rerwrite problem

[lnxa]

abc.com/nginx.text rewrite  www.abc.com/nginx.text
 service_name abc.com www.atans.com
 if ($host = 'abc.com' ) {
        rewrite  ^/(.*)$  http://www.abc.com/$1  permanent;
    }

Is this rewrite rule right?

Posted at Nginx Forum: http://forum.nginx.org/read.php?2,40554,40554#msg-40554