一些旧的Internet协议(如FTP)发送IP地址的端口号时使用一种6字节的格式,形如:XXX.XXX.XXX.XXX.XX.XXX。要将这种6字节地址转换为4段地址的端口号,你可以使用以下代码:
Procedure LongIPToShort(aLongIPAddress : String; Out ShortIPAddress : String; out PortNumber : Integer);
var I, DotPos, tempPort : Integer;
var tempAddy, temp : String;
var TempStr : String;
begin
tempAddy := '';
tempStr := '';
//Determine if the sender of the long IP is using , or . as the
// Delimator
if (POS(',', aLongIPAddress) <> 0) then TempStr := ','
else TempStr := '.';
For I := 1 to 4 do
begin
DotPOS := POS(TempStr, aLongIPAddress);
tempAddy := tempAddy + (Copy(aLongIPAddress, 1, (DotPos - 1)));
If I <> 4 then TempADdy := TempAddy + '.';
Delete(aLongIpAddress, 1, DotPos);
end;
DotPos := Pos(TempStr, aLongIpAddress);
temp := Copy(aLongIpAddress, 1, (DotPos - 1));
tempPort := (StrToInt(temp) * 256);
Delete(aLongIpAddress, 1, DotPos);
TempPort := tempPort + StrToInt(ALongIpAddress);
ShortIPAddress := TempADdy;
PortNumber := tempPort;
end;