Well, I think I went overboard in wanting to make up for being less than helpful. I wanted to at least confirm your symptoms, with the idea of lending more credence to the apparent fact that Microsoft lies (gasp!) about limits vis-a-vis environment variables.

So I typed in a simple Perl program as you indicated: 

#!/usr/bin/perl -w
#  vim:ft=perl:ts=4:sw=4:et:is:hls:ss=10:
use strict;
use warnings;

    my  $the_cmd    = 'dir';
    printf "About to call system('%s') ...\n", $the_cmd;
    my  $rc = system( $the_cmd );
    printf "Return code from system() call was %d (0x%04X)\n", $rc, $r
+c;

[download]
Then (and in part to remind myself why Perl is *so* much better) I typed in a batch file (WinXPSP2) to test with:

(oh faint of heart - shield your eyes!) 

@echo off

:menu1
echo c)lear all
echo f)ill a bunch
echo l)ist them
echo s)ize them
echo r)un Perl program
echo q)uit
set /p zans="what to do? [cflqrs] "
if "%zans%X"=="X" goto menu1
if /i "%zans%"=="c" goto docl1
if /i "%zans%"=="f" goto dofl1
if /i "%zans%"=="l" goto doli1
if /i "%zans%"=="q" goto doqu1
if /i "%zans%"=="r" goto doru1
if /i "%zans%"=="s" goto dosz1
goto menu1

:docl1
set zcount=350
set zcounter=1
:clagain
rem echo I see %zcounter% and %zcount%
if %zcount% LSS 1 goto :menu1
if not defined zenv%zcounter% goto menu1
rem echo Once again, doing zenv%zcounter% ...
set zenv%zcounter%=
set /a zcounter+=1
set /a zcount-=1
goto clagain

:dofl1  ---------------------------------------------------
set /p zans="how many should I fill? "
if "%zans%X"=="X" goto menu1

set zcount=%zans%
echo Will fill %zcount% environment variables with 100-char values

:flagain
if %zcount% LSS 1 goto :menu1
set zenv%zcount%=a123456789b123456789c123456789d123456789e123456789f12
+3456789g123456789h123456789i123456789j123456789
set /a zcount-=1
goto flagain

:doli1
set zenv
goto menu1

:dosz1
set zenv >zenv.size
set >all.env.size
dir zenv.size all.env.size
goto menu1

:doru1
perl -w joinersw1a.pl
goto menu1

:doqu1
echo okay, quitting, bye!
goto :eof

rem vim:ft=dosbatch:ts=2:sw=2:et:is:hls:ss=10:

[download]
I then ran it, asking for increasing numbers of environment variables to be filled with short 100-char strings. I did hit a limit fairly quickly. Below are snippets from the output: 
how many should I fill? 260
Will fill 260 environment variables with 100-char values
10/03/2004  23:33            29,983 all.env.size
10/03/2004  23:33            28,492 zenv.size
About to call system('dir') ...
CGI-Application-MailPage-1.2.tar.gz  hexdmpr.pl~      murugu1.pl
    ::      ::     ::
hexdmpr.pl~                          murugu1.pl
Return code from system() call was 0 (0x0000)

how many should I fill? 265
Will fill 265 environment variables with 100-char values
10/03/2004  23:34            30,533 all.env.size
10/03/2004  23:34            29,042 zenv.size
About to call system('dir') ...
CGI-Application-MailPage-1.2.tar.gz  hexdmpr.pl~      murugu1.pl
    ::      ::     ::
hexdmpr.pl~                          murugu1.pl
Return code from system() call was 0 (0x0000)

how many should I fill? 269
Will fill 269 environment variables with 100-char values
10/03/2004  23:36            30,973 all.env.size
10/03/2004  23:36            29,482 zenv.size
About to call system('dir') ...
CGI-Application-MailPage-1.2.tar.gz  hexdmpr.pl~      murugu1.pl
    ::      ::     ::
hexdmpr.pl~                          murugu1.pl
Return code from system() call was 0 (0x0000)

how many should I fill? 270
Will fill 270 environment variables with 100-char values
10/03/2004  23:35            31,083 all.env.size
10/03/2004  23:35            29,592 zenv.size
About to call system('dir') ...
Can't spawn "cmd.exe": No such file or directory at joinersw1a.pl line 9.
Return code from system() call was 65280 (0xFF00)
All I can really offer is that I can reproduce the problem, and quite close to your problem specification. I can't find any documentation at Microsoft that relates, other than their statements about 65MB max limits. (lies!)

But I do feel you should investigate one or more of the several configuration file solutions. I just have to believe it will be more manageable now and in the future.
(once over that little hiccup of totally changing the way you do things (ouch!))

In reply to Re^3: environment limitations by shenme
in thread environment limitations by joinersw

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