Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Path: utzoo!mnetor!uunet!husc6!mit-eddie!ll-xn!ames!ucbcad!ucbvax!sdcsvax!ucsdhub!hp-sdd!ncr-sd!ncrlnk!ncrcam!ncrcpx!craig
From: craig@ncrcpx.UUCP (R. Craig Peterson)
Newsgroups: comp.unix.wizards
Subject: Re: Absolutly hanging up a modem
Message-ID: <1821594@ncrcpx.UUCP>
Date: Thu, 22-Oct-87 17:26:13 EST
Article-I.D.: ncrcpx.1821594
Posted: Thu Oct 22 17:26:13 1987
Date-Received: Sun, 25-Oct-87 10:13:01 EST
References: <1548@bloom-beacon.MIT.EDU> <142700004@tiger.UUCP> <292@minya.UUCP>
Reply-To: craig@ncrcpx.UUCP (R. Craig Peterson)
Organization: NCR E&M Cambridge, Ohio
Lines: 27
Keywords: B0
Summary: how about B0?

In article <292@minya.UUCP> jc@minya.UUCP (John Chambers) writes:
>> > >		... and I need to make sure that after the call is
>> > >supposedly over, the line is definitely hung up. What can I do to
>> > >accomplish this?
>> >    Drop DTR.
>does anyone know the Unix call (for Sys/V and BSD and Xenix and ...)
>that does this?

I've worked with quite a few different UNIX systems over
the years including some V7, BSD, and SYSIII/V varients
and have found that they are fairly consistent in dropping
DTR if you set the baud rate on the line to 0.

I have found some exceptions to this where it wouldn't drop
untill all processes had closed the line first, but I guess
I've been lucky...

BTW setting the baud rate to zero would be done differently
(somewhat) on each system...



-- 
R. Craig Peterson		"Next time someone asks you if you're a god
ncrlnk!ncrcam!ncrcpx!craig	 say YES!!"
N8INO					Ghost Busters
E Pluribus Unum 	(NSA stuff - terrorist, DES, cipher, secret, NRO, CIA)