\" $NetBSD: mq_setattr.3,v 1.3 2012/03/15 19:04:47 njoly Exp $
\"
\" Copyright (c) 2001-2003 The Open Group, All Rights Reserved
\"
Dd June 7, 2010
Dt MQ_SETATTR 3
Os
Sh NAME
Nm mq_setattr
Nd set message queue attributes (REALTIME)
Sh LIBRARY
Lb librt
Sh SYNOPSIS
In mqueue.h
Ft int
Fo mq_setattr
Fa "mqd_t mqdes"
Fa "const struct mq_attr *restrict mqstat"
Fa "struct mq_attr *restrict omqstat"
Fc
Sh DESCRIPTION
The
Fn mq_setattr
function sets attributes associated with the open message queue
description referenced by the message queue descriptor specified by
Fa mqdes .
Pp
The message queue attributes corresponding to the following members
defined in the
Vt mq_attr
structure will be set to the specified values upon successful completion of
Fn mq_setattr :
Bl -tag -width mq_flags
It Va mq_flags
The value of this member is the bitwise-logical OR of zero or more of
Dv O_NONBLOCK
and any implementation-defined flags.
El
Pp
The values of the
Va mq_maxmsg ,
Va mq_msgsize ,
and
Va mq_curmsgs
members of the
Vt mq_attr
structure will be ignored by
Fn mq_setattr .
Pp
If
Fa omqstat
is
No non- Ns Dv NULL ,
the
Fn mq_setattr
function will store, in the location referenced by
Fa omqstat
the previous message queue attributes and the current queue status.
These values are the same as would be returned by a call to
Xr mq_getattr 3
at that point.
Sh RETURN VALUES
Upon successful completion, the
Fn mq_setattr
function returns zero and the attributes of the message queue will
have been changed as specified.
Otherwise, the message queue attributes are unchanged,
and the function returns a value of
\-1 and sets the global variable
Va errno
to indicate the error.
Sh ERRORS
The
Fn mq_setattr
function fails if:
Bl -tag -width Er
It Bq Er EBADF
The
Fa mqdes
argument is not a valid message queue descriptor.
El
Sh SEE ALSO
Xr mq 3 ,
Xr mq_getattr 3
Sh STANDARDS
This function conforms to the
St -p1003.1-2001
standard.
Sh HISTORY
This function first appeared in
Nx 5.0 .
Sh 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, Copyright (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
Lk
http://www.opengroup.org/unix/online.html .
