PHP获取客户端ip和服务器端IP方法

class getIP{
function clientIP(){
$cIP = getenv('REMOTE_ADDR');
$cIP1 = getenv('HTTP_X_FORWARDED_FOR');
$cIP2 = getenv('HTTP_CLIENT_IP');
$cIP1 ? $cIP = $cIP1 : null;
$cIP2 ? $cIP = $cIP2 : null;
return $cIP;
 }
function serverIP(){
return gethostbyname($_SERVER["SERVER_NAME"]);
 }
}

$getIP  = new getIP();
$clientIp = getIP::clientIP();
$serverIp = getIP::serverIP();

echo 'Client IP is ',$clientIp,'<br />';
echo 'Server IP is ',$serverIp,'<br />';

function GetIP() {
$ip = $_SERVER['REMOTE_ADDR'];
if (!empty($_SERVER['HTTP_CLIENT_IP'])) {
$ip = $_SERVER['HTTP_CLIENT_IP'];
    } elseif (!empty($_SERVER['HTTP_X_FORWARDED_FOR'])) {
$ip = $_SERVER['HTTP_X_FORWARDED_FOR'];
    }
return $ip;
}

function GetIP__(){
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);
}

echo GetIP();