'\" te
.\" Copyright (c) 2002, Sun Microsystems, Inc.  All Rights Reserved.
.\" Copyright 1989 AT&T
.\" The contents of this file are subject to the terms of the Common Development and Distribution License (the "License").  You may not use this file except in compliance with the License.
.\" You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE or http://www.opensolaris.org/os/licensing.  See the License for the specific language governing permissions and limitations under the License.
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.TH STROPTIONS 9S "Nov 14, 1996"
.SH NAME
stroptions \- options structure for M_SETOPTS message
.SH SYNOPSIS
.LP
.nf
#include <sys/stream.h>
#include <sys/stropts.h>
#include <sys/ddi.h>
#include <sys/sunddi.h>
.fi

.SH INTERFACE LEVEL
.sp
.LP
Architecture independent level 1 (DDI/DKI)
.SH DESCRIPTION
.sp
.LP
The \fBM_SETOPTS\fR message contains a \fBstroptions\fR structure and is used
to control options in the stream head.
.SH STRUCTURE MEMBERS
.sp
.in +2
.nf
uint_t           so_flags;      /* options to set */
short            so_readopt;    /* read option */
ushort_t         so_wroff;      /* write offset */
ssize_t          so_minpsz;     /* minimum read packet size */
ssize_t          so_maxpsz;     /* maximum read packet size */
size_t           so_hiwat;      /* read queue high water mark */
size_t           so_lowat;      /* read queue low water mark */
unsigned char    so_band;       /* band for water marks */
ushort_t         so_erropt;     /* error option */
.fi
.in -2

.sp
.LP
The following are the flags that can be set in the \fBso_flags\fR bit mask in
the \fBstroptions\fR structure.  Note that multiple flags can be set.
.sp
.ne 2
.na
\fB\fBSO_READOPT\fR\fR
.ad
.RS 21n
Set read option.
.RE

.sp
.ne 2
.na
\fB\fBSO_WROFF\fR\fR
.ad
.RS 21n
Set write offset.
.RE

.sp
.ne 2
.na
\fB\fBSO_MINPSZ\fR\fR
.ad
.RS 21n
Set minimum packet size
.RE

.sp
.ne 2
.na
\fB\fBSO_MAXPSZ\fR\fR
.ad
.RS 21n
Set maximum packet size.
.RE

.sp
.ne 2
.na
\fB\fBSO_HIWAT\fR\fR
.ad
.RS 21n
Set high water mark.
.RE

.sp
.ne 2
.na
\fB\fBSO_LOWAT\fR\fR
.ad
.RS 21n
Set low water mark.
.RE

.sp
.ne 2
.na
\fB\fBSO_MREADON\fR\fR
.ad
.RS 21n
Set read notification ON.
.RE

.sp
.ne 2
.na
\fB\fBSO_MREADOFF\fR\fR
.ad
.RS 21n
Set read notification OFF.
.RE

.sp
.ne 2
.na
\fB\fBSO_NDELON\fR\fR
.ad
.RS 21n
Old TTY semantics for NDELAY reads and writes.
.RE

.sp
.ne 2
.na
\fB\fBSO_NDELOFFSTREAMS\fR\fR
.ad
.RS 21n
Semantics for NDELAY reads and writes.
.RE

.sp
.ne 2
.na
\fB\fBSO_ISTTY\fR\fR
.ad
.RS 21n
The stream is acting as a terminal.
.RE

.sp
.ne 2
.na
\fB\fBSO_ISNTTY\fR\fR
.ad
.RS 21n
The stream is not acting as a terminal.
.RE

.sp
.ne 2
.na
\fB\fBSO_TOSTOP\fR\fR
.ad
.RS 21n
Stop on background writes to this stream.
.RE

.sp
.ne 2
.na
\fB\fBSO_TONSTOP\fR\fR
.ad
.RS 21n
Do not stop on background writes to this stream.
.RE

.sp
.ne 2
.na
\fB\fBSO_BAND\fR\fR
.ad
.RS 21n
Water marks affect band.
.RE

.sp
.ne 2
.na
\fB\fBSO_ERROPT\fR\fR
.ad
.RS 21n
Set error option.
.RE

.sp
.LP
When \fBSO_READOPT\fR is set, the \fBso_readopt\fR field of the
\fBstroptions\fR structure can take one of the following values. See
\fBread\fR(2).
.sp
.ne 2
.na
\fB\fBRNORM\fR\fR
.ad
.RS 9n
Read message normal.
.RE

.sp
.ne 2
.na
\fB\fBRMSGD\fR\fR
.ad
.RS 9n
Read message discard.
.RE

.sp
.ne 2
.na
\fB\fBRMSGN\fR\fR
.ad
.RS 9n
Read message, no discard.
.RE

.sp
.LP
When \fBSO_BAND\fR is set, \fBso_band\fR determines to which band
\fBso_hiwat\fR and \fBso_lowat\fR apply.
.sp
.LP
When \fBSO_ERROPT\fR is set, the \fBso_erropt\fR field of the \fBstroptions\fR
structure can take a value that is either none or one of:
.sp
.ne 2
.na
\fB\fBRERRNORM\fR\fR
.ad
.RS 18n
Persistent read errors; default.
.RE

.sp
.ne 2
.na
\fB\fBRERRNONPERSIST\fR\fR
.ad
.RS 18n
Non-persistent read errors.
.RE

.sp
.LP
\fBOR'ed \fRwith either none or one of:
.sp
.ne 2
.na
\fB\fBWERRNORM\fR\fR
.ad
.RS 18n
Persistent write errors; default.
.RE

.sp
.ne 2
.na
\fB\fBWERRNONPERSIST\fR\fR
.ad
.RS 18n
Non-persistent write errors.
.RE

.SH SEE ALSO
.sp
.LP
.BR read (2),
.BR streamio (4I)
.sp
.LP
\fISTREAMS Programming Guide\fR