From owner-freebsd-hackers Tue Sep 9 02:25:23 1997 Return-Path: Received: (from root@localhost) by hub.freebsd.org (8.8.7/8.8.7) id CAA16708 for hackers-outgoing; Tue, 9 Sep 1997 02:25:23 -0700 (PDT) Received: from freebie.lemis.com (gregl1.lnk.telstra.net [139.130.136.133]) by hub.freebsd.org (8.8.7/8.8.7) with ESMTP id CAA16689 for ; Tue, 9 Sep 1997 02:25:18 -0700 (PDT) Received: (from grog@localhost) by freebie.lemis.com (8.8.7/8.8.5) id SAA08343; Tue, 9 Sep 1997 18:55:09 +0930 (CST) Message-ID: <19970909185509.62821@lemis.com> Date: Tue, 9 Sep 1997 18:55:09 +0930 From: Greg Lehey To: Terry Lambert Cc: mrcpu@cdsnet.net, hackers@FreeBSD.ORG Subject: Re: How the heck do you drop DTR? References: <19970909170354.43104@lemis.com> <199709090910.CAA27827@usr09.primenet.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Mailer: Mutt 0.81e In-Reply-To: <199709090910.CAA27827@usr09.primenet.com>; from Terry Lambert on Tue, Sep 09, 1997 at 09:10:30AM +0000 Organisation: LEMIS, PO Box 460, Echunga SA 5153, Australia Phone: +61-8-8388-8250 Fax: +61-8-8388-8250 Mobile: +61-41-739-7062 WWW-Home-Page: http://www.lemis.com/~grog Fight-Spam-Now: http://www.cauce.org Sender: owner-freebsd-hackers@FreeBSD.ORG X-Loop: FreeBSD.org Precedence: bulk On Tue, Sep 09, 1997 at 09:10:30AM +0000, Terry Lambert wrote: >>> However, for the life of me, I can't figure out how to actually drop >>> DTR. >>> >>> Looking at the source for ppp, there's something in a HangupModem() >>> function about setting the baud rate to 0. It looks like this >>> does the trick, but I'm not sure it's the "right" way to do it. >> >> I suppose it's a matter for discussion (are you listening, Terry?) as >> to whether it's the "right" way to do it, but that's the way it's >> done. Thanks, Terry, I knew you wouldn't let us down :-) > Setting the baud rate to 0 is the traditionally correct way to drop > DTR. In System V. And before. From the UNIX Programmer's Manual, Seventh Edition (tty(4)): B0 0 hang up dataphone The System V difference was STREAMS instead of the old terminal driver, as I'm sure I don't have to tell you. > And we all know how much like System V we want BSD to be... even > when System V has good ideas (unlike that one). Was there ever any other way of doing it on an open fd? > Most modern modems ignore long breaks, in violation of 103C and > 212A, because modem designers are idiots. That'll be right. One day, when I have time, remind me about the story of the IBM junior thugs and their start-stop terminal (3101? I forget). Greg