bill@ssbn.WLK.COM (Bill Kennedy) (05/13/88)
A couple of days ago I posted a m'aidez about how to respawn a process
in Xenix 386 Vr2.2.3, SCO was not going to be able to help me until
today. I wasn't very happy about that, I was less happy when they called
today and said it would be tomorrow. Read "less happy" any way you want...
What I need to do is have a modem answer the phone, dialog some with a
credit authorization terminal and then disconnect. The application has
nothing to do with credit authorization, but it's what we're using for
data collection. In the two days from when I asked SCO how to do it and
today I found a myriad of bad techniques, wandering zombies, unkillable
processes, file systems busy at shutdown, I shall not repeat any of them
here but I will pass on the technique that SCO gave me on the phone, today.
I have intentionally forgotten the analysts name and he doesn't know how
grateful he is for that :-) The manual page for gettydefs(F) mentions a
login program following the next-label. The explanation isn't obvious to
me, so I'll just explain what he coached me through and it works!
1) Make a new gettydefs entry, call it `p', make the flags what you need,
mine needed ISTRIP and PARENB as well as baud rate changes. Finish
the new gettydefs line with "# p # AUTO /etc/login" (quotes are mine).
2) Make a new user name in /etc/passwd for the tty port names you want to
use this way, in my case, ttym06 and ttym07. SCO suggested that I make
the log in shell be /bin/sh, but that had a number of bad side effects
for me, not the least of which was making motd and /etc/profile speeches
to a device that was expecting a naked '\005', so I made the default
shell be my application program, /usr/lib/clubs/omron.
3) Set up /etc/ttys to the devices you want, 0pttym06 and 0pttym07 in my
case.
4) Enable the ports and you're on your way!
Mine raises DTR to the modem port, waits for DCD, logs in the user with the
tty device as "controlling terminal" (so that SIGHUP works...) and executes
the application program which kills the getty when it closes the file and a
brand new getty is activated promptly.
I can't, with a clear conscience, rag SCO for taking so long to get back to
me because, by definition, I couldn't do anything until I got this to work
anyway. Perhaps this article will help someone with the same but less urgent
problem. I doubt that you would enjoy screaming as loud as I did to get to
the right person, I didn't. Besides, it's the finished result that counts
and we have it.
--
Bill Kennedy usenet {rutgers,ihnp4!killer,cbosgd}!ssbn!bill
internet bill@ssbn.WLK.COM