Forwarding www.example.com/abc to abc.example.com

Question

I have a web directory that can be accessed via either http://www.example.com/abc or http://abc.example.com. Same physical directory, same contents, just different addresses.

I want to redirect to abc.example.com if it is accessed via www.example.com/abc. Can I do it by a simple PHP script?

The index.php will be the contents for either address anyway.

Answer 1

You can analyze the $_SERVER['HTTP_HOST'] variable in PHP:

if( $_SERVER['HTTP_HOST'] !== 'abc.example.com' ){
    header('Location: http://abc.example.com/', true, 301);
    exit;
}

If it's not abc.example.com it will redirect to it.

I guess you can put it into your index.php at the very top.

Answer 2

It would be much better to configure the webserver to handle this redirection. It is fairly trivial to configure Apache to do something along these lines. If you are using Apache, look up RewriteRule. Most other web servers have comparable features.