
  [;1m-spec truncate(IoDevice) -> ok | {error, Reason}[0m
  [;1m                  when[0m
  [;1m                      IoDevice :: io_device(),[0m
  [;1m                      Reason :: posix() | badarg | terminated.[0m

  Truncates the file referenced by [;;4mIoDevice[0m at the current
  position. Returns [;;4mok[0m if successful, otherwise [;;4m{error, Reason}[0m.
