PHP调用纯真IP数据库返回具体地址

    function convertip($ip) {   
      $ip1num = 0;  
      $ip2num = 0;  
      $ipAddr1 ="";  
      $ipAddr2 ="";  
      $dat_path = './QQWry.Dat';          
      if(!preg_match("/^\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}$/", $ip)) {   
        return 'IP Address Error';   
      }    
      if(!$fd = @fopen($dat_path, 'rb')){   
        return 'IP date file not exists or access denied';   
      }    
      $ip = explode('.', $ip);   
      $ipNum = $ip[0] * 16777216 + $ip[1] * 65536 + $ip[2] * 256 + $ip[3];    
      $DataBegin = fread($fd, 4);   
      $DataEnd = fread($fd, 4);   
      $ipbegin = implode('', unpack('L', $DataBegin));   
      if($ipbegin < 0) $ipbegin += pow(2, 32);   
        $ipend = implode('', unpack('L', $DataEnd));   
      if($ipend < 0) $ipend += pow(2, 32);   
        $ipAllNum = ($ipend - $ipbegin) / 7 + 1;   
      $BeginNum = 0;   
      $EndNum = $ipAllNum;    
      while($ip1num>$ipNum || $ip2num<$ipNum) {   
        $Middle= intval(($EndNum + $BeginNum) / 2);   
        fseek($fd, $ipbegin + 7 * $Middle);   
        $ipData1 = fread($fd, 4);   
        if(strlen($ipData1) < 4) {   
          fclose($fd);   
          return 'System Error';   
        }  
        $ip1num = implode('', unpack('L', $ipData1));   
        if($ip1num < 0) $ip1num += pow(2, 32);   
      
        if($ip1num > $ipNum) {   
          $EndNum = $Middle;   
          continue;   
        }   
        $DataSeek = fread($fd, 3);   
        if(strlen($DataSeek) < 3) {   
          fclose($fd);   
          return 'System Error';   
        }   
        $DataSeek = implode('', unpack('L', $DataSeek.chr(0)));   
        fseek($fd, $DataSeek);   
        $ipData2 = fread($fd, 4);   
        if(strlen($ipData2) < 4) {   
          fclose($fd);   
          return 'System Error';   
        }   
        $ip2num = implode('', unpack('L', $ipData2));   
        if($ip2num < 0) $ip2num += pow(2, 32);    
          if($ip2num < $ipNum) {   
            if($Middle == $BeginNum) {   
              fclose($fd);   
              return 'Unknown';   
            }   
            $BeginNum = $Middle;   
          }   
        }    
        $ipFlag = fread($fd, 1);   
        if($ipFlag == chr(1)) {   
          $ipSeek = fread($fd, 3);   
          if(strlen($ipSeek) < 3) {   
            fclose($fd);   
            return 'System Error';   
          }   
          $ipSeek = implode('', unpack('L', $ipSeek.chr(0)));   
          fseek($fd, $ipSeek);   
          $ipFlag = fread($fd, 1);   
        }   
        if($ipFlag == chr(2)) {   
          $AddrSeek = fread($fd, 3);   
          if(strlen($AddrSeek) < 3) {   
          fclose($fd);   
          return 'System Error';   
        }   
        $ipFlag = fread($fd, 1);   
        if($ipFlag == chr(2)) {   
          $AddrSeek2 = fread($fd, 3);   
          if(strlen($AddrSeek2) < 3) {   
            fclose($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;   
        $AddrSeek = implode('', unpack('L', $AddrSeek.chr(0)));   
        fseek($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($AddrSeek2) < 3) {   
            fclose($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);    
      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;   
    }