[users@httpd] DOCUMENT_ROOT and mod_vhost_alias

[Fury <furiosod@xxxxxxxxx>]

Hi,

I'm messing around with mass virutal hosting (found here:
http://httpd.apache.org/docs/2.0/vhosts/mass.html), and I'm having
trouble understanding what's going on with the DOCUMENT_ROOT
environment variable.

>From the page:

"The other thing to `fake' is the document root (configured
    with DocumentRoot and available to CGIs via the
    DOCUMENT_ROOT environment variable). In a normal
    configuration this setting is used by the core module when
    mapping URIs to filenames, but when the server is configured to
    do dynamic virtual hosting that job is taken over by another
    module (either mod_vhost_alias or
    mod_rewrite) which has a different way of doing
    the mapping. Neither of these modules is responsible for
    setting the DOCUMENT_ROOT environment variable so
    if any CGIs or SSI documents make use of it they will get a
    misleading value."

So how do I `fake' it?

Thanks for any help!

-Derek