xref: /netbsd-src/lib/libcurses/tty.c (revision deb6f0161a9109e7de9b519dc8dfb9478668dcdd)
1 /*	$NetBSD: tty.c,v 1.48 2018/11/16 10:12:00 blymn Exp $	*/
2 
3 /*-
4  * Copyright (c) 1992, 1993, 1994
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 #include <sys/cdefs.h>
33 #ifndef lint
34 #if 0
35 static char sccsid[] = "@(#)tty.c	8.6 (Berkeley) 1/10/95";
36 #else
37 __RCSID("$NetBSD: tty.c,v 1.48 2018/11/16 10:12:00 blymn Exp $");
38 #endif
39 #endif				/* not lint */
40 
41 #include <sys/fcntl.h>
42 #include <sys/ioctl.h>
43 #include <sys/param.h>
44 #include <sys/types.h>
45 
46 #include <stdlib.h>
47 #include <termios.h>
48 #include <unistd.h>
49 
50 #include "curses.h"
51 #include "curses_private.h"
52 
53 /*
54  * In general, curses should leave tty hardware settings alone (speed, parity,
55  * word size).  This is most easily done in BSD by using TCSASOFT on all
56  * tcsetattr calls.  On other systems, it would be better to get and restore
57  * those attributes at each change, or at least when stopped and restarted.
58  * See also the comments in getterm().
59  */
60 #ifndef TCSASOFT
61 #define	TCSASOFT	0
62 #endif
63 
64 int __tcaction = TCSASOFT != 0;		/* Ignore hardware settings */
65 
66 #ifndef	OXTABS
67 #ifdef	XTABS			/* SMI uses XTABS. */
68 #define	OXTABS	XTABS
69 #else
70 #define	OXTABS	0
71 #endif
72 #endif
73 
74 /*
75  * baudrate --
76  *	Return the current baudrate
77  */
78 int
79 baudrate(void)
80 {
81 
82 	if (_cursesi_screen->notty == TRUE)
83 		return 0;
84 
85 	return cfgetospeed(&_cursesi_screen->baset);
86 }
87 
88 /*
89  * gettmode --
90  *	Do terminal type initialization.
91  */
92 int
93 gettmode(void)
94 {
95 
96 	if (_cursesi_gettmode(_cursesi_screen) == ERR)
97 		return ERR;
98 
99 	__GT = _cursesi_screen->GT;
100 	__NONL = _cursesi_screen->NONL;
101 	return OK;
102 }
103 
104 /*
105  * _cursesi_gettmode --
106  *      Do the terminal type initialisation for the tty attached to the
107  *  given screen.
108  */
109 int
110 _cursesi_gettmode(SCREEN *screen)
111 {
112 	screen->useraw = 0;
113 
114 	if (tcgetattr(fileno(screen->infd), &screen->orig_termios)) {
115 		/* if the input fd is not a tty try the output */
116 		if (tcgetattr(fileno(screen->infd), &screen->orig_termios)) {
117 			/* not a tty ... we will disable tty related stuff */
118 			screen->notty = TRUE;
119 			__GT = 0;
120 			__NONL = 0;
121 			return OK;
122 		}
123 	}
124 
125 	screen->baset = screen->orig_termios;
126 	screen->baset.c_oflag &= ~OXTABS;
127 
128 	screen->GT = 0;	/* historical. was used before we wired OXTABS off */
129 	screen->NONL = (screen->baset.c_oflag & ONLCR) == 0;
130 
131 	/*
132 	 * XXX
133 	 * System V and SMI systems overload VMIN and VTIME, such that
134 	 * VMIN is the same as the VEOF element, and VTIME is the same
135 	 * as the VEOL element.  This means that, if VEOF was ^D, the
136 	 * default VMIN is 4.  Majorly stupid.
