xref: /netbsd-src/lib/libedit/read.c (revision e89934bbf778a6d6d6894877c4da59d0c7835b0f)
1 /*	$NetBSD: read.c,v 1.102 2016/12/11 15:47:06 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 1.102 2016/12/11 15:47:06 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_malloc(EL_MAXMACRO *
93 	    sizeof(*ma->macro))) == NULL) {
94 		free(el->el_read);
95 		return -1;
96 	}
97 	ma->level = -1;
98 	ma->offset = 0;
99 
100 	/* builtin read_char */
101 	el->el_read->read_char = read_char;
102 	return 0;
103 }
104 
105 /* el_read_end():
106  *	Free the data structures used by the read stuff.
107  */
108 libedit_private void
109 read_end(struct el_read_t *el_read)
110 {
111 	read_clearmacros(&el_read->macros);
112 	el_free(el_read->macros.macro);
113 	el_read->macros.macro = NULL;
114 	el_free(el_read);
115 }
116 
117 /* el_read_setfn():
118  *	Set the read char function to the one provided.
119  *	If it is set to EL_BUILTIN_GETCFN, then reset to the builtin one.
120  */
121 libedit_private int
122 el_read_setfn(struct el_read_t *el_read, el_rfunc_t rc)
123 {
124 	el_read->read_char = (rc == EL_BUILTIN_GETCFN) ? read_char : rc;
125 	return 0;
126 }
127 
128 
129 /* el_read_getfn():
130  *	return the current read char function, or EL_BUILTIN_GETCFN
131  *	if it is the default one
132  */
133 libedit_private el_rfunc_t
134 el_read_getfn(struct el_read_t *el_read)
135 {
136        return el_read->read_char == read_char ?
137 	    EL_BUILTIN_GETCFN : el_read->read_char;
138 }
139 
140 
141 /* read__fixio():
142  *	Try to recover from a read error
143  */
144 /* ARGSUSED */
145 static int
146 read__fixio(int fd __attribute__((__unused__)), int e)
147 {
148 
149 	switch (e) {
150 	case -1:		/* Make sure that the code is reachable */
151 
152 #ifdef EWOULDBLOCK
153 	case EWOULDBLOCK:
154 #ifndef TRY_AGAIN
155 #define TRY_AGAIN
156 #endif
157 #endif /* EWOULDBLOCK */
158 
159 #if defined(POSIX) && defined(EAGAIN)
160 #if defined(EWOULDBLOCK) && EWOULDBLOCK != EAGAIN
161 	case EAGAIN:
162 #ifndef TRY_AGAIN
163 #define TRY_AGAIN
164 #endif
165 #endif /* EWOULDBLOCK && EWOULDBLOCK != EAGAIN */
166 #endif /* POSIX && EAGAIN */
167 
168 		e = 0;
169 #ifdef TRY_AGAIN
170 #if defined(F_SETFL) && defined(O_NDELAY)
171 		if ((e = fcntl(fd, F_GETFL, 0)) == -1)
172 			return -1;
173 
174 		if (fcntl(fd, F_SETFL, e & ~O_NDELAY) == -1)
175 			return -1;
176 		else
177 			e = 1;
178 #endif /* F_SETFL && O_NDELAY */
179 
180 #ifdef FIONBIO
181 		{
182 			int zero = 0;
183 
184 			if (ioctl(fd, FIONBIO, &zero) == -1)
185 				return -1;
186 			else
187 				e = 1;
188 		}
189 #endif /* FIONBIO */
190 
191 #endif /* TRY_AGAIN */
192 		return e ? 0 : -1;
193 
194 	case EINTR:
195 		return 0;
196 
197 	default:
198 		return -1;
199 	}
200 }
201 
202 
203 /* el_push():
204  *	Push a macro
205  */
206 void
207 el_wpush(EditLine *el, const wchar_t *str)
208 {
209 	struct macros *ma = &el->el_read->macros;
210 
211 	if (str != NULL && ma->level + 1 < EL_MAXMACRO) {
212 		ma->level++;
213 		if ((ma->macro[ma->level] = wcsdup(str)) != NULL)
214 			return;
215 		ma->level--;
216 	}
217 	terminal_beep(el);
218 	terminal__flush(el);
219 }
220 
221 
222 /* read_getcmd():
223  *	Get next command from the input stream,
224  *	return 0 on success or -1 on EOF or error.
225  *	Character values > 255 are not looked up in the map, but inserted.
