如果你需要尽快获得国家，我会建议geoip插件为您的web服务器。

对于nginx;

正确设置后，您将从$_SERVER变量中获得国家代码。

我每秒执行500(+-)次，非常快。

您可以使用我的服务:https://SmartIP.io，它提供任何IP地址的完整国家名称和城市名称。我们还公开了时区、货币、代理检测、TOR节点检测和加密检测。

你只需要注册并获得一个免费的API密钥，允许每月25万次请求。

使用官方的PHP库，API调用变成:

$apiKey = "your API key";
$smartIp = new SmartIP($apiKey);
$response = $smartIp->requestIPData("8.8.8.8");

echo "\nstatus code: " . $response->{"status-code"};
echo "\ncountry name: " . $response->country->{"country-name"};

查看API文档了解更多信息: https://smartip.io/docs

我尝试了Chandra的答案，但我的服务器配置不允许file_get_contents()

PHP警告:file_get_contents() URL文件访问在服务器配置中被禁用

我修改了Chandra的代码，使它也适用于使用cURL的服务器:

function ip_visitor_country()
{

    $client  = @$_SERVER['HTTP_CLIENT_IP'];
    $forward = @$_SERVER['HTTP_X_FORWARDED_FOR'];
    $remote  = $_SERVER['REMOTE_ADDR'];
    $country  = "Unknown";

    if(filter_var($client, FILTER_VALIDATE_IP))
    {
        $ip = $client;
    }
    elseif(filter_var($forward, FILTER_VALIDATE_IP))
    {
        $ip = $forward;
    }
    else
    {
        $ip = $remote;
    }
    $ch = curl_init();
    curl_setopt($ch, CURLOPT_URL, "http://www.geoplugin.net/json.gp?ip=".$ip);
    curl_setopt($ch, CURLOPT_HEADER, 0);
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, TRUE);
    $ip_data_in = curl_exec($ch); // string
    curl_close($ch);

    $ip_data = json_decode($ip_data_in,true);
    $ip_data = str_replace('"', '"', $ip_data); // for PHP 5.2 see stackoverflow.com/questions/3110487/

    if($ip_data && $ip_data['geoplugin_countryName'] != null) {
        $country = $ip_data['geoplugin_countryName'];
    }

    return 'IP: '.$ip.' # Country: '.$country;
}

echo ip_visitor_country(); // output Coutry name

?>

希望能有所帮助;-)

以下是使用guzzle的更清晰的工作版本:

你可以使用curl而不是guzzle，这只是一个简单的get请求。

    function ip_info($ip = NULL, $purpose = "location", $deep_detect = TRUE) {
        $output = NULL;
        if (filter_var($ip, FILTER_VALIDATE_IP) === FALSE) {
            $ip = $_SERVER["REMOTE_ADDR"];
            if ($deep_detect) {
                if (filter_var(@$_SERVER['HTTP_X_FORWARDED_FOR'], FILTER_VALIDATE_IP))
                    $ip = $_SERVER['HTTP_X_FORWARDED_FOR'];
                if (filter_var(@$_SERVER['HTTP_CLIENT_IP'], FILTER_VALIDATE_IP))
                    $ip = $_SERVER['HTTP_CLIENT_IP'];
            }
        }
        $purpose    = str_replace(array("name", "\n", "\t", " ", "-", "_"), NULL, strtolower(trim($purpose)));
        $support    = array("country", "countrycode", "state", "region", "city", "location", "address");
        $continents = array(
            "AF" => "Africa",
            "AN" => "Antarctica",
            "AS" => "Asia",
            "EU" => "Europe",
            "OC" => "Australia (Oceania)",
            "NA" => "North America",
            "SA" => "South America"
        );
        if (filter_var($ip, FILTER_VALIDATE_IP) && in_array($purpose, $support, true)) {
            $client = New \GuzzleHttp\Client();
            $ipdat = json_decode($client->request('GET','http://www.geoplugin.net/json.gp',$params = [
                'query' => [
                    'ip' => $ip,
                ]
            ])->getBody()->getContents(),true);
            if (strlen(trim($ipdat['geoplugin_countryCode'])) === 2) {
                switch ($purpose) {
                    case "location":
                        $output = array(
                            "city"           => $ipdat['geoplugin_city'],
                            "state"          => $ipdat['geoplugin_regionName'],
                            "country"        => $ipdat['geoplugin_countryName'],
                            "country_code"   => $ipdat['geoplugin_countryCode'],
                            "continent"      => $continents[strtoupper($ipdat['geoplugin_continentCode'])],
                            "continent_code" => $ipdat['geoplugin_continentCode']
                        );
                        break;
                    case "address":
                        $address = array($ipdat['geoplugin_countryName']);
                        if (@strlen($ipdat['geoplugin_regionName']) >= 1)
                            $address[] = $ipdat['geoplugin_regionName'];
                        if (@strlen($ipdat['geoplugin_city']) >= 1)
                            $address[] = $ipdat['geoplugin_city'];
                        $output = implode(", ", array_reverse($address));
                        break;
                    case "city":
                        $output = $ipdat['geoplugin_city'];
                        break;
                    case "region":
                    case "state":
                        $output = $ipdat['geoplugin_regionName'];
                        break;
                    case "country":
                        $output = $ipdat['geoplugin_countryName'];
                        break;
                    case "countrycode":
                        $output = $ipdat['geoplugin_countryCode'];
                        break;
                }
            }
        }
        return $output;
    }

将127.0.0.1替换为访问者IpAddress。

$country = geoip_country_name_by_name('127.0.0.1');

安装说明在这里，并阅读了解如何获取城市，州，国家，经度，纬度等…

使用以下服务

1) http://api.hostip.info/get_html.php?ip=12.215.42.19

2)

$json = file_get_contents('http://freegeoip.appspot.com/json/66.102.13.106');
$expression = json_decode($json);
print_r($expression);

3) http://ipinfodb.com/ip_location_api.php