xref: /freebsd/contrib/less/command.c (revision d5cb458b4b58b0f0b3c058a32439f232fd5455ca)
1 /*
2  * Copyright (C) 1984-2025  Mark Nudelman
3  *
4  * You may distribute under the terms of either the GNU General Public
5  * License or the Less License, as specified in the README file.
6  *
7  * For more information, see the README file.
8  */
9 
10 
11 /*
12  * User-level command processor.
13  */
14 
15 #include "less.h"
16 #if MSDOS_COMPILER==WIN32C
17 #include <windows.h>
18 #endif
19 #include "position.h"
20 #include "option.h"
21 #include "cmd.h"
22 
23 extern int erase_char, erase2_char, kill_char;
24 extern int sigs;
25 extern int quit_if_one_screen;
26 extern int one_screen;
27 extern int sc_width;
28 extern int sc_height;
29 extern char *kent;
30 extern int swindow;
31 extern int jump_sline;
32 extern lbool quitting;
33 extern int wscroll;
34 extern int top_scroll;
35 extern int ignore_eoi;
36 extern int hshift;
37 extern int bs_mode;
38 extern int proc_backspace;
39 extern int show_attn;
40 extern int less_is_more;
41 extern int chopline;
42 extern POSITION highest_hilite;
43 extern char *every_first_cmd;
44 extern char version[];
45 extern struct scrpos initial_scrpos;
46 extern IFILE curr_ifile;
47 extern void *ml_search;
48 extern void *ml_examine;
49 extern int wheel_lines;
50 extern int def_search_type;
51 extern lbool search_wrapped;
52 extern lbool no_poll;
53 extern int no_paste;
54 extern lbool pasting;
55 extern int no_edit_warn;
56 extern POSITION soft_eof;
57 extern POSITION search_incr_start;
58 extern char *first_cmd_at_prompt;
59 #if SHELL_ESCAPE || PIPEC
60 extern void *ml_shell;
61 #endif
62 #if EDITOR
63 extern constant char *editproto;
64 #endif
65 #if OSC8_LINK
66 extern char *osc8_uri;
67 #endif
68 extern int shift_count;
69 extern int forw_prompt;
70 extern int incr_search;
71 extern int full_screen;
72 #if MSDOS_COMPILER==WIN32C
73 extern int utf_mode;
74 extern unsigned less_acp;
75 #endif
76 
77 #if SHELL_ESCAPE
78 static char *shellcmd = NULL;   /* For holding last shell command for "!!" */
79 #endif
80 static int mca;                 /* The multicharacter command (action) */
81 static int search_type;         /* The previous type of search */
82 static int last_search_type;    /* Type of last executed search */
83 static LINENUM number;          /* The number typed by the user */
84 static long fraction;           /* The fractional part of the number */
85 static struct loption *curropt;
86 static lbool opt_lower;
87 static int optflag;
88 static lbool optgetname;
89 static POSITION bottompos;
90 static int save_hshift;
91 static int save_bs_mode;
92 static int save_proc_backspace;
93 static int screen_trashed_value = 0;
94 static lbool literal_char = FALSE;
95 static lbool ignoring_input = FALSE;
96 static struct scrpos search_incr_pos = { NULL_POSITION, 0 };
97 static int search_incr_hshift;
98 #if HAVE_TIME
99 static time_type ignoring_input_time;
100 #endif
101 #if PIPEC
102 static char pipec;
103 #endif
104 
105 /* Stack of ungotten chars (via ungetcc) */
106 struct ungot {
107 	struct ungot *ug_next;
108 	char ug_char;
109 	lbool ug_end_command;
110 };
111 static struct ungot* ungot = NULL;
112 
113 static void multi_search(constant char *pattern, int n, int silent);
114 
115 /*
116  * Move the cursor to start of prompt line before executing a command.
117  * This looks nicer if the command takes a long time before
118  * updating the screen.
119  */
cmd_exec(void)120 public void cmd_exec(void)
121 {
122 	clear_attn();
123 	clear_bot();
124 	flush();
125 }
126 
127 /*
128  * Indicate we are reading a multi-character command.
129  */
set_mca(int action)130 static void set_mca(int action)
131 {
132 	mca = action;
133 	clear_bot();
134 	clear_cmd();
135 }
136 
137 /*
138  * Indicate we are not reading a multi-character command.
139  */
clear_mca(void)140 static void clear_mca(void)
141 {
142 	if (mca == 0)
143 		return;
144 	mca = 0;
145 }
146 
147 /*
148  * Set up the display to start a new multi-character command.
149  */
start_mca(int action,constant char * prompt,void * mlist,int cmdflags)150 static void start_mca(int action, constant char *prompt, void *mlist, int cmdflags)
151 {
152 	set_mca(action);
153 	cmd_putstr(prompt);
154 	set_mlist(mlist, cmdflags);
155 }
156 
in_mca(void)157 public int in_mca(void)
158 {
159 	return (mca != 0 && mca != A_PREFIX);
160 }
161 
162 /*
163  * Set up the display to start a new search command.
164  */
mca_search1(void)165 static void mca_search1(void)
166 {
167 	int i;
168 
169 #if HILITE_SEARCH
170 	if (search_type & SRCH_FILTER)
171 		set_mca(A_FILTER);
172 	else
173 #endif
174 	if (search_type & SRCH_FORW)
175 		set_mca(A_F_SEARCH);
176 	else
177 		set_mca(A_B_SEARCH);
178 
179 	if (search_type & SRCH_NO_MATCH)
180 		cmd_putstr("Non-match ");
181 	if (search_type & SRCH_FIRST_FILE)
182 		cmd_putstr("First-file ");
183 	if (search_type & SRCH_PAST_EOF)
184 		cmd_putstr("EOF-ignore ");
185 	if (search_type & SRCH_NO_MOVE)
186 		cmd_putstr("Keep-pos ");
187 	if (search_type & SRCH_NO_REGEX)
188 		cmd_putstr("Regex-off ");
189 	if (search_type & SRCH_WRAP)
190 		cmd_putstr("Wrap ");
191 	for (i = 1; i <= NUM_SEARCH_COLORS; i++)
192 	{
193 		if (search_type & SRCH_SUBSEARCH(i))
194 		{
195 			char buf[INT_STRLEN_BOUND(int)+8];
196 			SNPRINTF1(buf, sizeof(buf), "Sub-%d ", i);
197 			cmd_putstr(buf);
198 		}
199 	}
200 	if (literal_char)
201 		cmd_putstr("Lit ");
202 
203 #if HILITE_SEARCH
204 	if (search_type & SRCH_FILTER)
205 		cmd_putstr("&/");
206 	else
207 #endif
208 	if (search_type & SRCH_FORW)
209 		cmd_putstr("/");
210 	else
211 		cmd_putstr("?");
212 	forw_prompt = 0;
213 }
214 
mca_search(void)215 static void mca_search(void)
216 {
217 	if (incr_search)
218 	{
219 		/* Remember where the incremental search started. */
220 		get_scrpos(&search_incr_pos, TOP);
221 		search_incr_start = search_pos(search_type);
222 		search_incr_hshift = hshift;
223 	}
224 	mca_search1();
225 	set_mlist(ml_search, 0);
226 }
227 
228 /*
229  * Set up the display to start a new toggle-option command.
230  */
mca_opt_toggle(void)231 static void mca_opt_toggle(void)
232 {
233 	int no_prompt = (optflag & OPT_NO_PROMPT);
234 	int flag = (optflag & ~OPT_NO_PROMPT);
235 	constant char *dash = (flag == OPT_NO_TOGGLE) ? "_" : "-";
236 
237 	set_mca(A_OPT_TOGGLE);
238 	cmd_putstr(dash);
239 	if (optgetname)
240 		cmd_putstr(dash);
241 	if (no_prompt)
242 		cmd_putstr("(P)");
243 	switch (flag)
244 	{
245 	case OPT_UNSET:
246 		cmd_putstr("+");
247 		break;
248 	case OPT_SET:
249 		cmd_putstr("!");
250 		break;
251 	}
252 	forw_prompt = 0;
253 	set_mlist(NULL, CF_OPTION);
254 }
255 
256 /*
257  * Execute a multicharacter command.
258  */
exec_mca(void)259 static void exec_mca(void)
260 {
261 	constant char *cbuf;
262 
263 	cmd_exec();
264 	cbuf = get_cmdbuf();
265 	if (cbuf == NULL)
266 		return;
267 
268 	switch (mca)
269 	{
270 	case A_F_SEARCH:
271 	case A_B_SEARCH:
272 		multi_search(cbuf, (int) number, 0);
273 		break;
274 #if HILITE_SEARCH
275 	case A_FILTER:
276 		search_type ^= SRCH_NO_MATCH;
277 		set_filter_pattern(cbuf, search_type);
278 		soft_eof = NULL_POSITION;
279 		break;
280 #endif
281 	case A_FIRSTCMD:
282 		/*
283 		 * Skip leading spaces or + signs in the string.
