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(7I)
STREAMS Programming Guide
SunOS 5.10 14 Nov 1996 stroptions(9S)