xref: /netbsd-src/lib/libcurses/get_wch.c (revision c34236556bea94afcaca1782d7d228301edc3ea0)
1 /*   $NetBSD: get_wch.c,v 1.12 2017/01/06 13:53:18 roy Exp $ */
2 
3 /*
4  * Copyright (c) 2005 The NetBSD Foundation Inc.
5  * All rights reserved.
6  *
7  * This code is derived from code donated to the NetBSD Foundation
8  * by Ruibiao Qiu <ruibiao@arl.wustl.edu,ruibiao@gmail.com>.
9  *
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *	notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *	notice, this list of conditions and the following disclaimer in the
18  *	documentation and/or other materials provided with the distribution.
19  * 3. Neither the name of the NetBSD Foundation nor the names of its
20  *	contributors may be used to endorse or promote products derived
21  *	from this software without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND
24  * CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
25  * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
26  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34  * SUCH DAMAGE.
35  */
36 
37 #include <sys/cdefs.h>
38 #ifndef lint
39 __RCSID("$NetBSD: get_wch.c,v 1.12 2017/01/06 13:53:18 roy Exp $");
40 #endif						  /* not lint */
41 
42 #include <string.h>
43 #include <stdlib.h>
44 #include <unistd.h>
45 #include <stdio.h>
46 #include "curses.h"
47 #include "curses_private.h"
48 #include "keymap.h"
49 
50 #ifdef HAVE_WCHAR
51 static short   wstate;		  /* state of the wcinkey function */
52 #endif /* HAVE_WCHAR */
53 extern short state;		/* storage declared in getch.c */
54 
55 /* prototypes for private functions */
56 #ifdef HAVE_WCHAR
57 static int inkey(wchar_t *wc, int to, int delay);
58 #endif /* HAVE_WCHAR */
59 
60 #ifdef HAVE_WCHAR
61 /*
62  * __init_get_wch - initialise all the pointers & structures needed to make
63  * get_wch work in keypad mode.
64  *
65  */
66 void
67 __init_get_wch(SCREEN *screen)
68 {
69 	wstate = INKEY_NORM;
70 	memset(&screen->cbuf, 0, sizeof(screen->cbuf));
71 	screen->cbuf_head = screen->cbuf_tail = screen->cbuf_cur = 0;
72 }
73 #endif /* HAVE_WCHAR */
74 
75 
76 #ifdef HAVE_WCHAR
77 /*
78  * inkey - do the work to process keyboard input, check for multi-key
79  * sequences and return the appropriate symbol if we get a match.
80  *
81  */
82 static int
83 inkey(wchar_t *wc, int to, int delay)
84 {
85 	wchar_t		 k = 0;
86 	int		 c, mapping, ret = 0;
87 	size_t	  mlen = 0;
88 	keymap_t	*current = _cursesi_screen->base_keymap;
89 	FILE		*infd = _cursesi_screen->infd;
90 	int		 *start = &_cursesi_screen->cbuf_head,
91 				*working = &_cursesi_screen->cbuf_cur,
92 				*end = &_cursesi_screen->cbuf_tail;
93 	char		*inbuf = &_cursesi_screen->cbuf[ 0 ];
94 	int		escdelay = _cursesi_screen->ESCDELAY;
95 
96 #ifdef DEBUG
97 	__CTRACE(__CTRACE_INPUT, "inkey (%p, %d, %d)\n", wc, to, delay);
98 #endif
99 	for (;;) { /* loop until we get a complete key sequence */
100 		if (wstate == INKEY_NORM) {
101 			if (delay && __timeout(delay) == ERR)
102 				return ERR;
103 			c = fgetc(infd);
104 			if (c == WEOF) {
105 				clearerr(infd);
106 				return ERR;
107 			}
108 
109 			if (delay && (__notimeout() == ERR))
110 				return ERR;
111 
112 			k = (wchar_t)c;
113 #ifdef DEBUG
114 			__CTRACE(__CTRACE_INPUT,
115 			    "inkey (wstate normal) got '%s'\n", unctrl(k));
