xref: /freebsd/contrib/less/command.c (revision 5ca8e32633c4ffbbcd6762e5888b6a4ba0708c6c)
1 /* $FreeBSD$ */
2 /*
3  * Copyright (C) 1984-2023  Mark Nudelman
4  *
5  * You may distribute under the terms of either the GNU General Public
6  * License or the Less License, as specified in the README file.
7  *
8  * For more information, see the README file.
9  */
10 
11 
12 /*
13  * User-level command processor.
14  */
15 
16 #include "less.h"
17 #if MSDOS_COMPILER==WIN32C
18 #include <windows.h>
19 #endif
20 #include "position.h"
21 #include "option.h"
22 #include "cmd.h"
23 
24 extern int erase_char, erase2_char, kill_char;
25 extern int sigs;
26 extern int quit_if_one_screen;
27 extern int one_screen;
28 extern int squished;
29 extern int sc_width;
30 extern int sc_height;
31 extern char *kent;
32 extern int swindow;
33 extern int jump_sline;
34 extern int quitting;
35 extern int wscroll;
36 extern int top_scroll;
37 extern int ignore_eoi;
38 extern int secure;
39 extern int hshift;
40 extern int bs_mode;
41 extern int proc_backspace;
42 extern int show_attn;
43 extern int less_is_more;
44 extern int status_col;
45 extern POSITION highest_hilite;
46 extern POSITION start_attnpos;
47 extern POSITION end_attnpos;
48 extern char *every_first_cmd;
49 extern char version[];
50 extern struct scrpos initial_scrpos;
51 extern IFILE curr_ifile;
52 extern void *ml_search;
53 extern void *ml_examine;
54 extern int wheel_lines;
55 extern int header_lines;
56 extern int def_search_type;
57 extern int updown_match;
58 #if SHELL_ESCAPE || PIPEC
59 extern void *ml_shell;
60 #endif
61 #if EDITOR
62 extern char *editor;
63 extern char *editproto;
64 #endif
65 extern int screen_trashed;      /* The screen has been overwritten */
66 extern int shift_count;
67 extern int oldbot;
68 extern int forw_prompt;
69 extern int incr_search;
70 extern int full_screen;
71 #if MSDOS_COMPILER==WIN32C
72 extern int utf_mode;
73 #endif
74 
75 #if SHELL_ESCAPE
76 static char *shellcmd = NULL;   /* For holding last shell command for "!!" */
77 #endif
78 static int mca;                 /* The multicharacter command (action) */
79 static int search_type;         /* The previous type of search */
80 static int last_search_type;    /* Type of last executed search */
81 static LINENUM number;          /* The number typed by the user */
82 static long fraction;           /* The fractional part of the number */
83 static struct loption *curropt;
84 static int opt_lower;
85 static int optflag;
86 static int optgetname;
87 static POSITION bottompos;
88 static int save_hshift;
89 static int save_bs_mode;
90 static int save_proc_backspace;
91 #if PIPEC
92 static char pipec;
93 #endif
94 
95 /* Stack of ungotten chars (via ungetcc) */
96 struct ungot {
97 	struct ungot *ug_next;
98 	LWCHAR ug_char;
99 };
100 static struct ungot* ungot = NULL;
101 
102 static void multi_search (char *pattern, int n, int silent);
103 
104 /*
105  * Move the cursor to start of prompt line before executing a command.
106  * This looks nicer if the command takes a long time before
107  * updating the screen.
108  */
109 static void cmd_exec(void)
110 {
111 	clear_attn();
112 	clear_bot();
113 	flush();
114 }
115 
116 /*
117  * Indicate we are reading a multi-character command.
118  */
119 static void set_mca(int action)
120 {
121 	mca = action;
122 	clear_bot();
123 	clear_cmd();
124 }
125 
126 /*
127  * Indicate we are not reading a multi-character command.
128  */
129 static void clear_mca(void)
130 {
131 	if (mca == 0)
132 		return;
133 	mca = 0;
134 }
135 
136 /*
137  * Set up the display to start a new multi-character command.
138  */
139 static void start_mca(int action, constant char *prompt, void *mlist, int cmdflags)
140 {
141 	set_mca(action);
142 	cmd_putstr(prompt);
143 	set_mlist(mlist, cmdflags);
144 }
145 
146 public int in_mca(void)
147 {
148 	return (mca != 0 && mca != A_PREFIX);
149 }
150 
151 /*
152  * Set up the display to start a new search command.
