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
38static 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
61struct macros {
62	wchar_t	**macro;
63	int	  level;
64	int	  offset;
65};
66
67struct el_read_t {
68	struct macros	 macros;
69	el_rfunc_t	 read_char;	/* Function to read a character. */
70	int		 read_errno;
71};
72
73static int	read__fixio(int, int);
74static int	read_char(EditLine *, wchar_t *);
75static int	read_getcmd(EditLine *, el_action_t *, wchar_t *);
76static void	read_clearmacros(struct macros *);
77static void	read_pop(struct macros *);
78static const wchar_t *noedit_wgets(EditLine *, int *);
79
80/* read_init():
81 *	Initialize the read stuff
82 */
83libedit_private int
84read_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;
100out:
101	read_end(el);
102	return -1;
103}
104
105/* el_read_end():
106 *	Free the data structures used by the read stuff.
107 */
108libedit_private void
109read_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 */
123libedit_private int
124el_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 */
135libedit_private el_rfunc_t
136el_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 */
147static int
148read__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 */
208void
209el_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 */
229static int
230read_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 */
279static int
280read_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 */
357static void
358read_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
369static void
370read_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 */
380int
381el_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
422libedit_private void
423read_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
443libedit_private void
444read_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
452static const wchar_t *
453noedit_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
476const wchar_t *
477el_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