116 #endif
117 
118 			inbuf[*end] = k;
119 			*end = (*end + 1) % MAX_CBUF_SIZE;
120 			*working = *start;
121 			wstate = INKEY_ASSEMBLING; /* go to assembling state */
122 #ifdef DEBUG
123 			__CTRACE(__CTRACE_INPUT,
124 			    "inkey: NORM=>ASSEMBLING: start(%d), "
125 			    "current(%d), end(%d)\n", *start, *working, *end);
126 #endif /* DEBUG */
127 		} else if (wstate == INKEY_BACKOUT) {
128 			k = inbuf[*working];
129 			*working = (*working + 1) % MAX_CBUF_SIZE;
130 			if (*working == *end) {	/* see if run out of keys */
131 				/* if so, switch to assembling */
132 				wstate = INKEY_ASSEMBLING;
133 #ifdef DEBUG
134 				__CTRACE(__CTRACE_INPUT,
135 				    "inkey: BACKOUT=>ASSEMBLING, start(%d), "
136 				    "current(%d), end(%d)\n",
137 				    *start, *working, *end);
138 #endif /* DEBUG */
139 			}
140 		} else if (wstate == INKEY_ASSEMBLING) {
141 			/* assembling a key sequence */
142 			if (delay) {
143 				if (__timeout(to ? (escdelay / 100) : delay)
144 						== ERR)
145 					return ERR;
146 			} else {
147 				if (to && (__timeout(escdelay / 100) == ERR))
148 					return ERR;
149 			}
150 
151 			c = fgetc(infd);
152 			if (ferror(infd)) {
153 				clearerr(infd);
154 				return ERR;
155 			}
156 
157 			if ((to || delay) && (__notimeout() == ERR))
158 				return ERR;
159 
160 			k = (wchar_t)c;
161 #ifdef DEBUG
162 			__CTRACE(__CTRACE_INPUT,
163 			    "inkey (wstate assembling) got '%s'\n", unctrl(k));
164 #endif /* DEBUG */
165 			if (feof(infd)) { /* inter-char T/O, start backout */
166 				clearerr(infd);
167 				if (*start == *end)
168 					/* no chars in the buffer, restart */
169 					continue;
170 
171 				k = inbuf[*start];
172 				wstate = INKEY_TIMEOUT;
173 #ifdef DEBUG
174 				__CTRACE(__CTRACE_INPUT,
175 				    "inkey: ASSEMBLING=>TIMEOUT, start(%d), "
176 				    "current(%d), end(%d)\n",
177 				    *start, *working, *end);
178 #endif /* DEBUG */
179 			} else {
180 				inbuf[*end] = k;
181 				*working = *end;
182 				*end = (*end + 1) % MAX_CBUF_SIZE;
183 #ifdef DEBUG
184 				__CTRACE(__CTRACE_INPUT,
185 				    "inkey: ASSEMBLING: start(%d), "
186 				    "current(%d), end(%d)",
187 				    *start, *working, *end);
188 #endif /* DEBUG */
189 			}
190 		} else if (wstate == INKEY_WCASSEMBLING) {
191 			/* assembling a wide-char sequence */
192 			if (delay) {
193 				if (__timeout(to ? (escdelay / 100) : delay)
194 						== ERR)
195 					return ERR;
196 			} else {
197 				if (to && (__timeout(escdelay / 100) == ERR))
198 					return ERR;
199 			}
200 
201 			c = fgetc(infd);
202 			if (ferror(infd)) {
203 				clearerr(infd);
204 				return ERR;
205 			}
206 
207 			if ((to || delay) && (__notimeout() == ERR))
208 				return ERR;
209 
210 			k = (wchar_t)c;
211 #ifdef DEBUG
212 			__CTRACE(__CTRACE_INPUT,
213 			    "inkey (wstate wcassembling) got '%s'\n",
214 				unctrl(k));
215 #endif
216 			if (feof(infd)) { /* inter-char T/O, start backout */
217 				clearerr(infd);
218 				if (*start == *end)
219 					/* no chars in the buffer, restart */
220 					continue;
221 
222 				*wc = inbuf[*start];
223 				*working = *start = (*start +1) % MAX_CBUF_SIZE;
224 				if (*start == *end) {
225 					state = wstate = INKEY_NORM;
226 #ifdef DEBUG
227 					__CTRACE(__CTRACE_INPUT,
228 					    "inkey: WCASSEMBLING=>NORM, "
