Path: utzoo!mnetor!uunet!husc6!mit-eddie!ll-xn!ames!ptsfa!ihnp4!chinet!dag
From: dag@chinet.UUCP (Daniel A. Glasser)
Newsgroups: comp.sys.atari.st
Subject: Re: 2 Questions.
Message-ID: <2191@chinet.UUCP>
Date: 2 Feb 88 16:10:37 GMT
References: <8801261529.AA03656@ucbvax.Berkeley.EDU>
Reply-To: dag@chinet.UUCP (Daniel A. Glasser)
Organization: Chinet - Public Access Unix
Lines: 28
Summary: one answer -- basepage info and MWC shell

In article <8801261529.AA03656@ucbvax.Berkeley.EDU> NETWORK@FRSAC11.BITNET writes:
>Question #1 : How MWC's msh is discovering who called it ?
> (desktop, or other...) it is in the local shell variable 'calledfrom'.
>An other shell is able to tell the list of all parents programs...
>The base page does not contain any backward pointer, so what is it ?

The answer to this is that msh looks at the environment strings to determine
whether a the MWC environment is already there and if it is, it determines
how it was run, otherwise, it figures that it must be the desktop.  It
can check for \auto because the GEM stuff is not set up yet.

There is, in fact, a 'backward' pointer to the parent process basepage
in the program basepage.  This is documented in the include file
'basepage.h' supplied with Mark Williams C, though not in the manual.
It is at offset 0x24 from the beginning of the basepage.  There is a
LOT of information in the basepage that was not initially documented
by Atari.

[Question #2 omitted]
>Regards,
>
>Jean-Pierre H. Dumas
-- 
Nobody at the place where I work	Daniel A. Glasser
knows anything about my opinions	...!ihnp4!chinet!dag
my postings, or me for that matter!	...!ihnp4!mwc!dag
					...!ihnp4!mwc!gorgon!dag
	One of those things that goes "BUMP!!! (ouch!)" in the night.