*BSD News Article 61966


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From: j@uriah.heep.sax.de (J Wunsch)
Newsgroups: comp.unix.bsd.bsdi.misc,comp.unix.bsd.freebsd.misc
Subject: Re: Controlling Ports
Date: 22 Feb 1996 08:54:18 GMT
Organization: Private BSD site, Dresden
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jwshafto@atnet.net (John Shafto) writes:

(Disclaimer: i'm not a user of BSD/OS.  But i've seen your question
hanging around for some time.  Just guesses.)

> 1.) When user hangs up in Pine or Lynx (amoung others) BSDI does not
> shut down jobs associated with the port, and worse, the modem doesn't
> reset, nor does the getty restart on the port.  Hence, there is then
> a line in the middle of the hunt group that won't answer (until the
> errant job is killed, then everything resets).

Some programs like Lynx (or even the old vi and the old ftp, under
Illtrix) are known to cause problems with a dead tty line.  They
apparently ignore an error condition when reading, thus spinning
forever in the input loop.  This is most likely (without looking in
the code) the fault of these programs.

I don't have an idea however why the o/s doesn't free the process
group on loss of carrier, so that a new getty will be spawned to the
modem.  Unless, of course, the applications (intentionally or accid-
entally) turned the modem tty line into a ``local'' one, thus making
the driver ignore modem control signals.  The application should not
be allowed to do this, but that's kinda misconception in Unix.

-- 
cheers, J"org

joerg_wunsch@uriah.heep.sax.de -- http://www.sax.de/~joerg/ -- NIC: JW11-RIPE
Never trust an operating system you don't have sources for. ;-)