229 					    "start(%d), current(%d), end(%d)",
230 					    *start, *working, *end);
231 #endif /* DEBUG */
232 				} else {
233 					state = wstate = INKEY_BACKOUT;
234 #ifdef DEBUG
235 					__CTRACE(__CTRACE_INPUT,
236 					    "inkey: WCASSEMBLING=>BACKOUT, "
237 					    "start(%d), current(%d), end(%d)",
238 					    *start, *working, *end);
239 #endif /* DEBUG */
240 				}
241 				return OK;
242 			} else {
243 				/* assembling wide characters */
244 				inbuf[*end] = k;
245 				*working = *end;
246 				*end = (*end + 1) % MAX_CBUF_SIZE;
247 #ifdef DEBUG
248 				__CTRACE(__CTRACE_INPUT,
249 				    "inkey: WCASSEMBLING[head(%d), "
250 				    "urrent(%d), tail(%d)]\n",
251 				    *start, *working, *end);
252 #endif /* DEBUG */
253 				ret = (int)mbrtowc(wc, inbuf + (*working), 1,
254 						   &_cursesi_screen->sp);
255 #ifdef DEBUG
256 				__CTRACE(__CTRACE_INPUT,
257 				    "inkey: mbrtowc returns %d, wc(%x)\n",
258 				    ret, *wc);
259 #endif /* DEBUG */
260 				if (ret == -2) {
261 					*working = (*working+1) % MAX_CBUF_SIZE;
262 					continue;
263 				}
264 				if ( ret == 0 )
265 					ret = 1;
266 				if ( ret == -1 ) {
267 					/* return the 1st character we know */
268 					*wc = inbuf[*start];
269 					*working = *start = (*start + 1) % MAX_CBUF_SIZE;
270 #ifdef DEBUG
271 					__CTRACE(__CTRACE_INPUT,
272 					    "inkey: Invalid wide char(%x) "
273 					    "[head(%d), current(%d), "
274 					    "tail(%d)]\n",
275 					    *wc, *start, *working, *end);
276 #endif /* DEBUG */
277 				} else { /* > 0 */
278 					/* return the wide character */
279 					*start = *working
280 					       = (*working + ret)%MAX_CBUF_SIZE;
281 #ifdef DEBUG
282 					__CTRACE(__CTRACE_INPUT,
283 					    "inkey: Wide char found(%x) "
284 					    "[head(%d), current(%d), "
285 					    "tail(%d)]\n",
286 					    *wc, *start, *working, *end);
287 #endif /* DEBUG */
288 				}
289 
290 				if (*start == *end) {
291 					/* only one char processed */
292 					state = wstate = INKEY_NORM;
293 #ifdef DEBUG
294 					__CTRACE(__CTRACE_INPUT,
295 					    "inkey: WCASSEMBLING=>NORM, "
296 					    "start(%d), current(%d), end(%d)",
297 					    *start, *working, *end);
298 #endif /* DEBUG */
299 				} else {
300 					/* otherwise we must have more than
301 					 * one char to backout */
302 					state = wstate = INKEY_BACKOUT;
303 #ifdef DEBUG
304 					__CTRACE(__CTRACE_INPUT,
305 					    "inkey: WCASSEMBLING=>BACKOUT, "
306 					    "start(%d), current(%d), end(%d)",
307 					    *start, *working, *end);
308 #endif /* DEBUG */
309 				}
310 				return OK;
311 			}
312 		} else {
313 			fprintf(stderr, "Inkey wstate screwed - exiting!!!");
314 			exit(2);
315 		}
316 
317 		/*
318 		 * Check key has no special meaning and we have not
319 		 * timed out and the key has not been disabled
320 		 */
321 		mapping = current->mapping[k];
322 		if (((wstate == INKEY_TIMEOUT) || (mapping < 0))
323 				|| ((current->key[mapping]->type
324 					== KEYMAP_LEAF)
325 				&& (current->key[mapping]->enable == FALSE)))
326 		{
327 			/* wide-character specific code */
328 #ifdef DEBUG
329 			__CTRACE(__CTRACE_INPUT,
330 			    "inkey: Checking for wide char\n");
331 #endif /* DEBUG */
332 			mbrtowc( NULL, NULL, 1, &_cursesi_screen->sp );
333 			*working = *start;
334 			mlen = *end > *working ?
