.htaccess rewriting subdomain as maindomain

Question

The last couple of hours I have been learning about .htaccess rewrite. I haven't been able to get it right. I have read a lot of posts her on SO, but can't solve my problem. This is my situation:

www.example.com 

redirects to

example.example2.com

Now I want to show the original domain in the URL. I have this:

RewriteCond %{HTTP_HOST} ^example\.example2\.com/$ [NC]
RewriteRule ^(.*)$ http://www.example.com/$1 [L,R=301]

This doesn't work. I still see the example.example2.com instead of www.example.com

The .htaccess file is located at the top level in the folder for the subdomain.

I should note again that this is new to me and this is what I have been able to come up with from examples I found on the internet. Can someone tell how to get this right?

Thanks a lot

Edit:

1. I'm trying to install a Drupal multisite configuration. My problem seemed solvable with .htaccess instructions as explained here and here. Because of this I posted it here and not on the Drupal part of SO. The idea of a Drupal multisite configuration is to direct all traffic to the installment and then differentiate according to the request made.

2. I have no direct control over the redirect from www.example.com to example.example2.com. My hosting company provides a direct redirect or via frame. I can check either one in a form. I don't know what they do. With a direct redirect the URL changes from www.example.com to example.example2.com. (where the Drupal installation is now) If I choose frame the URL stays the same (of course), but hovering over a link still reveals the example.example2.com identity.

3. I didn't start out with a multisite configuration. I will move example.exampl2.com to www.example2.com/sites/www.example.com as in the instruction for a multisite. In the meanwhile the site is at example.example2.com. But that means I have two installments to maintain, which is not preferred. So I started out by trying to have example.example2.com look like www.example.com. Then at least visitors would never notice differences.

I now have this

RewriteCond %{ENV:REDIRECT_STATUS} 200
RewriteRule ^ - [L]
RewriteCond %{HTTP_HOST} ^example\.example2\.nl$ [NC]
RewriteRule ^(.*)$ http://www.example.com/$1 [L,R]

And it results in a loop.

Answer 1

First thing you have your requirement reversed. You probably want to redirect example.example2.com to www.example.com.

Second thing what you are trying to do will be possible with mod_proxy support only. Enable mod_proxy in httpd.conf then enable mod_rewrite and .htaccess through httpd.conf and then put this code in your .htaccess under DOCUMENT_ROOT directory:

Options +FollowSymLinks -MultiViews
# Turn mod_rewrite on
RewriteEngine On
RewriteBase /

RewriteCond %{HTTP_HOST} ^example\.example2\.com$ [NC]
RewriteRule ^ http://www.example.com%{REQUEST_URI} [L,P]

Note that flag P here is used for proxy support in mod_rewrite.

Answer 2

Your .htaccess is almost perfect. There's just one issue, HTTP_HOST is the host only, without a trailing slash /. The RewriteCond should be

RewriteCond %{HTTP_HOST} ^example\.example2\.com$ [NC]
RewriteRule ^(.*)$ http://www.example.com/$1 [L,R]

Now, there is a loop rewriting from www.example.com to example.example2.com and back again. To break this endless loop, you must add a terminating condition, which stops the rules. Prefix the rules with

RewriteCond %{ENV:REDIRECT_STATUS} 200
RewriteRule ^ - [L]

When everything works as you expect, you can change R to R=301.

Never test with 301 enabled, see this answer Tips for debugging .htaccess rewrite rules for details.