Newsgroups: comp.unix.aux
Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!sol.ctr.columbia.edu!ira.uka.de!smurf!urlichs
From: urlichs@smurf.sub.org (Matthias Urlichs)
Subject: Re: Scripts to deal with A/UX's buggy UUCP
Message-ID: <_WS_DAP@smurf.sub.org>
Date: Sat, 06 Apr 91 17:57:02 GMT
Organization: University of Karlsruhe, FRG
References: <1991Mar10.194813.10357@panix.uucp> <1991Mar27.014105.5418@intacc.uucp> <1991Apr6.052123.11234@mitem.uucp>
Lines: 40

In comp.unix.aux, article <1991Apr6.052123.11234@mitem.uucp>,
  unger@mitem.uucp (Tom Unger) writes:
< 
< I have a program called uugetty that lets one line be used for incomming
< and outgoing modem calls.  uugetty does the following:
< 
< 	1) initializes modem
< 	2) Listens for incomming calls on modem or other traffic on 
< 	   the port.
< 	3) If a call arrives it execs the standard getty to log the user in.
< 	4) If there is other traffic uugetty "gives up" the line  until
< 	   the outbound call is done.  (it knows it is done when the lock
< 	   file goes away).
< 
The standard getty should not initialise the modem. Why? The modem is reset
by DTR going down, and it won't accept calls until DTR comes up again.
(Disclaimer: Any reasonably configured modem ...)

It also shouldn't look at traffic. If the line can be opened, either there was
an incoming call or there's a lock file, i.e. an outgoing call. If the
latter, getty hangs until the lock file goes away and then dies, indirectly
reexecuting itself. (Cleaning up after opening a line that way is a lot of
hassle and definitely not worth the effort.)

There may be a problem because some uucico's first try to dial the phone and
then create a lock file, thus generating a race condition. I don't know if
the A/UX uucico has that bug.
It also seems that the A/UX getty first writes its login message out and
then looks for the lock, instead of the other way round. My uucico therefore
kills the current getty, and /etc/init spawns a small program that waits on
the lock before exec'ing /etc/getty.
NB: The above applies to A/UX 2.0. I haven't checked what, if anything, was
changed in 2.0.1 because the current setup works.

I'll package the UUCP binaries I have into something resembling usablility
and make them available for FTP. Sometime next week.

-- 
Matthias Urlichs -- urlichs@smurf.sub.org -- urlichs@smurf.ira.uka.de     /(o\
Humboldtstrasse 7 - 7500 Karlsruhe 1 - FRG -- +49-721-621127(0700-2330)   \o)/