获取IP地址方法

function getip() {

    static $ip = '';

    $ip = $_SERVER['REMOTE_ADDR'];

    if(isset($_SERVER['HTTP_CDN_SRC_IP'])) {

        $ip = $_SERVER['HTTP_CDN_SRC_IP'];

    } elseif (isset($_SERVER['HTTP_CLIENT_IP']) && preg_match('/^([0-9]{1,3}\.){3}[0-9]{1,3}$/', $_SERVER['HTTP_CLIENT_IP'])) {

        $ip = $_SERVER['HTTP_CLIENT_IP'];

    } elseif(isset($_SERVER['HTTP_X_FORWARDED_FOR']) AND preg_match_all('#\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}#s', $_SERVER['HTTP_X_FORWARDED_FOR'], $matches)) {

        foreach ($matches[0] AS $xip) {

            if (!preg_match('#^(10|172\.16|192\.168)\.#', $xip)) {

                $ip = $xip;

                break;

            }

        }

    }

    return $ip;

}