284 		 */
285 		while (*cbuf == '+' || *cbuf == ' ')
286 			cbuf++;
287 		if (every_first_cmd != NULL)
288 			free(every_first_cmd);
289 		if (*cbuf == '\0')
290 			every_first_cmd = NULL;
291 		else
292 			every_first_cmd = save(cbuf);
293 		break;
294 	case A_OPT_TOGGLE:
295 		toggle_option(curropt, opt_lower, cbuf, optflag);
296 		curropt = NULL;
297 		break;
298 	case A_F_BRACKET:
299 		match_brac(cbuf[0], cbuf[1], 1, (int) number);
300 		break;
301 	case A_B_BRACKET:
302 		match_brac(cbuf[1], cbuf[0], 0, (int) number);
303 		break;
304 #if EXAMINE
305 	case A_EXAMINE: {
306 		char *p;
307 		if (!secure_allow(SF_EXAMINE))
308 			break;
309 		p = save(cbuf);
310 		edit_list(p);
311 		free(p);
312 #if TAGS
313 		/* If tag structure is loaded then clean it up. */
314 		cleantags();
315 #endif
316 		break; }
317 #endif
318 #if SHELL_ESCAPE
319 	case A_SHELL: {
320 		/*
321 		 * !! just uses whatever is in shellcmd.
322 		 * Otherwise, copy cmdbuf to shellcmd,
323 		 * expanding any special characters ("%" or "#").
324 		 */
325 		constant char *done_msg = (*cbuf == CONTROL('P')) ? NULL : "!done";
326 		if (done_msg == NULL)
327 			++cbuf;
328 		if (*cbuf != '!')
329 		{
330 			if (shellcmd != NULL)
331 				free(shellcmd);
332 			shellcmd = fexpand(cbuf);
333 		}
334 		if (!secure_allow(SF_SHELL))
335 			break;
336 		if (shellcmd == NULL)
337 			shellcmd = "";
338 		lsystem(shellcmd, done_msg);
339 		break; }
340 	case A_PSHELL: {
341 		constant char *done_msg = (*cbuf == CONTROL('P')) ? NULL : "#done";
342 		if (done_msg == NULL)
343 			++cbuf;
344 		if (!secure_allow(SF_SHELL))
345 			break;
346 		lsystem(pr_expand(cbuf), done_msg);
347 		break; }
348 #endif
349 #if PIPEC
350 	case A_PIPE: {
351 		constant char *done_msg = (*cbuf == CONTROL('P')) ? NULL : "|done";
352 		if (done_msg == NULL)
353 			++cbuf;
354 		if (!secure_allow(SF_PIPE))
355 			break;
356 		(void) pipe_mark(pipec, cbuf);
357 		if (done_msg != NULL)
358 			error(done_msg, NULL_PARG);
359 		break; }
360 #endif
361 	}
362 }
363 
364 /*
365  * Is a character an erase or kill char?
366  */
is_erase_char(char c)367 static lbool is_erase_char(char c)
368 {
369 	return (c == erase_char || c == erase2_char || c == kill_char);
370 }
371 
372 /*
373  * Is a character a carriage return or newline?
374  */
is_newline_char(char c)375 static lbool is_newline_char(char c)
376 {
377 	return (c == '\n' || c == '\r');
378 }
379 
380 /*
381  * Handle the first char of an option (after the initial dash).
382  */
mca_opt_first_char(char c)383 static int mca_opt_first_char(char c)
384 {
385 	int no_prompt = (optflag & OPT_NO_PROMPT);
386 	int flag = (optflag & ~OPT_NO_PROMPT);
387 	if (flag == OPT_NO_TOGGLE)
388 	{
389 		switch (c)
390 		{
391 		case '_':
392 			/* "__" = long option name. */
393 			optgetname = TRUE;
394 			mca_opt_toggle();
395 			return (MCA_MORE);
396 		}
397 	} else
398 	{
399 		switch (c)
400 		{
401 		case '+':
402 			/* "-+" = UNSET. */
403 			optflag = no_prompt | ((flag == OPT_UNSET) ?
404 				OPT_TOGGLE : OPT_UNSET);
405 			mca_opt_toggle();
406 			return (MCA_MORE);
407 		case '!':
408 			/* "-!" = SET */
409 			optflag = no_prompt | ((flag == OPT_SET) ?
410 				OPT_TOGGLE : OPT_SET);
411 			mca_opt_toggle();
412 			return (MCA_MORE);
413 		case CONTROL('P'):
414 			optflag ^= OPT_NO_PROMPT;
415 			mca_opt_toggle();
416 			return (MCA_MORE);
417 		case '-':
418 			/* "--" = long option name. */
419 			optgetname = TRUE;
420 			mca_opt_toggle();
421 			return (MCA_MORE);
422 		}
423 	}
424 	/* Char was not handled here. */
425 	return (NO_MCA);
426 }
427 
428 /*
429  * Add a char to a long option name.
430  * See if we've got a match for an option name yet.
431  * If so, display the complete name and stop
432  * accepting chars until user hits RETURN.
433  */
mca_opt_nonfirst_char(char c)434 static int mca_opt_nonfirst_char(char c)
435 {
436 	constant char *p;
437 	constant char *oname;
438 	lbool ambig;
439 	struct loption *was_curropt;
440 
441 	if (curropt != NULL)
442 	{
443 		/* Already have a match for the name. */
444 		if (is_erase_char(c))
445 			return (MCA_DONE);
446 		/* {{ Checking for TAB here is ugly.
447 		 *    Also doesn't extend well -- can't do BACKTAB this way
448 		 *    because it's a multichar sequence. }} */
449 		if (c != '\t')
450 			return (MCA_MORE);
451 	}
452 	/*
453 	 * Add char to cmd buffer and try to match
454 	 * the option name.
455 	 */
456 	if (cmd_char(c) == CC_QUIT)
457 		return (MCA_DONE);
458 	p = get_cmdbuf();
459 	if (p == NULL || p[0] == '\0')
460 		return (MCA_MORE);
461 	opt_lower = ASCII_IS_LOWER(p[0]);
462 	was_curropt = curropt;
463 	curropt = findopt_name(&p, &oname, &ambig);
464 	if (curropt != NULL)
465 	{
466 		if (was_curropt == NULL)
467 		{
468 			/*
469 			 * Got a match.
470 			 * Remember the option and
471 			 * display the full option name.
472 			 */
473 			cmd_reset();
474 			mca_opt_toggle();
475 			cmd_setstring(oname, !opt_lower);
476 		}
477 	} else if (!ambig)
478 	{
479 		bell();
480 	}
481 	return (MCA_MORE);
482 }
483 
484 /*
485  * Handle a char of an option toggle command.
486  */
mca_opt_char(char c)487 static int mca_opt_char(char c)
488 {
489 	PARG parg;
490 
491 	/*
492 	 * This may be a short option (single char),
493 	 * or one char of a long option name,
494 	 * or one char of the option parameter.
495 	 */
496 	if (curropt == NULL && cmdbuf_empty())
497 	{
498 		int ret = mca_opt_first_char(c);
499 		if (ret != NO_MCA)
500 			return (ret);
501 	}
502 	if (optgetname)
503 	{
504 		/* We're getting a long option name.  */
505 		if (!is_newline_char(c) && c != '=')
506 			return (mca_opt_nonfirst_char(c));
507 		if (curropt == NULL)
508 		{
509 			parg.p_string = get_cmdbuf();
510 			if (parg.p_string == NULL)
511 				return (MCA_MORE);
512 			error("There is no --%s option", &parg);
513 			return (MCA_DONE);
514 		}
515 		optgetname = FALSE;
516 		cmd_reset();
517 	} else
518 	{
519 		if (is_erase_char(c))
520 			return (NO_MCA);
521 		if (curropt != NULL)
522 			/* We're getting the option parameter. */
523 			return (NO_MCA);
524 		curropt = findopt(c);
525 		if (curropt == NULL)
526 		{
527 			parg.p_string = propt(c);
528 			error("There is no %s option", &parg);
529 			return (MCA_DONE);
530 		}
531 		opt_lower = ASCII_IS_LOWER(c);
532 	}
533 	/*
534 	 * If the option which was entered does not take a
535 	 * parameter, toggle the option immediately,
536 	 * so user doesn't have to hit RETURN.
537 	 */
538 	if ((optflag & ~OPT_NO_PROMPT) != OPT_TOGGLE ||
539 	    !opt_has_param(curropt))
540 	{
541 		toggle_option(curropt, opt_lower, "", optflag);
542 		return (MCA_DONE);
543 	}
544 	/*
545 	 * Display a prompt appropriate for the option parameter.
546 	 */
547 	start_mca(A_OPT_TOGGLE, opt_prompt(curropt), NULL, CF_OPTION);
548 	return (MCA_MORE);
549 }
550 
551 /*
552  * Normalize search type.
553  */
norm_search_type(int st)554 public int norm_search_type(int st)
555 {
556 	/* WRAP and PAST_EOF are mutually exclusive. */
557 	if ((st & (SRCH_PAST_EOF|SRCH_WRAP)) == (SRCH_PAST_EOF|SRCH_WRAP))
558 		st ^= SRCH_PAST_EOF;
559 	return st;
560 }
561 
562 /*
563  * Handle a char of a search command.
