Path: utzoo!mnetor!uunet!husc6!cmcl2!brl-adm!umd5!ames!scubed!sweet
From: sweet@scubed.UUCP (Kevin Sweet)
Newsgroups: comp.sys.ibm.pc
Subject: Re: Environment space size?
Message-ID: <347@scubed.UUCP>
Date: 7 Jan 88 17:18:12 GMT
References: <1900@ukecc.engr.uky.edu> <554@leah.Albany.Edu>
Reply-To: sweet@scubed.UUCP (Kevin Sweet)
Distribution: na
Organization: S-Cubed, San Diego California
Lines: 57
Keywords: environment variables size
Summary: DOS 3.10 specific

In article <554@leah.Albany.Edu> emb978@leah.Albany.Edu (Eric M. Boehm) writes:
->In article <1900@ukecc.engr.uky.edu>, agollum@engr.uky.edu (David Herron) writes:
->-> Maybe I'm being dense, but how does one determine the size of the
->-> environmment space (ie, how much room there is for environment
->-> variables) from within a program?  I can read the environment just
->-> fine, I just don't know how much free space there is.
->-> 
->
->Assuming you are running MS-DOS 3.2, the default environment space is (I
->believe) 256 bytes.
->
->You can change this by inserting the following line into your config.sys
->file:
->
->shell=c:\dos\command.com c:\dos /e:nnnn /p
->
->where C:\dos\command.com tells DOS where to load command.com from the
->*FIRST* time it is loaded, c:\dos tells dos the pathname to load subsequent
->copies of command.com (in case that area of memory is overwritten by your
->application program), /e:nnnn tells DOS how many bytes to reserve for
->environment space (in 3.1 this number is in paragraphs [16 bytes] so just
->divide by 16), and /p tells DOS that this is the primary processor for the

             ^ but it is limited to 62 paragraphs in DOS 3.10 (still alot).
               Any number greater than 62 is ignored and you get the default
               of 10 paragraphs.

->exit command (usually to get out of child processes).
->
->I don't believe this works below 3.x (I have had conflicting reports) but it
->does work in 3.1 and 3.2 (at least for me).
->
->You can change the path to your copy of command.com as suits your needs. One
->last note, you will still need a copy of command.com in the root in order to
->format disks properly (no, I don't know why).
->
->Also note that no environment variable can occupy more than 127 (128?) bytes
->each!
->
->Eric M. Boehm
->EMB978@ALBNY1VX.BITNET
->EMB978@LEAH.ALBANY.EDU

I know this isn't really an answer to the original poster's question but I
found the information very useful. I have a copy of some patches to DOS 3.10
that I received from a recent poster (harvard!lhasa!Jerry.Lotto) that cover 
many different areas (like a patch to command.com that makes 'echo off' the 
default for batch files) and will send them to anyone who sends me an e-mail 
request.

Stupid, Stupid, DOS. ( no smiley on that last statement |^)
Kevin
-- 
---- kevin sweet -------------------------------- email: sweet@scubed.ARPA ----
work:             3398 carmel mountain,  san diego, ca 92121-1095, 619-587-8499
home:            12205 carmel vista 242, san diego, ca 92130-2237, 619-259-9338
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