获取访问者的IP地址

function getIp()
{
    $realip = NULL;
    if(isset($_SERVER[‘HTTP_X_FORWARDED_FOR‘]))
    {
        $ipArray = explode(‘,‘, $_SERVER[‘HTTP_X_FORWARDED_FOR‘]);
        foreach($ipArray as $rs)
        {
            $rs = trim($rs);
            if($rs != ‘unknown‘)
            {
                $realip = $rs;
                break;
            }
        }
    }
    else if(isset($_SERVER[‘HTTP_CLIENT_IP‘]))
    {
        $realip = $_SERVER[‘HTTP_CLIENT_IP‘];
    }
    else
    {
        $realip = $_SERVER[‘REMOTE_ADDR‘];
    }

    preg_match("/[\d\.]{7,15}/", $realip, $match);
    $realip = !empty($match[0]) ? $match[0] : ‘0.0.0.0‘;
    return $realip;
}