你可以使用ipstack地理API获取访问者国家和城市。你需要获得自己的ipstack API，然后使用下面的代码:

<?php
 $ip = $_SERVER['REMOTE_ADDR']; 
 $api_key = "YOUR_API_KEY";
 $freegeoipjson = file_get_contents("http://api.ipstack.com/".$ip."?access_key=".$api_key."");
 $jsondata = json_decode($freegeoipjson);
 $countryfromip = $jsondata->country_name;
 echo "Country: ". $countryfromip ."";
?>

来源:使用ipstack API在PHP中获取访问者国家和城市

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;
    }

我们可以使用geobytes.com来获得使用用户IP地址的位置

$user_ip = getIP();
$meta_tags = get_meta_tags('http://www.geobytes.com/IPLocator.htm?GetLocation&template=php3.txt&IPAddress=' . $user_ip);
echo '<pre>';
print_r($meta_tags);

它将返回这样的数据

Array(
    [known] => true
    [locationcode] => USCALANG
    [fips104] => US
    [iso2] => US
    [iso3] => USA
    [ison] => 840
    [internet] => US
    [countryid] => 254
    [country] => United States
    [regionid] => 126
    [region] => California
    [regioncode] => CA
    [adm1code] =>     
    [cityid] => 7275
    [city] => Los Angeles
    [latitude] => 34.0452
    [longitude] => -118.2840
    [timezone] => -08:00
    [certainty] => 53
    [mapbytesremaining] => Free
)

函数获取用户IP

function getIP(){
if (isset($_SERVER["HTTP_X_FORWARDED_FOR"])){
    $pattern = "/^(([1-9]?[0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5]).){3}([1-9]?[0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])$/";
    if(preg_match($pattern, $_SERVER["HTTP_X_FORWARDED_FOR"])){
            $userIP = $_SERVER["HTTP_X_FORWARDED_FOR"];
    }else{
            $userIP = $_SERVER["REMOTE_ADDR"];
    }
}
else{
  $userIP = $_SERVER["REMOTE_ADDR"];
}
return $userIP;
}

这只是关于get_client_ip()功能的一个安全说明，这里的大多数答案都包含在get_geo_info_for_this_ip()的主函数中。

不要过分依赖请求头中的IP数据，如client -IP或X-Forwarded-For，因为它们很容易被欺骗，但是你应该依赖于我们的服务器和客户端$_SERVER['REMOTE_ADDR']之间实际建立的TCP连接的源IP，因为它不能被欺骗

$_SERVER['HTTP_CLIENT_IP'] // can be spoofed 
$_SERVER['HTTP_X_FORWARDED_FOR'] // can be spoofed 
$_SERVER['REMOTE_ADDR']// can't be spoofed 

获取被欺骗IP的国家是可以的，但请记住，在任何安全模型中使用这个IP(例如:禁止发送频繁请求的IP)都会破坏整个安全模型。恕我直言，我更喜欢使用实际的客户端IP，即使它是代理服务器的IP。

我知道这是旧的，但我尝试了其他一些解决方案在这里，他们似乎是过时的或只是返回null。我是这么做的。

使用http://www.geoplugin.net/json.gp?ip=，不需要任何类型的注册或支付服务。

function get_client_ip_server() {
  $ipaddress = '';
if (isset($_SERVER['HTTP_CLIENT_IP']))
  $ipaddress = $_SERVER['HTTP_CLIENT_IP'];
else if(isset($_SERVER['HTTP_X_FORWARDED_FOR']))
  $ipaddress = $_SERVER['HTTP_X_FORWARDED_FOR'];
else if(isset($_SERVER['HTTP_X_FORWARDED']))
  $ipaddress = $_SERVER['HTTP_X_FORWARDED'];
else if(isset($_SERVER['HTTP_FORWARDED_FOR']))
  $ipaddress = $_SERVER['HTTP_FORWARDED_FOR'];
else if(isset($_SERVER['HTTP_FORWARDED']))
  $ipaddress = $_SERVER['HTTP_FORWARDED'];
else if(isset($_SERVER['REMOTE_ADDR']))
  $ipaddress = $_SERVER['REMOTE_ADDR'];
else
  $ipaddress = 'UNKNOWN';

  return $ipaddress;
}

$ipaddress = get_client_ip_server();

function getCountry($ip){
    $curlSession = curl_init();
    curl_setopt($curlSession, CURLOPT_URL, 'http://www.geoplugin.net/json.gp?ip='.$ip);
    curl_setopt($curlSession, CURLOPT_BINARYTRANSFER, true);
    curl_setopt($curlSession, CURLOPT_RETURNTRANSFER, true);

    $jsonData = json_decode(curl_exec($curlSession));
    curl_close($curlSession);

    return $jsonData->geoplugin_countryCode;
}

echo "County: " .getCountry($ipaddress);

如果你想要更多关于它的信息，这是一个完整的Json返回:

{
  "geoplugin_request":"IP_ADDRESS",
  "geoplugin_status":200,
  "geoplugin_delay":"2ms",
  "geoplugin_credit":"Some of the returned data includes GeoLite data created by MaxMind, available from <a href='http:\/\/www.maxmind.com'>http:\/\/www.maxmind.com<\/a>.",
  "geoplugin_city":"Current City",
  "geoplugin_region":"Region",
  "geoplugin_regionCode":"Region Code",
  "geoplugin_regionName":"Region Name",
  "geoplugin_areaCode":"",
  "geoplugin_dmaCode":"650",
  "geoplugin_countryCode":"US",
  "geoplugin_countryName":"United States",
  "geoplugin_inEU":0,
  "geoplugin_euVATrate":false,
  "geoplugin_continentCode":"NA",
  "geoplugin_continentName":"North America",
  "geoplugin_latitude":"37.5563",
  "geoplugin_longitude":"-99.9413",
  "geoplugin_locationAccuracyRadius":"5",
  "geoplugin_timezone":"America\/Chicago",
  "geoplugin_currencyCode":"USD",
  "geoplugin_currencySymbol":"$",
  "geoplugin_currencySymbol_UTF8":"$",
  "geoplugin_currencyConverter":1
}

不确定这是否是一个新的服务，但现在(2016)在php中最简单的方法是使用geoplugin的php web服务:http://www.geoplugin.net/php.gp:

基本用法:

// GET IP ADDRESS
if (!empty($_SERVER['HTTP_CLIENT_IP'])) {
    $ip = $_SERVER['HTTP_CLIENT_IP'];
} else if (!empty($_SERVER['HTTP_X_FORWARDED_FOR'])) {
    $ip = $_SERVER['HTTP_X_FORWARDED_FOR'];
} else if (!empty($_SERVER['REMOTE_ADDR'])) {
    $ip = $_SERVER['REMOTE_ADDR'];
} else {
    $ip = false;
}

// CALL THE WEBSERVICE
$ip_info = unserialize(file_get_contents('http://www.geoplugin.net/php.gp?ip='.$ip));

它们还提供了一个现成的类:http://www.geoplugin.com/_media/webservices/geoplugin.class.php.tgz?id=webservices%3Aphp&cache=cache