RewriteCond %{HTTP_HOST} ^site.ru$ [NC] RewriteRule ^(.*)$ http://www.site.ru/$1 [R=301,L]
RewriteEngine On RewriteCond %{HTTP_HOST} ^site.ru RewriteRule (.*) http://www.site.ru/$1 [R=301,L]
RewriteEngine on RewriteCond %{ENV:HTTPS} on RewriteRule .* - [E=SSL:s] RewriteCond %{HTTP_HOST} !^www\.(.*) [NC] RewriteRule .* http%{ENV:SSL}://www.%{HTTP_HOST}/$0 [R=301,L]