How to keep URL unchanged after redirecting from one subdomain to another subdomain

I want to redirect all the queries from mobile.mydomain.net to web.mydomain.net, keeping the URL mobile.mydomain.net displayed in the address bar.

The directory structure in my service provider is the following:

/root  
-/vrmd  
--/homepages  
---/myusername  
----/mydomain  
-----/subdomains  
------/web  
-------/public  
------/mobile

In my service provider configuration the address www.mydomain.net points to /mydomain/, the address web.mydomain.net points to /mydomain/subdomains/web/public/ and the address mobile.mydomain.net points to /mydomain/subdomains/mobile/.

If I echo the value of the $_SERVER['DOCUMENT_ROOT'] constant in a simple PHP script (/mobile/index.php), it outputs /homepages/myusername/mydomain/subdomains/mobile开发者_Go百科.

I have some questions:

1) Where should I put the rewrite conditions and rules? In an .htaccess file under /mydomain or better under /mydomain/subdomains/mobile...?

2) Which conditions and rules should I write? For example, I want mobile.mydomain.net/blog to show only the contents of web.mydomain.net/blogs, but not the address.

Can anyone help me?

You can't silently redirect domains like that with the Apache rewrite engine - which is probably a good thing, since this could end up as a pretty nasty security breach if someone was able to upload a malicious .htaccess to your site somehow.

You would be better off implementing a front-facing controller in your mobile site that then included the content and libraries from your main website.