STREAMS Modules                                          pckt(7M)



NAME
     pckt - STREAMS Packet Mode module

SYNOPSIS
     int ioctl( fd, IPUSH, "pckt");


DESCRIPTION
     pckt is a STREAMS module that may be used with a pseudo ter-
     minal  to packetize certain messages. The pckt module should
     be pushed (see  IPUSH on   streamio(7I))  onto  the  master
     side of a pseudo terminal.


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


     On the  read-side,  only  the  MPROTO,  MPCPROTO,  MSTOP,
     MSTART,  MSTOPI,  MSTARTI,  MIOCTL, MDATA, MFLUSH, and
     MREAD 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() function. The control part of the message  con-
     tains  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.

SEE ALSO
     getmsg(2),  ioctl(2),  ldterm(7M),  ptem(7M),  streamio(7I),
     termio(7I)


     STREAMS Programming Guide










SunOS 5.11           Last change: 3 Jul 1990                    1