Re: Whats the %=C:% environment variable used for ?

Kenny,

> First, to answer the thread question: My understanding is that this
> *is* how processes in DOS/Windows keep track of the current directory
> for each drive.

I doubt it.  I tried but could not find any DLL function to change the path 
for a specific drive.

> neither does the real underlying (NT) OS in modern Windows

Nor do GUI programs running ontop of it (no "=c:" or similar entry to be 
seen). iow, it seems to be a quirk of just the command-processors.

But an NT-era command-processor which actually *uses* environment-variables 
to keep track of them - instead of keeping those paths in some internal 
memory and just updates the environment variable when needed ?   Thats hard 
to believe.

> So, the point is that there are "hidden" environment variables for each
> drive that has a current directory other than \.

Not really my point, and no (see below).

> For example, on the machine I just tested this on, every drive
> other than C: had its current directory at the root, so the only
> env var I could find was the "=C:\foo\bar\whatever".

Not quite : I just did the test to CD to some folder, change back to the 
root and than executed the program showing all the environment-variables. 
It showed the entry "=C:=c:\".

iow, it looks like that if an entry for a drive has been created it stays.

> That said, I am genuinely (non-rhetorically) curious as to how
> you discovered this in the first place, given that these variables
> are not displayed by the DOS "set" command.

Thats easy to explain : the GetEnvironmentStrings function in Kernel32.DLL 
retrieves them all. :-)

> You'd have needed to use some other tool to scan the environment
> table.  For that reason, a screenshot would actually have been
> useful.

So you guys could see a program named "test.exe" with a number of strings 
below it, which look like the output of a commandline "set" command ?  How 
would that help anyone ?

> Or, you could just tell us how you found it...

:-)  I did.  Now you can ask yourself *why* I used that 
GetEnvironmentStrings function. :-p

> Two other notes:
...
> That other product (tool) does, indeed, have the ability to access
> these variables.

SetEnvironmentVariable, GetEnvironmentVariable and GetEnvironmentStrings are 
all part of Kernel32.DLL .  Most programming languages (and even some 
scripting ones) can call them them.

> 2) (Speaking of screenshots) Given that this is Usenet, and Usenet
>    is (supposed to be) a text-only medium, how would one go about
>    posting a screenshot, should one desire to do so?  Is there any
>    established protocol?

As these newsgroups (on news.eternal-september.org) do not allow attachments 
you would need to upload them to some image-server, and add the link to it 
to your post.

Ofcourse, most of those image-servers will want you to create an account 
with them, and will only allow the others to see the uploaded image after 
having passed some Javascript hurdles.

For the same reason as Google doesn't work for me those image-servers do not 
work for me either.

By the way : some newsgroup servers do allow HTML posting as well as 
attachments.  news.ethernal.september.org mostly disallows them pretty-much 
everywhere.

Regards,
Rudy Wieser