'\" te
.\" Copyright (c) 2002, Sun Microsystems, Inc.  All Rights Reserved.
.\" Copyright 1989 AT&T
.TH stroptions 9S "14 Nov 1996" "SunOS 5.11" "Data Structures for Drivers"
.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
.mk
.na
\fB\fBSO_READOPT\fR\fR
.ad
.RS 21n
.rt  
Set read option.
.RE

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

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

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

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

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

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

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

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

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

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

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

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

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

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

.sp
.ne 2
.mk
.na
\fB\fBSO_ERROPT\fR\fR
.ad
.RS 21n
.rt  
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
.mk
.na
\fB\fBRNORM\fR\fR
.ad
.RS 9n
.rt  
Read message normal.
.RE

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

.sp
.ne 2
.mk
.na
\fB\fBRMSGN\fR\fR
.ad
.RS 9n
.rt  
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
.mk
.na
\fB\fBRERRNORM\fR\fR
.ad
.RS 18n
.rt  
Persistent read errors; default.
.RE

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

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

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

.SH SEE ALSO
.sp
.LP
\fBread\fR(2), \fBstreamio\fR(7I) 
.sp
.LP
\fISTREAMS Programming Guide\fR