xref: /freebsd/contrib/libedit/read.c (revision 8ddb146abcdf061be9f2c0db7e391697dafad85c) 
1 /*	$NetBSD: read.c,v 1.107 2021/08/15 10:08:41 christos Exp $	*/
2 
3 /*-
4  * Copyright (c) 1992, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * This code is derived from software contributed to Berkeley by
8  * Christos Zoulas of Cornell University.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. Neither the name of the University nor the names of its contributors
19  *    may be used to endorse or promote products derived from this software
20  *    without specific prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  */
34 
35 #include "config.h"
36 #if !defined(lint) && !defined(SCCSID)
37 #if 0
38 static char sccsid[] = "@(#)read.c	8.1 (Berkeley) 6/4/93";
39 #else
40 __RCSID("$NetBSD: read.c,v 1.107 2021/08/15 10:08:41 christos Exp $");
41 #endif
42 #endif /* not lint && not SCCSID */
43 
44 /*
45  * read.c: Terminal read functions
46  */
47 #include <ctype.h>
48 #include <errno.h>
49 #include <fcntl.h>
50 #include <limits.h>
51 #include <stdlib.h>
52 #include <string.h>
53 #include <unistd.h>
54 
55 #include "el.h"
56 #include "fcns.h"
57 #include "read.h"
58 
59 #define	EL_MAXMACRO	10
60 
61 struct macros {
62 	wchar_t	**macro;
63 	int	  level;
64 	int	  offset;
65 };
66 
67 struct el_read_t {
68 	struct macros	 macros;
69 	el_rfunc_t	 read_char;	/* Function to read a character. */
70 	int		 read_errno;
71 };
72 
73 static int	read__fixio(int, int);
74 static int	read_char(EditLine *, wchar_t *);
75 static int	read_getcmd(EditLine *, el_action_t *, wchar_t *);
76 static void	read_clearmacros(struct macros *);
77 static void	read_pop(struct macros *);
78 static const wchar_t *noedit_wgets(EditLine *, int *);
79 
80 /* read_init():
81  *	Initialize the read stuff
82  */
83 libedit_private int
84 read_init(EditLine *el)
85 {
86 	struct macros *ma;
87 
88 	if ((el->el_read = el_malloc(sizeof(*el->el_read))) == NULL)
89 		return -1;
90 
91 	ma = &el->el_read->macros;
92 	if ((ma->macro = el_calloc(EL_MAXMACRO, sizeof(*ma->macro))) == NULL) {
93 		free(el->el_read);
94 		return -1;
95 	}
96 	ma->level = -1;
97 	ma->offset = 0;
98 
99 	/* builtin read_char */
100 	el->el_read->read_char = read_char;
101 	return 0;
102 }
103 
104 /* el_read_end():
105  *	Free the data structures used by the read stuff.
106  */
107 libedit_private void
108 read_end(struct el_read_t *el_read)
109 {
110 	read_clearmacros(&el_read->macros);
111 	el_free(el_read->macros.macro);
112 	el_read->macros.macro = NULL;
113 	el_free(el_read);
114 }
115 
116 /* el_read_setfn():
117  *	Set the read char function to the one provided.
118  *	If it is set to EL_BUILTIN_GETCFN, then reset to the builtin one.
119  */
120 libedit_private int
121 el_read_setfn(struct el_read_t *el_read, el_rfunc_t rc)
122 {
123 	el_read->read_char = (rc == EL_BUILTIN_GETCFN) ? read_char : rc;
124 	return 0;
125 }
126 
127 
128 /* el_read_getfn():
129  *	return the current read char function, or EL_BUILTIN_GETCFN
130  *	if it is the default one
131  */
132 libedit_private el_rfunc_t
133 el_read_getfn(struct el_read_t *el_read)
134 {
135        return el_read->read_char == read_char ?
