Path: utzoo!attcan!uunet!mcsun!hp4nl!svin02!eba!wjw
From: wjw@eba.eb.ele.tue.nl (Willem Jan Withagen)
Newsgroups: comp.sys.apollo
Subject: Re: How do you create a persistent background process from DM?
Keywords: DM, cps, background process. (SR9.7??)
Message-ID: <636@eba.eb.ele.tue.nl>
Date: 12 Sep 90 15:37:37 GMT
References: <2411@dover.sps.mot.com>
Sender: news@eba.eb.ele.tue.nl (The News system)
Organization: Eindhoven University of Technology, The Netherlands
Lines: 34

In article <2411@dover.sps.mot.com> talent@spanky.sps.mot.com () writes:
>I need to start a background process from a display manager window that
>will continue running after logout.  I've tried nohup, nice, and &.
>The process is started from a /bin/csh script running in a DM window.
>
>The problem is that any process started from a DM window will be stopped
>at logout.
>

My guess is that you're still running OS SR 9.7?
If that's the case, this is your problem:
	When the DM halts is sends a signal to all processes at 'owns'.
	the signal send is SIGAPOLLO, which is something different from
	SIGHUP. Now most processes don't like the Apollo signal and kill
	themselves.
The solution:
	I always used for this is to remote loging into the same node 
	with rsh and start the program then. Now when you exit, get the
	program the SIGHUP and that is caught by either nohup or others.
	Then exit the remote shell, now the process becomes parent-less.
	Upon exit of the DM does it not send a signal to the newly
	created process, since it does not have a parent. (So certainly
	not the DM.)

This feature took use several weeks to find out what was going on.

Succes, and let us know it it worked,

		Willem Jan Withagen

Eindhoven University of Technology   DomainName:  wjw@eb.ele.tue.nl    
Digital Systems Group, Room EH 10.10 BITNET: ELEBWJ@HEITUE5.BITNET
P.O. 513                             Tel: +31-40-473401
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