gistfile1.txt

    $HTTP["url"] !~ "^/(?:(?:css|js|img|images?|statis|tmp)/|[^/]+\.[^/]+$)" {
        $HTTP["url"] !~ "^/(en|ja)/" {
            $HTTP["language"] =~ "(en|ja)" {
                url.redirect = ( "^/(.*)" => "/%1/$1" )
            }
            $HTTP["language"] !~ "(en|ja)" {
                url.redirect = ( "^/(.*)" => "/en/$1" )
            }
        }
    }