Nginx doesn't redirect www no m in Safari, iPhone, iPad

[ramsoft75]

The "^/$" came from :

#to detect if the device with www entered in domain is mobile
if ($http_user_agent ~* '(iPhone|iPod|iPad|Android|BlackBerry|webOS|Windows
Phone)') {
  rewrite ^/$ http://m.domain.com$request_uri;
}

Posted at Nginx Forum: http://forum.nginx.org/read.php?2,260033,260097#msg-260097