xref: /openbsd/lib/libedit/read.c (revision 2a75a88e)
1 /*	$OpenBSD: read.c,v 1.49 2021/08/13 10:21:25 schwarze Exp $	*/
2 /*	$NetBSD: read.c,v 1.100 2016/05/24 19:31:27 christos Exp $	*/
3 
4 /*-
5  * Copyright (c) 1992, 1993
6  *	The Regents of the University of California.  All rights reserved.
7  *
8  * This code is derived from software contributed to Berkeley by
9  * Christos Zoulas of Cornell University.
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 University nor the names of its contributors
20  *    may be used to endorse or promote products derived from this software
21  *    without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  */
35 
36 #include "config.h"
37 
38 /*
39  * read.c: Clean this junk up! This is horrible code.
40  *	   Terminal read functions
41  */
42 #include <sys/ioctl.h>
43 
44 #include <ctype.h>
45 #include <errno.h>
46 #include <limits.h>
47 #include <stdlib.h>
48 #include <string.h>
49 #include <unistd.h>
50 
51 #include "el.h"
52 #include "fcns.h"
53 #include "read.h"
54 
55 #define	EL_MAXMACRO	10
56 
57 struct macros {
58 	wchar_t	**macro;
59 	int	  level;
60 	int	  offset;
61 };
62 
63 struct el_read_t {
64 	struct macros	 macros;
65 	el_rfunc_t	 read_char;	/* Function to read a character. */
66 	int		 read_errno;
67 };
68 
69 static int	read_char(EditLine *, wchar_t *);
70 static int	read_getcmd(EditLine *, el_action_t *, wchar_t *);
71 static void	read_clearmacros(struct macros *);
72 static void	read_pop(struct macros *);
73 
74 /* read_init():
75  *	Initialize the read stuff
76  */
77 protected int
read_init(EditLine * el)78 read_init(EditLine *el)
79 {
80 	struct macros *ma;
81 
82 	if ((el->el_read = malloc(sizeof(*el->el_read))) == NULL)
83 		return -1;
84 
85 	ma = &el->el_read->macros;
86 	if ((ma->macro = reallocarray(NULL, EL_MAXMACRO,
87 	    sizeof(*ma->macro))) == NULL) {
88 		free(el->el_read);
89 		return -1;
90 	}
91 	ma->level = -1;
92 	ma->offset = 0;
93 
94 	/* builtin read_char */
95 	el->el_read->read_char = read_char;
96 	return 0;
97 }
98 
99 /* el_read_end():
100  *	Free the data structures used by the read stuff.
101  */
102 protected void
read_end(struct el_read_t * el_read)103 read_end(struct el_read_t *el_read)
104 {
105 	read_clearmacros(&el_read->macros);
106 	free(el_read->macros.macro);
107 	el_read->macros.macro = NULL;
108 }
109 
110 /* el_read_setfn():
111  *	Set the read char function to the one provided.
112  *	If it is set to EL_BUILTIN_GETCFN, then reset to the builtin one.
113  */
114 protected int
el_read_setfn(struct el_read_t * el_read,el_rfunc_t rc)115 el_read_setfn(struct el_read_t *el_read, el_rfunc_t rc)
116 {
117 	el_read->read_char = (rc == EL_BUILTIN_GETCFN) ? read_char : rc;
118 	return 0;
119 }
120 
121 
122 /* el_read_getfn():
123  *	return the current read char function, or EL_BUILTIN_GETCFN
124  *	if it is the default one
125  */
126 protected el_rfunc_t
el_read_getfn(struct el_read_t * el_read)127 el_read_getfn(struct el_read_t *el_read)
128 {
129 	return el_read->read_char == read_char ?
130 	    EL_BUILTIN_GETCFN : el_read->read_char;
131 }
132 
133 
134 /* el_push():
135  *	Push a macro
136  */
137 void
el_wpush(EditLine * el,const wchar_t * str)138 el_wpush(EditLine *el, const wchar_t *str)
139 {
140 	struct macros *ma = &el->el_read->macros;
141 
142 	if (str != NULL && ma->level + 1 < EL_MAXMACRO) {
143 		ma->level++;
144 		if ((ma->macro[ma->level] = wcsdup(str)) != NULL)
145 			return;
146 		ma->level--;
147 	}
148 	terminal_beep(el);
149 	terminal__flush(el);
150 }
151 
152 
153 /* read_getcmd():
154  *	Get next command from the input stream,
155  *	return 0 on success or -1 on EOF or error.
156  *	Character values > 255 are not looked up in the map, but inserted.
