.htaccess Redirect based on subdomain

Question

I'm looking for some help in accomplishing redirects based on the subdomain. For example if some tries to access:

http://1.test.com

it will redirect to:

/file.php?test=something

and if they go to:

http://2.test.com

it will redirect to:

/file.php?test=somethingelse

I only need the root redirected, so if they go to:

http://1.test.com/blah

it will not redirect.

I know the basics of creating htaccess files, I just can't seem to get it right for some reason to accomplish this. Any help is highly appreciated.

Thanks.

P.S. I should mention that all these subdomains point to the same document root.

Answer 1

With mod_rewrite active try

RewriteEngine on
RewriteCond %{HTTP_HOST} !^1.test.com$
RewriteRule ^$ /file.php?test=something [L,R=301]
RewriteCond %{HTTP_HOST} !^2.test.com$
RewriteRule ^$ /file.php?test=somethingelse [L,R=301]