Path: utzoo!attcan!uunet!lll-winken!lll-tis!helios.ee.lbl.gov!pasteur!ucbvax!hplabs!hp-pcd!hpcvlx!everett
From: everett@hpcvlx.HP.COM (Everett Kaser)
Newsgroups: comp.sys.ibm.pc
Subject: Re: Help! Info wanted of Environment Variable Access
Message-ID: <101000018@hpcvlx.HP.COM>
Date: 1 Nov 88 16:47:45 GMT
References: <599@sppy00.UUCP>
Organization: Hewlett-Packard Co., Corvallis, OR, USA
Lines: 11

There are two bytes in your PSP (Program Segment Prefix) at offset 0x2c that
contain the segment address of your environment block.  However, this doesn't
tell you how LONG the environment memory block is; I think you would have to
"cheat" and look in the memory control block that immediately precedes the
environment segment to find the length of the segment, in order to know if
you have room in the segment to expand a variable's length.  (hell of a
sentence, huh?).  What you want to do is perfectly possible, but is not
supported in anyway by DOS, so you get into a LOT of dirty tricks trying to
do it.

Everett Kaser
!hplabs!hp-pcd!everett