[The Shadow]

Код:

procedure TForm1.Button1Click(Sender: TObject);
var
  SR: TSearchRec;
begin
  if FindFirst('Папка\*.txt', faAnyFile, SR) = 0 then
  repeat
    with TStringList.Create do
    begin
      LoadFromFile('Папка\' + SR.Name);
      if Count > 1 then
      Delete(0);
      SaveToFile('Папка\' + SR.Name);
      Free;
    end;
  until FindNext(SR) <> 0;
  FindClose(SR);
end;