136 	    EL_BUILTIN_GETCFN : el_read->read_char;
137 }
138 
139 
140 /* read__fixio():
141  *	Try to recover from a read error
142  */
143 /* ARGSUSED */
144 static int
145 read__fixio(int fd __attribute__((__unused__)), int e)
146 {
147 
148 	switch (e) {
149 	case -1:		/* Make sure that the code is reachable */
150 
151 #ifdef EWOULDBLOCK
152 	case EWOULDBLOCK:
153 #ifndef TRY_AGAIN
154 #define TRY_AGAIN
155 #endif
156 #endif /* EWOULDBLOCK */
157 
158 #if defined(POSIX) && defined(EAGAIN)
159 #if defined(EWOULDBLOCK) && EWOULDBLOCK != EAGAIN
160 	case EAGAIN:
161 #ifndef TRY_AGAIN
162 #define TRY_AGAIN
163 #endif
164 #endif /* EWOULDBLOCK && EWOULDBLOCK != EAGAIN */
165 #endif /* POSIX && EAGAIN */
166 
167 		e = 0;
168 #ifdef TRY_AGAIN
169 #if defined(F_SETFL) && defined(O_NDELAY)
170 		if ((e = fcntl(fd, F_GETFL, 0)) == -1)
171 			return -1;
172 
173 		if (fcntl(fd, F_SETFL, e & ~O_NDELAY) == -1)
174 			return -1;
175 		else
176 			e = 1;
177 #endif /* F_SETFL && O_NDELAY */
178 
179 #ifdef FIONBIO
180 		{
181 			int zero = 0;
182 
183 			if (ioctl(fd, FIONBIO, &zero) == -1)
184 				return -1;
185 			else
186 				e = 1;
187 		}
188 #endif /* FIONBIO */
189 
190 #endif /* TRY_AGAIN */
191 		return e ? 0 : -1;
192 
193 	case EINTR:
194 		return 0;
195 
196 	default:
197 		return -1;
198 	}
199 }
200 
201 
202 /* el_push():
203  *	Push a macro
204  */
205 void
206 el_wpush(EditLine *el, const wchar_t *str)
207 {
208 	struct macros *ma = &el->el_read->macros;
209 
210 	if (str != NULL && ma->level + 1 < EL_MAXMACRO) {
211 		ma->level++;
212 		if ((ma->macro[ma->level] = wcsdup(str)) != NULL)
213 			return;
214 		ma->level--;
215 	}
216 	terminal_beep(el);
217 	terminal__flush(el);
218 }
219 
220 
221 /* read_getcmd():
222  *	Get next command from the input stream,
223  *	return 0 on success or -1 on EOF or error.
224  *	Character values > 255 are not looked up in the map, but inserted.
225  */
226 static int
227 read_getcmd(EditLine *el, el_action_t *cmdnum, wchar_t *ch)
228 {
229 	static const wchar_t meta = (wchar_t)0x80;
230 	el_action_t cmd;
231 
232 	do {
233 		if (el_wgetc(el, ch) != 1)
234 			return -1;
235 
236 #ifdef	KANJI
237 		if ((*ch & meta)) {
238 			el->el_state.metanext = 0;
239 			cmd = CcViMap[' '];
240 			break;
241 		} else
242 #endif /* KANJI */
243 
244 		if (el->el_state.metanext) {
245 			el->el_state.metanext = 0;
246 			*ch |= meta;
247 		}
248 		if (*ch >= N_KEYS)
249 			cmd = ED_INSERT;
250 		else
251 			cmd = el->el_map.current[(unsigned char) *ch];
252 		if (cmd == ED_SEQUENCE_LEAD_IN) {
253 			keymacro_value_t val;
254 			switch (keymacro_get(el, ch, &val)) {
255 			case XK_CMD:
256 				cmd = val.cmd;
257 				break;
258 			case XK_STR:
259 				el_wpush(el, val.str);
260 				break;
261 			case XK_NOD:
262 				return -1;
263 			default:
264 				EL_ABORT((el->el_errfile, "Bad XK_ type \n"));
265 				break;
266 			}
267 		}
268 	} while (cmd == ED_SEQUENCE_LEAD_IN);
269 	*cmdnum = cmd;
270 	return 0;
271 }
272 
273 /* read_char():
274  *	Read a character from the tty.
