Getting the entire URL from the address

[Anon]

I know I can get everything beyond the domain with $REQUEST_URI... like the /foo/bar from http://www.foobar.com/foo/bar... Is there a way to get everything up to $REQUEST_URI? I'd like my site to display different pages based on domain aliasing, so when a user comes to my site via foobar.com, they get specific content, while users coming to my site via barfoo.com get different content. Thanks!
Eric

[Anon]

$HTTP_HOST contains the requested hostname. But why would you do this with PHP? Apache supports name-based hosting directly.

http://httpd.apache.org/docs/mod/core.html#virtualhost

[Anon]

Works like a charm, thanks. I can't get into the whole apache configuration deal with my service. This is just perfect though!
Eric