rammsteinik

RewriteEngine On
RewriteBase /
RewriteCond %{HTTP_HOST} !^www\.site\.ru$
RewriteCond %{HTTP_HOST} ^(.*)\.site\.ru$
RewriteRule ^(.*)$ http://site.ru/users.php?login=%1 [L,P]

function get_client_ip() {
    $ipaddress = '';
    if (!empty($_SERVER['HTTP_CLIENT_IP'])) {
        $ipaddress = $_SERVER['HTTP_CLIENT_IP'];
    } elseif (!empty($_SERVER['HTTP_X_FORWARDED_FOR'])) {
        $ipaddress = $_SERVER['HTTP_X_FORWARDED_FOR'];
    } else {
        $ipaddress = $_SERVER['REMOTE_ADDR'];
    }

    return $ipaddress;
}