275  */
276 static int
277 read_char(EditLine *el, wchar_t *cp)
278 {
279 	ssize_t num_read;
280 	int tried = (el->el_flags & FIXIO) == 0;
281 	char cbuf[MB_LEN_MAX];
282 	size_t cbp = 0;
283 	int save_errno = errno;
284 
285  again:
286 	el->el_signal->sig_no = 0;
287 	while ((num_read = read(el->el_infd, cbuf + cbp, (size_t)1)) == -1) {
288 		int e = errno;
289 		switch (el->el_signal->sig_no) {
290 		case SIGCONT:
291 			el_wset(el, EL_REFRESH);
292 			/*FALLTHROUGH*/
293 		case SIGWINCH:
294 			sig_set(el);
295 			goto again;
296 		default:
297 			break;
298 		}
299 		if (!tried && read__fixio(el->el_infd, e) == 0) {
300 			errno = save_errno;
301 			tried = 1;
302 		} else {
303 			errno = e;
304 			*cp = L'\0';
305 			return -1;
306 		}
307 	}
308 
309 	/* Test for EOF */
310 	if (num_read == 0) {
311 		*cp = L'\0';
312 		return 0;
313 	}
314 
315 	for (;;) {
316 		mbstate_t mbs;
317 
318 		++cbp;
319 		/* This only works because UTF8 is stateless. */
320 		memset(&mbs, 0, sizeof(mbs));
321 		switch (mbrtowc(cp, cbuf, cbp, &mbs)) {
322 		case (size_t)-1:
323 			if (cbp > 1) {
324 				/*
325 				 * Invalid sequence, discard all bytes
326 				 * except the last one.
327 				 */
328 				cbuf[0] = cbuf[cbp - 1];
329 				cbp = 0;
330 				break;
331 			} else {
332 				/* Invalid byte, discard it. */
333 				cbp = 0;
334 				goto again;
335 			}
336 		case (size_t)-2:
337 			if (cbp >= MB_LEN_MAX) {
338 				errno = EILSEQ;
339 				*cp = L'\0';
340 				return -1;
341 			}
342 			/* Incomplete sequence, read another byte. */
343 			goto again;
344 		default:
345 			/* Valid character, process it. */
346 			return 1;
347 		}
348 	}
349 }
350 
351 /* read_pop():
352  *	Pop a macro from the stack
353  */
354 static void
355 read_pop(struct macros *ma)
356 {
357 	int i;
358 
359 	el_free(ma->macro[0]);
360 	for (i = 0; i < ma->level; i++)
361 		ma->macro[i] = ma->macro[i + 1];
362 	ma->level--;
363 	ma->offset = 0;
364 }
365 
366 static void
367 read_clearmacros(struct macros *ma)
368 {
369 	while (ma->level >= 0)
370 		el_free(ma->macro[ma->level--]);
371 	ma->offset = 0;
372 }
373 
374 /* el_wgetc():
375  *	Read a wide character
376  */
377 int
378 el_wgetc(EditLine *el, wchar_t *cp)
379 {
380 	struct macros *ma = &el->el_read->macros;
381 	int num_read;
382 
383 	terminal__flush(el);
384 	for (;;) {
385 		if (ma->level < 0)
386 			break;
387 
388 		if (ma->macro[0][ma->offset] == '\0') {
389 			read_pop(ma);
390 			continue;
391 		}
392 
393 		*cp = ma->macro[0][ma->offset++];
394 
395 		if (ma->macro[0][ma->offset] == '\0') {
396 			/* Needed for QuoteMode On */
397 			read_pop(ma);
398 		}
399 
400 		return 1;
401 	}
402 
403 	if (tty_rawmode(el) < 0)/* make sure the tty is set up correctly */
404 		return 0;
405 
406 	num_read = (*el->el_read->read_char)(el, cp);
407 
408 	/*
409 	 * Remember the original reason of a read failure
410 	 * such that el_wgets() can restore it after doing
411 	 * various cleanup operation that might change errno.