137 	 */
138 	screen->cbreakt = screen->baset;
139 	screen->cbreakt.c_lflag &= ~(ECHO | ECHONL | ICANON);
140 	screen->cbreakt.c_cc[VMIN] = 1;
141 	screen->cbreakt.c_cc[VTIME] = 0;
142 
143 	screen->rawt = screen->cbreakt;
144 	screen->rawt.c_iflag &= ~(IGNBRK | BRKINT | PARMRK | INLCR | IGNCR |
145 				  ICRNL | IXON);
146 	screen->rawt.c_oflag &= ~OPOST;
147 	screen->rawt.c_lflag &= ~(ISIG | IEXTEN);
148 
149 #if TCSASOFT == 0
150 	/*
151 	 * In general, curses should leave hardware-related settings alone.
152 	 * This includes parity and word size.  Older versions set the tty
153 	 * to 8 bits, no parity in raw(), but this is considered to be an
154 	 * artifact of the old tty interface.  If it's desired to change
155 	 * parity and word size, the TCSASOFT bit has to be removed from the
156 	 * calls that switch to/from "raw" mode.
157 	 */
158 	screen->rawt.c_iflag &= ~ISTRIP;
159 	screen->rawt.c_cflag &= ~(CSIZE | PARENB);
160 	screen->rawt.c_cflag |= CS8;
161 #endif
162 
163 	screen->curt = &screen->baset;
164 	return tcsetattr(fileno(screen->infd), TCSASOFT | TCSADRAIN,
165 	    screen->curt) ? ERR : OK;
166 }
167 
168 /*
169  * raw --
170  *	Put the terminal into raw mode
171  */
172 int
173 raw(void)
174 {
175 #ifdef DEBUG
176 	__CTRACE(__CTRACE_MISC, "raw()\n");
177 #endif
178 	/* Check if we need to restart ... */
179 	if (_cursesi_screen->endwin)
180 		__restartwin();
181 
182 	_cursesi_screen->useraw = __pfast = __rawmode = 1;
183 	_cursesi_screen->curt = &_cursesi_screen->rawt;
184 	if (_cursesi_screen->notty == TRUE)
185 		return OK;
186 	return tcsetattr(fileno(_cursesi_screen->infd), TCSASOFT | TCSADRAIN,
187 	    _cursesi_screen->curt) ? ERR : OK;
188 }
189 
190 /*
191  * noraw --
192  *	Put the terminal into cooked mode
193  */
194 int
195 noraw(void)
196 {
197 #ifdef DEBUG
198 	__CTRACE(__CTRACE_MISC, "noraw()\n");
199 #endif
200 	/* Check if we need to restart ... */
201 	if (_cursesi_screen->endwin)
202 		__restartwin();
203 
204 	_cursesi_screen->useraw = __pfast = __rawmode = 0;
205 	if (_cursesi_screen->notty == TRUE)
206 		return OK;
207 	_cursesi_screen->curt = &_cursesi_screen->baset;
208 	return tcsetattr(fileno(_cursesi_screen->infd), TCSASOFT | TCSADRAIN,
209 	    _cursesi_screen->curt) ? ERR : OK;
210 }
211 
212 /*
213  * cbreak --
214  * 	Enable cbreak mode
215  */
216 int
217 cbreak(void)
218 {
219 #ifdef DEBUG
220 	__CTRACE(__CTRACE_MISC, "cbreak()\n");
221 #endif
222 	/* Check if we need to restart ... */
223 	if (_cursesi_screen->endwin)
224 		__restartwin();
225 
226 	__rawmode = 1;
227 	if (_cursesi_screen->notty == TRUE)
228 		return OK;
229 	_cursesi_screen->curt = _cursesi_screen->useraw ?
230 		&_cursesi_screen->rawt : &_cursesi_screen->cbreakt;
231 	return tcsetattr(fileno(_cursesi_screen->infd), TCSASOFT | TCSADRAIN,
232 	    _cursesi_screen->curt) ? ERR : OK;
233 }
234 
235 /*
236  * nocbreak --
237  *	Disable cbreak mode
238  */
239 int
240 nocbreak(void)
241 {
242 #ifdef DEBUG
243 	__CTRACE(__CTRACE_MISC, "nocbreak()\n");
244 #endif
245 	/* Check if we need to restart ... */
246 	if (_cursesi_screen->endwin)
247 		__restartwin();
248 
249 	__rawmode = 0;
250 	if (_cursesi_screen->notty == TRUE)
251 		return OK;
252 	  /* if we were in halfdelay mode then nuke the timeout */
253 	if ((stdscr->flags & __HALFDELAY) &&
254 	    (__notimeout() == ERR))
255 		return ERR;
256 
257 	stdscr->flags &= ~__HALFDELAY;
258 	_cursesi_screen->curt = _cursesi_screen->useraw ?
