php 获取真实ip

/**
 * 获取真实IP
 * @param int $type
 * @param bool $client
 * @return mixed
 */
function get_client_ip($type = 0,$client=true)
{
    $type       =  $type ? 1 : 0;
    static $ip  =   NULL;
    if ($ip !== NULL) return $ip[$type];
    if($client){
        if (isset($_SERVER['HTTP_X_FORWARDED_FOR'])) {
            $arr    =   explode(',', $_SERVER['HTTP_X_FORWARDED_FOR']);
            $pos    =   array_search('unknown',$arr);
            if(false !== $pos) unset($arr[$pos]);
            $ip     =   trim($arr[0]);
        }elseif (isset($_SERVER['HTTP_CLIENT_IP'])) {
            $ip     =   $_SERVER['HTTP_CLIENT_IP'];
        }elseif (isset($_SERVER['REMOTE_ADDR'])) {
            $ip     =   $_SERVER['REMOTE_ADDR'];
        }
    }elseif (isset($_SERVER['REMOTE_ADDR'])) {
        $ip     =   $_SERVER['REMOTE_ADDR'];
    }
    // 防止IP伪造
    $long = sprintf("%u",ip2long($ip));
    $ip   = $long ? array($ip, $long) : array('0.0.0.0', 0);
    return $ip[$type];
}