153  */
154 static void mca_search1(void)
155 {
156 	int i;
157 
158 #if HILITE_SEARCH
159 	if (search_type & SRCH_FILTER)
160 		set_mca(A_FILTER);
161 	else
162 #endif
163 	if (search_type & SRCH_FORW)
164 		set_mca(A_F_SEARCH);
165 	else
166 		set_mca(A_B_SEARCH);
167 
168 	if (search_type & SRCH_NO_MATCH)
169 		cmd_putstr("Non-match ");
170 	if (search_type & SRCH_FIRST_FILE)
171 		cmd_putstr("First-file ");
172 	if (search_type & SRCH_PAST_EOF)
173 		cmd_putstr("EOF-ignore ");
174 	if (search_type & SRCH_NO_MOVE)
175 		cmd_putstr("Keep-pos ");
176 	if (search_type & SRCH_NO_REGEX)
177 		cmd_putstr("Regex-off ");
178 	if (search_type & SRCH_WRAP)
179 		cmd_putstr("Wrap ");
180 	for (i = 1; i <= NUM_SEARCH_COLORS; i++)
181 	{
182 		if (search_type & SRCH_SUBSEARCH(i))
183 		{
184 			char buf[INT_STRLEN_BOUND(int)+8];
185 			SNPRINTF1(buf, sizeof(buf), "Sub-%d ", i);
186 			cmd_putstr(buf);
187 		}
188 	}
189 
190 #if HILITE_SEARCH
191 	if (search_type & SRCH_FILTER)
192 		cmd_putstr("&/");
193 	else
194 #endif
195 	if (search_type & SRCH_FORW)
196 		cmd_putstr("/");
197 	else
198 		cmd_putstr("?");
199 	forw_prompt = 0;
200 }
201 
202 static void mca_search(void)
203 {
204 	mca_search1();
205 	set_mlist(ml_search, 0);
206 }
207 
208 /*
209  * Set up the display to start a new toggle-option command.
210  */
211 static void mca_opt_toggle(void)
212 {
213 	int no_prompt;
214 	int flag;
215 	char *dash;
216 
217 	no_prompt = (optflag & OPT_NO_PROMPT);
218 	flag = (optflag & ~OPT_NO_PROMPT);
219 	dash = (flag == OPT_NO_TOGGLE) ? "_" : "-";
220 
221 	set_mca(A_OPT_TOGGLE);
222 	cmd_putstr(dash);
223 	if (optgetname)
224 		cmd_putstr(dash);
225 	if (no_prompt)
226 		cmd_putstr("(P)");
227 	switch (flag)
228 	{
229 	case OPT_UNSET:
230 		cmd_putstr("+");
231 		break;
232 	case OPT_SET:
233 		cmd_putstr("!");
234 		break;
235 	}
236 	forw_prompt = 0;
237 	set_mlist(NULL, 0);
238 }
239 
240 /*
241  * Execute a multicharacter command.
242  */
243 static void exec_mca(void)
244 {
245 	char *cbuf;
246 
247 	cmd_exec();
248 	cbuf = get_cmdbuf();
249 	if (cbuf == NULL)
250 		return;
251 
252 	switch (mca)
253 	{
254 	case A_F_SEARCH:
255 	case A_B_SEARCH:
256 		multi_search(cbuf, (int) number, 0);
257 		break;
258 #if HILITE_SEARCH
259 	case A_FILTER:
260 		search_type ^= SRCH_NO_MATCH;
261 		set_filter_pattern(cbuf, search_type);
262 		break;
263 #endif
264 	case A_FIRSTCMD:
265 		/*
266 		 * Skip leading spaces or + signs in the string.
267 		 */
268 		while (*cbuf == '+' || *cbuf == ' ')
269 			cbuf++;
270 		if (every_first_cmd != NULL)
271 			free(every_first_cmd);
272 		if (*cbuf == '\0')
273 			every_first_cmd = NULL;
274 		else
275 			every_first_cmd = save(cbuf);
276 		break;
277 	case A_OPT_TOGGLE:
278 		toggle_option(curropt, opt_lower, cbuf, optflag);
279 		curropt = NULL;
280 		break;
281 	case A_F_BRACKET:
282 		match_brac(cbuf[0], cbuf[1], 1, (int) number);
283 		break;
284 	case A_B_BRACKET:
285 		match_brac(cbuf[1], cbuf[0], 0, (int) number);
286 		break;
287 #if EXAMINE
288 	case A_EXAMINE:
289 		if (secure)
290 			break;
291 		edit_list(cbuf);
292 #if TAGS
293 		/* If tag structure is loaded then clean it up. */
294 		cleantags();
295 #endif
296 		break;
297 #endif
298 #if SHELL_ESCAPE
299 	case A_SHELL:
300 		/*
301 		 * !! just uses whatever is in shellcmd.
302 		 * Otherwise, copy cmdbuf to shellcmd,
303 		 * expanding any special characters ("%" or "#").
304 		 */
305 		if (*cbuf != '!')
