
[;1m  read_line(IoDevice)[0m

  Reads a line of bytes/characters from the file referenced by [;;4m[0m
  [;;4mIoDevice[0m.

  Lines are defined to be delimited by the linefeed (LF, [;;4m\n[0m)
  character, but any carriage return (CR, [;;4m\r[0m) followed by a
  newline is also treated as a single LF character (the carriage
  return is silently ignored). The line is returned including the
  LF, but excluding any CR immediately followed by an LF. This
  behaviour is consistent with the behaviour of [;;4mio:get_line/2[0m. If
  end of file is reached without any LF ending the last line, a line
  with no trailing LF is returned.

  The function can be used on files opened in [;;4mraw[0m mode. However,
  it is inefficient to use it on [;;4mraw[0m files if the file is not
  opened with option [;;4m{read_ahead, Size}[0m specified. Thus, combining [;;4m[0m
  [;;4mraw[0m and [;;4m{read_ahead, Size}[0m is highly recommended when opening a
  text file for raw line-oriented reading.

  If [;;4mencoding[0m is set to something else than [;;4mlatin1[0m, the [;;4m[0m
  [;;4mread_line/1[0m call fails if the data contains characters larger
  than 255, why [;;4mio:get_line/2[0m is to be preferred when reading such
  a file.

  The function returns:

   • [;;4m{ok, Data}[0m - One line from the file is returned, including
     the trailing LF, but with CRLF sequences replaced by a
     single LF (see above).

     If the file is opened in binary mode, the read bytes are
     returned in a binary, otherwise in a list.

   • [;;4meof[0m - Returned if end of file was reached before anything
     at all could be read.

   • [;;4m{error, Reason}[0m - An error occurred.

  Typical error reasons:

   • [;;4mebadf[0m - The file is not opened for reading.

   • [;;4m{no_translation, unicode, latin1}[0m - The file is opened with
     another [;;4mencoding[0m than [;;4mlatin1[0m and the data on the file
     cannot be translated to the byte-oriented data that this
     function returns.