226  */
227 static int
228 read_getcmd(EditLine *el, el_action_t *cmdnum, wchar_t *ch)
229 {
230 	static const wchar_t meta = (wchar_t)0x80;
231 	el_action_t cmd;
232 	int num;
233 
234 	do {
235 		if ((num = el_wgetc(el, ch)) != 1)
236 			return -1;
237 
238 #ifdef	KANJI
239 		if ((*ch & meta)) {
240 			el->el_state.metanext = 0;
241 			cmd = CcViMap[' '];
242 			break;
243 		} else
244 #endif /* KANJI */
245 
246 		if (el->el_state.metanext) {
247 			el->el_state.metanext = 0;
248 			*ch |= meta;
249 		}
250 		if (*ch >= N_KEYS)
251 			cmd = ED_INSERT;
252 		else
253 			cmd = el->el_map.current[(unsigned char) *ch];
254 		if (cmd == ED_SEQUENCE_LEAD_IN) {
255 			keymacro_value_t val;
256 			switch (keymacro_get(el, ch, &val)) {
257 			case XK_CMD:
258 				cmd = val.cmd;
259 				break;
260 			case XK_STR:
261 				el_wpush(el, val.str);
262 				break;
263 			case XK_NOD:
264 				return -1;
265 			default:
266 				EL_ABORT((el->el_errfile, "Bad XK_ type \n"));
267 				break;
268 			}
269 		}
270 	} while (cmd == ED_SEQUENCE_LEAD_IN);
271 	*cmdnum = cmd;
272 	return 0;
273 }
274 
275 /* read_char():
276  *	Read a character from the tty.
277  */
278 static int
279 read_char(EditLine *el, wchar_t *cp)
280 {
281 	ssize_t num_read;
282 	int tried = 0;
283 	char cbuf[MB_LEN_MAX];
284 	size_t cbp = 0;
285 	int save_errno = errno;
286 
287  again:
288 	el->el_signal->sig_no = 0;
289 	while ((num_read = read(el->el_infd, cbuf + cbp, (size_t)1)) == -1) {
290 		int e = errno;
291 		switch (el->el_signal->sig_no) {
292 		case SIGCONT:
293 			el_wset(el, EL_REFRESH);
294 			/*FALLTHROUGH*/
295 		case SIGWINCH:
296 			sig_set(el);
297 			goto again;
298 		default:
299 			break;
300 		}
301 		if (!tried && read__fixio(el->el_infd, e) == 0) {
302 			errno = save_errno;
303 			tried = 1;
304 		} else {
305 			errno = e;
306 			*cp = L'\0';
307 			return -1;
308 		}
309 	}
310 
311 	/* Test for EOF */
312 	if (num_read == 0) {
313 		*cp = L'\0';
314 		return 0;
315 	}
316 
317 	for (;;) {
318 		mbstate_t mbs;
319 
320 		++cbp;
321 		/* This only works because UTF8 is stateless. */
322 		memset(&mbs, 0, sizeof(mbs));
323 		switch (mbrtowc(cp, cbuf, cbp, &mbs)) {
324 		case (size_t)-1:
325 			if (cbp > 1) {
326 				/*
327 				 * Invalid sequence, discard all bytes
328 				 * except the last one.
329 				 */
330 				cbuf[0] = cbuf[cbp - 1];
331 				cbp = 0;
332 				break;
333 			} else {
334 				/* Invalid byte, discard it. */
335 				cbp = 0;
336 				goto again;
337 			}
338 		case (size_t)-2:
339 			/*
340 			 * We don't support other multibyte charsets.
341 			 * The second condition shouldn't happen
342 			 * and is here merely for additional safety.
