tty_con->instream = make_filedesc_input_stream (tty_con->infd, 0, -1, 0);
tty_con->outstream = make_filedesc_output_stream (tty_con->outfd, 0, -1, 0);
tty_con->instream = make_filedesc_input_stream (tty_con->infd, 0, -1, 0);
tty_con->outstream = make_filedesc_output_stream (tty_con->outfd, 0, -1, 0);