306 		{
307 			if (shellcmd != NULL)
308 				free(shellcmd);
309 			shellcmd = fexpand(cbuf);
310 		}
311 
312 		if (secure)
313 			break;
314 		if (shellcmd == NULL)
315 			lsystem("", "!done");
316 		else
317 			lsystem(shellcmd, "!done");
318 		break;
319 	case A_PSHELL:
320 		if (secure)
321 			break;
322 		lsystem(pr_expand(cbuf), "#done");
323 		break;
324 #endif
325 #if PIPEC
326 	case A_PIPE:
327 		if (secure)
328 			break;
329 		(void) pipe_mark(pipec, cbuf);
330 		error("|done", NULL_PARG);
331 		break;
332 #endif
333 	}
334 }
335 
336 /*
337  * Is a character an erase or kill char?
338  */
339 static int is_erase_char(int c)
340 {
341 	return (c == erase_char || c == erase2_char || c == kill_char);
342 }
343 
344 /*
345  * Is a character a carriage return or newline?
346  */
347 static int is_newline_char(int c)
348 {
349 	return (c == '\n' || c == '\r');
350 }
351 
352 /*
353  * Handle the first char of an option (after the initial dash).
354  */
355 static int mca_opt_first_char(int c)
356 {
357 	int no_prompt = (optflag & OPT_NO_PROMPT);
358 	int flag = (optflag & ~OPT_NO_PROMPT);
359 	if (flag == OPT_NO_TOGGLE)
360 	{
361 		switch (c)
362 		{
363 		case '_':
364 			/* "__" = long option name. */
365 			optgetname = TRUE;
366 			mca_opt_toggle();
367 			return (MCA_MORE);
368 		}
369 	} else
370 	{
371 		switch (c)
372 		{
373 		case '+':
374 			/* "-+" = UNSET. */
375 			optflag = no_prompt | ((flag == OPT_UNSET) ?
376 				OPT_TOGGLE : OPT_UNSET);
377 			mca_opt_toggle();
378 			return (MCA_MORE);
379 		case '!':
380 			/* "-!" = SET */
381 			optflag = no_prompt | ((flag == OPT_SET) ?
382 				OPT_TOGGLE : OPT_SET);
383 			mca_opt_toggle();
384 			return (MCA_MORE);
385 		case CONTROL('P'):
386 			optflag ^= OPT_NO_PROMPT;
387 			mca_opt_toggle();
388 			return (MCA_MORE);
389 		case '-':
390 			/* "--" = long option name. */
391 			optgetname = TRUE;
392 			mca_opt_toggle();
393 			return (MCA_MORE);
394 		}
395 	}
396 	/* Char was not handled here. */
397 	return (NO_MCA);
398 }
399 
400 /*
401  * Add a char to a long option name.
402  * See if we've got a match for an option name yet.
403  * If so, display the complete name and stop
404  * accepting chars until user hits RETURN.
405  */
406 static int mca_opt_nonfirst_char(int c)
407 {
408 	char *p;
409 	char *oname;
410 	int err;
411 
412 	if (curropt != NULL)
413 	{
414 		/*
415 		 * Already have a match for the name.
416 		 * Don't accept anything but erase/kill.
417 		 */
418 		if (is_erase_char(c))
419 			return (MCA_DONE);
420 		return (MCA_MORE);
421 	}
422 	/*
423 	 * Add char to cmd buffer and try to match
424 	 * the option name.
425 	 */
426 	if (cmd_char(c) == CC_QUIT)
427 		return (MCA_DONE);
428 	p = get_cmdbuf();
429 	if (p == NULL)
430 		return (MCA_MORE);
431 	opt_lower = ASCII_IS_LOWER(p[0]);
432 	err = 0;
433 	curropt = findopt_name(&p, &oname, &err);
434 	if (curropt != NULL)
435 	{
436 		/*
437 		 * Got a match.
438 		 * Remember the option and
439 		 * display the full option name.
440 		 */
441 		cmd_reset();
442 		mca_opt_toggle();
443 		for (p = oname;  *p != '\0';  p++)
444 		{
445 			c = *p;
446 			if (!opt_lower && ASCII_IS_LOWER(c))
447 				c = ASCII_TO_UPPER(c);
448 			if (cmd_char(c) != CC_OK)
449 				return (MCA_DONE);
450 		}
451 	} else if (err != OPT_AMBIG)
452 	{
453 		bell();
454 	}
455 	return (MCA_MORE);
456 }
457 
458 /*
459  * Handle a char of an option toggle command.
460  */
461 static int mca_opt_char(int c)
462 {
463 	PARG parg;
464 
465 	/*
466 	 * This may be a short option (single char),
467 	 * or one char of a long option name,
468 	 * or one char of the option parameter.