259 		&_cursesi_screen->rawt : &_cursesi_screen->baset;
260 	return tcsetattr(fileno(_cursesi_screen->infd), TCSASOFT | TCSADRAIN,
261 	    _cursesi_screen->curt) ? ERR : OK;
262 }
263 
264 /*
265  * halfdelay --
266  *    Put the terminal into cbreak mode with the specified timeout.
267  *
268  */
269 int
270 halfdelay(int duration)
271 {
272 	if ((duration < 1) || (duration > 255))
273 		return ERR;
274 
275 	if (cbreak() == ERR)
276 		return ERR;
277 
278 	if (duration > 255)
279 		stdscr->delay = 255;
280 	else
281 		stdscr->delay = duration;
282 
283 	stdscr->flags |= __HALFDELAY;
284 	return OK;
285 }
286 
287 int
288 __delay(void)
289  {
290 #ifdef DEBUG
291 	__CTRACE(__CTRACE_MISC, "__delay()\n");
292 #endif
293 	/* Check if we need to restart ... */
294 	if (_cursesi_screen->endwin)
295 		__restartwin();
296 
297 	if (_cursesi_screen->notty == TRUE)
298 		return OK;
299 	_cursesi_screen->rawt.c_cc[VMIN] = 1;
300 	_cursesi_screen->rawt.c_cc[VTIME] = 0;
301 	_cursesi_screen->cbreakt.c_cc[VMIN] = 1;
302 	_cursesi_screen->cbreakt.c_cc[VTIME] = 0;
303 	_cursesi_screen->baset.c_cc[VMIN] = 1;
304 	_cursesi_screen->baset.c_cc[VTIME] = 0;
305 
306 	if (tcsetattr(fileno(_cursesi_screen->infd), TCSASOFT | TCSANOW,
307 	    _cursesi_screen->curt)) {
308 		__restore_termios();
309 		return ERR;
310 	}
311 
312 	return OK;
313 }
314 
315 int
316 __nodelay(void)
317 {
318 #ifdef DEBUG
319 	__CTRACE(__CTRACE_MISC, "__nodelay()\n");
320 #endif
321 	/* Check if we need to restart ... */
322 	if (_cursesi_screen->endwin)
323 		__restartwin();
324 
325 	if (_cursesi_screen->notty == TRUE)
326 		return OK;
327 	_cursesi_screen->rawt.c_cc[VMIN] = 0;
328 	_cursesi_screen->rawt.c_cc[VTIME] = 0;
329 	_cursesi_screen->cbreakt.c_cc[VMIN] = 0;
330 	_cursesi_screen->cbreakt.c_cc[VTIME] = 0;
331 	_cursesi_screen->baset.c_cc[VMIN] = 0;
332 	_cursesi_screen->baset.c_cc[VTIME] = 0;
333 
334 	if (tcsetattr(fileno(_cursesi_screen->infd), TCSASOFT | TCSANOW,
335 	    _cursesi_screen->curt)) {
336 		__restore_termios();
337 		return ERR;
338 	}
339 
340 	return OK;
341 }
342 
343 void
344 __save_termios(void)
345 {
346 	/* Check if we need to restart ... */
347 	if (_cursesi_screen->endwin)
348 		__restartwin();
349 
350 	if (_cursesi_screen->notty == TRUE)
351 		return;
352 	_cursesi_screen->ovmin = _cursesi_screen->cbreakt.c_cc[VMIN];
353 	_cursesi_screen->ovtime = _cursesi_screen->cbreakt.c_cc[VTIME];
354 }
355 
356 void
357 __restore_termios(void)
358 {
359 	/* Check if we need to restart ... */
360 	if (_cursesi_screen->endwin)
361 		__restartwin();
362 
363 	if (_cursesi_screen->notty == TRUE)
364 		return;
365 	_cursesi_screen->rawt.c_cc[VMIN] = _cursesi_screen->ovmin;
366 	_cursesi_screen->rawt.c_cc[VTIME] = _cursesi_screen->ovtime;
