.TH PKON 2.SH NAMEpkon, pkoff \- establish packet protocol.SH SYNOPSIS.B pkon(fd, size).PP.B pkoff(fd).SH DESCRIPTION.I Pkonestablishes packet protocol (see.IR pk (4))on the open character special file whose filedescriptor is.I fd..I Sizeis a desired packet size, a power of 2 in the range.RI 32\(<= size \(<=4096.The size is negotiated with a remote packet driver,and a possibly smaller actual packet size is returned..PPAn asynchronous line used for packetcommunication should be in raw mode;see.IR tty (4)..PP.I Pkoffturns off the packet driver on the channel whosefile descriptor is.I fd..SH SEE ALSOpk(4), pkopen(3), tty(4), signal(2).SH DIAGNOSTICS.I Pkonreturns \-1 if .I fddoes not describe an open file, or ifpacket communication cannotbe established..PP.I Pkoffreturns \-1 for an unknown file descriptor..PPWriting on a packet driver link that has been shut downby.I closeor.I pkoffat the other end raises signal SIGPIPEin the writing process.