'\" te
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.TH mq_setattr 3C "31 Jan 2012" "SunOS 5.11" "Standard C Library Functions"
.SH NAME
mq_setattr \- set/get message queue attributes
.SH SYNOPSIS
.LP
.nf
#include <mqueue.h>

\fBint\fR \fBmq_setattr\fR(\fBmqd_t\fR \fImqdes\fR, \fBconst struct mq_attr *\fR\fImqstat\fR,
     \fBstruct mq_attr *\fR\fIomqstat\fR);
.fi

.SH DESCRIPTION
.sp
.LP
The \fBmq_setattr()\fR function is used to set attributes associated with the open message queue description referenced by the message queue descriptor specified by \fImqdes\fR.
.sp
.LP
The message queue attributes corresponding to the following members defined in the \fBmq_attr\fR structure are set to the specified values upon successful completion of \fBmq_setattr()\fR: 
.sp
.ne 2
.mk
.na
\fB\fBmq_flags\fR\fR
.ad
.RS 12n
.rt  
The value of this member is either \fB0\fR or  \fBO_NONBLOCK.\fR 
.RE

.sp
.LP
The values of \fBmq_maxmsg\fR, \fBmq_msgsize\fR, and \fBmq_curmsgs\fR are ignored by \fBmq_setattr()\fR. 
.sp
.LP
If \fIomqstat\fR is non-\fINULL\fR, \fBmq_setattr()\fR stores, in the location referenced by \fIomqstat\fR, the previous message queue attributes and the current queue status. These values are the same as would be returned by a call to \fBmq_getattr()\fR at that point.
.SH RETURN VALUES
.sp
.LP
Upon successful completion, \fBmq_setattr()\fR returns \fB0\fR and the attributes of the message queue will have been changed as specified. Otherwise, the message queue attributes are unchanged, and the function returns \fB\(mi1\fR and sets \fBerrno\fR to indicate the error.
.SH ERRORS
.sp
.LP
The \fBmq_setattr()\fR function will fail if:
.sp
.ne 2
.mk
.na
\fB\fBEBADF\fR\fR
.ad
.RS 10n
.rt  
The \fImqdes\fR argument is not a valid message queue descriptor.
.RE

.sp
.ne 2
.mk
.na
\fB\fBENOSYS\fR\fR
.ad
.RS 10n
.rt  
The \fBmq_setattr()\fR function is not supported by the system.
.RE

.SH ATTRIBUTES
.sp
.LP
See \fBattributes\fR(5) for descriptions of the following attributes:
.sp

.sp
.TS
tab() box;
cw(2.75i) |cw(2.75i) 
lw(2.75i) |lw(2.75i) 
.
ATTRIBUTE TYPEATTRIBUTE VALUE
_
Interface StabilityCommitted
_
MT-LevelMT-Safe
_
StandardSee \fBstandards\fR(5).
.TE

.SH SEE ALSO
.sp
.LP
\fBmsgctl\fR(2), \fBmsgget\fR(2), \fBmsgrcv\fR(2), \fBmsgsnd\fR(2), \fBmq_getattr\fR(3C), \fBmq_open\fR(3C), \fBmq_receive\fR(3C), \fBmq_send\fR(3C), \fBmqueue.h\fR(3HEAD), \fBattributes\fR(5), \fBstandards\fR(5)