157  */
158 static int
read_getcmd(EditLine * el,el_action_t * cmdnum,wchar_t * ch)159 read_getcmd(EditLine *el, el_action_t *cmdnum, wchar_t *ch)
160 {
161 	static const wchar_t meta = (wchar_t)0x80;
162 	el_action_t cmd;
163 	int num;
164 
165 	do {
166 		if ((num = el_wgetc(el, ch)) != 1)
167 			return -1;
168 
169 #ifdef	KANJI
170 		if ((*ch & meta)) {
171 			el->el_state.metanext = 0;
172 			cmd = CcViMap[' '];
173 			break;
174 		} else
175 #endif /* KANJI */
176 
177 		if (el->el_state.metanext) {
178 			el->el_state.metanext = 0;
179 			*ch |= meta;
180 		}
181 		if (*ch >= N_KEYS)
182 			cmd = ED_INSERT;
183 		else
184 			cmd = el->el_map.current[(unsigned char) *ch];
185 		if (cmd == ED_SEQUENCE_LEAD_IN) {
186 			keymacro_value_t val;
187 			switch (keymacro_get(el, ch, &val)) {
188 			case XK_CMD:
189 				cmd = val.cmd;
190 				break;
191 			case XK_STR:
192 				el_wpush(el, val.str);
193 				break;
194 			case XK_NOD:
195 				return -1;
196 			default:
197 				EL_ABORT((el->el_errfile, "Bad XK_ type \n"));
198 				break;
199 			}
200 		}
201 	} while (cmd == ED_SEQUENCE_LEAD_IN);
202 	*cmdnum = cmd;
203 	return 0;
204 }
205 
206 /* read_char():
207  *	Read a character from the tty.
208  */
209 static int
read_char(EditLine * el,wchar_t * cp)210 read_char(EditLine *el, wchar_t *cp)
211 {
212 	char cbuf[MB_LEN_MAX];
213 	int cbp = 0;
214 
215  again:
216 	el->el_signal->sig_no = 0;
217 	switch (read(el->el_infd, cbuf + cbp, 1)) {
218 	case -1:
219 		if (errno == EINTR) {
220 			switch (el->el_signal->sig_no) {
221 			case SIGCONT:
222 				el_set(el, EL_REFRESH);
223 				/*FALLTHROUGH*/
224 			case SIGWINCH:
225 				sig_set(el);
226 				goto again;
227 			default:
228 				break;
229 			}
230 		}
231 		*cp = L'\0';
232 		return -1;
233 	case 0:
234 		*cp = L'\0';
235 		return 0;
236 	default:
237 		break;
238 	}
239 
240 	for (;;) {
241 		mbstate_t mbs;
242 
243 		++cbp;
244 		/* This only works because UTF8 is stateless. */
245 		memset(&mbs, 0, sizeof(mbs));
246 		switch (mbrtowc(cp, cbuf, cbp, &mbs)) {
247 		case (size_t)-1:
248 			if (cbp > 1) {
249 				/*
250 				 * Invalid sequence, discard all bytes
251 				 * except the last one.
252 				 */
253 				cbuf[0] = cbuf[cbp - 1];
254 				cbp = 0;
255 				break;
256 			} else {
257 				/* Invalid byte, discard it. */
258 				cbp = 0;
259 				goto again;
260 			}
261 		case (size_t)-2:
262 			/*
263 			 * We don't support other multibyte charsets.
264 			 * The second condition shouldn't happen
265 			 * and is here merely for additional safety.
266 			 */
267 			if ((el->el_flags & CHARSET_IS_UTF8) == 0 ||
268 			    cbp >= MB_LEN_MAX) {
269 				errno = EILSEQ;
270 				*cp = L'\0';
271 				return -1;
272 			}
273 			/* Incomplete sequence, read another byte. */
274 			goto again;
275 		default:
276 			/* Valid character, process it. */
277 			return 1;
278 		}
279 	}
280 }
281 
282 /* read_pop():
283  *	Pop a macro from the stack
284  */
285 static void
read_pop(struct macros * ma)286 read_pop(struct macros *ma)
287 {
288 	int i;
289 
290 	free(ma->macro[0]);
291 	for (i = 0; i < ma->level; i++)
292 		ma->macro[i] = ma->macro[i + 1];
293 	ma->level--;
294 	ma->offset = 0;
295 }
296 
297 static void
read_clearmacros(struct macros * ma)298 read_clearmacros(struct macros *ma)
299 {
300 	while (ma->level >= 0)
301 		free(ma->macro[ma->level--]);
302 	ma->offset = 0;
303 }
304 
305 /* el_wgetc():
306  *	Read a wide character
307  */
308 int
el_wgetc(EditLine * el,wchar_t * cp)309 el_wgetc(EditLine *el, wchar_t *cp)
310 {
311 	struct macros *ma = &el->el_read->macros;
312 	int num_read;
313 
314 	terminal__flush(el);
315 	for (;;) {
316 		if (ma->level < 0)
317 			break;
318 
319 		if (ma->macro[0][ma->offset] == '\0') {
320 			read_pop(ma);
321 			continue;
322 		}
323 
324 		*cp = ma->macro[0][ma->offset++];
325 
326 		if (ma->macro[0][ma->offset] == '\0') {
327 			/* Needed for QuoteMode On */
328 			read_pop(ma);
329 		}
330 
331 		return 1;
332 	}
333 
334 	if (tty_rawmode(el) < 0)/* make sure the tty is set up correctly */
335 		return 0;
336 
337 	num_read = (*el->el_read->read_char)(el, cp);
338 
339 	/*
340 	 * Remember the original reason of a read failure
341 	 * such that el_wgets() can restore it after doing
342 	 * various cleanup operation that might change errno.
