php获取访问者ip

方法一：$_SERVER['HTTP_X_FORWARDED_FOR']来获取相应的地址

/**
     * 获取访问者IP
     *
     */
    public static function get_client_ip() {
        if (getenv('HTTP_CLIENT_IP') && strcasecmp(getenv('HTTP_CLIENT_IP'), 'unknown')) {
            $CLIENT_IP = getenv('HTTP_CLIENT_IP');
        } elseif (getenv('HTTP_X_FORWARDED_FOR') && strcasecmp(getenv('HTTP_X_FORWARDED_FOR'), 'unknown')) {
            $CLIENT_IP = getenv('HTTP_X_FORWARDED_FOR');
        } elseif (getenv('REMOTE_ADDR') && strcasecmp(getenv('REMOTE_ADDR'), 'unknown')) {
            $CLIENT_IP = getenv('REMOTE_ADDR');
        } elseif (isset($_SERVER['REMOTE_ADDR']) && $_SERVER['REMOTE_ADDR'] && strcasecmp($_SERVER['REMOTE_ADDR'], 'unknown')) {
            $CLIENT_IP = $_SERVER['REMOTE_ADDR'];
        }
        return $CLIENT_IP;
    }

方法二：利用curl依靠第三方来获取，如http://www.ip138.com/ip2city.asp

function get_onlineip() {
    $ch = curl_init('http://www.ip138.com/ip2city.asp');
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
    $a  = curl_exec($ch);
    preg_match('/\[(.*)\]/', $a, $ip);
    return $ip[1];
 }

http://blogread.cn/it/article/3855?f=wb