php IP获取城市API(纯真IP数据库)

2. /**
3. * 根据IP地址取得城市名称 纯真IP数据库
4. * edit: bbs.it-home.org
5. */
6. function convertip($ip) {
7. //IP数据文件路径
8. $dat_path = 'QQWry.Dat';
10. //检查IP地址
11. if(!filter_var($ip, FILTER_VALIDATE_IP)) {
12. return 'IP Address Error';
13. }
14. //打开IP数据文件
15. if(!$fd = @fopen($dat_path, 'rb')){
16. return 'IP date file not exists or access denied';
17. }
19. //分解IP进行运算，得出整形数
20. $ipNum = ip2long($ip);
22. //获取IP数据索引开始和结束位置
23. $DataBegin = fread($fd, 4);
24. $DataEnd = fread($fd, 4);
25. $ipbegin = implode('', unpack('L', $DataBegin));
26. if($ipbegin $ipend = implode('', unpack('L', $DataEnd));
27. if($ipend $ipNum || $ip2num $Middle= intval(($EndNum + $BeginNum) / 2);
29. //偏移指针到索引位置读取4个字节
30. fseek($fd, $ipbegin + 7 * $Middle);
31. $ipData1 = fread($fd, 4);
32. if(strlen($ipData1) fclose($fd);
33. return 'System Error';
34. }
35. //提取出来的数据转换成长整形，如果数据是负数则加上2的32次幂
36. $ip1num = implode('', unpack('L', $ipData1));
37. if($ip1num $ipNum) {
38. $EndNum = $Middle;
39. continue;
40. }
42. //取完上一个索引后取下一个索引
43. $DataSeek = fread($fd, 3);
44. if(strlen($DataSeek) fclose($fd);
45. return 'System Error';
46. }
47. $DataSeek = implode('', unpack('L', $DataSeek.chr(0)));
48. fseek($fd, $DataSeek);
49. $ipData2 = fread($fd, 4);
50. if(strlen($ipData2) fclose($fd);
51. return 'System Error';
52. }
53. $ip2num = implode('', unpack('L', $ipData2));
54. if($ip2num
55. //没找到提示未知
56. if($ip2num if($Middle == $BeginNum) {
57. fclose($fd);
58. return 'Unknown';
59. }
60. $BeginNum = $Middle;
61. }
62. }
64. //下面的代码读晕了，没读明白，有兴趣的慢慢读
65. $ipFlag = fread($fd, 1);
66. if($ipFlag == chr(1)) {
67. $ipSeek = fread($fd, 3);
68. if(strlen($ipSeek) fclose($fd);
69. return 'System Error';
70. }
71. $ipSeek = implode('', unpack('L', $ipSeek.chr(0)));
72. fseek($fd, $ipSeek);
73. $ipFlag = fread($fd, 1);
74. }
76. if($ipFlag == chr(2)) {
77. $AddrSeek = fread($fd, 3);
78. if(strlen($AddrSeek) fclose($fd);
79. return 'System Error';
80. }
81. $ipFlag = fread($fd, 1);
82. if($ipFlag == chr(2)) {
83. $AddrSeek2 = fread($fd, 3);
84. if(strlen($AddrSeek2) fclose($fd);
85. return 'System Error';
86. }
87. $AddrSeek2 = implode('', unpack('L', $AddrSeek2.chr(0)));
88. fseek($fd, $AddrSeek2);
89. } else {
90. fseek($fd, -1, SEEK_CUR);
91. }
93. while(($char = fread($fd, 1)) != chr(0))
94. $ipAddr2 .= $char;
96. $AddrSeek = implode('', unpack('L', $AddrSeek.chr(0)));
97. fseek($fd, $AddrSeek);
99. while(($char = fread($fd, 1)) != chr(0))
100. $ipAddr1 .= $char;
101. } else {
102. fseek($fd, -1, SEEK_CUR);
103. while(($char = fread($fd, 1)) != chr(0))
104. $ipAddr1 .= $char;
106. $ipFlag = fread($fd, 1);
107. if($ipFlag == chr(2)) {
108. $AddrSeek2 = fread($fd, 3);
109. if(strlen($AddrSeek2) fclose($fd);
110. return 'System Error';
111. }
112. $AddrSeek2 = implode('', unpack('L', $AddrSeek2.chr(0)));
113. fseek($fd, $AddrSeek2);
114. } else {
115. fseek($fd, -1, SEEK_CUR);
116. }
117. while(($char = fread($fd, 1)) != chr(0)){
118. $ipAddr2 .= $char;
119. }
120. }
121. fclose($fd);
123. //最后做相应的替换操作后返回结果
124. if(preg_match('/http/i', $ipAddr2)) {
125. $ipAddr2 = '';
126. }
127. $ipaddr = "$ipAddr1 $ipAddr2";
128. $ipaddr = preg_replace('/CZ88.Net/is', '', $ipaddr);
129. $ipaddr = preg_replace('/^s*/is', '', $ipaddr);
130. $ipaddr = preg_replace('/s*$/is', '', $ipaddr);
131. if(preg_match('/http/i', $ipaddr) || $ipaddr == '') {
132. $ipaddr = 'Unknown';
133. }
135. return $ipaddr;
136. }
137. header("Content-type: text/html; charset=utf-8");
138. $ip = $_SERVER['HTTP_X_FORWARDED_FOR'];
139. if(isset($_GET['q'])){
140. $ip = $_GET['q'];
141. if(filter_var("http://".$ip,FILTER_VALIDATE_URL,FILTER_FLAG_HOST_REQUIRED)){
142. $ip = gethostbyname($ip);
143. }
144. }
145. echo "$ip,".mb_convert_encoding(convertip($ip),"utf-8","gb2312");
147. ?>

复制代码