343 	 */
344 	if (num_read < 0)
345 		el->el_read->read_errno = errno;
346 
347 	return num_read;
348 }
349 
350 protected void
read_prepare(EditLine * el)351 read_prepare(EditLine *el)
352 {
353 	if (el->el_flags & HANDLE_SIGNALS)
354 		sig_set(el);
355 	if (el->el_flags & NO_TTY)
356 		return;
357 	if ((el->el_flags & (UNBUFFERED|EDIT_DISABLED)) == UNBUFFERED)
358 		tty_rawmode(el);
359 
360 	/* This is relatively cheap, and things go terribly wrong if
361 	   we have the wrong size. */
362 	el_resize(el);
363 	re_clear_display(el);	/* reset the display stuff */
364 	ch_reset(el);
365 	re_refresh(el);		/* print the prompt */
366 
367 	if (el->el_flags & UNBUFFERED)
368 		terminal__flush(el);
369 }
370 
371 protected void
read_finish(EditLine * el)372 read_finish(EditLine *el)
373 {
374 	if ((el->el_flags & UNBUFFERED) == 0)
375 		(void) tty_cookedmode(el);
376 	if (el->el_flags & HANDLE_SIGNALS)
377 		sig_clr(el);
378 }
379 
380 const wchar_t *
el_wgets(EditLine * el,int * nread)381 el_wgets(EditLine *el, int *nread)
382 {
383 	int retval;
384 	el_action_t cmdnum = 0;
385 	int num;		/* how many chars we have read at NL */
386 	wchar_t wc;
387 	wchar_t ch, *cp;
388 	int crlf = 0;
389 	int nrb;
390 
391 	if (nread == NULL)
392 		nread = &nrb;
393 	*nread = 0;
394 	el->el_read->read_errno = 0;
395 
396 	if (el->el_flags & NO_TTY) {
397 		size_t idx;
398 
399 		cp = el->el_line.buffer;
400 		while ((num = (*el->el_read->read_char)(el, &wc)) == 1) {
401 			*cp = wc;
402 			/* make sure there is space for next character */
403 			if (cp + 1 >= el->el_line.limit) {
404 				idx = (cp - el->el_line.buffer);
405 				if (!ch_enlargebufs(el, 2))
406 					break;
407 				cp = &el->el_line.buffer[idx];
408 			}
409 			cp++;
410 			if (el->el_flags & UNBUFFERED)
411 				break;
412 			if (cp[-1] == '\r' || cp[-1] == '\n')
413 				break;
414 		}
415 		if (num == -1 && errno == EINTR)
416 			cp = el->el_line.buffer;
417 		goto noedit;
418 	}
419 
420 
421 #ifdef FIONREAD
422 	if (el->el_tty.t_mode == EX_IO && el->el_read->macros.level < 0) {
423 		int chrs = 0;
424 
425 		(void) ioctl(el->el_infd, FIONREAD, &chrs);
426 		if (chrs == 0) {
427 			if (tty_rawmode(el) < 0) {
428 				errno = 0;
429 				*nread = 0;
430 				return NULL;
431 			}
432 		}
433 	}
434 #endif /* FIONREAD */
435 
436 	if ((el->el_flags & UNBUFFERED) == 0)
437 		read_prepare(el);
438 
439 	if (el->el_flags & EDIT_DISABLED) {
440 		size_t idx;
441 
442 		if ((el->el_flags & UNBUFFERED) == 0)
443 			cp = el->el_line.buffer;
444 		else
445 			cp = el->el_line.lastchar;
446 
447 		terminal__flush(el);
448 
449 		while ((num = (*el->el_read->read_char)(el, &wc)) == 1) {
450 			*cp = wc;
451 			/* make sure there is space next character */
452 			if (cp + 1 >= el->el_line.limit) {
453 				idx = (cp - el->el_line.buffer);
454 				if (!ch_enlargebufs(el, 2))
455 					break;
456 				cp = &el->el_line.buffer[idx];
457 			}
458 			cp++;
459 			crlf = cp[-1] == '\r' || cp[-1] == '\n';
460 			if (el->el_flags & UNBUFFERED)
461 				break;
462 			if (crlf)
463 				break;
464 		}
465 		if (num == -1 && errno == EINTR)
466 			cp = el->el_line.buffer;
467 		goto noedit;
468 	}
469 
470 	for (num = -1; num == -1;) {  /* while still editing this line */
