Xref: utzoo comp.unix.wizards:13911 comp.unix.questions:10964
Path: utzoo!utgpu!attcan!uunet!mcvax!ukc!dcl-cs!nott-cs!ucms!dave
From: dave@ucms.UUCP (Dave Settle)
Newsgroups: comp.unix.wizards,comp.unix.questions
Subject: Controlling ttys, and how to get rid of them.
Summary: background process grabs the tty, login fails to work.
Keywords: System V, login, tty
Message-ID: <176@ucms.ucms.uucp>
Date: 6 Jan 89 13:52:00 GMT
Reply-To: dave@ucms.UUCP (Dave Settle)
Organization: Universal (CMS) Ltd, Leicester, UK
Lines: 40


I'm having intermittent problems with 'login' on System V machines. It's
happened on a number of machines, ranging from AT&T 3B2's to more
flavoursome versions of SVR2.

What happens is that in some circumstances, I can only login using an account
without a password. If I try to login as a user who has a password, I get:

Machine XYZ .... etc
login: dave
Login incorrect
login:

This affects every user who has a password, but only affects the one terminal -
I can login on other terminals fine (it asks for my password as per usual).

Poking around the system, in particular looking at the 'ps' output, it looks
as though a process which normally runs in the background (but occasionally
writes output to this terminal) has become attached to the terminal (TTY shows
'002' [or whatever]), but the getty process has not (TTY line shows '?').

"Maybe this is to do with process groups and controlling ttys", I think 
to myself, "I'll go read the manual ... ". However, the manual is less than
terrifically helpful. In fact, it is exceedingly cagey about controlling
ttys and how they get assigned (and de-assigned).

If I knew how to get rid of one, then I could run my background process without
it messing up the login procedure.

Any help appreciated.

Cheers,
	Dave Settle
--

Dave Settle, Universal (CMS) Ltd, Thames Tower, Burleys Way, Leicester, UK.

dave@ucms.co.uk			...mcvax!ukc!nott-cs!ucms!dave

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