335 				*end - *working : MAX_CBUF_SIZE - *working;
336 			if (!mlen)
337 				return ERR;
338 #ifdef DEBUG
339 			__CTRACE(__CTRACE_INPUT,
340 			    "inkey: Check wide char[head(%d), "
341 			    "current(%d), tail(%d), mlen(%ld)]\n",
342 			    *start, *working, *end, (long) mlen);
343 #endif /* DEBUG */
344 			ret = (int)mbrtowc(wc, inbuf + (*working), mlen,
345 			                   &_cursesi_screen->sp);
346 #ifdef DEBUG
347 			__CTRACE(__CTRACE_INPUT,
348 			    "inkey: mbrtowc returns %d, wc(%x)\n", ret, *wc);
349 #endif /* DEBUG */
350 			if (ret == -2 && *end < *working) {
351 				/* second half of a wide character */
352 				*working = 0;
353 				mlen = *end;
354 				if (mlen)
355 					ret = (int)mbrtowc(wc, inbuf, mlen,
356 							  &_cursesi_screen->sp);
357 			}
358 			if (ret == -2 && wstate != INKEY_TIMEOUT) {
359 				*working = (*working + (int) mlen)
360 					% MAX_CBUF_SIZE;
361 				wstate = INKEY_WCASSEMBLING;
362 				continue;
363 			}
364 			if (ret == 0)
365 				ret = 1;
366 			if (ret == -1) {
367 				/* return the first key we know about */
368 				*wc = inbuf[*start];
369 				*working = *start
370 					= (*start + 1) % MAX_CBUF_SIZE;
371 #ifdef DEBUG
372 				__CTRACE(__CTRACE_INPUT,
373 				    "inkey: Invalid wide char(%x)[head(%d), "
374 				    "current(%d), tail(%d)]\n",
375 				    *wc, *start, *working, *end);
376 #endif /* DEBUG */
377 			} else { /* > 0 */
378 				/* return the wide character */
379 				*start = *working
380 					= (*working + ret) % MAX_CBUF_SIZE;
381 #ifdef DEBUG
382 				__CTRACE(__CTRACE_INPUT,
383 				    "inkey: Wide char found(%x)[head(%d), "
384 				    "current(%d), tail(%d)]\n",
385 				    *wc, *start, *working, *end);
386 #endif /* DEBUG */
387 			}
388 
389 			if (*start == *end) {	/* only one char processed */
390 				state = wstate = INKEY_NORM;
391 #ifdef DEBUG
392 				__CTRACE(__CTRACE_INPUT,
393 				    "inkey: Empty cbuf=>NORM, "
394 				    "start(%d), current(%d), end(%d)\n",
395 				    *start, *working, *end);
396 #endif /* DEBUG */
397 			} else {
398 				/* otherwise we must have more than one
399 				 * char to backout */
400 				state = wstate = INKEY_BACKOUT;
401 #ifdef DEBUG
402 				__CTRACE(__CTRACE_INPUT,
403 				    "inkey: Non-empty cbuf=>BACKOUT, "
404 				    "start(%d), current(%d), end(%d)\n",
405 				    *start, *working, *end);
406 #endif /* DEBUG */
407 			}
408 			return OK;
