xref: /freebsd/contrib/libedit/read.c (revision 61e21613) 
1 /*	$NetBSD: read.c,v 1.108 2022/10/30 19:11:31 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 1.108 2022/10/30 19:11:31 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 		goto out;
94 	ma->level = -1;
95 	ma->offset = 0;
96 
97 	/* builtin read_char */
98 	el->el_read->read_char = read_char;
99 	return 0;
100 out:
101 	read_end(el);
102 	return -1;
103 }
104 
105 /* el_read_end():
106  *	Free the data structures used by the read stuff.
107  */
108 libedit_private void
109 read_end(EditLine *el)
110 {
111 
112 	read_clearmacros(&el->el_read->macros);
113 	el_free(el->el_read->macros.macro);
114 	el->el_read->macros.macro = NULL;
115 	el_free(el->el_read);
116 	el->el_read = NULL;
117 }
118 
119 /* el_read_setfn():
120  *	Set the read char function to the one provided.
121  *	If it is set to EL_BUILTIN_GETCFN, then reset to the builtin one.
122  */
123 libedit_private int
124 el_read_setfn(struct el_read_t *el_read, el_rfunc_t rc)
125 {
126 	el_read->read_char = (rc == EL_BUILTIN_GETCFN) ? read_char : rc;
127 	return 0;
128 }
129 
130 
131 /* el_read_getfn():
132  *	return the current read char function, or EL_BUILTIN_GETCFN
133  *	if it is the default one
134  */
135 libedit_private el_rfunc_t
136 el_read_getfn(struct el_read_t *el_read)
137 {
138        return el_read->read_char == read_char ?
139 	    EL_BUILTIN_GETCFN : el_read->read_char;
140 }
141 
142 
143 /* read__fixio():
144  *	Try to recover from a read error
145  */
146 /* ARGSUSED */
147 static int
148 read__fixio(int fd __attribute__((__unused__)), int e)
149 {
150 
151 	switch (e) {
152 	case -1:		/* Make sure that the code is reachable */
153 
154 #ifdef EWOULDBLOCK
155 	case EWOULDBLOCK:
156 #ifndef TRY_AGAIN
157 #define TRY_AGAIN
158 #endif
159 #endif /* EWOULDBLOCK */
160 
161 #if defined(POSIX) && defined(EAGAIN)
162 #if defined(EWOULDBLOCK) && EWOULDBLOCK != EAGAIN
163 	case EAGAIN:
164 #ifndef TRY_AGAIN
165 #define TRY_AGAIN
166 #endif
167 #endif /* EWOULDBLOCK && EWOULDBLOCK != EAGAIN */
168 #endif /* POSIX && EAGAIN */
169 
170 		e = 0;
171 #ifdef TRY_AGAIN
172 #if defined(F_SETFL) && defined(O_NDELAY)
173 		if ((e = fcntl(fd, F_GETFL, 0)) == -1)
174 			return -1;
175 
176 		if (fcntl(fd, F_SETFL, e & ~O_NDELAY) == -1)
177 			return -1;
178 		else
179 			e = 1;
180 #endif /* F_SETFL && O_NDELAY */
181 
182 #ifdef FIONBIO
183 		{
184 			int zero = 0;
185 
186 			if (ioctl(fd, FIONBIO, &zero) == -1)
187 				return -1;
188 			else
189 				e = 1;
190 		}
191 #endif /* FIONBIO */
192 
193 #endif /* TRY_AGAIN */
194 		return e ? 0 : -1;
195 
196 	case EINTR:
197 		return 0;
198 
199 	default:
200 		return -1;
201 	}
202 }
203 
204 
205 /* el_push():
206  *	Push a macro
207  */
208 void
209 el_wpush(EditLine *el, const wchar_t *str)
210 {
211 	struct macros *ma = &el->el_read->macros;
212 
213 	if (str != NULL && ma->level + 1 < EL_MAXMACRO) {
214 		ma->level++;
215 		if ((ma->macro[ma->level] = wcsdup(str)) != NULL)
216 			return;
217 		ma->level--;
218 	}
219 	terminal_beep(el);
220 	terminal__flush(el);
221 }
222 
223 
224 /* read_getcmd():
225  *	Get next command from the input stream,
226  *	return 0 on success or -1 on EOF or error.
227  *	Character values > 255 are not looked up in the map, but inserted.
