let say i want to force any people that visit this site to visit http://www.blindtext.info, not http://blindtext.info , there”s a very simple way.

use .htacces

copy this code on text editor, and save as .htacces

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

will visit http://www.blindtext.info rather than http://blindtext.info

www seem much sweeter, isn’t see?