Snippets → PHP
Detect location by IP
Here is an useful code snippet to detect the location of a specific IP. The function below takes one IP as a parameter, and returns the location of the IP. If no location is found, UNKNOWN is returned.
function detect_city($ip) {
$default = 'UNKNOWN';
if (!is_string($ip) || strlen($ip) < 1 || $ip == '127.0.0.1' || $ip == 'localhost')
$ip = '8.8.8.8';
$curlopt_useragent = 'Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.2) Gecko/20100115 Firefox/3.6 (.NET CLR 3.5.30729)';
$url = 'http://ipinfodb.com/ip_locator.php?ip=' . urlencode($ip);
$ch = curl_init();
$curl_opt = array(
CURLOPT_FOLLOWLOCATION => 1,
CURLOPT_HEADER => 0,
CURLOPT_RETURNTRANSFER => 1,
CURLOPT_USERAGENT => $curlopt_useragent,
CURLOPT_URL => $url,
CURLOPT_TIMEOUT => 1,
CURLOPT_REFERER => 'http://' . $_SERVER['HTTP_HOST'],
);
curl_setopt_array($ch, $curl_opt);
$content = curl_exec($ch);
if (!is_null($curl_info)) {
$curl_info = curl_getinfo($ch);
}
curl_close($ch);
if ( preg_match('{<li>City : ([^<]*)</li>}i', $content, $regs) ) {
$city = $regs[1];
}
if ( preg_match('{<li>State/Province : ([^<]*)</li>}i', $content, $regs) ) {
$state = $regs[1];
}
if( $city!='' && $state!='' ){
$location = $city . ', ' . $state;
return $location;
}else{
return $default;
}
}
Source: http://snipplr.com/view/48386/detect-location-by-ip-city-sta...
Oooh, nice one if you don’t have access to your own database or for very quick prototying. Couple of problems for production use: heavily relying on this ipinfodb website. Tomorrow they might add a captcha, change their markup (the regexp will break), or completely fail as a site and shut down. There are no guarantees, you may end up getting a call at 3 AM because the IP2Location system you developed is down. Problem two: no caching. Get an IPv4/6 database, it isn’t usually too large, lookups will be much faster, guaranteed and reliable.
What do you mean by your second point “no caching”? And also where to get the IPv4/6 db?
I’ve used GeoIP for this many times: http://www.maxmind.com/app/geolitecity
PHP/Apache integration is available.
Awesome!