228  */
229 static int
230 read_getcmd(EditLine *el, el_action_t *cmdnum, wchar_t *ch)
231 {
232 	static const wchar_t meta = (wchar_t)0x80;
233 	el_action_t cmd;
234 
235 	do {
236 		if (el_wgetc(el, ch) != 1)
237 			return -1;
238 
239 #ifdef	KANJI
240 		if ((*ch & meta)) {
241 			el->el_state.metanext = 0;
242 			cmd = CcViMap[' '];
243 			break;
244 		} else
245 #endif /* KANJI */
246 
247 		if (el->el_state.metanext) {
248 			el->el_state.metanext = 0;
249 			*ch |= meta;
250 		}
251 		if (*ch >= N_KEYS)
252 			cmd = ED_INSERT;
253 		else
254 			cmd = el->el_map.current[(unsigned char) *ch];
255 		if (cmd == ED_SEQUENCE_LEAD_IN) {
256 			keymacro_value_t val;
257 			switch (keymacro_get(el, ch, &val)) {
258 			case XK_CMD:
259 				cmd = val.cmd;
260 				break;
261 			case XK_STR:
262 				el_wpush(el, val.str);
263 				break;
264 			case XK_NOD:
265 				return -1;
266 			default:
267 				EL_ABORT((el->el_errfile, "Bad XK_ type \n"));
268 				break;
269 			}
270 		}
271 	} while (cmd == ED_SEQUENCE_LEAD_IN);
272 	*cmdnum = cmd;
273 	return 0;
274 }
275 
276 /* read_char():
277  *	Read a character from the tty.
278  */
279 static int
280 read_char(EditLine *el, wchar_t *cp)
281 {
282 	ssize_t num_read;
283 	int tried = (el->el_flags & FIXIO) == 0;
284 	char cbuf[MB_LEN_MAX];
285 	size_t cbp = 0;
286 	int save_errno = errno;
287 
288  again:
289 	el->el_signal->sig_no = 0;
290 	while ((num_read = read(el->el_infd, cbuf + cbp, (size_t)1)) == -1) {
291 		int e = errno;
292 		switch (el->el_signal->sig_no) {
293 		case SIGCONT:
294 			el_wset(el, EL_REFRESH);
295 			/*FALLTHROUGH*/
296 		case SIGWINCH:
297 			sig_set(el);
298 			goto again;
299 		default:
300 			break;
301 		}
302 		if (!tried && read__fixio(el->el_infd, e) == 0) {
303 			errno = save_errno;
304 			tried = 1;
305 		} else {
306 			errno = e;
307 			*cp = L'\0';
308 			return -1;
309 		}
310 	}
311 
312 	/* Test for EOF */
313 	if (num_read == 0) {
314 		*cp = L'\0';
315 		return 0;
316 	}
317 
318 	for (;;) {
319 		mbstate_t mbs;
320 
321 		++cbp;
322 		/* This only works because UTF8 is stateless. */
323 		memset(&mbs, 0, sizeof(mbs));
324 		switch (mbrtowc(cp, cbuf, cbp, &mbs)) {
325 		case (size_t)-1:
326 			if (cbp > 1) {
327 				/*
328 				 * Invalid sequence, discard all bytes
329 				 * except the last one.
330 				 */
331 				cbuf[0] = cbuf[cbp - 1];
332 				cbp = 0;
333 				break;
334 			} else {
335 				/* Invalid byte, discard it. */
336 				cbp = 0;
337 				goto again;
338 			}
339 		case (size_t)-2:
340 			if (cbp >= MB_LEN_MAX) {
341 				errno = EILSEQ;
342 				*cp = L'\0';
343 				return -1;
344 			}
345 			/* Incomplete sequence, read another byte. */
346 			goto again;
347 		default:
348 			/* Valid character, process it. */
349 			return 1;
350 		}
351 	}
352 }
353 
354 /* read_pop():
355  *	Pop a macro from the stack
356  */
357 static void
358 read_pop(struct macros *ma)
359 {
360 	int i;
361 
362 	el_free(ma->macro[0]);
363 	for (i = 0; i < ma->level; i++)
364 		ma->macro[i] = ma->macro[i + 1];
365 	ma->level--;
366 	ma->offset = 0;
367 }
368 
369 static void
370 read_clearmacros(struct macros *ma)
371 {
372 	while (ma->level >= 0)
373 		el_free(ma->macro[ma->level--]);
374 	ma->offset = 0;
375 }
376 
377 /* el_wgetc():
378  *	Read a wide character
379  */
380 int
381 el_wgetc(EditLine *el, wchar_t *cp)
382 {
383 	struct macros *ma = &el->el_read->macros;
384 	int num_read;
385 
386 	terminal__flush(el);
387 	for (;;) {
388 		if (ma->level < 0)
389 			break;
390 
391 		if (ma->macro[0][ma->offset] == '\0') {
392 			read_pop(ma);
393 			continue;
394 		}
395 
396 		*cp = ma->macro[0][ma->offset++];
397 
398 		if (ma->macro[0][ma->offset] == '\0') {
399 			/* Needed for QuoteMode On */
400 			read_pop(ma);
401 		}
402 
403 		return 1;
404 	}
405 
406 	if (tty_rawmode(el) < 0)/* make sure the tty is set up correctly */
407 		return 0;
408 
409 	num_read = (*el->el_read->read_char)(el, cp);
410 
411 	/*
412 	 * Remember the original reason of a read failure
413 	 * such that el_wgets() can restore it after doing
414 	 * various cleanup operation that might change errno.
