php获取客户端IP地址的几种方法

PHP Code one: //php获取ip的算法
$iipp=$_SERVER["REMOTE_ADDR"];
echo $iipp; PHP Code two: //php获取ip的算法
$user_IP = ($_SERVER["HTTP_VIA"]) ? $_SERVER["HTTP_X_FORWARDED_FOR"] : $_SERVER["REMOTE_ADDR"];
$user_IP = ($user_IP) ? $user_IP : $_SERVER["REMOTE_ADDR"];
echo $user_IP; function get_real_ip(){
$ip=false;
if(!empty($_SERVER["HTTP_CLIENT_IP"])){
$ip = $_SERVER["HTTP_CLIENT_IP"];
}
if (!empty($_SERVER['HTTP_X_FORWARDED_FOR'])) {
    $ips = explode (", ", $_SERVER['HTTP_X_FORWARDED_FOR']);
if ($ip) { array_unshift($ips, $ip); $ip = FALSE; }
    for ($i = 0; $i < count($ips); $i++) {
         if (!eregi ("^(10│172.16│192.168).", $ips[$i])) {
            $ip = $ips[$i];
            break;
        }
    }
}
    return ($ip ? $ip : $_SERVER['REMOTE_ADDR']);
}
echo get_real_ip(); PHP Code three:   //php获取ip的算法
if ($HTTP_SERVER_VARS["HTTP_X_FORWARDED_FOR"])
{
      $ip = $HTTP_SERVER_VARS["HTTP_X_FORWARDED_FOR"];
}
  elseif ($HTTP_SERVER_VARS["HTTP_CLIENT_IP"])
{
      $ip = $HTTP_SERVER_VARS["HTTP_CLIENT_IP"];
}
elseif ($HTTP_SERVER_VARS["REMOTE_ADDR"])
{
     $ip = $HTTP_SERVER_VARS["REMOTE_ADDR"];
}
elseif (getenv("HTTP_X_FORWARDED_FOR"))
{
     $ip = getenv("HTTP_X_FORWARDED_FOR");
}
elseif (getenv("HTTP_CLIENT_IP"))
{
     $ip = getenv("HTTP_CLIENT_IP");
}
elseif (getenv("REMOTE_ADDR"))
{
     $ip = getenv("REMOTE_ADDR");
}
else
{