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/*
函数名称：ipCity
参数说明：$userip——用户IP地址
函数功能：PHP通过IP地址判断用户所在城市
author:lee
contact:xpsem2010@gmail.com
*/
function ipCity($userip) {
//IP数据库路径，这里用的是QQ IP数据库 20110405 纯真版
$dat_path = 'QQWry.dat';
//判断IP地址是否有效
if(!ereg("^([0-9]{1,3}.){3}[0-9]{1,3}$", $userip)){
return 'IP Address Invalid';
}
//打开IP数据库
if(!$fd = @fopen($dat_path, 'rb')){
return 'IP data file not exists or access denied';
}
//explode函数分解IP地址，运算得出整数形结果
$userip = explode('.', $userip);
$useripNum = $userip[0] * 16777216 + $userip[1] * 65536 + $userip[2] * 256 + $userip[3];
//获取IP地址索引开始和结束位置
$DataBegin = fread($fd, 4);
$DataEnd = fread($fd, 4);
$useripbegin = implode('', unpack('L', $DataBegin));
if($useripbegin $useripend = implode('', unpack('L', $DataEnd));
if($useripend $useripAllNum = ($useripend - $useripbegin) / 7 + 1;
$BeginNum = 0;
$EndNum = $useripAllNum;
//使用二分查找法从索引记录中搜索匹配的IP地址记录
while($userip1num>$useripNum || $userip2num $Middle= intval(($EndNum + $BeginNum) / 2);
//偏移指针到索引位置读取4个字节
fseek($fd, $useripbegin + 7 * $Middle);
$useripData1 = fread($fd, 4);
if(strlen($useripData1) fclose($fd);
return 'File Error';
}
//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
$userip1num = implode('', unpack('L', $useripData1));
if($userip1num
//提取的长整型数大于我们IP地址则修改结束位置进行下一次循环
if($userip1num > $useripNum) {
$EndNum = $Middle;
continue;
}
//取完上一个索引后取下一个索引
$DataSeek = fread($fd, 3);
if(strlen($DataSeek) fclose($fd);
return 'File Error';
}
$DataSeek = implode('', unpack('L', $DataSeek.chr(0)));
fseek($fd, $DataSeek);
$useripData2 = fread($fd, 4);
if(strlen($useripData2) fclose($fd);
return 'File Error';
}
$userip2num = implode('', unpack('L', $useripData2));
if($userip2num
//找不到IP地址对应城市
if($userip2num if($Middle == $BeginNum) {
fclose($fd);
return 'No Data';
}
$BeginNum = $Middle;
}
}
$useripFlag = fread($fd, 1);
if($useripFlag == chr(1)) {
$useripSeek = fread($fd, 3);
if(strlen($useripSeek) fclose($fd);
return 'System Error';
}
$useripSeek = implode('', unpack('L', $useripSeek.chr(0)));
fseek($fd, $useripSeek);
$useripFlag = fread($fd, 1);
}
if($useripFlag == chr(2)) {
$AddrSeek = fread($fd, 3);
if(strlen($AddrSeek) fclose($fd);
return 'System Error';
}
$useripFlag = fread($fd, 1);
if($useripFlag == chr(2)) {
$AddrSeek2 = fread($fd, 3);
if(strlen($AddrSeek2) fclose($fd);
return 'System Error';
}
$AddrSeek2 = implode('', unpack('L', $AddrSeek2.chr(0)));
fseek($fd, $AddrSeek2);
} else {
fseek($fd, -1, SEEK_CUR);
}
while(($char = fread($fd, 1)) != chr(0))
$useripAddr2 .= $char;
$AddrSeek = implode('', unpack('L', $AddrSeek.chr(0)));
fseek($fd, $AddrSeek);
while(($char = fread($fd, 1)) != chr(0))
$useripAddr1 .= $char;
} else {
fseek($fd, -1, SEEK_CUR);
while(($char = fread($fd, 1)) != chr(0))
$useripAddr1 .= $char;
$useripFlag = fread($fd, 1);
if($useripFlag == chr(2)) {
$AddrSeek2 = fread($fd, 3);
if(strlen($AddrSeek2) fclose($fd);
return 'System Error';
}
$AddrSeek2 = implode('', unpack('L', $AddrSeek2.chr(0)));
fseek($fd, $AddrSeek2);
} else {
fseek($fd, -1, SEEK_CUR);
}
while(($char = fread($fd, 1)) != chr(0)){
$useripAddr2 .= $char;
}
}
fclose($fd);
//返回IP地址对应的城市结果
if(preg_match('/http/i', $useripAddr2)) {
$useripAddr2 = '';
}
$useripaddr = "$useripAddr1 $useripAddr2";
$useripaddr = preg_replace('/CZ88.Net/is', '', $useripaddr);
$useripaddr = preg_replace('/^s*/is', '', $useripaddr);
$useripaddr = preg_replace('/s*$/is', '', $useripaddr);
if(preg_match('/http/i', $useripaddr) || $useripaddr == '') {
$useripaddr = 'No Data';
}
return $useripaddr;
}
?>
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