469 	 */
470 	if (curropt == NULL && len_cmdbuf() == 0)
471 	{
472 		int ret = mca_opt_first_char(c);
473 		if (ret != NO_MCA)
474 			return (ret);
475 	}
476 	if (optgetname)
477 	{
478 		/* We're getting a long option name.  */
479 		if (!is_newline_char(c) && c != '=')
480 			return (mca_opt_nonfirst_char(c));
481 		if (curropt == NULL)
482 		{
483 			parg.p_string = get_cmdbuf();
484 			if (parg.p_string == NULL)
485 				return (MCA_MORE);
486 			error("There is no --%s option", &parg);
487 			return (MCA_DONE);
488 		}
489 		optgetname = FALSE;
490 		cmd_reset();
491 	} else
492 	{
493 		if (is_erase_char(c))
494 			return (NO_MCA);
495 		if (curropt != NULL)
496 			/* We're getting the option parameter. */
497 			return (NO_MCA);
498 		curropt = findopt(c);
499 		if (curropt == NULL)
500 		{
501 			parg.p_string = propt(c);
502 			error("There is no %s option", &parg);
503 			return (MCA_DONE);
504 		}
505 		opt_lower = ASCII_IS_LOWER(c);
506 	}
507 	/*
508 	 * If the option which was entered does not take a
509 	 * parameter, toggle the option immediately,
510 	 * so user doesn't have to hit RETURN.
511 	 */
512 	if ((optflag & ~OPT_NO_PROMPT) != OPT_TOGGLE ||
513 	    !opt_has_param(curropt))
514 	{
515 		toggle_option(curropt, opt_lower, "", optflag);
516 		return (MCA_DONE);
517 	}
518 	/*
519 	 * Display a prompt appropriate for the option parameter.
520 	 */
521 	start_mca(A_OPT_TOGGLE, opt_prompt(curropt), (void*)NULL, 0);
522 	return (MCA_MORE);
523 }
524 
525 /*
526  * Normalize search type.
527  */
528 public int norm_search_type(int st)
529 {
530 	/* WRAP and PAST_EOF are mutually exclusive. */
531 	if ((st & (SRCH_PAST_EOF|SRCH_WRAP)) == (SRCH_PAST_EOF|SRCH_WRAP))
532 		st ^= SRCH_PAST_EOF;
533 	return st;
534 }
535 
536 /*
537  * Handle a char of a search command.
538  */
539 static int mca_search_char(int c)
540 {
541 	int flag = 0;
542 
543 	/*
544 	 * Certain characters as the first char of
545 	 * the pattern have special meaning:
546 	 *      !  Toggle the NO_MATCH flag
547 	 *      *  Toggle the PAST_EOF flag
548 	 *      @  Toggle the FIRST_FILE flag
549 	 */
550 	if (len_cmdbuf() > 0)
551 		return (NO_MCA);
552 
553 	switch (c)
554 	{
555 	case '*':
556 		if (less_is_more)
557 			break;
558 	case CONTROL('E'): /* ignore END of file */
559 		if (mca != A_FILTER)
560 			flag = SRCH_PAST_EOF;
561 		search_type &= ~SRCH_WRAP;
562 		break;
563 	case '@':
564 		if (less_is_more)
565 			break;
566 	case CONTROL('F'): /* FIRST file */
567 		if (mca != A_FILTER)
568 			flag = SRCH_FIRST_FILE;
569 		break;
570 	case CONTROL('K'): /* KEEP position */
571 		if (mca != A_FILTER)
572 			flag = SRCH_NO_MOVE;
573 		break;
574 	case CONTROL('S'): { /* SUBSEARCH */
575 		char buf[INT_STRLEN_BOUND(int)+24];
576 		SNPRINTF1(buf, sizeof(buf), "Sub-pattern (1-%d):", NUM_SEARCH_COLORS);
577 		clear_bot();
578 		cmd_putstr(buf);
579 		flush();
580 		c = getcc();
581 		if (c >= '1' && c <= '0'+NUM_SEARCH_COLORS)
582 			flag = SRCH_SUBSEARCH(c-'0');
583 		else
584 			flag = -1; /* calls mca_search() below to repaint */
585 		break; }
586 	case CONTROL('W'): /* WRAP around */
587 		if (mca != A_FILTER)
588 			flag = SRCH_WRAP;
589 		break;
590 	case CONTROL('R'): /* Don't use REGULAR EXPRESSIONS */
591 		flag = SRCH_NO_REGEX;
592 		break;
593 	case CONTROL('N'): /* NOT match */
594 	case '!':
595 		flag = SRCH_NO_MATCH;
596 		break;
597 	}
598 
599 	if (flag != 0)
600 	{
601 		if (flag != -1)
602 			search_type = norm_search_type(search_type ^ flag);
603 		mca_search();
604 		return (MCA_MORE);
605 	}
606 	return (NO_MCA);
607 }
608 
609 /*
610  * Handle a character of a multi-character command.
611  */
612 static int mca_char(int c)
613 {
614 	int ret;
615 
616 	switch (mca)
617 	{
618 	case 0:
619 		/*
620 		 * We're not in a multicharacter command.
621 		 */
622 		return (NO_MCA);
623 
624 	case A_PREFIX:
625 		/*
626 		 * In the prefix of a command.
627 		 * This not considered a multichar command
628 		 * (even tho it uses cmdbuf, etc.).