564  */
mca_search_char(char c)565 static int mca_search_char(char c)
566 {
567 	int flag = 0;
568 
569 	/*
570 	 * Certain characters as the first char of
571 	 * the pattern have special meaning:
572 	 *      !  Toggle the NO_MATCH flag
573 	 *      *  Toggle the PAST_EOF flag
574 	 *      @  Toggle the FIRST_FILE flag
575 	 */
576 	if (!cmdbuf_empty() || literal_char)
577 	{
578 		literal_char = FALSE;
579 		return (NO_MCA);
580 	}
581 
582 	switch (c)
583 	{
584 	case '*':
585 		if (less_is_more)
586 			break;
587 	case CONTROL('E'): /* ignore END of file */
588 		if (mca != A_FILTER)
589 			flag = SRCH_PAST_EOF;
590 		search_type &= ~SRCH_WRAP;
591 		break;
592 	case '@':
593 		if (less_is_more)
594 			break;
595 	case CONTROL('F'): /* FIRST file */
596 		if (mca != A_FILTER)
597 			flag = SRCH_FIRST_FILE;
598 		break;
599 	case CONTROL('K'): /* KEEP position */
600 		if (mca != A_FILTER)
601 			flag = SRCH_NO_MOVE;
602 		break;
603 	case CONTROL('S'): { /* SUBSEARCH */
604 		char buf[INT_STRLEN_BOUND(int)+24];
605 		SNPRINTF1(buf, sizeof(buf), "Sub-pattern (1-%d):", NUM_SEARCH_COLORS);
606 		clear_bot();
607 		cmd_putstr(buf);
608 		flush();
609 		c = getcc();
610 		if (c >= '1' && c <= '0'+NUM_SEARCH_COLORS)
611 			flag = SRCH_SUBSEARCH(c-'0');
612 		else
613 			flag = -1; /* calls mca_search() below to repaint */
614 		break; }
615 	case CONTROL('W'): /* WRAP around */
616 		if (mca != A_FILTER)
617 			flag = SRCH_WRAP;
618 		break;
619 	case CONTROL('R'): /* Don't use REGULAR EXPRESSIONS */
620 		flag = SRCH_NO_REGEX;
621 		break;
622 	case CONTROL('N'): /* NOT match */
623 	case '!':
624 		flag = SRCH_NO_MATCH;
625 		break;
626 	case CONTROL('L'):
627 		literal_char = TRUE;
628 		flag = -1;
629 		break;
630 	}
631 
632 	if (flag != 0)
633 	{
634 		if (flag != -1)
635 			search_type = norm_search_type(search_type ^ flag);
636 		mca_search();
637 		return (MCA_MORE);
638 	}
639 	return (NO_MCA);
640 }
641 
642 /*
643  * Handle a character of a multi-character command.
644  */
mca_char(char c)645 static int mca_char(char c)
646 {
647 	int ret;
648 
649 	switch (mca)
650 	{
651 	case 0:
652 		/*
653 		 * We're not in a multicharacter command.
654 		 */
655 		return (NO_MCA);
656 
657 	case A_PREFIX:
658 		/*
659 		 * In the prefix of a command.
660 		 * This not considered a multichar command
661 		 * (even tho it uses cmdbuf, etc.).
662 		 * It is handled in the commands() switch.
663 		 */
664 		return (NO_MCA);
665 
666 	case A_DIGIT:
667 		/*
668 		 * Entering digits of a number.
669 		 * Terminated by a non-digit.
670 		 */
671 		if ((c >= '0' && c <= '9') || c == '.')
672 			break;
673 		switch (editchar(c, ECF_PEEK|ECF_NOHISTORY|ECF_NOCOMPLETE|ECF_NORIGHTLEFT))
674 		{
675 		case A_NOACTION:
676 			/*
677 			 * Ignore this char and get another one.
678 			 */
679 			return (MCA_MORE);
680 		case A_INVALID:
681 			/*
682 			 * Not part of the number.
683 			 * End the number and treat this char
684 			 * as a normal command character.
685 			 */
686 			number = cmd_int(&fraction);
687 			clear_mca();
688 			cmd_accept();
689 			return (NO_MCA);
690 		}
691 		break;
692 
693 	case A_OPT_TOGGLE:
694 		ret = mca_opt_char(c);
695 		if (ret != NO_MCA)
696 			return (ret);
697 		break;
698 
699 	case A_F_SEARCH:
700 	case A_B_SEARCH:
701 	case A_FILTER:
702 		ret = mca_search_char(c);
703 		if (ret != NO_MCA)
704 			return (ret);
705 		break;
706 
707 	default:
708 		/* Other multicharacter command. */
709 		break;
710 	}
711 
712 	/*
713 	 * The multichar command is terminated by a newline.
714 	 */
715 	if (is_newline_char(c))
716 	{
717 		if (pasting && no_paste)
718 		{
719 			/* Ignore pasted input after (and including) the first newline */
720 			start_ignoring_input();
721 			return (MCA_MORE);
722 		}
723 		/* Execute the command. */
724 		exec_mca();
725 		return (MCA_DONE);
726 	}
727 
728 	/*
729 	 * Append the char to the command buffer.
730 	 */
731 	if (cmd_char(c) == CC_QUIT)
732 		/*
733 		 * Abort the multi-char command.
734 		 */
735 		return (MCA_DONE);
736 
737 	switch (mca)
738 	{
739 	case A_F_BRACKET:
740 	case A_B_BRACKET:
741 		if (len_cmdbuf() >= 2)
742 		{
743 			/*
744 			 * Special case for the bracket-matching commands.
745 			 * Execute the command after getting exactly two
746 			 * characters from the user.
747 			 */
748 			exec_mca();
749 			return (MCA_DONE);
750 		}
751 		break;
752 	case A_F_SEARCH:
753 	case A_B_SEARCH:
754 		if (incr_search)
755 		{
756 			/* Incremental search: do a search after every input char. */
757 			int st = (search_type & (SRCH_FORW|SRCH_BACK|SRCH_NO_MATCH|SRCH_NO_REGEX|SRCH_NO_MOVE|SRCH_WRAP|SRCH_SUBSEARCH_ALL));
758 			ssize_t save_updown;
759 			constant char *pattern = get_cmdbuf();
760 			if (pattern == NULL)
761 				return (MCA_MORE);
762 			/* Defer searching if more chars of the pattern are available. */
763 			if (ttyin_ready())
764 				return (MCA_MORE);
765 			/*
766 			 * Must save updown_match because mca_search
767 			 * reinits it. That breaks history scrolling.
768 			 * {{ This is ugly. mca_search probably shouldn't call set_mlist. }}
769 			 */
770 			save_updown = save_updown_match();
771 			cmd_exec();
772 			if (*pattern == '\0')
773 			{
774 				/* User has backspaced to an empty pattern. */
775 				undo_search(1);
776 				hshift = search_incr_hshift;
777 				jump_loc(search_incr_pos.pos, search_incr_pos.ln);
778 			} else
779 			{
780 				/*
781 				 * Suppress tty polling while searching.
782 				 * This avoids a problem where tty input
783 				 * can cause the search to be interrupted.
784 				 */
785 				no_poll = TRUE;
786 				if (search(st | SRCH_INCR, pattern, 1) != 0)
787 				{
788 					/* No match, invalid pattern, etc. */
789 					undo_search(1);
790 					hshift = search_incr_hshift;
791 					jump_loc(search_incr_pos.pos, search_incr_pos.ln);
792 				}
793 				no_poll = FALSE;
794 			}
795 			/* Redraw the search prompt and search string. */
796 			if (is_screen_trashed() || !full_screen)
797 			{
798 				clear();
799 				repaint();
800 			}
801 			mca_search1();
802 			restore_updown_match(save_updown);
803 			cmd_repaint(NULL);
804 		}
805 		break;
806 	}
807 
808 	/*
809 	 * Need another character.
810 	 */
811 	return (MCA_MORE);
812 }
813 
814 /*
815  * Discard any buffered file data.
816  */
clear_buffers(void)817 static void clear_buffers(void)
818 {
819 	if (!(ch_getflags() & CH_CANSEEK))
820 		return;
821 	ch_flush();
822 	clr_linenum();
823 #if HILITE_SEARCH
824 	clr_hilite();
825 #endif
826 	set_line_contig_pos(NULL_POSITION);
827 }
828 
screen_trashed_num(int trashed)829 public void screen_trashed_num(int trashed)
830 {
831 	screen_trashed_value = trashed;
832 }
833 
screen_trashed(void)834 public void screen_trashed(void)
835 {
836 	screen_trashed_num(1);
837 }
838 
is_screen_trashed(void)839 public int is_screen_trashed(void)
840 {
841 	return screen_trashed_value;
842 }
843 
844 /*
845  * Make sure the screen is displayed.
846  */
make_display(void)847 static void make_display(void)
848 {
849 	/*
850 	 * If not full_screen, we can't rely on scrolling to fill the screen.
851 	 * We need to clear and repaint screen before any change.
852 	 */
853 	if (!full_screen && !(quit_if_one_screen && one_screen))
854 		clear();
855 	/*
856 	 * If nothing is displayed yet, display starting from initial_scrpos.
857 	 */
858 	if (empty_screen())
859 	{
860 		if (initial_scrpos.pos == NULL_POSITION)
861 			jump_loc(ch_zero(), 1);
862 		else
863 			jump_loc(initial_scrpos.pos, initial_scrpos.ln);
864 	} else if (is_screen_trashed() || !full_screen)
865 	{
866 		int save_top_scroll = top_scroll;
867 		int save_ignore_eoi = ignore_eoi;
868 		top_scroll = 1;
869 		ignore_eoi = 0;
870 		if (is_screen_trashed() == 2)
871 		{
872 			/* Special case used by ignore_eoi: re-open the input file
873 			 * and jump to the end of the file. */
874 			reopen_curr_ifile();
875 			jump_forw();
876 		}
877 		repaint();
878 		top_scroll = save_top_scroll;
879 		ignore_eoi = save_ignore_eoi;
880 	}
881 }
882 
883 /*
884  * Display the appropriate prompt.
