gistfile1.txt

root@h5bp:~# cat /etc/nginx/sites-enabled/nginx 
server {
	listen 80;
	server_name   ~^(www\.)(?<domain>.+)$;
	return 301 $scheme://$domain$request_uri;
}

server {
	listen 80 default_server;
	return 301 $scheme://www.$host$request_uri;
}
root@h5bp:~# exit
logout
Connection to 10.10.10.12 closed.
andy@work:~$ curl -I -H "host: example.com" http://10.10.10.12/asdfasdf?foo=bar
HTTP/1.1 301 Moved Permanently
Server: nginx
Date: Mon, 17 Nov 2014 13:39:27 GMT
Content-Type: text/html
Content-Length: 178
Connection: keep-alive
Location: http://www.example.com/asdfasdf?foo=bar

andy@work:~$ curl -I -H "host: www.example.com" http://10.10.10.12/asdfasdf?foo=bar
HTTP/1.1 301 Moved Permanently
Server: nginx
Date: Mon, 17 Nov 2014 13:39:31 GMT
Content-Type: text/html
Content-Length: 178
Connection: keep-alive
Location: http://example.com/asdfasdf?foo=bar

andy@work:~$