343 			 */
344 			if ((el->el_flags & CHARSET_IS_UTF8) == 0 ||
345 			    cbp >= MB_LEN_MAX) {
346 				errno = EILSEQ;
347 				*cp = L'\0';
348 				return -1;
349 			}
350 			/* Incomplete sequence, read another byte. */
351 			goto again;
352 		default:
353 			/* Valid character, process it. */
354 			return 1;
355 		}
356 	}
357 }
358 
359 /* read_pop():
360  *	Pop a macro from the stack
361  */
362 static void
363 read_pop(struct macros *ma)
364 {
365 	int i;
366 
367 	el_free(ma->macro[0]);
368 	for (i = 0; i < ma->level; i++)
369 		ma->macro[i] = ma->macro[i + 1];
370 	ma->level--;
371 	ma->offset = 0;
372 }
373 
374 static void
375 read_clearmacros(struct macros *ma)
376 {
377 	while (ma->level >= 0)
378 		el_free(ma->macro[ma->level--]);
379 	ma->offset = 0;
380 }
381 
382 /* el_wgetc():
383  *	Read a wide character
384  */
385 int
386 el_wgetc(EditLine *el, wchar_t *cp)
387 {
388 	struct macros *ma = &el->el_read->macros;
389 	int num_read;
390 
391 	terminal__flush(el);
392 	for (;;) {
393 		if (ma->level < 0)
394 			break;
395 
396 		if (ma->macro[0][ma->offset] == '\0') {
397 			read_pop(ma);
398 			continue;
399 		}
400 
401 		*cp = ma->macro[0][ma->offset++];
402 
403 		if (ma->macro[0][ma->offset] == '\0') {
404 			/* Needed for QuoteMode On */
405 			read_pop(ma);
406 		}
407 
408 		return 1;
409 	}
410 
411 	if (tty_rawmode(el) < 0)/* make sure the tty is set up correctly */
412 		return 0;
413 
414 	num_read = (*el->el_read->read_char)(el, cp);
415 
416 	/*
417 	 * Remember the original reason of a read failure
418 	 * such that el_wgets() can restore it after doing
419 	 * various cleanup operation that might change errno.
420 	 */
421 	if (num_read < 0)
422 		el->el_read->read_errno = errno;
423 
424 	return num_read;
425 }
426 
427 libedit_private void
428 read_prepare(EditLine *el)
429 {
430 	if (el->el_flags & HANDLE_SIGNALS)
431 		sig_set(el);
432 	if (el->el_flags & NO_TTY)
433 		return;
434 	if ((el->el_flags & (UNBUFFERED|EDIT_DISABLED)) == UNBUFFERED)
435 		tty_rawmode(el);
436 
437 	/* This is relatively cheap, and things go terribly wrong if
438 	   we have the wrong size. */
439 	el_resize(el);
440 	re_clear_display(el);	/* reset the display stuff */
441 	ch_reset(el);
442 	re_refresh(el);		/* print the prompt */
443 
444 	if (el->el_flags & UNBUFFERED)
445 		terminal__flush(el);
446 }
447 
448 libedit_private void
449 read_finish(EditLine *el)
450 {
451 	if ((el->el_flags & UNBUFFERED) == 0)
452 		(void) tty_cookedmode(el);
453 	if (el->el_flags & HANDLE_SIGNALS)
454 		sig_clr(el);
455 }
456 
457 static const wchar_t *
458 noedit_wgets(EditLine *el, int *nread)
459 {
460 	el_line_t	*lp = &el->el_line;
461 	int		 num;
462 
463 	while ((num = (*el->el_read->read_char)(el, lp->lastchar)) == 1) {
464 		if (lp->lastchar + 1 >= lp->limit &&
465 		    !ch_enlargebufs(el, (size_t)2))
466 			break;
467 		lp->lastchar++;
468 		if (el->el_flags & UNBUFFERED ||
469 		    lp->lastchar[-1] == '\r' ||
470 		    lp->lastchar[-1] == '\n')
471 			break;
472 	}
473 	if (num == -1 && errno == EINTR)
474 		lp->lastchar = lp->buffer;
475 	lp->cursor = lp->lastchar;
476 	*lp->lastchar = '\0';
477 	*nread = (int)(lp->lastchar - lp->buffer);
478 	return *nread ? lp->buffer : NULL;
479 }
480 
481 const wchar_t *
482 el_wgets(EditLine *el, int *nread)
483 {
484 	int retval;
485 	el_action_t cmdnum = 0;
486 	int num;		/* how many chars we have read at NL */
487 	wchar_t ch;
488 	int nrb;
489 
490 	if (nread == NULL)
491 		nread = &nrb;
492 	*nread = 0;
493 	el->el_read->read_errno = 0;
494 
495 	if (el->el_flags & NO_TTY) {
496 		el->el_line.lastchar = el->el_line.buffer;
497 		return noedit_wgets(el, nread);
498 	}
499 
500 #ifdef FIONREAD