885  */
prompt(void)886 static void prompt(void)
887 {
888 	constant char *p;
889 
890 	if (ungot != NULL && !ungot->ug_end_command)
891 	{
892 		/*
893 		 * No prompt necessary if commands are from
894 		 * ungotten chars rather than from the user.
895 		 */
896 		return;
897 	}
898 
899 	/*
900 	 * Make sure the screen is displayed.
901 	 */
902 	make_display();
903 	bottompos = position(BOTTOM_PLUS_ONE);
904 
905 	/*
906 	 * If we've hit EOF on the last file and the -E flag is set, quit.
907 	 */
908 	if (get_quit_at_eof() == OPT_ONPLUS &&
909 	    eof_displayed(FALSE) && !(ch_getflags() & CH_HELPFILE) &&
910 	    next_ifile(curr_ifile) == NULL_IFILE)
911 		quit(QUIT_OK);
912 
913 	/*
914 	 * If the entire file is displayed and the -F flag is set, quit.
915 	 */
916 	if (quit_if_one_screen &&
917 	    entire_file_displayed() && !(ch_getflags() & CH_HELPFILE) &&
918 	    next_ifile(curr_ifile) == NULL_IFILE)
919 		quit(QUIT_OK);
920 	quit_if_one_screen = FALSE; /* only get one chance at this */
921 	if (first_cmd_at_prompt != NULL)
922 	{
923 		ungetsc(first_cmd_at_prompt);
924 		first_cmd_at_prompt = NULL;
925 		return;
926 	}
927 
928 #if MSDOS_COMPILER==WIN32C
929 	/*
930 	 * In Win32, display the file name in the window title.
931 	 */
932 	if (!(ch_getflags() & CH_HELPFILE))
933 	{
934 		WCHAR w[MAX_PATH+16];
935 		p = pr_expand("Less?f - %f.");
936 		MultiByteToWideChar(less_acp, 0, p, -1, w, countof(w));
937 		SetConsoleTitleW(w);
938 	}
939 #endif
940 
941 	/*
942 	 * Select the proper prompt and display it.
943 	 */
944 	/*
945 	 * If the previous action was a forward movement,
946 	 * don't clear the bottom line of the display;
947 	 * just print the prompt since the forward movement guarantees
948 	 * that we're in the right position to display the prompt.
949 	 * Clearing the line could cause a problem: for example, if the last
950 	 * line displayed ended at the right screen edge without a newline,
951 	 * then clearing would clear the last displayed line rather than
952 	 * the prompt line.
953 	 */
954 	if (!forw_prompt)
955 		clear_bot();
956 	clear_cmd();
957 	forw_prompt = 0;
958 	p = pr_string();
959 #if HILITE_SEARCH
960 	if (is_filtering())
961 		putstr("& ");
962 #endif
963 	if (search_wrapped)
964 	{
965 		if (search_type & SRCH_BACK)
966 			error("Search hit top; continuing at bottom", NULL_PARG);
967 		else
968 			error("Search hit bottom; continuing at top", NULL_PARG);
969 		search_wrapped = FALSE;
970 	}
971 #if OSC8_LINK
972 	if (osc8_uri != NULL)
973 	{
974 		PARG parg;
975 		parg.p_string = osc8_uri;
976 		error("Link: %s", &parg);
977 		free(osc8_uri);
978 		osc8_uri = NULL;
979 	}
980 #endif
981 	if (p == NULL || *p == '\0')
982 	{
983 		at_enter(AT_NORMAL|AT_COLOR_PROMPT);
984 		putchr(':');
985 		at_exit();
986 	} else
987 	{
988 #if MSDOS_COMPILER==WIN32C
989 		WCHAR w[MAX_PATH*2];
990 		char  a[MAX_PATH*2];
991 		MultiByteToWideChar(less_acp, 0, p, -1, w, countof(w));
992 		WideCharToMultiByte(utf_mode ? CP_UTF8 : GetConsoleOutputCP(),
993 		                    0, w, -1, a, sizeof(a), NULL, NULL);
994 		p = a;
995 #endif
996 		load_line(p);
997 		put_line(FALSE);
998 	}
999 	clear_eol();
1000 	resume_screen();
1001 }
1002 
1003 /*
1004  * Display the less version message.
1005  */
dispversion(void)1006 public void dispversion(void)
1007 {
1008 	PARG parg;
1009 
1010 	parg.p_string = version;
1011 	error("less %s", &parg);
1012 }
1013 
1014 /*
1015  * Return a character to complete a partial command, if possible.
1016  */
getcc_end_command(void)1017 static char getcc_end_command(void)
1018 {
1019 	int ch;
1020 	switch (mca)
1021 	{
1022 	case A_DIGIT:
1023 		/* We have a number but no command.  Treat as #g. */
1024 		return ('g');
1025 	case A_F_SEARCH:
1026 	case A_B_SEARCH:
1027 	case A_FILTER:
1028 		/* We have "/string" but no newline.  Add the \n. */
1029 		return ('\n');
1030 	default:
1031 		/* Some other incomplete command.  Let user complete it. */
1032 		if (ungot != NULL)
1033 			return ('\0');
1034 		ch = getchr();
1035 		if (ch < 0) ch = '\0';
1036 		return (char) ch;
1037 	}
1038 }
1039 
1040 /*
1041  * Get a command character from the ungotten stack.
1042  */
get_ungot(lbool * p_end_command)1043 static char get_ungot(lbool *p_end_command)
1044 {
1045 	struct ungot *ug = ungot;
1046 	char c = ug->ug_char;
1047 	if (p_end_command != NULL)
1048 		*p_end_command = ug->ug_end_command;
1049 	ungot = ug->ug_next;
1050 	free(ug);
1051 	return c;
1052 }
1053 
1054 /*
1055  * Delete all ungotten characters.
1056  */
getcc_clear(void)1057 public void getcc_clear(void)
1058 {
1059 	while (ungot != NULL)
1060 		(void) get_ungot(NULL);
1061 }
1062 
1063 /*
1064  * Get command character.
1065  * The character normally comes from the keyboard,
1066  * but may come from ungotten characters
1067  * (characters previously given to ungetcc or ungetsc).
1068  */
getccu(void)1069 static char getccu(void)
1070 {
1071 	int c = 0;
1072 	while (c == 0 && sigs == 0)
1073 	{
1074 		if (ungot == NULL)
1075 		{
1076 			/* Normal case: no ungotten chars.
1077 			 * Get char from the user. */
1078 			c = getchr();
1079 			if (c < 0) c = '\0';
1080 		} else
1081 		{
1082 			/* Ungotten chars available:
1083 			 * Take the top of stack (most recent). */
1084 			lbool end_command;
1085 			c = get_ungot(&end_command);
1086 			if (end_command)
1087 				c = getcc_end_command();
1088 		}
1089 	}
1090 	return ((char) c);
1091 }
1092 
1093 /*
1094  * Get a command character, but if we receive the orig sequence,
1095  * convert it to the repl sequence.
1096  */
getcc_repl(char constant * orig,char constant * repl,char (* gr_getc)(void),void (* gr_ungetc)(char))1097 static char getcc_repl(char constant *orig, char constant *repl, char (*gr_getc)(void), void (*gr_ungetc)(char))
1098 {
1099 	char c;
1100 	char keys[16];
1101 	size_t ki = 0;
1102 
1103 	c = (*gr_getc)();
1104 	if (orig == NULL || orig[0] == '\0')
1105 		return c;
1106 	for (;;)
1107 	{
1108 		keys[ki] = c;
1109 		if (c != orig[ki] || ki >= sizeof(keys)-1)
1110 		{
1111 			/* This is not orig we have been receiving.
1112 			 * If we have stashed chars in keys[],
1113 			 * unget them and return the first one. */
1114 			while (ki > 0)
1115 				(*gr_ungetc)(keys[ki--]);
1116 			return keys[0];
1117 		}
1118 		if (orig[++ki] == '\0')
1119 		{
1120 			/* We've received the full orig sequence.
1121 			 * Return the repl sequence. */
1122 			ki = strlen(repl)-1;
1123 			while (ki > 0)
1124 				(*gr_ungetc)(repl[ki--]);
1125 			return repl[0];
1126 		}
1127 		/* We've received a partial orig sequence (ki chars of it).
1128 		 * Get next char and see if it continues to match orig. */
1129 		c = (*gr_getc)();
1130 	}
1131 }
1132 
1133 /*
1134  * Get command character.
1135  */
getcc(void)1136 public char getcc(void)
1137 {
1138 	/* Replace kent (keypad Enter) with a newline. */
1139 	return getcc_repl(kent, "\n", getccu, ungetcc);
1140 }
1141 
1142 /*
1143  * "Unget" a command character.
1144  * The next getcc() will return this character.
1145  */
ungetcc(char c)1146 public void ungetcc(char c)
1147 {
1148 	struct ungot *ug = (struct ungot *) ecalloc(1, sizeof(struct ungot));
1149 
1150 	ug->ug_char = c;
1151 	ug->ug_next = ungot;
1152 	ungot = ug;
1153 }
1154 
1155 /*
1156  * "Unget" a command character.
