Hi,

Could someone help me out here. I didn't even write this pascal file, yet it throws 'Range Check Errors' in the program particularly with this ip address: 200.34.32.196

If it chucks an error with that address, the function mustn't work very well, but I can't seem to see what's wrong with it.

function StrToAddr(s : String) : LongInt;
var
   r, i, p, c : LongInt;
   t : String;
begin
   r := 0;
   for i := 0 to 3 do
   begin
      p := Pos('.', s);
      if p = 0 then p := Length(s) + 1;
      if p <= 1 then exit;
      t := Copy(s, 1, p - 1);
      Delete(s, 1, p);
      Val(t, p, c);
      if (c  0) or (p < 0) or (p > 255) then exit;
      r := r or p shl (i * 8);
   end;
   StrToAddr := r;
end;

Does someone have a fixed version of this function, or can someone fix it please?

thank you
James

Simple, in the last iteration you shift a 8 bit number by 3*8=24. So if the last value is larger than 127, the longint (which is 31-bit + 1 sign) overflows.

So the problem is r (and the expression with the shl) being calculated in longints. Use a 32-bit _unsigned_ value, like cardinal.

Try to make r and p cardinal