Question

How to redirect an ’empty’ subdomain http://domain.com to http://www.domain.com using htaccess rewrite engine. It has to be a 301 permanent redirect and convey the rest of the url and query string.

Answer 1

Try putting these rules in the htaccess file in your document root:

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

The query string gets automatically appended.