629 		 * It is handled in the commands() switch.
630 		 */
631 		return (NO_MCA);
632 
633 	case A_DIGIT:
634 		/*
635 		 * Entering digits of a number.
636 		 * Terminated by a non-digit.
637 		 */
638 		if ((c >= '0' && c <= '9') || c == '.')
639 			break;
640 		switch (editchar(c, ECF_PEEK|ECF_NOHISTORY|ECF_NOCOMPLETE|ECF_NORIGHTLEFT))
641 		{
642 		case A_NOACTION:
643 			/*
644 			 * Ignore this char and get another one.
645 			 */
646 			return (MCA_MORE);
647 		case A_INVALID:
648 			/*
649 			 * Not part of the number.
650 			 * End the number and treat this char
651 			 * as a normal command character.
652 			 */
653 			number = cmd_int(&fraction);
654 			clear_mca();
655 			cmd_accept();
656 			return (NO_MCA);
657 		}
658 		break;
659 
660 	case A_OPT_TOGGLE:
661 		ret = mca_opt_char(c);
662 		if (ret != NO_MCA)
663 			return (ret);
664 		break;
665 
666 	case A_F_SEARCH:
667 	case A_B_SEARCH:
668 	case A_FILTER:
669 		ret = mca_search_char(c);
670 		if (ret != NO_MCA)
671 			return (ret);
672 		break;
673 
674 	default:
675 		/* Other multicharacter command. */
676 		break;
677 	}
678 
679 	/*
680 	 * The multichar command is terminated by a newline.
681 	 */
682 	if (is_newline_char(c))
683 	{
684 		/*
685 		 * Execute the command.
686 		 */
687 		exec_mca();
688 		return (MCA_DONE);
689 	}
690 
691 	/*
692 	 * Append the char to the command buffer.
693 	 */
694 	if (cmd_char(c) == CC_QUIT)
695 		/*
696 		 * Abort the multi-char command.
697 		 */
698 		return (MCA_DONE);
699 
700 	switch (mca)
701 	{
702 	case A_F_BRACKET:
703 	case A_B_BRACKET:
704 		if (len_cmdbuf() >= 2)
705 		{
706 			/*
707 			 * Special case for the bracket-matching commands.
708 			 * Execute the command after getting exactly two
709 			 * characters from the user.
710 			 */
711 			exec_mca();
712 			return (MCA_DONE);
713 		}
714 		break;
715 	case A_F_SEARCH:
716 	case A_B_SEARCH:
717 		if (incr_search)
718 		{
719 			/* Incremental search: do a search after every input char. */
720 			int st = (search_type & (SRCH_FORW|SRCH_BACK|SRCH_NO_MATCH|SRCH_NO_REGEX|SRCH_NO_MOVE|SRCH_WRAP|SRCH_SUBSEARCH_ALL));
721 			char *pattern = get_cmdbuf();
722 			if (pattern == NULL)
723 				return (MCA_MORE);
724 			/*
725 			 * Must save updown_match because mca_search
726 			 * reinits it. That breaks history scrolling.
727 			 * {{ This is ugly. mca_search probably shouldn't call set_mlist. }}
728 			 */
729 			int save_updown_match = updown_match;
730 			cmd_exec();
731 			if (*pattern == '\0')
732 			{
733 				/* User has backspaced to an empty pattern. */
734 				undo_search(1);
735 			} else
736 			{
737 				if (search(st | SRCH_INCR, pattern, 1) != 0)
738 					/* No match, invalid pattern, etc. */
739 					undo_search(1);
740 			}
741 			/* Redraw the search prompt and search string. */
742 			if (!full_screen)
743 			{
744 				clear();
745 				repaint();
746 			}
747 			mca_search1();
748 			updown_match = save_updown_match;
749 			cmd_repaint(NULL);
750 		}
751 		break;
752 	}
753 
754 	/*
755 	 * Need another character.
756 	 */
757 	return (MCA_MORE);
758 }
759 
760 /*
761  * Discard any buffered file data.
762  */
763 static void clear_buffers(void)
764 {
765 	if (!(ch_getflags() & CH_CANSEEK))
766 		return;
767 	ch_flush();
768 	clr_linenum();
769 #if HILITE_SEARCH
770 	clr_hilite();
771 #endif
772 }
773 
774 /*
775  * Make sure the screen is displayed.
776  */
777 static void make_display(void)
778 {
779 	/*
780 	 * If not full_screen, we can't rely on scrolling to fill the screen.
781 	 * We need to clear and repaint screen before any change.
782 	 */
783 	if (!full_screen && !(quit_if_one_screen && one_screen))
784 		clear();
785 	/*
786 	 * If nothing is displayed yet, display starting from initial_scrpos.
