function Touch(const FileName: string): Boolean;
var
  FileH: Integer; // handle of file
begin
  // Assume failure
  Result := False;
  // Try to open file: bail out if can't open
  FileH := SysUtils.FileOpen(
    FileName, SysUtils.fmOpenWrite or SysUtils.fmShareDenyWrite
  );
  if FileH = -1 then
    Exit;
  try
    // Set date to current date and time: return true if succeed
    if SysUtils.FileSetDate(
      FileH, SysUtils.DateTimeToFileDate(SysUtils.Now())
    ) = 0 then
      Result := True;
  finally
    // Close the file
    SysUtils.FileClose(FileH);
  end;
end;
//delphi/2229