简单的php获取IP地址的函数：

/**

获取IP

*/

function GetIp()

{

    if (getenv('HTTP_CLIENT_IP')) {

        $IP = getenv('HTTP_CLIENT_IP');

    }

    elseif (getenv('HTTP_X_FORWARDED_FOR')) {

        $IP = getenv('HTTP_X_FORWARDED_FOR');

    }

    elseif (getenv('HTTP_X_FORWARDED')) {

        $IP = getenv('HTTP_X_FORWARDED');

    }

    elseif (getenv('HTTP_FORWARDED_FOR')) {

        $IP = getenv('HTTP_FORWARDED_FOR');

    }

    elseif (getenv('HTTP_FORWARDED')) {

        $IP = getenv('HTTP_FORWARDED');

    }

    else {

        $IP = $_SERVER['REMOTE_ADDR'];

    }

    if(isset($_GET['debug'])){

      return $_GET['debug'];

    }

    return $IP;

}