409 		} else {	/* must be part of a multikey sequence */
410 					/* check for completed key sequence */
411 			if (current->key[current->mapping[k]]->type
412 					== KEYMAP_LEAF) {
413 				/* eat the key sequence in cbuf */
414 				*start = *working = ( *working + 1 )
415 				    % MAX_CBUF_SIZE;
416 
417 				/* check if inbuf empty now */
418 #ifdef DEBUG
419 				__CTRACE(__CTRACE_INPUT,
420 				    "inkey: Key found(%s)\n",
421 				    key_name(current->key[mapping]->value.symbol));
422 #endif /* DEBUG */
423 				if (*start == *end) {
424 					/* if it is go back to normal */
425 					state = wstate = INKEY_NORM;
426 #ifdef DEBUG
427 					__CTRACE(__CTRACE_INPUT,
428 					    "[inkey]=>NORM, start(%d), "
429 					    "current(%d), end(%d)",
430 					    *start, *working, *end);
431 #endif /* DEBUG */
432 				} else {
433 					/* otherwise go to backout state */
434 					state = wstate = INKEY_BACKOUT;
435 #ifdef DEBUG
436 					__CTRACE(__CTRACE_INPUT,
437 					    "[inkey]=>BACKOUT, start(%d), "
438 					    "current(%d), end(%d)",
439 					    *start, *working, *end );
440 #endif /* DEBUG */
441 				}
442 
443 				/* return the symbol */
444 				*wc = current->key[mapping]->value.symbol;
445 				return KEY_CODE_YES;
446 			} else {
447 				/* Step to next part of multi-key sequence */
448 				current = current->key[current->mapping[k]]->value.next;
449 			}
450 		}
451 	}
452 }
453 #endif /* HAVE_WCHAR */
454 
455 /*
456  * get_wch --
457  *	Read in a wide character from stdscr.
458  */
459 int
460 get_wch(wint_t *ch)
461 {
462 #ifndef HAVE_WCHAR
463 	return ERR;
464 #else
465 	return wget_wch(stdscr, ch);
466 #endif /* HAVE_WCHAR */
467 }
468 
469 /*
470  * mvget_wch --
471  *	  Read in a character from stdscr at the given location.
472  */
473 int
474 mvget_wch(int y, int x, wint_t *ch)
475 {
476 #ifndef HAVE_WCHAR
477 	return ERR;
478 #else
479 	return mvwget_wch(stdscr, y, x, ch);
480 #endif /* HAVE_WCHAR */
481 }
482 
483 /*
484  * mvwget_wch --
485  *	  Read in a character from stdscr at the given location in the
486  *	  given window.
487  */
488 int
489 mvwget_wch(WINDOW *win, int y, int x, wint_t *ch)
490 {
491 #ifndef HAVE_WCHAR
492 	return ERR;
493 #else
494 	if (wmove(win, y, x) == ERR)
495 		return ERR;
496 
497 	return wget_wch(win, ch);
498 #endif /* HAVE_WCHAR */
499 }
500 
501 /*
502  * wget_wch --
503  *	Read in a wide character from the window.
