Command Environment Memory Limits

[Thomas Tierney]

Hey all,

I am wondering if anyone knows of any environment variable limitations with regards to CMD.EXE in the NT Type machines (NT, 2K, XP, VISTA, 2K3). We have a need to store data in environment variables and I fear that we may run out of memory if we need to store alot of data there

TIA

[Michael Mattias]

Source: http://www.computerhope.com/cmd.htm, found quickly by Google-ing "environment size cmd.exe"

CMD.EXE ... /E:nnnnn
Sets the initial environment size to nnnnn bytes. (nnnnn should be between 256 and 32,768).

Kinda suggests you can set it yourself, but not larger than 32,768

Not tested; exercise left to user.

Need more - or rather, want more space in which to share data? In that case we need more info about the application... like is it an MS-DOS or Windows appliacation would be a really good start.

MCM

[Thomas Tierney]

Hey Michael,

Thanks for the reply. It is actually a windows app that uses the environment to store test specific data. This is a legacy test framework that I would like to get changed to use xml as the data source instead of Environment variables

CMD.EXE /E:ON or OFF is for enabling or disabling command extensions on XP and 2K3

Thanks for the Info

[Michael Mattias]

I would like to get changed to use xml as the data source instead of Environment variables

How about an INI file? that would surely be easier to use to set parameters for a test run, wouldn't it? OR even a simple text file

param1
param2
string_Parameter
...
end data

[Thomas Tierney]

your absolutely right michael, anything would be easier than environment variables but the problem with the ini file is it doesnt support unicode (never did). I did check and the limit is 32K of data. With 256 bytes of data I can use 128 enviroment vars.

[Michael Mattias]

If it's just a "text" file, you can save Unicode strings... or even save as ANSI and convert to Unicode as required. (And you can save the ANSI in an INI).

I think we have here one more example: When designing your applications one of the questions you must ask and answer BEFORE writing that first line of code is, "How am I going to test this?"

MCM