Analysis of functions of reading Innocence IP database in Discuz 50

Discuz 5.0 no longer uses its own IP data, but uses the data format of Innocence IP. Accessing Innocence IP database is a little troublesome. Its storage format is special and interesting. For specific format analysis, please refer to the following two links. Implementation in other languages See the link at the end of the article.
"Detailed Explanation of Innocence IP Database Format"
Link 1: http://blog.csdn.net/heiyeshuwu/archive/2006/05/12/725675.aspx
Link 2: http://lumaqq.linuxsir.org/article /qqwry_format_detail.html
Innocent IP database official website: http://www.cz88.net/ip/
Innocent IP database download: http://update.cz88.net/soft/qqwry.rar
The following function conrvertip() is located Discuz!5_GBK/upload/include/misc.func.php path, if you are interested, you can read and analyze it in detail.(I have made simple modifications to the code below to make it easier to read, and the core has not been modified)

//========================== ==========
//
// Function: IP address to obtain the real address function
// Parameters: $ip - IP address
// Author: [Discuz!] (C) Comsenz Inc.
//
//====================================
function convertip($ip) {
/ /IP data file path
$dat_path = 'QQWry.Dat';
//Check IP address
if(!preg_match("/^d{1,3}.d{1,3}.d{1,3} .d {1,3} $/", $ IP)) {
Return 'IP Address Error';
}
// Open the IP data file
if (! $ fd = @fopen ($ dat_path, 'rb') ){
                                                      using using using using         using using     ‐       off           ‐ ‐                                                           to to 0] * 16777216 + $ip[1] * 65536 + $ip[2] * 256 + $ip[3];
//Get the start and end position of the IP data index
$DataBegin = fread($fd, 4);
$DataEnd = fread($fd, 4);
$ipbegin = implode('', unpack('L', $DataBegin));
if($ipbegin $ipend = implode('', unpack('L', $DataEnd));
if($ipend $ipAllNum = ($ipend - $ipbegin) / 7 + 1;
$BeginNum = 0;
$EndNum = $ipAllNum;
//Use binary search method to search for matching IP records from the index records
while($ip1num>$ipNum || $ip2num       $Middle= intval(($EndNum + $BeginNum)  / 2);
                                     ;
                                                          $ipData1                                                                                                                                                                                          }
                              // Extracted data conversion Growing up and plastic surgery, if the data is negative, plus 2 32 power
$ ip1num = Implode ('', unpack ('l', $ ipdata1)); 2, 32);
            // If the extracted long integer is greater than our IP address, modify the end position for the next cycle
                                                                         }
//Get the next index after getting the previous index
                                                                                                                                                                          ;
    }
          $DataSeek   = implode('',   unpack('L',  $DataSeek.chr(0)));                                               using   using using use using using using  --                                                  
           if(strlen($ipData2)               $ip2num                                                                                                                  $ip2num                                                                                       
                                                                                        using I’m confused when reading the code. I don’t understand it. If you are interested, read it slowly
$ipFlag = fread($fd, 1);
if($ipFlag == chr(1)) {
$ipSeek = fread($fd, 3 ; ('L', $ipSeek.chr (0)));
fseek($fd, $ipSeek);
$ipFlag = fread($fd, 1);
}
if($ipFlag == chr(2)) {
$AddrSeek = fread($ fd, 3);
if(strlen($AddrSeek) fclose($fd); return 'System Error';
$ipFlag = fread( $fd, 1);
if($ ipFlag == chr(2)) {
                                                                                                                                                                                                                                              return 'System Error';                                      
          $AddrSeek2 = implode('', unpack('L', $AddrSeek2.chr(0)));
                                                                                                           seek($fd, -1, SEEK_CUR) ;
} i While (($ CHIL = FREAD ($ FD, 1))! = Chr (0))
$ iPaddr2. = $ Char; .chr(0)));
fseek($fd, $AddrSeek);
while(($char = fread($fd, 1)) != chr(0))
$ipAddr1 .= $char;
} else {
       fseek($fd, -1, SEEK_CUR);
       while(($char = fread($fd, 1)) != chr(0))
           $ipAddr1 .= $char;
       $ipFlag = fread($fd, 1);
       if($ipFlag == 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)){
           $ipAddr2 .= $char;
       }
   }
   fclose($fd);
   //最后做相应的替换操作后返回结果
   if(preg_match('/http/i', $ipAddr2)) {
       $ipAddr2 = '';
   }
   $ipaddr = "$ipAddr1 $ipAddr2";
   $ipaddr = preg_replace('/CZ88.NET/is', '', $ipaddr);
   $ipaddr = preg_replace('/^s*/is', '', $ipaddr);
   $ipaddr = preg_replace('/s*$/is', '', $ipaddr);
   if(preg_match('/http/i', $ipaddr) || $ipaddr == '') {
       $ipaddr = 'Unknown';
   }
   return $ipaddr;
}
//========================
//
//  调用举例（速度很快）
//
//========================
echo convertip('219.238.235.10');
//输出: 北京市 电信通
echo convertip('23.56.82.12');
//输出：IANA
echo convertip('250.69.52.0');
//输出：IANA保留地址
echo convertip('238.69.52.0');
//输出：IANA保留地址 用于多点传送
echo convertip('192.168.0.1');
//输出：局域网 对方和您在同一内部网
echo convertip('255.255.255.255');
//输出：纯真网络 2006年11月20日IP数据
?>

以上就介绍了纯真ip数据库 Discuz 50 中读取纯真IP数据库函数分析，包括了纯真ip数据库方面的内容，希望对PHP教程有兴趣的朋友有所帮助。