pckt(7)                                                      pckt(7)


       NAME
             pckt - STREAMS Packet Mode module

       DESCRIPTION
             pckt is a STREAMS module that may be used with a pseudo
             terminal to packetize certain messages.  The pckt module
             should be pushed [see I_PUSH, streamio(7)] onto the master
             side of a pseudo terminal.

             Packetizing is performed by prefixing a message with an
             M_PROTO message.  The original message type is stored in the 4
             byte data portion of the M_PROTO message.

             On the read-side, only the M_PROTO, M_PCPROTO, M_STOP,
             M_START, M_STOPI, M_STARTI, M_IOCTL, M_DATA, M_FLUSH, and
             M_READ messages are packetized.  All other message types are
             passed upstream unmodified.

             Since all unread state information is held in the master's
             stream head read queue, flushing of this queue is disabled.

             On the write-side, all messages are sent down unmodified.

             With this module in place, all reads from the master side of
             the pseudo terminal should be performed with the getmsg(2) or
             getpmsg system call.  The control part of the message contains
             the message type.  The data part contains the actual data
             associated with that message type.  The onus is on the
             application to separate the data into its component parts.

       REFERENCES
             crash(1M), getmsg(2), ioctl(2), ldterm(7), ptem(7), pty(7),
             streamio(7), termio(7)















                           Copyright 1994 Novell, Inc.               Page 1