415 	 */
416 	if (num_read < 0)
417 		el->el_read->read_errno = errno;
418 
419 	return num_read;
420 }
421 
422 libedit_private void
423 read_prepare(EditLine *el)
424 {
425 	if (el->el_flags & HANDLE_SIGNALS)
426 		sig_set(el);
427 	if (el->el_flags & NO_TTY)
428 		return;
429 	if ((el->el_flags & (UNBUFFERED|EDIT_DISABLED)) == UNBUFFERED)
430 		tty_rawmode(el);
431 
432 	/* This is relatively cheap, and things go terribly wrong if
433 	   we have the wrong size. */
434 	el_resize(el);
435 	re_clear_display(el);	/* reset the display stuff */
436 	ch_reset(el);
437 	re_refresh(el);		/* print the prompt */
438 
439 	if (el->el_flags & UNBUFFERED)
440 		terminal__flush(el);
441 }
442 
443 libedit_private void
444 read_finish(EditLine *el)
445 {
446 	if ((el->el_flags & UNBUFFERED) == 0)
447 		(void) tty_cookedmode(el);
448 	if (el->el_flags & HANDLE_SIGNALS)
449 		sig_clr(el);
450 }
451 
452 static const wchar_t *
453 noedit_wgets(EditLine *el, int *nread)
454 {
455 	el_line_t	*lp = &el->el_line;
456 	int		 num;
457 
458 	while ((num = (*el->el_read->read_char)(el, lp->lastchar)) == 1) {
459 		if (lp->lastchar + 1 >= lp->limit &&
460 		    !ch_enlargebufs(el, (size_t)2))
461 			break;
462 		lp->lastchar++;
463 		if (el->el_flags & UNBUFFERED ||
464 		    lp->lastchar[-1] == '\r' ||
465 		    lp->lastchar[-1] == '\n')
466 			break;
467 	}
468 	if (num == -1 && errno == EINTR)
469 		lp->lastchar = lp->buffer;
470 	lp->cursor = lp->lastchar;
471 	*lp->lastchar = '\0';
472 	*nread = (int)(lp->lastchar - lp->buffer);
473 	return *nread ? lp->buffer : NULL;
474 }
475 
476 const wchar_t *
477 el_wgets(EditLine *el, int *nread)
478 {
479 	int retval;
480 	el_action_t cmdnum = 0;
481 	int num;		/* how many chars we have read at NL */
482 	wchar_t ch;
483 	int nrb;
484 
485 	if (nread == NULL)
486 		nread = &nrb;
487 	*nread = 0;
488 	el->el_read->read_errno = 0;
489 
490 	if (el->el_flags & NO_TTY) {
491 		el->el_line.lastchar = el->el_line.buffer;
492 		return noedit_wgets(el, nread);
493 	}
494 
495 #ifdef FIONREAD
496 	if (el->el_tty.t_mode == EX_IO && el->el_read->macros.level < 0) {
497 		int chrs = 0;
498 
499 		(void) ioctl(el->el_infd, FIONREAD, &chrs);
500 		if (chrs == 0) {
501 			if (tty_rawmode(el) < 0) {
502 				errno = 0;
503 				*nread = 0;
504 				return NULL;
505 			}
506 		}
507 	}
508 #endif /* FIONREAD */
509 
510 	if ((el->el_flags & UNBUFFERED) == 0)
511 		read_prepare(el);
512 
513 	if (el->el_flags & EDIT_DISABLED) {
514 		if ((el->el_flags & UNBUFFERED) == 0)
515 			el->el_line.lastchar = el->el_line.buffer;
516 		terminal__flush(el);
517 		return noedit_wgets(el, nread);
518 	}
519 
520 	for (num = -1; num == -1;) {  /* while still editing this line */
521 		/* if EOF or error */
522 		if (read_getcmd(el, &cmdnum, &ch) == -1)
523 			break;
524 		if ((size_t)cmdnum >= el->el_map.nfunc) /* BUG CHECK command */
525 			continue;	/* try again */
