Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!mnetor!seismo!brl-adm!adm!PAAAAAR%CALSTATE.BITNET@wiscvm.wisc.EDU From: PAAAAAR%CALSTATE.BITNET@wiscvm.wisc.EDU Newsgroups: comp.unix.questions Subject: Re: how do i drop connection on hang up Message-ID: <6933@brl-adm.ARPA> Date: Fri, 17-Apr-87 00:16:10 EST Article-I.D.: brl-adm.6933 Posted: Fri Apr 17 00:16:10 1987 Date-Received: Sun, 19-Apr-87 10:09:44 EST Sender: news@brl-adm.ARPA Lines: 54 Carles Shub writes >we have microvaxen...hp-9000s...the system comes back with a login. We have this problem on a diddy PDP11 running BSD2.9 (optimized BSD4.2) connected to a multiplexer (MUX). We have a kludge/hack for Hayestype modems. There are two signals on a RS232 to hangup a line - BREAK and "DTRdrop". Normal terminals send both. Manual entries for ioctl, tty and stty give several ways for UNIX programs to send a BREAK signal and/or "hang up a line". HOWEVER: None of these work because our multiplexer(MUX) only transmits the BREAK signals but the port selector/terminal server(a MICOM) requires a "DTR drop" to disconnect a computer - even tho' it will accept a BREAK from a terminal. Thus a VT100 can send a BREAK+DTRdrop to the MUX. The MUX transmits the BREAK only. The port selector passes it thru to a computer. If it is a nearby machine with no MUX it drops the DTR line with or without a *long* break. This makes the portselector disconnect the terminal from the terminal. BUT when there is a MUX between PDP and MICOM the DTRdrop never arrives. This problem becomes intolerable when someone uses a modem or a MUX to make the connection. Modems can lose BREAK and/or hangup on DTRdrop. One connection stayed alive for 48hours with the PDP powered down last weekend! Since the multiplexed wire is between buildings we are stuck with it. A different weirdo stopped us hanging up the modem on the system. But here is my kludge/hack for hanging up Hayes compatable modems. Add a shell script /etc/hangup: ----- echo 'Hanging up!';sleep 10;echo '+++';sleep 10; echo ATH;echo ATH;stty 0 ----- Note - the 'sleep' statements and duplicated ATH commands are needed for our modems. This will switch most modems to command state and ask'em to hang up. Add a user 'bye' with no password and /etc/hangup as a shell. When a user is fed up with "login:" they respond - 'bye' and the modem hangs up. Is there a wizardly solution out there? Dick Botting, Comp Sci, CSU San Bernardino. paaaaar@ccs.csuscc.edu paaaaar@calstate.bitnet 714-887-7365(modem) login as 'guest' 714-887-7368(voice)