PHP实战：PHP实现获取客户端IP并获取IP信息

<?php
/**
 * 获取客户端IP
 * @param  integer $type 返回类型 0:string,1:long
 * @return string|long
 */
function getClientIp($type = 0) {
    $ip = NULL;
    if (isset($_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'];
    }
    $long = sprintf("%u", ip2long($ip));
    $ip   = $long ? array($ip, $long) : array('0.0.0.0', 0);
    return $ip[$type];
}
/**
 * 获取IP信息
 * @param  string|long $ip  IP地址
 * @return array
 */
function getIpInfo($ip)
{
    if (is_long($ip)) {
        $ip = long2ip($ip);
    }
    $api = 'http://ip.taobao.com/service/getIpInfo.php';
    $ret = file_get_contents($api . '?ip=' . $ip);
    $ret = json_decode($ret, true);
    if ($ret['code'] == 0) {
        return $ret['data'];
    }
    return array();
}