471 		/* if EOF or error */
472 		if (read_getcmd(el, &cmdnum, &ch) == -1)
473 			break;
474 		if ((int)cmdnum >= el->el_map.nfunc) /* BUG CHECK command */
475 			continue;	/* try again */
476 		/* now do the real command */
477 		/* vi redo needs these way down the levels... */
478 		el->el_state.thiscmd = cmdnum;
479 		el->el_state.thisch = ch;
480 		if (el->el_map.type == MAP_VI &&
481 		    el->el_map.current == el->el_map.key &&
482 		    el->el_chared.c_redo.pos < el->el_chared.c_redo.lim) {
483 			if (cmdnum == VI_DELETE_PREV_CHAR &&
484 			    el->el_chared.c_redo.pos != el->el_chared.c_redo.buf
485 			    && iswprint(el->el_chared.c_redo.pos[-1]))
486 				el->el_chared.c_redo.pos--;
487 			else
488 				*el->el_chared.c_redo.pos++ = ch;
489 		}
490 		retval = (*el->el_map.func[cmdnum]) (el, ch);
491 
492 		/* save the last command here */
493 		el->el_state.lastcmd = cmdnum;
494 
495 		/* use any return value */
496 		switch (retval) {
497 		case CC_CURSOR:
498 			re_refresh_cursor(el);
499 			break;
500 
501 		case CC_REDISPLAY:
502 			re_clear_lines(el);
503 			re_clear_display(el);
504 			/* FALLTHROUGH */
505 
506 		case CC_REFRESH:
507 			re_refresh(el);
508 			break;
509 
510 		case CC_REFRESH_BEEP:
511 			re_refresh(el);
512 			terminal_beep(el);
513 			break;
514 
515 		case CC_NORM:	/* normal char */
516 			break;
517 
518 		case CC_ARGHACK:	/* Suggested by Rich Salz */
519 			/* <rsalz@pineapple.bbn.com> */
520 			continue;	/* keep going... */
521 
522 		case CC_EOF:	/* end of file typed */
523 			if ((el->el_flags & UNBUFFERED) == 0)
524 				num = 0;
525 			else if (num == -1) {
526 				*el->el_line.lastchar++ = CONTROL('d');
527 				el->el_line.cursor = el->el_line.lastchar;
528 				num = 1;
529 			}
530 			break;
531 
532 		case CC_NEWLINE:	/* normal end of line */
533 			num = (int)(el->el_line.lastchar - el->el_line.buffer);
534 			break;
535 
536 		case CC_FATAL:	/* fatal error, reset to known state */
537 			/* put (real) cursor in a known place */
538 			re_clear_display(el);	/* reset the display stuff */
539 			ch_reset(el);	/* reset the input pointers */
540 			read_clearmacros(&el->el_read->macros);
541 			re_refresh(el); /* print the prompt again */
542 			break;
543 
544 		case CC_ERROR:
545 		default:	/* functions we don't know about */
546 			terminal_beep(el);
547 			terminal__flush(el);
548 			break;
549 		}
550 		el->el_state.argument = 1;
551 		el->el_state.doingarg = 0;
552 		el->el_chared.c_vcmd.action = NOP;
553 		if (el->el_flags & UNBUFFERED)
554 			break;
555 	}
556 
557 	terminal__flush(el);		/* flush any buffered output */
558 	/* make sure the tty is set up correctly */
559 	if ((el->el_flags & UNBUFFERED) == 0) {
560 		read_finish(el);
561 		*nread = num != -1 ? num : 0;
562 	} else {
563 		*nread = (int)(el->el_line.lastchar - el->el_line.buffer);
564 	}
565 	goto done;
566 noedit:
567 	el->el_line.cursor = el->el_line.lastchar = cp;
568 	*cp = '\0';
569 	*nread = (int)(el->el_line.cursor - el->el_line.buffer);
570 done:
571 	if (*nread == 0) {
572 		if (num == -1) {
573 			*nread = -1;
574 			if (el->el_read->read_errno)
575 				errno = el->el_read->read_errno;
576 		}
577 		return NULL;
578 	} else
579 		return el->el_line.buffer;
580 }
581