Function tty_rawmode

extern/editline/src/tty.c:978–1057

tty_rawmode(): * Set terminal into 1 character at a time mode. */

 * 	Set terminal into 1 character at a time mode.
 */
protected int
tty_rawmode(EditLine *el)
{

	if (el->el_tty.t_mode == ED_IO || el->el_tty.t_mode == QU_IO)
		return 0;

	if (el->el_flags & EDIT_DISABLED)
		return 0;

	if (tty_getty(el, &el->el_tty.t_ts) == -1) {
#ifdef DEBUG_TTY
		(void) fprintf(el->el_errfile, "%s: tty_getty: %s\n", __func__,
		    strerror(errno));
#endif /* DEBUG_TTY */
		return -1;
	}
	/*
         * We always keep up with the eight bit setting and the speed of the
         * tty. But we only believe changes that are made to cooked mode!
         */
	el->el_tty.t_eight = tty__geteightbit(&el->el_tty.t_ts);
	el->el_tty.t_speed = tty__getspeed(&el->el_tty.t_ts);

	if (tty__getspeed(&el->el_tty.t_ex) != el->el_tty.t_speed ||
	    tty__getspeed(&el->el_tty.t_ed) != el->el_tty.t_speed) {
		(void) cfsetispeed(&el->el_tty.t_ex, el->el_tty.t_speed);
		(void) cfsetospeed(&el->el_tty.t_ex, el->el_tty.t_speed);
		(void) cfsetispeed(&el->el_tty.t_ed, el->el_tty.t_speed);
		(void) cfsetospeed(&el->el_tty.t_ed, el->el_tty.t_speed);
	}
	if (tty__cooked_mode(&el->el_tty.t_ts)) {
		int i;

		for (i = MD_INP; i <= MD_LIN; i++)
			tty_update_flags(el, i);

		if (tty__gettabs(&el->el_tty.t_ex) == 0)
			el->el_tty.t_tabs = 0;
		else
			el->el_tty.t_tabs = EL_CAN_TAB ? 1 : 0;

		tty__getchar(&el->el_tty.t_ts, el->el_tty.t_c[TS_IO]);
		/*
		 * Check if the user made any changes.
		 * If he did, then propagate the changes to the
		 * edit and execute data structures.
		 */
		for (i = 0; i < C_NCC; i++)
			if (el->el_tty.t_c[TS_IO][i] !=
			    el->el_tty.t_c[EX_IO][i])
				break;

		if (i != C_NCC) {
			/*
			 * Propagate changes only to the unprotected
			 * chars that have been modified just now.
			 */