367 	_cursesi_screen->cbreakt.c_cc[VMIN] = _cursesi_screen->ovmin;
368 	_cursesi_screen->cbreakt.c_cc[VTIME] = _cursesi_screen->ovtime;
369 	_cursesi_screen->baset.c_cc[VMIN] = _cursesi_screen->ovmin;
370 	_cursesi_screen->baset.c_cc[VTIME] = _cursesi_screen->ovtime;
371 }
372 
373 int
374 __timeout(int delay)
375 {
376 #ifdef DEBUG
377 	__CTRACE(__CTRACE_MISC, "__timeout()\n");
378 #endif
379 	/* Check if we need to restart ... */
380 	if (_cursesi_screen->endwin)
381 		__restartwin();
382 
383 	if (_cursesi_screen->notty == TRUE)
384 		return OK;
385 	_cursesi_screen->ovmin = _cursesi_screen->cbreakt.c_cc[VMIN];
386 	_cursesi_screen->ovtime = _cursesi_screen->cbreakt.c_cc[VTIME];
387 	_cursesi_screen->rawt.c_cc[VMIN] = 0;
388 	_cursesi_screen->rawt.c_cc[VTIME] = delay;
389 	_cursesi_screen->cbreakt.c_cc[VMIN] = 0;
390 	_cursesi_screen->cbreakt.c_cc[VTIME] = delay;
391 	_cursesi_screen->baset.c_cc[VMIN] = 0;
392 	_cursesi_screen->baset.c_cc[VTIME] = delay;
393 
394 	if (tcsetattr(fileno(_cursesi_screen->infd), TCSASOFT | TCSANOW,
395 	    _cursesi_screen->curt)) {
396 		__restore_termios();
397 		return ERR;
398 	}
399 
400 	return OK;
401 }
402 
403 int
404 __notimeout(void)
405 {
406 #ifdef DEBUG
407 	__CTRACE(__CTRACE_MISC, "__notimeout()\n");
408 #endif
409 	/* Check if we need to restart ... */
410 	if (_cursesi_screen->endwin)
411 		__restartwin();
412 
413 	if (_cursesi_screen->notty == TRUE)
414 		return OK;
415 	_cursesi_screen->rawt.c_cc[VMIN] = 1;
416 	_cursesi_screen->rawt.c_cc[VTIME] = 0;
417 	_cursesi_screen->cbreakt.c_cc[VMIN] = 1;
418 	_cursesi_screen->cbreakt.c_cc[VTIME] = 0;
419 	_cursesi_screen->baset.c_cc[VMIN] = 1;
420 	_cursesi_screen->baset.c_cc[VTIME] = 0;
421 
422 	return tcsetattr(fileno(_cursesi_screen->infd), TCSASOFT | TCSANOW,
423 	    _cursesi_screen->curt) ? ERR : OK;
424 }
425 
426 int
427 echo(void)
428 {
429 #ifdef DEBUG
430 	__CTRACE(__CTRACE_MISC, "echo()\n");
431 #endif
432 	/* Check if we need to restart ... */
433 	if (_cursesi_screen->endwin)
434 		__restartwin();
435 
436 	__echoit = 1;
437 	return OK;
438 }
439 
440 int
441 noecho(void)
442 {
443 #ifdef DEBUG
444 	__CTRACE(__CTRACE_MISC, "noecho()\n");
445 #endif
446 	/* Check if we need to restart ... */
447 	if (_cursesi_screen->endwin)
448 		__restartwin();
449 
450 	__echoit = 0;
451 	return OK;
452 }
453 
454 int
455 nl(void)
456 {
457 #ifdef DEBUG
458 	__CTRACE(__CTRACE_MISC, "nl()\n");
459 #endif
460 	/* Check if we need to restart ... */
461 	if (_cursesi_screen->endwin)
462 		__restartwin();
463 
464 	if (_cursesi_screen->notty == TRUE)
465 		return OK;
466 	_cursesi_screen->rawt.c_iflag |= ICRNL;
467 	_cursesi_screen->rawt.c_oflag |= ONLCR;
468 	_cursesi_screen->cbreakt.c_iflag |= ICRNL;
469 	_cursesi_screen->cbreakt.c_oflag |= ONLCR;
470 	_cursesi_screen->baset.c_iflag |= ICRNL;
