec-
     ifications	Issue 6, Copyright (C) 2001-2004 by the	Institute of Electri-
     cal 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 ref-
     eree document.  The original Standard can be obtained online at
     http://www.opengroup.org/unix/online.html.

BSD			       February	21, 2014			   BSD

NAME | LIBRARY | SYNOPSIS | DESCRIPTION | RETURN VALUES | ERRORS | SEE ALSO | STANDARDS | HISTORY | COPYRIGHT

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