1157  * If any other chars are already ungotten, put this one after those.
1158  */
ungetcc_back1(char c,lbool end_command)1159 static void ungetcc_back1(char c, lbool end_command)
1160 {
1161 	struct ungot *ug = (struct ungot *) ecalloc(1, sizeof(struct ungot));
1162 	ug->ug_char = c;
1163 	ug->ug_end_command = end_command;
1164 	ug->ug_next = NULL;
1165 	if (ungot == NULL)
1166 		ungot = ug;
1167 	else
1168 	{
1169 		struct ungot *pu;
1170 		for (pu = ungot; pu->ug_next != NULL; pu = pu->ug_next)
1171 			continue;
1172 		pu->ug_next = ug;
1173 	}
1174 }
1175 
ungetcc_back(char c)1176 public void ungetcc_back(char c)
1177 {
1178 	ungetcc_back1(c, FALSE);
1179 }
1180 
ungetcc_end_command(void)1181 public void ungetcc_end_command(void)
1182 {
1183 	ungetcc_back1('\0', TRUE);
1184 }
1185 
1186 /*
1187  * Unget a whole string of command characters.
1188  * The next sequence of getcc()'s will return this string.
1189  */
ungetsc(constant char * s)1190 public void ungetsc(constant char *s)
1191 {
1192 	while (*s != '\0')
1193 		ungetcc_back(*s++);
1194 }
1195 
1196 /*
1197  * Peek the next command character, without consuming it.
1198  */
peekcc(void)1199 public char peekcc(void)
1200 {
1201 	char c = getcc();
1202 	ungetcc(c);
1203 	return c;
1204 }
1205 
1206 /*
1207  * Search for a pattern, possibly in multiple files.
1208  * If SRCH_FIRST_FILE is set, begin searching at the first file.
1209  * If SRCH_PAST_EOF is set, continue the search thru multiple files.
1210  */
multi_search(constant char * pattern,int n,int silent)1211 static void multi_search(constant char *pattern, int n, int silent)
1212 {
1213 	int nomore;
1214 	IFILE save_ifile;
1215 	lbool changed_file;
1216 
1217 	changed_file = FALSE;
1218 	save_ifile = save_curr_ifile();
1219 
1220 	if ((search_type & (SRCH_FORW|SRCH_BACK)) == 0)
1221 		search_type |= SRCH_FORW;
1222 	if (search_type & SRCH_FIRST_FILE)
1223 	{
1224 		/*
1225 		 * Start at the first (or last) file
1226 		 * in the command line list.
1227 		 */
1228 		if (search_type & SRCH_FORW)
1229 			nomore = edit_first();
1230 		else
1231 			nomore = edit_last();
1232 		if (nomore)
1233 		{
1234 			unsave_ifile(save_ifile);
1235 			return;
1236 		}
1237 		changed_file = TRUE;
1238 		search_type &= ~SRCH_FIRST_FILE;
1239 	}
1240 
1241 	for (;;)
1242 	{
1243 		n = search(search_type, pattern, n);
1244 		/*
1245 		 * The SRCH_NO_MOVE flag doesn't "stick": it gets cleared
1246 		 * after being used once.  This allows "n" to work after
1247 		 * using a /@@ search.
1248 		 */
1249 		search_type &= ~SRCH_NO_MOVE;
1250 		last_search_type = search_type;
1251 		if (n == 0)
1252 		{
1253 			/*
1254 			 * Found it.
1255 			 */
1256 			unsave_ifile(save_ifile);
1257 			return;
1258 		}
1259 
1260 		if (n < 0)
1261 			/*
1262 			 * Some kind of error in the search.
1263 			 * Error message has been printed by search().
1264 			 */
1265 			break;
1266 
1267 		if ((search_type & SRCH_PAST_EOF) == 0)
1268 			/*
1269 			 * We didn't find a match, but we're
1270 			 * supposed to search only one file.
1271 			 */
1272 			break;
1273 		/*
1274 		 * Move on to the next file.
1275 		 */
1276 		if (search_type & SRCH_FORW)
1277 			nomore = edit_next(1);
1278 		else
1279 			nomore = edit_prev(1);
1280 		if (nomore)
1281 			break;
1282 		changed_file = TRUE;
1283 	}
1284 
1285 	/*
1286 	 * Didn't find it.
1287 	 * Print an error message if we haven't already.
1288 	 */
1289 	if (n > 0 && !silent)
1290 		error("Pattern not found", NULL_PARG);
1291 
1292 	if (changed_file)
1293 	{
1294 		/*
1295 		 * Restore the file we were originally viewing.
1296 		 */
1297 		reedit_ifile(save_ifile);
1298 	} else
1299 	{
1300 		unsave_ifile(save_ifile);
1301 	}
1302 }
1303 
1304 /*
1305  * Forward forever, or until a highlighted line appears.
1306  */
forw_loop(int until_hilite)1307 static int forw_loop(int until_hilite)
1308 {
1309 	POSITION curr_len;
1310 
1311 	if (ch_getflags() & CH_HELPFILE)
1312 		return (A_NOACTION);
1313 
1314 	cmd_exec();
1315 	jump_forw_buffered();
1316 	curr_len = ch_length();
1317 	highest_hilite = until_hilite ? curr_len : NULL_POSITION;
1318 	ignore_eoi = 1;
1319 	while (!sigs)
1320 	{
1321 		if (until_hilite && highest_hilite > curr_len)
1322 		{
1323 			bell();
1324 			break;
1325 		}
1326 		make_display();
1327 		forward(1, FALSE, FALSE, FALSE);
1328 	}
1329 	ignore_eoi = 0;
1330 	ch_set_eof();
1331 
1332 	/*
1333 	 * This gets us back in "F mode" after processing
1334 	 * a non-abort signal (e.g. window-change).
1335 	 */
1336 	if (sigs && !ABORT_SIGS())
1337 		return (until_hilite ? A_F_UNTIL_HILITE : A_F_FOREVER);
1338 
1339 	return (A_NOACTION);
1340 }
1341 
1342 /*
1343  * Ignore subsequent (pasted) input chars.
1344  */
start_ignoring_input()1345 public void start_ignoring_input()
1346 {
1347 	ignoring_input = TRUE;
1348 #if HAVE_TIME
1349 	ignoring_input_time = get_time();
1350 #endif
1351 }
1352 
1353 /*
1354  * Stop ignoring input chars.
1355  */
stop_ignoring_input()1356 public void stop_ignoring_input()
1357 {
1358 	ignoring_input = FALSE;
1359 	pasting = FALSE;
1360 }
1361 
1362 /*
1363  * Are we ignoring input chars?
1364  */
is_ignoring_input(int action)1365 public lbool is_ignoring_input(int action)
1366 {
1367 	if (!ignoring_input)
1368 		return FALSE;
1369 	if (action == A_END_PASTE)
1370 		stop_ignoring_input();
1371 #if HAVE_TIME
1372 	if (get_time() >= ignoring_input_time + MAX_PASTE_IGNORE_SEC)
1373 		stop_ignoring_input();
1374 #endif
1375 	/*
1376 	 * Don't ignore prefix chars so we can parse a full command
1377 	 * (which might be A_END_PASTE).
1378 	 */
1379 	return (action != A_PREFIX);
1380 }
1381 
1382 /*
1383  * Main command processor.
1384  * Accept and execute commands until a quit command.
1385  */
commands(void)1386 public void commands(void)
1387 {
1388 	char c;
1389 	int action;
1390 	constant char *cbuf;
1391 	constant char *msg;
1392 	int newaction;
1393 	int save_jump_sline;
1394 	int save_search_type;
1395 	constant char *extra;
1396 	PARG parg;
1397 	IFILE old_ifile;
1398 	IFILE new_ifile;
1399 #if TAGS
1400 	constant char *tagfile;
1401 #endif
1402 
1403 	search_type = SRCH_FORW;
1404 	wscroll = (sc_height + 1) / 2;
1405 	newaction = A_NOACTION;
1406 
1407 	for (;;)
1408 	{
1409 		clear_mca();
1410 		cmd_accept();
1411 		number = 0;
1412 		curropt = NULL;
1413 
1414 		/*
1415 		 * See if any signals need processing.
1416 		 */
1417 		if (sigs)
1418 		{
1419 			psignals();
1420 			if (quitting)
1421 				quit(QUIT_SAVED_STATUS);
1422 		}
1423 
1424 		/*
1425 		 * See if window size changed, for systems that don't
1426 		 * generate SIGWINCH.
1427 		 */
1428 		check_winch();
1429 
1430 		/*
1431 		 * Display prompt and accept a character.
1432 		 */
1433 		cmd_reset();
1434 		prompt();
1435 		if (sigs)
1436 			continue;
1437 		if (newaction == A_NOACTION)
1438 			c = getcc();
1439 
1440 	again:
1441 		if (sigs)
1442 			continue;
1443 
1444 		if (newaction != A_NOACTION)
1445 		{
1446 			action = newaction;
1447 			newaction = A_NOACTION;
1448 		} else
1449 		{
1450 			/*
1451 			 * If we are in a multicharacter command, call mca_char.
1452 			 * Otherwise we call fcmd_decode to determine the
1453 			 * action to be performed.
1454 			 */
1455 			if (mca)
1456 				switch (mca_char(c))
1457 				{
1458 				case MCA_MORE:
1459 					/*
1460 					 * Need another character.
