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Date: Fri, 6 Jun 2003 15:40:24 -0400
From: Ashok Vadekar <avadekar AT certicom DOT com>
To: cygwin AT cygwin DOT com
Subject: Weird top bug?
Message-ID: <20030606194024.GA10935@certicom.com>
Reply-To: avadekar AT certicom DOT com
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I've stumbled across some peculiar behaviour for top.  I've got the following
script (vping) that I use to keep a VPN connection alive:
	#!/bin/sh
		while true;
		do
			ping -n 1 remoteMachine >/dev/null
			sleep 60
		done

I typically run this as a background task (vping &), then telnet to
remoteMachine.

Now when I quit telnet, then exit the shell (vping was run from), the shell
stays around.  My script has a stdout handle, I suppose.  That's OK, I can
close the window with the mouse, and then vping dies.  Seems normal.  But if I
leave the shell open after typing exit, then run top in another shell, it
clears the screen, shows exactly one line of output (in this specific case):
	 15:23:03 up  8:00,  2 users,  load average: 0.00, 0.00, 0.00

and locks up.  Control C does not regain shell control.

If I open another shell and use ps to find the process number for top, I can
kill it (kill pid, no explicit signal type).

It doesn't seem to me that my specific script should have anything to do with
how top is behaving, but I supose it is possible.  Seems more like top is
having trouble because the parent process of my script is no longer valid.
Maybe the parent process is gone, but top uses a windows thing to enumerate
processes, and the open shell still has an entry in that list?



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