787 	 */
788 	if (empty_screen())
789 	{
790 		if (initial_scrpos.pos == NULL_POSITION)
791 			jump_loc(ch_zero(), 1);
792 		else
793 			jump_loc(initial_scrpos.pos, initial_scrpos.ln);
794 	} else if (screen_trashed || !full_screen)
795 	{
796 		int save_top_scroll = top_scroll;
797 		int save_ignore_eoi = ignore_eoi;
798 		top_scroll = 1;
799 		ignore_eoi = 0;
800 		if (screen_trashed == 2)
801 		{
802 			/* Special case used by ignore_eoi: re-open the input file
803 			 * and jump to the end of the file. */
804 			reopen_curr_ifile();
805 			jump_forw();
806 		}
807 		repaint();
808 		top_scroll = save_top_scroll;
809 		ignore_eoi = save_ignore_eoi;
810 	}
811 }
812 
813 /*
814  * Display the appropriate prompt.
815  */
816 static void prompt(void)
817 {
818 	constant char *p;
819 
820 	if (ungot != NULL && ungot->ug_char != CHAR_END_COMMAND)
821 	{
822 		/*
823 		 * No prompt necessary if commands are from
824 		 * ungotten chars rather than from the user.
825 		 */
826 		return;
827 	}
828 
829 	/*
830 	 * Make sure the screen is displayed.
831 	 */
832 	make_display();
833 	bottompos = position(BOTTOM_PLUS_ONE);
834 
835 	/*
836 	 * If we've hit EOF on the last file and the -E flag is set, quit.
837 	 */
838 	if (get_quit_at_eof() == OPT_ONPLUS &&
839 	    eof_displayed() && !(ch_getflags() & CH_HELPFILE) &&
840 	    next_ifile(curr_ifile) == NULL_IFILE)
841 		quit(QUIT_OK);
842 
843 	/*
844 	 * If the entire file is displayed and the -F flag is set, quit.
845 	 */
846 	if (quit_if_one_screen &&
847 	    entire_file_displayed() && !(ch_getflags() & CH_HELPFILE) &&
848 	    next_ifile(curr_ifile) == NULL_IFILE)
849 		quit(QUIT_OK);
850 	quit_if_one_screen = FALSE; /* only get one chance at this */
851 
852 #if MSDOS_COMPILER==WIN32C
853 	/*
854 	 * In Win32, display the file name in the window title.
855 	 */
856 	if (!(ch_getflags() & CH_HELPFILE))
857 	{
858 		WCHAR w[MAX_PATH+16];
859 		p = pr_expand("Less?f - %f.");
860 		MultiByteToWideChar(CP_ACP, 0, p, -1, w, sizeof(w)/sizeof(*w));
861 		SetConsoleTitleW(w);
862 	}
863 #endif
864 
865 	/*
866 	 * Select the proper prompt and display it.
867 	 */
868 	/*
869 	 * If the previous action was a forward movement,
870 	 * don't clear the bottom line of the display;
871 	 * just print the prompt since the forward movement guarantees
872 	 * that we're in the right position to display the prompt.
873 	 * Clearing the line could cause a problem: for example, if the last
874 	 * line displayed ended at the right screen edge without a newline,
875 	 * then clearing would clear the last displayed line rather than
876 	 * the prompt line.
877 	 */
878 	if (!forw_prompt)
879 		clear_bot();
880 	clear_cmd();
881 	forw_prompt = 0;
882 	p = pr_string();
883 #if HILITE_SEARCH
884 	if (is_filtering())
885 		putstr("& ");
886 #endif
887 	if (p == NULL || *p == '\0')
888 	{
889 		at_enter(AT_NORMAL|AT_COLOR_PROMPT);
890 		putchr(':');
891 		at_exit();
892 	} else
893 	{
894 #if MSDOS_COMPILER==WIN32C
895 		WCHAR w[MAX_PATH*2];
896 		char  a[MAX_PATH*2];
897 		MultiByteToWideChar(CP_ACP, 0, p, -1, w, sizeof(w)/sizeof(*w));
898 		WideCharToMultiByte(utf_mode ? CP_UTF8 : GetConsoleOutputCP(),
899 		                    0, w, -1, a, sizeof(a), NULL, NULL);
900 		p = a;
901 #endif
902 		load_line(p);
903 		put_line();
904 	}
905 	clear_eol();
906 }
907 
908 /*
909  * Display the less version message.
910  */
911 public void dispversion(void)
912 {
913 	PARG parg;
914 
915 	parg.p_string = version;
916 	error("less %s", &parg);
917 }
918 
919 /*
920  * Return a character to complete a partial command, if possible.
921  */
922 static LWCHAR getcc_end_command(void)
923 {
924 	switch (mca)
925 	{
926 	case A_DIGIT:
927 		/* We have a number but no command.  Treat as #g. */
928 		return ('g');
929 	case A_F_SEARCH:
930 	case A_B_SEARCH:
931 	case A_FILTER:
932 		/* We have "/string" but no newline.  Add the \n. */
933 		return ('\n');
934 	default:
935 		/* Some other incomplete command.  Let user complete it. */
936 		return ((ungot == NULL) ? getchr() : 0);
937 	}
938 }
939 
940 /*
941  * Get command character.