412 	 */
413 	if (num_read < 0)
414 		el->el_read->read_errno = errno;
415 
416 	return num_read;
417 }
418 
419 libedit_private void
420 read_prepare(EditLine *el)
421 {
422 	if (el->el_flags & HANDLE_SIGNALS)
423 		sig_set(el);
424 	if (el->el_flags & NO_TTY)
425 		return;
426 	if ((el->el_flags & (UNBUFFERED|EDIT_DISABLED)) == UNBUFFERED)
427 		tty_rawmode(el);
428 
429 	/* This is relatively cheap, and things go terribly wrong if
430 	   we have the wrong size. */
431 	el_resize(el);
432 	re_clear_display(el);	/* reset the display stuff */
433 	ch_reset(el);
434 	re_refresh(el);		/* print the prompt */
435 
436 	if (el->el_flags & UNBUFFERED)
437 		terminal__flush(el);
438 }
439 
440 libedit_private void
441 read_finish(EditLine *el)
442 {
443 	if ((el->el_flags & UNBUFFERED) == 0)
444 		(void) tty_cookedmode(el);
445 	if (el->el_flags & HANDLE_SIGNALS)
446 		sig_clr(el);
447 }
448 
449 static const wchar_t *
450 noedit_wgets(EditLine *el, int *nread)
451 {
452 	el_line_t	*lp = &el->el_line;
453 	int		 num;
454 
455 	while ((num = (*el->el_read->read_char)(el, lp->lastchar)) == 1) {
456 		if (lp->lastchar + 1 >= lp->limit &&
457 		    !ch_enlargebufs(el, (size_t)2))
458 			break;
459 		lp->lastchar++;
460 		if (el->el_flags & UNBUFFERED ||
461 		    lp->lastchar[-1] == '\r' ||
462 		    lp->lastchar[-1] == '\n')
463 			break;
464 	}
465 	if (num == -1 && errno == EINTR)
466 		lp->lastchar = lp->buffer;
467 	lp->cursor = lp->lastchar;
468 	*lp->lastchar = '\0';
469 	*nread = (int)(lp->lastchar - lp->buffer);
470 	return *nread ? lp->buffer : NULL;
471 }
472 
473 const wchar_t *
474 el_wgets(EditLine *el, int *nread)
475 {
476 	int retval;
477 	el_action_t cmdnum = 0;
478 	int num;		/* how many chars we have read at NL */
479 	wchar_t ch;
480 	int nrb;
481 
482 	if (nread == NULL)
483 		nread = &nrb;
484 	*nread = 0;
485 	el->el_read->read_errno = 0;
486 
487 	if (el->el_flags & NO_TTY) {
488 		el->el_line.lastchar = el->el_line.buffer;
489 		return noedit_wgets(el, nread);
490 	}
491 
492 #ifdef FIONREAD
493 	if (el->el_tty.t_mode == EX_IO && el->el_read->macros.level < 0) {
494 		int chrs = 0;
495 
496 		(void) ioctl(el->el_infd, FIONREAD, &chrs);
497 		if (chrs == 0) {
498 			if (tty_rawmode(el) < 0) {
499 				errno = 0;
500 				*nread = 0;
501 				return NULL;
502 			}
503 		}
504 	}
505 #endif /* FIONREAD */
506 
507 	if ((el->el_flags & UNBUFFERED) == 0)
508 		read_prepare(el);
509 
510 	if (el->el_flags & EDIT_DISABLED) {
511 		if ((el->el_flags & UNBUFFERED) == 0)
512 			el->el_line.lastchar = el->el_line.buffer;
513 		terminal__flush(el);
514 		return noedit_wgets(el, nread);
515 	}
516 
517 	for (num = -1; num == -1;) {  /* while still editing this line */
518 		/* if EOF or error */
519 		if (read_getcmd(el, &cmdnum, &ch) == -1)
520 			break;
521 		if ((size_t)cmdnum >= el->el_map.nfunc) /* BUG CHECK command */
522 			continue;	/* try again */
