This reads data from the file descriptor.

        This is a simple implementation suitable for a regular file. Subclasses using ptys or pipes should override it.

        The timeout parameter is ignored.

def read_nonblocking(self, size=1, timeout=None):
        """This reads data from the file descriptor.

        This is a simple implementation suitable for a regular file. Subclasses using ptys or pipes should override it.

        The timeout parameter is ignored.
        """

        try:
            s = os.read(self.child_fd, size)
        except OSError as err:
            if err.args[0] == errno.EIO:
                # Linux-style EOF
                self.flag_eof = True
                raise EOF('End Of File (EOF). Exception style platform.')
            raise
        if s == b'':
            # BSD-style EOF
            self.flag_eof = True
            raise EOF('End Of File (EOF). Empty string style platform.')

        s = self._decoder.decode(s, final=False)
        self._log(s, 'read')
        return s