942  * The character normally comes from the keyboard,
943  * but may come from ungotten characters
944  * (characters previously given to ungetcc or ungetsc).
945  */
946 static LWCHAR getccu(void)
947 {
948 	LWCHAR c = 0;
949 	while (c == 0)
950 	{
951 		if (ungot == NULL)
952 		{
953 			/* Normal case: no ungotten chars.
954 			 * Get char from the user. */
955 			c = getchr();
956 		} else
957 		{
958 			/* Ungotten chars available:
959 			 * Take the top of stack (most recent). */
960 			struct ungot *ug = ungot;
961 			c = ug->ug_char;
962 			ungot = ug->ug_next;
963 			free(ug);
964 
965 			if (c == CHAR_END_COMMAND)
966 				c = getcc_end_command();
967 		}
968 	}
969 	return (c);
970 }
971 
972 /*
973  * Get a command character, but if we receive the orig sequence,
974  * convert it to the repl sequence.
975  */
976 static LWCHAR getcc_repl(char constant *orig, char constant *repl, LWCHAR (*gr_getc)(void), void (*gr_ungetc)(LWCHAR))
977 {
978 	LWCHAR c;
979 	LWCHAR keys[16];
980 	int ki = 0;
981 
982 	c = (*gr_getc)();
983 	if (orig == NULL || orig[0] == '\0')
984 		return c;
985 	for (;;)
986 	{
987 		keys[ki] = c;
988 		if (c != orig[ki] || ki >= sizeof(keys)-1)
989 		{
990 			/* This is not orig we have been receiving.
991 			 * If we have stashed chars in keys[],
992 			 * unget them and return the first one. */
993 			while (ki > 0)
994 				(*gr_ungetc)(keys[ki--]);
995 			return keys[0];
996 		}
997 		if (orig[++ki] == '\0')
998 		{
999 			/* We've received the full orig sequence.
1000 			 * Return the repl sequence. */
1001 			ki = strlen(repl)-1;
1002 			while (ki > 0)
1003 				(*gr_ungetc)(repl[ki--]);
1004 			return repl[0];
1005 		}
1006 		/* We've received a partial orig sequence (ki chars of it).
1007 		 * Get next char and see if it continues to match orig. */
1008 		c = (*gr_getc)();
1009 	}
1010 }
1011 
1012 /*
1013  * Get command character.
1014  */
1015 public int getcc(void)
1016 {
1017 	/* Replace kent (keypad Enter) with a newline. */
1018 	return getcc_repl(kent, "\n", getccu, ungetcc);
1019 }
1020 
1021 /*
1022  * "Unget" a command character.
1023  * The next getcc() will return this character.
1024  */
1025 public void ungetcc(LWCHAR c)
1026 {
1027 	struct ungot *ug = (struct ungot *) ecalloc(1, sizeof(struct ungot));
1028 
1029 	ug->ug_char = c;
1030 	ug->ug_next = ungot;
1031 	ungot = ug;
1032 }
1033 
1034 /*
1035  * "Unget" a command character.
1036  * If any other chars are already ungotten, put this one after those.
1037  */
1038 public void ungetcc_back(LWCHAR c)
1039 {
1040 	struct ungot *ug = (struct ungot *) ecalloc(1, sizeof(struct ungot));
1041 	ug->ug_char = c;
1042 	ug->ug_next = NULL;
1043 	if (ungot == NULL)
1044 		ungot = ug;
1045 	else
1046 	{
1047 		struct ungot *pu;
1048 		for (pu = ungot; pu->ug_next != NULL; pu = pu->ug_next)
1049 			continue;
1050 		pu->ug_next = ug;
1051 	}
1052 }
1053 
1054 /*
1055  * Unget a whole string of command characters.
1056  * The next sequence of getcc()'s will return this string.
1057  */
1058 public void ungetsc(char *s)
1059 {
1060 	while (*s != '\0')
1061 		ungetcc_back(*s++);
1062 }
1063 
1064 /*
1065  * Peek the next command character, without consuming it.
1066  */
1067 public LWCHAR peekcc(void)
1068 {
1069 	LWCHAR c = getcc();
1070 	ungetcc(c);
1071 	return c;
1072 }
1073 
1074 /*
1075  * Search for a pattern, possibly in multiple files.
1076  * If SRCH_FIRST_FILE is set, begin searching at the first file.
1077  * If SRCH_PAST_EOF is set, continue the search thru multiple files.
1078  */
1079 static void multi_search(char *pattern, int n, int silent)
1080 {
1081 	int nomore;
1082 	IFILE save_ifile;
1083 	int changed_file;
1084 
1085 	changed_file = 0;
1086 	save_ifile = save_curr_ifile();
1087 
1088 	if ((search_type & (SRCH_FORW|SRCH_BACK)) == 0)
1089 		search_type |= SRCH_FORW;
1090 	if (search_type & SRCH_FIRST_FILE)
1091 	{
1092 		/*
1093 		 * Start at the first (or last) file
1094 		 * in the command line list.
