How can I increase IP address by given number in Delphi?

Question

I want to do someting like that:

var
ip,ip2: string;
begin
ip:= '127.0.0.1';
ip2:= ip+1;
end;

after this code executed ip2 should be 127.0.0.2

Question is: How can I increase an IP address like that?

Answer 1

You might try the following:

type
  TIPAddress = array[0..3] of Byte;

function IncIPAddress(const IPAddress: TIPAddress;
  Value: Integer = 1): TIPAddress;
begin
  PInteger(@Result)^ := PInteger(@IPAddress)^ + Value;
end;

procedure TForm1.Button1Click(Sender: TObject);
var
  S: string;
  IPAddress: TIPAddress;
  IPAddress2: TIPAddress;
begin
  IPAddress[3] := 127;
  IPAddress[2] := 0;
  IPAddress[1] := 0;
  IPAddress[0] := 1;

  S := Format('%d.%d.%d.%d', [IPAddress[3], IPAddress[2],
    IPAddress[1], IPAddress[0]]);
  ShowMessage(S);

  IPAddress2 := IncIPAddress(IPAddress);

  S := Format('%d.%d.%d.%d', [IPAddress2[3], IPAddress2[2],
    IPAddress2[1], IPAddress2[0]]);
  ShowMessage(S);
end;