On Sunday, September 6, 2009 at 7:29:09, Igor Sysoev wrote:

IS> server {
IS> server_name ~^([^.]\.com)$;
IS> set $name $1;
IS> rewrite ^ http://www.$name$request_uri? permanent;
IS> }

server {
server_name ~^(?!www\.);
rewrite ^ http://www.$host$request_uri? permanent;
}

(c) Igor Sysoev, 15 Sep 2008, http://www.lexa.ru/nginx-ru/msg19431.html

--
Best regards,
Gena