Xenix login source

Chip Rosenthal chip at vector.UUCP
Wed Mar 1 14:33:07 AEST 1989


In article <168 at biar.UUCP> trebor at biar.UUCP (Robert J Woodhead) writes:
>I am running SCO Xenix 386 on Tandy 4000 and 4000lx boxes.  I am setting up
>a special access system and want to bypass login; in other words, when 
>activity is detected on a serial line, I want to spoof the login procedure,
>log into a specific account, and start running my program.

Two points:  first, the "login" sources won't help, and second, you don't
want to do this.

The reason "login" won't help is that the "login:" prompt doesn't come
from the login program, it comes from getty.  Once getty has successfully
read a login user name, it then calls the login program to get the
password.  Therefore, there is nothing you can do at the login level to
get rid of this prompt, short of trashing getty.

The reason why you don't want to do this is that you are going to have
big problems with noise on the serial line starting your program.  I
have experienced this with a printer server I wrote to which runs on a tty
line to a PC.  I need to specifically watch for isolated glitches on the
line, otherwise I'd be generating garbage printouts every time somebody
cycled power on the PC.

My suggestion is that you use the existing init/getty/login stuff, just
customize things appropriately.  First, setup a username with no
password which directly runs your program.  Second, you can customize
your /etc/gettydefs file to put a prompt other than "login:" on the
line.  For example, if you create the username "run", change the login
prompt from "login:" to "Type 'run' to begin the program > ".  Of
course, you will have to modify /etc/ttys to point to this gettydefs
entry.

By the way, if you still want to mess around with "login", jfh at rpp386
recently posted one to comp.sources.misc.  I am running it under SCO
XENIX 386 and am very happy with it.
-- 
Chip Rosenthal     chip at vector.UUCP    |      Choke me in the shallow water
Dallas Semiconductor   214-450-5337    |         before I get too deep.



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