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  strop-
     tions  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