1461 					 */
1462 					c = getcc();
1463 					goto again;
1464 				case MCA_DONE:
1465 					/*
1466 					 * Command has been handled by mca_char.
1467 					 * Start clean with a prompt.
1468 					 */
1469 					continue;
1470 				case NO_MCA:
1471 					/*
1472 					 * Not a multi-char command
1473 					 * (at least, not anymore).
1474 					 */
1475 					break;
1476 				}
1477 
1478 			/*
1479 			 * Decode the command character and decide what to do.
1480 			 */
1481 			extra = NULL;
1482 			if (mca)
1483 			{
1484 				/*
1485 				 * We're in a multichar command.
1486 				 * Add the character to the command buffer
1487 				 * and display it on the screen.
1488 				 * If the user backspaces past the start
1489 				 * of the line, abort the command.
1490 				 */
1491 				if (cmd_char(c) == CC_QUIT || cmdbuf_empty())
1492 					continue;
1493 				cbuf = get_cmdbuf();
1494 				if (cbuf == NULL)
1495 				{
1496 					c = getcc();
1497 					goto again;
1498 				}
1499 				action = fcmd_decode(cbuf, &extra);
1500 			} else
1501 			{
1502 				/*
1503 				 * Don't use cmd_char if we're starting fresh
1504 				 * at the beginning of a command, because we
1505 				 * don't want to echo the command until we know
1506 				 * it is a multichar command.  We also don't
1507 				 * want erase_char/kill_char to be treated
1508 				 * as line editing characters.
1509 				 */
1510 				constant char tbuf[2] = { c, '\0' };
1511 				action = fcmd_decode(tbuf, &extra);
1512 			}
1513 			/*
1514 			 * If an "extra" string was returned,
1515 			 * process it as a string of command characters.
1516 			 */
1517 			if (extra != NULL)
1518 				ungetsc(extra);
1519 		}
1520 		/*
1521 		 * Clear the cmdbuf string.
1522 		 * (But not if we're in the prefix of a command,
1523 		 * because the partial command string is kept there.)
1524 		 */
1525 		if (action != A_PREFIX)
1526 			cmd_reset();
1527 
1528 		if (is_ignoring_input(action))
1529 			continue;
1530 
1531 		switch (action)
1532 		{
1533 		case A_START_PASTE:
1534 			if (no_paste)
1535 				start_ignoring_input();
1536 			break;
1537 
1538 		case A_DIGIT:
1539 			/*
1540 			 * First digit of a number.
1541 			 */
1542 			start_mca(A_DIGIT, ":", NULL, CF_QUIT_ON_ERASE);
1543 			goto again;
1544 
1545 		case A_F_WINDOW:
1546 			/*
1547 			 * Forward one window (and set the window size).
1548 			 */
1549 			if (number > 0)
1550 				swindow = (int) number;
1551 			/* FALLTHRU */
1552 		case A_F_SCREEN:
1553 			/*
1554 			 * Forward one screen.
1555 			 */
1556 			if (number <= 0)
1557 				number = get_swindow();
1558 			cmd_exec();
1559 			if (show_attn)
1560 				set_attnpos(bottompos);
1561 			forward((int) number, FALSE, TRUE, FALSE);
1562 			break;
1563 
1564 		case A_B_WINDOW:
1565 			/*
1566 			 * Backward one window (and set the window size).
1567 			 */
1568 			if (number > 0)
1569 				swindow = (int) number;
1570 			/* FALLTHRU */
1571 		case A_B_SCREEN:
1572 			/*
1573 			 * Backward one screen.
1574 			 */
1575 			if (number <= 0)
1576 				number = get_swindow();
1577 			cmd_exec();
1578 			backward((int) number, FALSE, TRUE, FALSE);
1579 			break;
1580 
1581 		case A_F_LINE:
1582 		case A_F_NEWLINE:
1583 
1584 			/*
1585 			 * Forward N (default 1) line.
1586 			 */
1587 			if (number <= 0)
1588 				number = 1;
1589 			cmd_exec();
1590 			if (show_attn == OPT_ONPLUS && number > 1)
1591 				set_attnpos(bottompos);
1592 			forward((int) number, FALSE, FALSE, action == A_F_NEWLINE && !chopline);
1593 			break;
1594 
1595 		case A_B_LINE:
1596 		case A_B_NEWLINE:
1597 			/*
1598 			 * Backward N (default 1) line.
1599 			 */
1600 			if (number <= 0)
1601 				number = 1;
1602 			cmd_exec();
1603 			backward((int) number, FALSE, FALSE, action == A_B_NEWLINE && !chopline);
1604 			break;
1605 
1606 		case A_F_MOUSE:
1607 			/*
1608 			 * Forward wheel_lines lines.
1609 			 */
1610 			cmd_exec();
1611 			forward(wheel_lines, FALSE, FALSE, FALSE);
1612 			break;
1613 
1614 		case A_B_MOUSE:
1615 			/*
1616 			 * Backward wheel_lines lines.
1617 			 */
1618 			cmd_exec();
1619 			backward(wheel_lines, FALSE, FALSE, FALSE);
1620 			break;
1621 
1622 		case A_FF_LINE:
1623 			/*
1624 			 * Force forward N (default 1) line.
1625 			 */
1626 			if (number <= 0)
1627 				number = 1;
1628 			cmd_exec();
1629 			if (show_attn == OPT_ONPLUS && number > 1)
1630 				set_attnpos(bottompos);
1631 			forward((int) number, TRUE, FALSE, FALSE);
1632 			break;
1633 
1634 		case A_BF_LINE:
1635 			/*
1636 			 * Force backward N (default 1) line.
1637 			 */
1638 			if (number <= 0)
1639 				number = 1;
1640 			cmd_exec();
1641 			backward((int) number, TRUE, FALSE, FALSE);
1642 			break;
1643 
1644 		case A_FF_SCREEN:
1645 			/*
1646 			 * Force forward one screen.
1647 			 */
1648 			if (number <= 0)
1649 				number = get_swindow();
1650 			cmd_exec();
1651 			if (show_attn == OPT_ONPLUS)
1652 				set_attnpos(bottompos);
1653 			forward((int) number, TRUE, FALSE, FALSE);
1654 			break;
1655 
1656 		case A_BF_SCREEN:
1657 			/*
1658 			 * Force backward one screen.
1659 			 */
1660 			if (number <= 0)
1661 				number = get_swindow();
1662 			cmd_exec();
1663 			backward((int) number, TRUE, FALSE, FALSE);
1664 			break;
1665 
1666 		case A_F_FOREVER:
1667 			/*
1668 			 * Forward forever, ignoring EOF.
1669 			 */
1670 			if (get_altfilename(curr_ifile) != NULL)
1671 				error("Warning: command may not work correctly when file is viewed via LESSOPEN", NULL_PARG);
1672 			if (show_attn)
1673 				set_attnpos(bottompos);
1674 			newaction = forw_loop(0);
1675 			break;
1676 
1677 		case A_F_UNTIL_HILITE:
1678 			newaction = forw_loop(1);
1679 			break;
1680 
1681 		case A_F_SCROLL:
1682 			/*
1683 			 * Forward N lines
1684 			 * (default same as last 'd' or 'u' command).
1685 			 */
1686 			if (number > 0)
1687 				wscroll = (int) number;
1688 			cmd_exec();
1689 			if (show_attn == OPT_ONPLUS)
1690 				set_attnpos(bottompos);
1691 			forward(wscroll, FALSE, FALSE, FALSE);
1692 			break;
1693 
1694 		case A_B_SCROLL:
1695 			/*
1696 			 * Forward N lines
1697 			 * (default same as last 'd' or 'u' command).
1698 			 */
1699 			if (number > 0)
1700 				wscroll = (int) number;
1701 			cmd_exec();
1702 			backward(wscroll, FALSE, FALSE, FALSE);
1703 			break;
1704 
1705 		case A_FREPAINT:
1706 			/*
1707 			 * Flush buffers, then repaint screen.
1708 			 * Don't flush the buffers on a pipe!
1709 			 */
1710 			clear_buffers();
1711 			/* FALLTHRU */
1712 		case A_REPAINT:
1713 			/*
1714 			 * Repaint screen.
1715 			 */
1716 			cmd_exec();
1717 			repaint();
1718 			break;
1719 
1720 		case A_GOLINE:
1721 			/*
1722 			 * Go to line N, default beginning of file.
1723 			 * If N <= 0, ignore jump_sline in order to avoid
1724 			 * empty lines before the beginning of the file.
1725 			 */
1726 			save_jump_sline = jump_sline;
1727 			if (number <= 0)
1728 			{
1729 				number = 1;
1730 				jump_sline = 0;
1731 			}
1732 			cmd_exec();
1733 			jump_back(number);
1734 			jump_sline = save_jump_sline;
1735 			break;
1736 
1737 		case A_PERCENT:
1738 			/*
1739 			 * Go to a specified percentage into the file.
1740 			 */
1741 			if (number < 0)
1742 			{
1743 				number = 0;
1744 				fraction = 0;
1745 			}
1746 			if (number > 100 || (number == 100 && fraction != 0))
1747 			{
1748 				number = 100;
1749 				fraction = 0;
1750 			}
1751 			cmd_exec();
1752 			jump_percent((int) number, fraction);
1753 			break;
1754 
1755 		case A_GOEND:
1756 			/*
1757 			 * Go to line N, default end of file.
