function get_client_ip() {
 if (getenv("HTTP_CLIENT_IP") && strcasecmp(getenv("HTTP_CLIENT_IP"), "unknown"))
  $ip = getenv("HTTP_CLIENT_IP");
 else
  if (getenv("HTTP_X_FORWARDED_FOR") && strcasecmp(getenv("HTTP_X_FORWARDED_FOR"), "unknown"))
   $ip = getenv("HTTP_X_FORWARDED_FOR");
  else
   if (getenv("REMOTE_ADDR") && strcasecmp(getenv("REMOTE_ADDR"), "unknown"))
    $ip = getenv("REMOTE_ADDR");
   else
    if (isset ($_SERVER['REMOTE_ADDR']) && $_SERVER['REMOTE_ADDR'] && strcasecmp($_SERVER['REMOTE_ADDR'], "unknown"))
     $ip = $_SERVER['REMOTE_ADDR'];
    else
     $ip = "unknown";
 return ($ip);
}
$ip = get_client_ip();
echo '您的IP地址是:'.$ip.''; ?