STROPTIONS(9S) Data Structures for Drivers STROPTIONS(9S)

NAME

stroptions - options structure for M_SETOPTS message

SYNOPSIS

#include <sys/stream.h>
#include <sys/stropts.h>
#include <sys/ddi.h>
#include <sys/sunddi.h>

INTERFACE LEVEL

Architecture independent level 1 (DDI/DKI)

DESCRIPTION

The M_SETOPTS message contains a stroptions structure and is used to
control options in the stream head.

STRUCTURE MEMBERS

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 */


The following are the flags that can be set in the so_flags bit mask
in the stroptions structure. Note that multiple flags can be set.

SO_READOPT
Set read option.


SO_WROFF
Set write offset.


SO_MINPSZ
Set minimum packet size


SO_MAXPSZ
Set maximum packet size.


SO_HIWAT
Set high water mark.


SO_LOWAT
Set low water mark.


SO_MREADON
Set read notification ON.


SO_MREADOFF
Set read notification OFF.


SO_NDELON
Old TTY semantics for NDELAY reads and writes.


SO_NDELOFFSTREAMS
Semantics for NDELAY reads and writes.


SO_ISTTY
The stream is acting as a terminal.


SO_ISNTTY
The stream is not acting as a terminal.


SO_TOSTOP
Stop on background writes to this stream.


SO_TONSTOP
Do not stop on background writes to this stream.


SO_BAND
Water marks affect band.


SO_ERROPT
Set error option.


When SO_READOPT is set, the so_readopt field of the stroptions
structure can take one of the following values. See read(2).

RNORM
Read message normal.


RMSGD
Read message discard.


RMSGN
Read message, no discard.


When SO_BAND is set, so_band determines to which band so_hiwat and
so_lowat apply.


When SO_ERROPT is set, the so_erropt field of the stroptions
structure can take a value that is either none or one of:

RERRNORM
Persistent read errors; default.


RERRNONPERSIST
Non-persistent read errors.


OR'ed with either none or one of:

WERRNORM
Persistent write errors; default.


WERRNONPERSIST
Non-persistent write errors.

SEE ALSO

read(2), streamio(4I)


STREAMS Programming Guide

November 14, 1996 STROPTIONS(9S)