1758 			 */
1759 			cmd_exec();
1760 			if (number <= 0)
1761 				jump_forw();
1762 			else
1763 				jump_back(number);
1764 			break;
1765 
1766 		case A_GOEND_BUF:
1767 			/*
1768 			 * Go to line N, default last buffered byte.
1769 			 */
1770 			cmd_exec();
1771 			if (number <= 0)
1772 				jump_forw_buffered();
1773 			else
1774 				jump_back(number);
1775 			break;
1776 
1777 		case A_GOPOS:
1778 			/*
1779 			 * Go to a specified byte position in the file.
1780 			 */
1781 			cmd_exec();
1782 			if (number < 0)
1783 				number = 0;
1784 			jump_line_loc((POSITION) number, jump_sline);
1785 			break;
1786 
1787 		case A_STAT:
1788 			/*
1789 			 * Print file name, etc.
1790 			 */
1791 			if (ch_getflags() & CH_HELPFILE)
1792 				break;
1793 			cmd_exec();
1794 			parg.p_string = eq_message();
1795 			error("%s", &parg);
1796 			break;
1797 
1798 		case A_VERSION:
1799 			/*
1800 			 * Print version number.
1801 			 */
1802 			cmd_exec();
1803 			dispversion();
1804 			break;
1805 
1806 		case A_QUIT:
1807 			/*
1808 			 * Exit.
1809 			 */
1810 			if (curr_ifile != NULL_IFILE &&
1811 			    ch_getflags() & CH_HELPFILE)
1812 			{
1813 				/*
1814 				 * Quit while viewing the help file
1815 				 * just means return to viewing the
1816 				 * previous file.
1817 				 */
1818 				hshift = save_hshift;
1819 				bs_mode = save_bs_mode;
1820 				proc_backspace = save_proc_backspace;
1821 				if (edit_prev(1) == 0)
1822 					break;
1823 			}
1824 			if (extra != NULL)
1825 				quit(*extra);
1826 			quit(QUIT_OK);
1827 			break;
1828 
1829 /*
1830  * Define abbreviation for a commonly used sequence below.
1831  */
1832 #define DO_SEARCH() \
1833 			if (number <= 0) number = 1;    \
1834 			mca_search();                   \
1835 			cmd_exec();                     \
1836 			multi_search(NULL, (int) number, 0);
1837 
1838 		case A_F_SEARCH:
1839 			/*
1840 			 * Search forward for a pattern.
1841 			 * Get the first char of the pattern.
1842 			 */
1843 			search_type = SRCH_FORW | def_search_type;
1844 			if (number <= 0)
1845 				number = 1;
1846 			literal_char = FALSE;
1847 			mca_search();
1848 			c = getcc();
1849 			goto again;
1850 
1851 		case A_B_SEARCH:
1852 			/*
1853 			 * Search backward for a pattern.
1854 			 * Get the first char of the pattern.
1855 			 */
1856 			search_type = SRCH_BACK | def_search_type;
1857 			if (number <= 0)
1858 				number = 1;
1859 			literal_char = FALSE;
1860 			mca_search();
1861 			c = getcc();
1862 			goto again;
1863 
1864 		case A_OSC8_F_SEARCH:
1865 #if OSC8_LINK
1866 			cmd_exec();
1867 			if (number <= 0)
1868 				number = 1;
1869 			osc8_search(SRCH_FORW, NULL, number);
1870 #else
1871 			error("Command not available", NULL_PARG);
1872 #endif
1873 			break;
1874 
1875 		case A_OSC8_B_SEARCH:
1876 #if OSC8_LINK
1877 			cmd_exec();
1878 			if (number <= 0)
1879 				number = 1;
1880 			osc8_search(SRCH_BACK, NULL, number);
1881 #else
1882 			error("Command not available", NULL_PARG);
1883 #endif
1884 			break;
1885 
1886 		case A_OSC8_OPEN:
1887 #if OSC8_LINK
1888 			if (secure_allow(SF_OSC8_OPEN))
1889 			{
1890 				cmd_exec();
1891 				osc8_open();
1892 				break;
1893 			}
1894 #endif
1895 			error("Command not available", NULL_PARG);
1896 			break;
1897 
1898 		case A_OSC8_JUMP:
1899 #if OSC8_LINK
1900 			cmd_exec();
1901 			osc8_jump();
1902 #else
1903 			error("Command not available", NULL_PARG);
1904 #endif
1905 			break;
1906 
1907 		case A_FILTER:
1908 #if HILITE_SEARCH
1909 			search_type = SRCH_FORW | SRCH_FILTER;
1910 			literal_char = FALSE;
1911 			mca_search();
1912 			c = getcc();
1913 			goto again;
1914 #else
1915 			error("Command not available", NULL_PARG);
1916 			break;
1917 #endif
1918 
1919 		case A_AGAIN_SEARCH:
1920 			/*
1921 			 * Repeat previous search.
1922 			 */
1923 			search_type = last_search_type;
1924 			DO_SEARCH();
1925 			break;
1926 
1927 		case A_T_AGAIN_SEARCH:
1928 			/*
1929 			 * Repeat previous search, multiple files.
1930 			 */
1931 			search_type = last_search_type | SRCH_PAST_EOF;
1932 			DO_SEARCH();
1933 			break;
1934 
1935 		case A_REVERSE_SEARCH:
1936 			/*
1937 			 * Repeat previous search, in reverse direction.
1938 			 */
1939 			save_search_type = search_type = last_search_type;
1940 			search_type = SRCH_REVERSE(search_type);
1941 			DO_SEARCH();
1942 			last_search_type = save_search_type;
1943 			break;
1944 
1945 		case A_T_REVERSE_SEARCH:
1946 			/*
1947 			 * Repeat previous search,
1948 			 * multiple files in reverse direction.
1949 			 */
1950 			save_search_type = search_type = last_search_type;
1951 			search_type = SRCH_REVERSE(search_type) | SRCH_PAST_EOF;
1952 			DO_SEARCH();
1953 			last_search_type = save_search_type;
1954 			break;
1955 
1956 		case A_UNDO_SEARCH:
1957 		case A_CLR_SEARCH:
1958 			/*
1959 			 * Clear search string highlighting.
1960 			 */
1961 			undo_search(action == A_CLR_SEARCH);
1962 			break;
1963 
1964 		case A_HELP:
1965 			/*
1966 			 * Help.
1967 			 */
1968 			if (ch_getflags() & CH_HELPFILE)
1969 				break;
1970 			cmd_exec();
1971 			save_hshift = hshift;
1972 			hshift = 0;
1973 			save_bs_mode = bs_mode;
1974 			bs_mode = BS_SPECIAL;
1975 			save_proc_backspace = proc_backspace;
1976 			proc_backspace = OPT_OFF;
1977 			(void) edit(FAKE_HELPFILE);
1978 			break;
1979 
1980 		case A_EXAMINE:
1981 			/*
1982 			 * Edit a new file.  Get the filename.
1983 			 */
1984 #if EXAMINE
1985 			if (secure_allow(SF_EXAMINE))
1986 			{
1987 				start_mca(A_EXAMINE, "Examine: ", ml_examine, 0);
1988 				c = getcc();
1989 				goto again;
1990 			}
1991 #endif
1992 			error("Command not available", NULL_PARG);
1993 			break;
1994 
1995 		case A_VISUAL:
1996 			/*
1997 			 * Invoke an editor on the input file.
1998 			 */
1999 #if EDITOR
2000 			if (secure_allow(SF_EDIT))
2001 			{
2002 				if (ch_getflags() & CH_HELPFILE)
2003 					break;
2004 				if (strcmp(get_filename(curr_ifile), "-") == 0)
2005 				{
2006 					error("Cannot edit standard input", NULL_PARG);
2007 					break;
2008 				}
2009 				if (!no_edit_warn && get_altfilename(curr_ifile) != NULL)
2010 				{
2011 					error("WARNING: This file was viewed via LESSOPEN", NULL_PARG);
2012 				}
2013 				start_mca(A_SHELL, "!", ml_shell, 0);
2014 				/*
2015 				 * Expand the editor prototype string
2016 				 * and pass it to the system to execute.
2017 				 * (Make sure the screen is displayed so the
2018 				 * expansion of "+%lm" works.)
2019 				 */
2020 				make_display();
2021 				cmd_exec();
2022 				lsystem(pr_expand(editproto), NULL);
2023 				break;
2024 			}
2025 #endif
2026 			error("Command not available", NULL_PARG);
2027 			break;
2028 
2029 		case A_NEXT_FILE:
2030 			/*
2031 			 * Examine next file.
2032 			 */
2033 #if TAGS
2034 			if (ntags())
2035 			{
2036 				error("No next file", NULL_PARG);
2037 				break;
2038 			}
2039 #endif
2040 			if (number <= 0)
2041 				number = 1;
2042 			cmd_exec();
2043 			if (edit_next((int) number))
2044 			{
2045 				if (get_quit_at_eof() && eof_displayed(FALSE) &&
2046 				    !(ch_getflags() & CH_HELPFILE))
2047 					quit(QUIT_OK);
2048 				parg.p_string = (number > 1) ? "(N-th) " : "";
2049 				error("No %snext file", &parg);
2050 			}
2051 			break;
2052 
2053 		case A_PREV_FILE:
2054 			/*
2055 			 * Examine previous file.