504  */
505 int
506 wget_wch(WINDOW *win, wint_t *ch)
507 {
508 #ifndef HAVE_WCHAR
509 	return ERR;
510 #else
511 	int ret, weset;
512 	int c;
513 	FILE *infd = _cursesi_screen->infd;
514 	cchar_t wc;
515 	wchar_t inp, ws[2];
516 
517 	if (!(win->flags & __SCROLLOK)
518 	    && (win->flags & __FULLWIN)
519 	    && win->curx == win->maxx - 1
520 	    && win->cury == win->maxy - 1
521 	    && __echoit)
522 		return ERR;
523 
524 	if (is_wintouched(win))
525 		wrefresh(win);
526 #ifdef DEBUG
527 	__CTRACE(__CTRACE_INPUT, "wget_wch: __echoit = %d, "
528 	    "__rawmode = %d, __nl = %d, flags = %#.4x\n",
529 	    __echoit, __rawmode, _cursesi_screen->nl, win->flags);
530 #endif
531 	if (_cursesi_screen->resized) {
532 		_cursesi_screen->resized = 0;
533 		*ch = KEY_RESIZE;
534 		return KEY_CODE_YES;
535 	}
536 	if (_cursesi_screen->unget_pos) {
537 #ifdef DEBUG
538 		__CTRACE(__CTRACE_INPUT, "wget_wch returning char at %d\n",
539 		    _cursesi_screen->unget_pos);
540 #endif
541 		_cursesi_screen->unget_pos--;
542 		*ch = _cursesi_screen->unget_list[_cursesi_screen->unget_pos];
543 		if (__echoit) {
544 			ws[0] = *ch, ws[1] = L'\0';
545 			setcchar(&wc, ws, win->wattr, 0, NULL);
546 			wadd_wch(win, &wc);
547 		}
548 		return KEY_CODE_YES;
549 	}
550 	if (__echoit && !__rawmode) {
551 		cbreak();
552 		weset = 1;
553 	} else
554 		weset = 0;
555 
556 	__save_termios();
557 
558 	if (win->flags & __KEYPAD) {
559 		switch (win->delay) {
560 			case -1:
561 				ret = inkey(&inp,
562 					win->flags & __NOTIMEOUT ? 0 : 1, 0);
563 				break;
564 			case 0:
565 				if (__nodelay() == ERR)
566 					return ERR;
567 				ret = inkey(&inp, 0, 0);
568 				break;
569 			default:
570 				ret = inkey(&inp,
571 					win->flags & __NOTIMEOUT ? 0 : 1,
572 					win->delay);
573 				break;
574 		}
575 		if ( ret == ERR )
576 			return ERR;
577 	} else {
578 		switch (win->delay) {
579 			case -1:
580 				break;
581 			case 0:
582 				if (__nodelay() == ERR)
583 					return ERR;
584 				break;
585 			default:
586 				if (__timeout(win->delay) == ERR)
587 					return ERR;
588 				break;
589 		}
590 
591 		c = getwchar();
592 		if (feof(infd)) {
593 			clearerr(infd);
594 			__restore_termios();
595 			return ERR;	/* we have timed out */
596 		}
597 
598 		if (ferror(infd)) {
599 			clearerr(infd);
600 			return ERR;
601 		} else {
602 			ret = c;
603 			inp = c;
604 		}
605 	}
606 #ifdef DEBUG
607 	if (inp > 255)
608 		/* we have a key symbol - treat it differently */
609 		/* XXXX perhaps __unctrl should be expanded to include
610 		 * XXXX the keysyms in the table....
611 		 */
612 		__CTRACE(__CTRACE_INPUT, "wget_wch assembled keysym 0x%x\n",
613 		    inp);
614 	else
615 		__CTRACE(__CTRACE_INPUT, "wget_wch got '%s'\n", unctrl(inp));
616 #endif
617 	if (win->delay > -1) {
618 		if (__delay() == ERR)
619 			return ERR;
620 	}
621 
622 	__restore_termios();
623 
624 	if (__echoit) {
625 		if ( ret == KEY_CODE_YES ) {
626 			/* handle [DEL], [BS], and [LEFT] */
627 			if ( win->curx &&
628 					( inp == KEY_DC ||
629 					  inp == KEY_BACKSPACE ||
630 					  inp == KEY_LEFT )) {
631 				wmove( win, win->cury, win->curx - 1 );
632 				wdelch( win );
633 			}
634 		} else {
635 			ws[ 0 ] = inp, ws[ 1 ] = L'\0';
636 			setcchar( &wc, ws, win->wattr, 0, NULL );
637 			wadd_wch( win, &wc );
638 		}
639 	}
640 
641 	if (weset)
642 		nocbreak();
643 
644 	if (_cursesi_screen->nl && inp == 13)
645 		inp = 10;
646 
647 	*ch = inp;
648 
649 	if ( ret == KEY_CODE_YES )
650 		return KEY_CODE_YES;
651 	return inp < 0 ? ERR : OK;
652 #endif /* HAVE_WCHAR */
653 }
654 
655 /*
656  * unget_wch --
657  *	 Put the wide character back into the input queue.
658  */
659 int
660 unget_wch(const wchar_t c)
661 {
662 	return __unget((wint_t)c);
663 }
664