redirect not-active subdomains

Question

EDIT:

How can you redirect all non-active subdomains to 'www'?

Here I try to redirect all subdomains not listed to 'www'.. I can't make it work properly because %1 and %2 doesn't return anything.. Here I'm trying to redirect to google.com just to check the returned %2 value.., but it doesn't return anything and the redirect url is http://www.google.com/

RewriteCond %{HTTP_HOST}        !^(admin|demo|www)\.([^\.]+\.[^\.]+)$ [NC]
RewriteRule ^(.*)$          http://www.google.com/%2 [L,R=301]

this is what I really want to do

RewriteCond %{HTTP_HOST}        !^(admin|demo|www)\.([^\.]+\.[^\.]+)$ [NC]
RewriteRule ^(.*)$          http://www.%2/$1 [L,R=301]

Answer 1

RewriteCond %{HTTP_HOST} !^(www|admin|files|mysql\.)domain\.com$ [NC]
RewriteRule ^ http://www.domain.com%{REQUEST_URI} [NE,L,R=301]

Untested but it should work..

Answer 2

Presuming DNS entries already exist, you could use something I do on a couple domains:

    RewriteEngine on
    RewriteCond %{HTTP_HOST} ^([^.]+)\.mydomain\.com$
    RewriteRule ^/(.*)$ http://mydomain.com/%1/$1 [L,R]

This takes requests in the form of sub.domain.com and pushes it to domain.com/sub.

You could remove the %1 and get the following which would not use the subdomain-to-path method I'm employing thusly:

    RewriteEngine on
    RewriteCond %{HTTP_HOST} ^([^.]+)\.mydomain\.com$
    RewriteRule ^/(.*)$ http://mydomain.com/$1 [L,R]