2056 			 */
2057 #if TAGS
2058 			if (ntags())
2059 			{
2060 				error("No previous file", NULL_PARG);
2061 				break;
2062 			}
2063 #endif
2064 			if (number <= 0)
2065 				number = 1;
2066 			cmd_exec();
2067 			if (edit_prev((int) number))
2068 			{
2069 				parg.p_string = (number > 1) ? "(N-th) " : "";
2070 				error("No %sprevious file", &parg);
2071 			}
2072 			break;
2073 
2074 		case A_NEXT_TAG:
2075 			/*
2076 			 * Jump to the next tag in the current tag list.
2077 			 */
2078 #if TAGS
2079 			if (number <= 0)
2080 				number = 1;
2081 			tagfile = nexttag((int) number);
2082 			if (tagfile == NULL)
2083 			{
2084 				error("No next tag", NULL_PARG);
2085 				break;
2086 			}
2087 			cmd_exec();
2088 			if (edit(tagfile) == 0)
2089 			{
2090 				POSITION pos = tagsearch();
2091 				if (pos != NULL_POSITION)
2092 					jump_loc(pos, jump_sline);
2093 			}
2094 #else
2095 			error("Command not available", NULL_PARG);
2096 #endif
2097 			break;
2098 
2099 		case A_PREV_TAG:
2100 			/*
2101 			 * Jump to the previous tag in the current tag list.
2102 			 */
2103 #if TAGS
2104 			if (number <= 0)
2105 				number = 1;
2106 			tagfile = prevtag((int) number);
2107 			if (tagfile == NULL)
2108 			{
2109 				error("No previous tag", NULL_PARG);
2110 				break;
2111 			}
2112 			cmd_exec();
2113 			if (edit(tagfile) == 0)
2114 			{
2115 				POSITION pos = tagsearch();
2116 				if (pos != NULL_POSITION)
2117 					jump_loc(pos, jump_sline);
2118 			}
2119 #else
2120 			error("Command not available", NULL_PARG);
2121 #endif
2122 			break;
2123 
2124 		case A_INDEX_FILE:
2125 			/*
2126 			 * Examine a particular file.
2127 			 */
2128 			if (number <= 0)
2129 				number = 1;
2130 			cmd_exec();
2131 			if (edit_index((int) number))
2132 				error("No such file", NULL_PARG);
2133 			break;
2134 
2135 		case A_REMOVE_FILE:
2136 			/*
2137 			 * Remove a file from the input file list.
2138 			 */
2139 			if (ch_getflags() & CH_HELPFILE)
2140 				break;
2141 			old_ifile = curr_ifile;
2142 			new_ifile = getoff_ifile(curr_ifile);
2143 			cmd_exec();
2144 			if (new_ifile == NULL_IFILE)
2145 			{
2146 				bell();
2147 				break;
2148 			}
2149 			if (edit_ifile(new_ifile) != 0)
2150 			{
2151 				reedit_ifile(old_ifile);
2152 				break;
2153 			}
2154 			del_ifile(old_ifile);
2155 			break;
2156 
2157 		case A_OPT_TOGGLE:
2158 			/*
2159 			 * Change the setting of an  option.
2160 			 */
2161 			optflag = OPT_TOGGLE;
2162 			optgetname = FALSE;
2163 			mca_opt_toggle();
2164 			c = getcc();
2165 			msg = opt_toggle_disallowed(c);
2166 			if (msg != NULL)
2167 			{
2168 				error(msg, NULL_PARG);
2169 				break;
2170 			}
2171 			goto again;
2172 
2173 		case A_DISP_OPTION:
2174 			/*
2175 			 * Report the setting of an option.
2176 			 */
2177 			optflag = OPT_NO_TOGGLE;
2178 			optgetname = FALSE;
2179 			mca_opt_toggle();
2180 			c = getcc();
2181 			goto again;
2182 
2183 		case A_FIRSTCMD:
2184 			/*
2185 			 * Set an initial command for new files.
2186 			 */
2187 			start_mca(A_FIRSTCMD, "+", NULL, 0);
2188 			c = getcc();
2189 			goto again;
2190 
2191 		case A_SHELL:
2192 		case A_PSHELL:
2193 			/*
2194 			 * Shell escape.
2195 			 */
2196 #if SHELL_ESCAPE
2197 			if (secure_allow(SF_SHELL))
2198 			{
2199 				start_mca(action, (action == A_SHELL) ? "!" : "#", ml_shell, 0);
2200 				c = getcc();
2201 				goto again;
2202 			}
2203 #endif
2204 			error("Command not available", NULL_PARG);
2205 			break;
2206 
2207 		case A_SETMARK:
2208 		case A_SETMARKBOT:
2209 			/*
2210 			 * Set a mark.
2211 			 */
2212 			if (ch_getflags() & CH_HELPFILE)
2213 			{
2214 				if (ungot != NULL)
2215 				{
2216 					/*
2217 					 * Probably from a lesskey file, in which case there
2218 					 * is probably an ungotten letter from the "extra" string.
2219 					 * Eat it so it is not interpreted as a command.
2220 					 */
2221 					(void) getcc();
2222 				}
2223 				break;
2224 			}
2225 			start_mca(A_SETMARK, "set mark: ", NULL, 0);
2226 			c = getcc();
2227 			if (is_erase_char(c) || is_newline_char(c))
2228 				break;
2229 			setmark(c, action == A_SETMARKBOT ? BOTTOM : TOP);
2230 			repaint();
2231 			break;
2232 
2233 		case A_CLRMARK:
2234 			/*
2235 			 * Clear a mark.
2236 			 */
2237 			start_mca(A_CLRMARK, "clear mark: ", NULL, 0);
2238 			c = getcc();
2239 			if (is_erase_char(c) || is_newline_char(c))
2240 				break;
2241 			clrmark(c);
2242 			repaint();
2243 			break;
2244 
2245 		case A_GOMARK:
2246 			/*
2247 			 * Jump to a marked position.
2248 			 */
2249 			start_mca(A_GOMARK, "goto mark: ", NULL, 0);
2250 			c = getcc();
2251 			if (is_erase_char(c) || is_newline_char(c))
2252 				break;
2253 			cmd_exec();
2254 			gomark(c);
2255 			break;
2256 
2257 		case A_PIPE:
2258 			/*
2259 			 * Write part of the input to a pipe to a shell command.
2260 			 */
2261 #if PIPEC
2262 			if (secure_allow(SF_PIPE))
2263 			{
2264 				start_mca(A_PIPE, "|mark: ", NULL, 0);
2265 				c = getcc();
2266 				if (is_erase_char(c))
2267 					break;
2268 				if (is_newline_char(c))
2269 					c = '.';
2270 				if (badmark(c))
2271 					break;
2272 				pipec = c;
2273 				start_mca(A_PIPE, "!", ml_shell, 0);
2274 				c = getcc();
2275 				goto again;
2276 			}
2277 #endif
2278 			error("Command not available", NULL_PARG);
2279 			break;
2280 
2281 		case A_B_BRACKET:
2282 		case A_F_BRACKET:
2283 			start_mca(action, "Brackets: ", NULL, 0);
2284 			c = getcc();
2285 			goto again;
2286 
2287 		case A_LSHIFT:
2288 			/*
2289 			 * Shift view left.
2290 			 */
2291 			if (number > 0)
2292 				shift_count = (int) number;
2293 			else
2294 				number = (shift_count > 0) ? shift_count : sc_width / 2;
2295 			if (number > hshift)
2296 				number = hshift;
2297 			pos_rehead();
2298 			hshift -= (int) number;
2299 			screen_trashed();
2300 			cmd_exec();
2301 			break;
2302 
2303 		case A_RSHIFT:
2304 			/*
2305 			 * Shift view right.
2306 			 */
2307 			if (number > 0)
2308 				shift_count = (int) number;
2309 			else
2310 				number = (shift_count > 0) ? shift_count : sc_width / 2;
2311 			pos_rehead();
2312 			hshift += (int) number;
2313 			screen_trashed();
2314 			cmd_exec();
2315 			break;
2316 
2317 		case A_LLSHIFT:
2318 			/*
2319 			 * Shift view left to margin.
2320 			 */
2321 			pos_rehead();
2322 			hshift = 0;
2323 			screen_trashed();
2324 			cmd_exec();
2325 			break;
2326 
2327 		case A_RRSHIFT:
2328 			/*
2329 			 * Shift view right to view rightmost char on screen.
2330 			 */
2331 			pos_rehead();
2332 			hshift = rrshift();
2333 			screen_trashed();
2334 			cmd_exec();
2335 			break;
2336 
2337 		case A_PREFIX:
2338 			/*
2339 			 * The command is incomplete (more chars are needed).
2340 			 * Display the current char, so the user knows
2341 			 * what's going on, and get another character.
2342 			 */
2343 			if (mca != A_PREFIX)
2344 			{
2345 				cmd_reset();
2346 				start_mca(A_PREFIX, " ", NULL, CF_QUIT_ON_ERASE);
2347 				(void) cmd_char(c);
2348 			}
2349 			c = getcc();
2350 			goto again;
2351 
2352 		case A_NOACTION:
2353 			break;
2354 
2355 		default:
2356 			bell();
2357 			break;
2358 		}
2359 	}
2360 }
2361