织梦CMS如何将IP地址转换为纯真IP数据库

function convertip($ip){ 
$dat_path = DEDEDATA.'/ip/QQWry.dat'; 
if(!ereg("^([0-9]{1,3}.){3}[0-9]{1,3}$",$ip)){ 
return 'IP格式错误'; 
} 
if(!$fd = @fopen($dat_path,'rb')){ 
return '无法打开IP数据库'; 
} 
$ip = explode('.',$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); 
$ipend = implode('',$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'; 
} 
$ip1num = implode('',$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'; 
} 
$DataSeek = implode('',$DataSeek.chr(0))); 
fseek($fd,$DataSeek); 
$ipData2 = fread($fd,4); 
if(strlen($ipData2) < 4) { 
fclose($fd); 
return 'System Error'; 
} 
$ip2num = implode('',$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'; 
} 
$ipSeek = implode('',$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'; 
} 
$AddrSeek2 = implode('',$AddrSeek2.chr(0))); 
fseek($fd,$AddrSeek2); 
} else { 
fseek($fd,-1,SEEK_CUR); 
} 
while(($char = fread($fd,1)) != chr(0)) 
$ipAddr2 .= $char; 
$AddrSeek = implode('',$AddrSeek.chr(0))); 
fseek($fd,$AddrSeek); 
while(($char = fread($fd,1)) != chr(0)) 
$ipAddr1 .= $char; 
} else { 
fseek($fd,SEEK_CUR); 
while(($char = fread($fd,1)) != chr(0)) 
$ipAddr1 .= $char; 
$ipFlag = fread($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; 
}