523 		/* now do the real command */
524 		/* vi redo needs these way down the levels... */
525 		el->el_state.thiscmd = cmdnum;
526 		el->el_state.thisch = ch;
527 		if (el->el_map.type == MAP_VI &&
528 		    el->el_map.current == el->el_map.key &&
529 		    el->el_chared.c_redo.pos < el->el_chared.c_redo.lim) {
530 			if (cmdnum == VI_DELETE_PREV_CHAR &&
531 			    el->el_chared.c_redo.pos != el->el_chared.c_redo.buf
532 			    && iswprint(el->el_chared.c_redo.pos[-1]))
533 				el->el_chared.c_redo.pos--;
534 			else
535 				*el->el_chared.c_redo.pos++ = ch;
536 		}
537 		retval = (*el->el_map.func[cmdnum]) (el, ch);
538 
539 		/* save the last command here */
540 		el->el_state.lastcmd = cmdnum;
541 
542 		/* use any return value */
543 		switch (retval) {
544 		case CC_CURSOR:
545 			re_refresh_cursor(el);
546 			break;
547 
548 		case CC_REDISPLAY:
549 			re_clear_lines(el);
550 			re_clear_display(el);
551 			/* FALLTHROUGH */
552 
553 		case CC_REFRESH:
554 			re_refresh(el);
555 			break;
556 
557 		case CC_REFRESH_BEEP:
558 			re_refresh(el);
559 			terminal_beep(el);
560 			break;
561 
562 		case CC_NORM:	/* normal char */
563 			break;
564 
565 		case CC_ARGHACK:	/* Suggested by Rich Salz */
566 			/* <rsalz@pineapple.bbn.com> */
567 			continue;	/* keep going... */
568 
569 		case CC_EOF:	/* end of file typed */
570 			if ((el->el_flags & UNBUFFERED) == 0)
571 				num = 0;
572 			else if (num == -1) {
573 				*el->el_line.lastchar++ = CONTROL('d');
574 				el->el_line.cursor = el->el_line.lastchar;
575 				num = 1;
576 			}
577 			break;
578 
579 		case CC_NEWLINE:	/* normal end of line */
580 			num = (int)(el->el_line.lastchar - el->el_line.buffer);
581 			break;
582 
583 		case CC_FATAL:	/* fatal error, reset to known state */
584 			/* put (real) cursor in a known place */
585 			re_clear_display(el);	/* reset the display stuff */
586 			ch_reset(el);	/* reset the input pointers */
587 			read_clearmacros(&el->el_read->macros);
588 			re_refresh(el); /* print the prompt again */
589 			break;
590 
591 		case CC_ERROR:
592 		default:	/* functions we don't know about */
593 			terminal_beep(el);
594 			terminal__flush(el);
595 			break;
596 		}
597 		el->el_state.argument = 1;
598 		el->el_state.doingarg = 0;
599 		el->el_chared.c_vcmd.action = NOP;
600 		if (el->el_flags & UNBUFFERED)
601 			break;
602 	}
603 
604 	terminal__flush(el);		/* flush any buffered output */
605 	/* make sure the tty is set up correctly */
606 	if ((el->el_flags & UNBUFFERED) == 0) {
607 		read_finish(el);
608 		*nread = num != -1 ? num : 0;
609 	} else
610 		*nread = (int)(el->el_line.lastchar - el->el_line.buffer);
611 
612 	if (*nread == 0) {
613 		if (num == -1) {
614 			*nread = -1;
615 			if (el->el_read->read_errno)
616 				errno = el->el_read->read_errno;
617 		}
618 		return NULL;
619 	} else
620 		return el->el_line.buffer;
621 }
622