471 	_cursesi_screen->baset.c_oflag |= ONLCR;
472 
473 	_cursesi_screen->nl = 1;
474 	_cursesi_screen->pfast = _cursesi_screen->rawmode;
475 	return tcsetattr(fileno(_cursesi_screen->infd), TCSASOFT | TCSADRAIN,
476 	    _cursesi_screen->curt) ? ERR : OK;
477 }
478 
479 int
480 nonl(void)
481 {
482 #ifdef DEBUG
483 	__CTRACE(__CTRACE_MISC, "nonl()\n");
484 #endif
485 	/* Check if we need to restart ... */
486 	if (_cursesi_screen->endwin)
487 		__restartwin();
488 
489 	if (_cursesi_screen->notty == TRUE)
490 		return OK;
491 	_cursesi_screen->rawt.c_iflag &= ~ICRNL;
492 	_cursesi_screen->rawt.c_oflag &= ~ONLCR;
493 	_cursesi_screen->cbreakt.c_iflag &= ~ICRNL;
494 	_cursesi_screen->cbreakt.c_oflag &= ~ONLCR;
495 	_cursesi_screen->baset.c_iflag &= ~ICRNL;
496 	_cursesi_screen->baset.c_oflag &= ~ONLCR;
497 
498 	_cursesi_screen->nl = 0;
499 	__pfast = 1;
500 	return tcsetattr(fileno(_cursesi_screen->infd), TCSASOFT | TCSADRAIN,
501 	    _cursesi_screen->curt) ? ERR : OK;
502 }
503 
504 #ifndef _CURSES_USE_MACROS
505 void
506 noqiflush(void)
507 {
508 
509 	(void)intrflush(stdscr, FALSE);
510 }
511 
512 void
513 qiflush(void)
514 {
515 
516 	(void)intrflush(stdscr, TRUE);
517 }
518 #endif	/* _CURSES_USE_MACROS */
519 
520 /*ARGSUSED*/
521 int
522 intrflush(WINDOW *win, bool bf)
523 {
524 	/* Check if we need to restart ... */
525 	if (_cursesi_screen->endwin)
526 		__restartwin();
527 
528 	if (_cursesi_screen->notty == TRUE)
529 		return OK;
530 	if (bf) {
531 		_cursesi_screen->rawt.c_lflag &= ~NOFLSH;
532 		_cursesi_screen->cbreakt.c_lflag &= ~NOFLSH;
533 		_cursesi_screen->baset.c_lflag &= ~NOFLSH;
534 	} else {
535 		_cursesi_screen->rawt.c_lflag |= NOFLSH;
536 		_cursesi_screen->cbreakt.c_lflag |= NOFLSH;
537 		_cursesi_screen->baset.c_lflag |= NOFLSH;
538 	}
539 
540 	__pfast = 1;
541 	return tcsetattr(fileno(_cursesi_screen->infd), TCSASOFT | TCSADRAIN,
542 	    _cursesi_screen->curt) ? ERR : OK;
543 }
544 
545 void
546 __startwin(SCREEN *screen)
547 {
548 
549 	(void)fflush(screen->infd);
550 
551 #ifdef BSD
552 	/*
553 	 * Some C libraries default to a 1K buffer when talking to a tty.
554 	 * With a larger screen, especially across a network, we'd like
555 	 * to get it to all flush in a single write.  Make it twice as big
556 	 * as just the characters (so that we have room for cursor motions
557 	 * and attribute information) but no more than 8K.
558 	 *
559 	 * However, setvbuf may only be used after opening a stream and
560 	 * before any operations have been performed on it.
561 	 * This means we cannot work portably if an application wants
562 	 * to stop curses and start curses after a resize.
563 	 * Curses resizing is not standard, and thus not strictly portable
564 	 * even though all curses today support it.