526 		/* now do the real command */
527 		/* vi redo needs these way down the levels... */
528 		el->el_state.thiscmd = cmdnum;
529 		el->el_state.thisch = ch;
530 		if (el->el_map.type == MAP_VI &&
531 		    el->el_map.current == el->el_map.key &&
532 		    el->el_chared.c_redo.pos < el->el_chared.c_redo.lim) {
533 			if (cmdnum == VI_DELETE_PREV_CHAR &&
534 			    el->el_chared.c_redo.pos != el->el_chared.c_redo.buf
535 			    && iswprint(el->el_chared.c_redo.pos[-1]))
536 				el->el_chared.c_redo.pos--;
537 			else
538 				*el->el_chared.c_redo.pos++ = ch;
539 		}
540 		retval = (*el->el_map.func[cmdnum]) (el, ch);
541 
542 		/* save the last command here */
543 		el->el_state.lastcmd = cmdnum;
544 
545 		/* use any return value */
546 		switch (retval) {
547 		case CC_CURSOR:
548 			re_refresh_cursor(el);
549 			break;
550 
551 		case CC_REDISPLAY:
552 			re_clear_lines(el);
553 			re_clear_display(el);
554 			/* FALLTHROUGH */
555 
556 		case CC_REFRESH:
557 			re_refresh(el);
558 			break;
559 
560 		case CC_REFRESH_BEEP:
561 			re_refresh(el);
562 			terminal_beep(el);
563 			break;
564 
565 		case CC_NORM:	/* normal char */
566 			break;
567 
568 		case CC_ARGHACK:	/* Suggested by Rich Salz */
569 			/* <rsalz@pineapple.bbn.com> */
570 			continue;	/* keep going... */
571 
572 		case CC_EOF:	/* end of file typed */
573 			if ((el->el_flags & UNBUFFERED) == 0)
574 				num = 0;
575 			else if (num == -1) {
576 				*el->el_line.lastchar++ = CONTROL('d');
577 				el->el_line.cursor = el->el_line.lastchar;
578 				num = 1;
579 			}
580 			break;
581 
582 		case CC_NEWLINE:	/* normal end of line */
583 			num = (int)(el->el_line.lastchar - el->el_line.buffer);
584 			break;
585 
586 		case CC_FATAL:	/* fatal error, reset to known state */
587 			/* put (real) cursor in a known place */
588 			re_clear_display(el);	/* reset the display stuff */
589 			ch_reset(el);	/* reset the input pointers */
590 			read_clearmacros(&el->el_read->macros);
591 			re_refresh(el); /* print the prompt again */
592 			break;
593 
594 		case CC_ERROR:
595 		default:	/* functions we don't know about */
596 			terminal_beep(el);
597 			terminal__flush(el);
598 			break;
599 		}
600 		el->el_state.argument = 1;
601 		el->el_state.doingarg = 0;
602 		el->el_chared.c_vcmd.action = NOP;
603 		if (el->el_flags & UNBUFFERED)
604 			break;
605 	}
606 
607 	terminal__flush(el);		/* flush any buffered output */
608 	/* make sure the tty is set up correctly */
609 	if ((el->el_flags & UNBUFFERED) == 0) {
610 		read_finish(el);
611 		*nread = num != -1 ? num : 0;
612 	} else
613 		*nread = (int)(el->el_line.lastchar - el->el_line.buffer);
614 
615 	if (*nread == 0) {
616 		if (num == -1) {
617 			*nread = -1;
618 			if (el->el_read->read_errno)
619 				errno = el->el_read->read_errno;
620 		}
621 		return NULL;
622 	} else
623 		return el->el_line.buffer;
624 }
625