Clarify the DOCUMENT_ROOT environment variable oddity.

<P>The other thing to `fake' is the document root (configured

with <CODE>DocumentRoot</CODE> and available to CGIs via the

<CODE>DOCUMENT_ROOT</CODE> environment variable). 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. If any CGIs or SSI documents

make use of the <CODE>DOCUMENT_ROOT</CODE> environment variable

they will therefore get a misleading value; there isn't any way to

change <CODE>DOCUMENT_ROOT</CODE> dynamically.</P>

<CODE>DOCUMENT_ROOT</CODE> 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

<CODE>mod_vhost_alias</CODE> or <CODE>mod_rewrite</CODE>) which has

a different way of doing the mapping. Neither of these modules is

responsible for setting the <CODE>DOCUMENT_ROOT</CODE> environment

variable so if any CGIs or SSI documents make use of it they will

get a misleading value.</P>

<HR><H2><A NAME="simple">Simple dynamic virtual hosts</A></H2>