501 	if (el->el_tty.t_mode == EX_IO && el->el_read->macros.level < 0) {
502 		int chrs = 0;
503 
504 		(void) ioctl(el->el_infd, FIONREAD, &chrs);
505 		if (chrs == 0) {
506 			if (tty_rawmode(el) < 0) {
507 				errno = 0;
508 				*nread = 0;
509 				return NULL;
510 			}
511 		}
512 	}
513 #endif /* FIONREAD */
514 
515 	if ((el->el_flags & UNBUFFERED) == 0)
516 		read_prepare(el);
517 
518 	if (el->el_flags & EDIT_DISABLED) {
519 		if ((el->el_flags & UNBUFFERED) == 0)
520 			el->el_line.lastchar = el->el_line.buffer;
521 		terminal__flush(el);
522 		return noedit_wgets(el, nread);
523 	}
524 
525 	for (num = -1; num == -1;) {  /* while still editing this line */
526 		/* if EOF or error */
527 		if (read_getcmd(el, &cmdnum, &ch) == -1)
528 			break;
529 		if ((size_t)cmdnum >= el->el_map.nfunc) /* BUG CHECK command */
530 			continue;	/* try again */
531 		/* now do the real command */
532 		/* vi redo needs these way down the levels... */
533 		el->el_state.thiscmd = cmdnum;
534 		el->el_state.thisch = ch;
535 		if (el->el_map.type == MAP_VI &&
536 		    el->el_map.current == el->el_map.key &&
537 		    el->el_chared.c_redo.pos < el->el_chared.c_redo.lim) {
538 			if (cmdnum == VI_DELETE_PREV_CHAR &&
539 			    el->el_chared.c_redo.pos != el->el_chared.c_redo.buf
540 			    && iswprint(el->el_chared.c_redo.pos[-1]))
541 				el->el_chared.c_redo.pos--;
542 			else
543 				*el->el_chared.c_redo.pos++ = ch;
544 		}
545 		retval = (*el->el_map.func[cmdnum]) (el, ch);
546 
547 		/* save the last command here */
548 		el->el_state.lastcmd = cmdnum;
549 
550 		/* use any return value */
551 		switch (retval) {
552 		case CC_CURSOR:
553 			re_refresh_cursor(el);
554 			break;
555 
556 		case CC_REDISPLAY:
557 			re_clear_lines(el);
558 			re_clear_display(el);
559 			/* FALLTHROUGH */
560 
561 		case CC_REFRESH:
562 			re_refresh(el);
563 			break;
564 
565 		case CC_REFRESH_BEEP:
566 			re_refresh(el);
567 			terminal_beep(el);
568 			break;
569 
570 		case CC_NORM:	/* normal char */
571 			break;
572 
573 		case CC_ARGHACK:	/* Suggested by Rich Salz */
574 			/* <rsalz@pineapple.bbn.com> */
575 			continue;	/* keep going... */
576 
577 		case CC_EOF:	/* end of file typed */
578 			if ((el->el_flags & UNBUFFERED) == 0)
579 				num = 0;
580 			else if (num == -1) {
581 				*el->el_line.lastchar++ = CONTROL('d');
582 				el->el_line.cursor = el->el_line.lastchar;
583 				num = 1;
584 			}
585 			break;
586 
587 		case CC_NEWLINE:	/* normal end of line */
588 			num = (int)(el->el_line.lastchar - el->el_line.buffer);
589 			break;
590 
591 		case CC_FATAL:	/* fatal error, reset to known state */
592 			/* put (real) cursor in a known place */
593 			re_clear_display(el);	/* reset the display stuff */
594 			ch_reset(el);	/* reset the input pointers */
595 			read_clearmacros(&el->el_read->macros);
596 			re_refresh(el); /* print the prompt again */
597 			break;
598 
599 		case CC_ERROR:
600 		default:	/* functions we don't know about */
601 			terminal_beep(el);
602 			terminal__flush(el);
603 			break;
604 		}
605 		el->el_state.argument = 1;
606 		el->el_state.doingarg = 0;
607 		el->el_chared.c_vcmd.action = NOP;
608 		if (el->el_flags & UNBUFFERED)
609 			break;
610 	}
611 
612 	terminal__flush(el);		/* flush any buffered output */
613 	/* make sure the tty is set up correctly */
614 	if ((el->el_flags & UNBUFFERED) == 0) {
615 		read_finish(el);
616 		*nread = num != -1 ? num : 0;
617 	} else
618 		*nread = (int)(el->el_line.lastchar - el->el_line.buffer);
619 
620 	if (*nread == 0) {
621 		if (num == -1) {
622 			*nread = -1;
623 			if (el->el_read->read_errno)
624 				errno = el->el_read->read_errno;
625 		}
626 		return NULL;
627 	} else
628 		return el->el_line.buffer;
629 }
630