使用IP判断访问用户是在哪个城市的PHP代码

1. function detect_city($ip) {
3. $default = 'UNKNOWN';
5. $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)';
7. $url = 'http://ipinfodb.com/ip_locator.php?ip=' . urlencode($ip);
8. $ch = curl_init();
10. $curl_opt = array(
11. CURLOPT_FOLLOWLOCATION => 1,
12. CURLOPT_HEADER => 0,
13. CURLOPT_RETURNTRANSFER => 1,
14. CURLOPT_USERAGENT => $curlopt_useragent,
15. CURLOPT_URL => $url,
16. CURLOPT_TIMEOUT => 1,
17. CURLOPT_REFERER => 'http://' . $_SERVER['HTTP_HOST'],
18. );
20. curl_setopt_array($ch, $curl_opt);
22. $content = curl_exec($ch);
24. if (!is_null($curl_info)) {
25. $curl_info = curl_getinfo($ch);
26. }
28. curl_close($ch);
30. if ( preg_match('{
31. City : ([^<]*)
}i', $content, $regs) ) {
32. $city = $regs[1];
33. }
34. if ( preg_match('{
35. State/Province : ([^<]*)
}i', $content, $regs) ) {
36. $state = $regs[1];
37. }
39. if( $city!='' && $state!='' ){
40. $location = $city . ', ' . $state;
41. return $location;
42. }else{
43. return $default;
44. }
46. }

用法：

1. $ip = $_SERVER['REMOTE_ADDR'];
2. $city = detect_city($ip);
3. echo $city;
4. ?>