program newlines;
{$APPTYPE CONSOLE}

uses
  SysUtils,Classes;

procedure Help;
begin
  writeln(' Program that finds new lines from file.');
  writeln(' The files are sorted and then every line from new file');
  writeln(' is taken and n first chracters are');
  writeln(' compared agains every line in oldfile');
  writeln(' and if they do not match, the line is new.');
  writeln(' Only new lines are printed.');
  writeln('');
  writeln(' Call');
  writeln('   newlines oldfile newfile [n]');
  writeln('');
  writeln(' Vesa Lappalainen 13.8.2005');
end;


procedure Subtract(s1,s2:TStrings; n:integer);
var ss1,ss2:string; i1,i2:integer;
begin
  for i2:=0 to s2.Count-1 do begin
    ss2 := Copy(s2[i2],1,n);
    for i1:=0 to s1.Count-1 do begin
      ss1 := Copy(s1[i1],1,n);
      if ( ss1 = ss2 ) then begin
        s1.Delete(i1);
        break;
      end;
    end;
  end;
end;


var f1,f2:TStringList;
    i:integer;
begin
  if ( ParamCount <= 1 ) or ( Pos('?',ParamStr(1)) > 0 ) then begin Help; Exit; end;

  f1 := TStringList.Create;
  f2 := TStringList.Create;
  try try
    f1.LoadFromFile(ParamStr(1));
    f2.LoadFromFile(ParamStr(2));
    f1.Sort;
    f2.Sort;
    Subtract(f2,f1,StrToIntDef(ParamStr(3),100));
    for i:=0 to f2.Count-1 do begin
      writeln(f2[i]);
    end;
  except on e: Exception do begin
    writeln(e.Message);
    Help;
  end; end;

  finally
    f1.Free;
    f2.Free;
  end;
end.