565 	 * The BSD systems do not suffer from this limitation on setvbuf.
566 	 */
567 	if (screen->stdbuf == NULL) {
568 		screen->len = LINES * COLS * 2;
569 		if (screen->len > 8192)
570 			screen->len = 8192;
571 		if ((screen->stdbuf = malloc(screen->len)) == NULL)
572 			screen->len = 0;
573 	}
574 	(void)setvbuf(screen->outfd, screen->stdbuf, _IOFBF, screen->len);
575 #endif
576 
577 	ti_puts(screen->term, t_enter_ca_mode(screen->term), 0,
578 		__cputchar_args, (void *) screen->outfd);
579 	ti_puts(screen->term, t_cursor_normal(screen->term), 0,
580 	    __cputchar_args, (void *) screen->outfd);
581 	if (screen->curscr->flags & __KEYPAD)
582 		ti_puts(screen->term, t_keypad_xmit(screen->term), 0,
583 		    __cputchar_args, (void *) screen->outfd);
584 	screen->endwin = 0;
585 }
586 
587 int
588 endwin(void)
589 {
590 #ifdef DEBUG
591 	__CTRACE(__CTRACE_MISC, "endwin\n");
592 #endif
593 	return __stopwin();
594 }
595 
596 bool
597 isendwin(void)
598 {
599 
600 	return _cursesi_screen->endwin ? TRUE : FALSE;
601 }
602 
603 int
604 flushinp(void)
605 {
606 
607 	(void)fpurge(_cursesi_screen->infd);
608 	return OK;
609 }
610 
611 /*
612  * The following routines, savetty and resetty are completely useless and
613  * are left in only as stubs.  If people actually use them they will almost
614  * certainly screw up the state of the world.
615  */
616 /*static struct termios savedtty;*/
617 int
618 savetty(void)
619 {
620 
621 	if (_cursesi_screen->notty == TRUE)
622 		return OK;
623 	return tcgetattr(fileno(_cursesi_screen->infd),
624 			 &_cursesi_screen->savedtty) ? ERR : OK;
625 }
626 
627 int
628 resetty(void)
629 {
630 
631 	if (_cursesi_screen->notty == TRUE)
632 		return OK;
633 	return tcsetattr(fileno(_cursesi_screen->infd), TCSASOFT | TCSADRAIN,
634 			 &_cursesi_screen->savedtty) ? ERR : OK;
635 }
636 
637 /*
638  * erasechar --
639  *     Return the character of the erase key.
640  */
641 char
642 erasechar(void)
643 {
644 
645 	if (_cursesi_screen->notty == TRUE)
646 		return 0;
647 	return _cursesi_screen->baset.c_cc[VERASE];
648 }
649 
650 /*
651  * killchar --
652  *     Return the character of the kill key.
653  */
654 char
655 killchar(void)
656 {
657 
658 	if (_cursesi_screen->notty == TRUE)
659 		return 0;
660 	return _cursesi_screen->baset.c_cc[VKILL];
661 }
662 
663 /*
664  * erasewchar --
665  *     Return the wide character of the erase key.
666  */
667 int
668 erasewchar(wchar_t *ch)
669 {
670 
671 #ifndef HAVE_WCHAR
672 	return ERR;
673 #else
674 	if (_cursesi_screen->notty == TRUE)
675 		return ERR;
676 	*ch = _cursesi_screen->baset.c_cc[VERASE];
677 	return OK;
678 #endif /* HAVE_WCHAR */
679 }
680 
681 /*
682  * killwchar --
683  *     Return the wide character of the kill key.
684  */
685 int
686 killwchar( wchar_t *ch )
687 {
688 
689 #ifndef HAVE_WCHAR
690 	return ERR;
691 #else
692 	if (_cursesi_screen->notty == TRUE)
693 		return 0;
694 	*ch = _cursesi_screen->baset.c_cc[VKILL];
695 	return OK;
696 #endif /* HAVE_WCHAR */
697 }
698 
699 int
700 typeahead(int filedes)
701 {
702 
703 	_cursesi_screen->checkfd = filedes;
704 	return OK;
705 }
706