1095 		 */
1096 		if (search_type & SRCH_FORW)
1097 			nomore = edit_first();
1098 		else
1099 			nomore = edit_last();
1100 		if (nomore)
1101 		{
1102 			unsave_ifile(save_ifile);
1103 			return;
1104 		}
1105 		changed_file = 1;
1106 		search_type &= ~SRCH_FIRST_FILE;
1107 	}
1108 
1109 	for (;;)
1110 	{
1111 		n = search(search_type, pattern, n);
1112 		/*
1113 		 * The SRCH_NO_MOVE flag doesn't "stick": it gets cleared
1114 		 * after being used once.  This allows "n" to work after
1115 		 * using a /@@ search.
1116 		 */
1117 		search_type &= ~SRCH_NO_MOVE;
1118 		last_search_type = search_type;
1119 		if (n == 0)
1120 		{
1121 			/*
1122 			 * Found it.
1123 			 */
1124 			unsave_ifile(save_ifile);
1125 			return;
1126 		}
1127 
1128 		if (n < 0)
1129 			/*
1130 			 * Some kind of error in the search.
1131 			 * Error message has been printed by search().
1132 			 */
1133 			break;
1134 
1135 		if ((search_type & SRCH_PAST_EOF) == 0)
1136 			/*
1137 			 * We didn't find a match, but we're
1138 			 * supposed to search only one file.
1139 			 */
1140 			break;
1141 		/*
1142 		 * Move on to the next file.
1143 		 */
1144 		if (search_type & SRCH_FORW)
1145 			nomore = edit_next(1);
1146 		else
1147 			nomore = edit_prev(1);
1148 		if (nomore)
1149 			break;
1150 		changed_file = 1;
1151 	}
1152 
1153 	/*
1154 	 * Didn't find it.
1155 	 * Print an error message if we haven't already.
1156 	 */
1157 	if (n > 0 && !silent)
1158 		error("Pattern not found", NULL_PARG);
1159 
1160 	if (changed_file)
1161 	{
1162 		/*
1163 		 * Restore the file we were originally viewing.
1164 		 */
1165 		reedit_ifile(save_ifile);
1166 	} else
1167 	{
1168 		unsave_ifile(save_ifile);
1169 	}
1170 }
1171 
1172 /*
1173  * Forward forever, or until a highlighted line appears.
1174  */
1175 static int forw_loop(int until_hilite)
1176 {
1177 	POSITION curr_len;
1178 
1179 	if (ch_getflags() & CH_HELPFILE)
1180 		return (A_NOACTION);
1181 
1182 	cmd_exec();
1183 	jump_forw_buffered();
1184 	curr_len = ch_length();
1185 	highest_hilite = until_hilite ? curr_len : NULL_POSITION;
1186 	ignore_eoi = 1;
1187 	while (!sigs)
1188 	{
1189 		if (until_hilite && highest_hilite > curr_len)
1190 		{
1191 			bell();
1192 			break;
1193 		}
1194 		make_display();
1195 		forward(1, 0, 0);
1196 	}
1197 	ignore_eoi = 0;
1198 	ch_set_eof();
1199 
1200 	/*
1201 	 * This gets us back in "F mode" after processing
1202 	 * a non-abort signal (e.g. window-change).
1203 	 */
1204 	if (sigs && !ABORT_SIGS())
1205 		return (until_hilite ? A_F_UNTIL_HILITE : A_F_FOREVER);
1206 
1207 	return (A_NOACTION);
1208 }
1209 
1210 /*
1211  * Main command processor.
1212  * Accept and execute commands until a quit command.
1213  */
1214 public void commands(void)
1215 {
1216 	int c;
1217 	int action;
1218 	char *cbuf;
1219 	int newaction;
1220 	int save_jump_sline;
1221 	int save_search_type;
1222 	char *extra;
1223 	char tbuf[2];
1224 	PARG parg;
1225 	IFILE old_ifile;
1226 	IFILE new_ifile;
1227 	char *tagfile;
1228 
1229 	search_type = SRCH_FORW;
1230 	wscroll = (sc_height + 1) / 2;
1231 	newaction = A_NOACTION;
1232 
1233 	for (;;)
1234 	{
1235 		clear_mca();
1236 		cmd_accept();
1237 		number = 0;
1238 		curropt = NULL;
1239 
1240 		/*
1241 		 * See if any signals need processing.
1242 		 */
1243 		if (sigs)
1244 		{
1245 			psignals();
1246 			if (quitting)
1247 				quit(QUIT_SAVED_STATUS);
1248 		}
1249 
1250 		/*
1251 		 * See if window size changed, for systems that don't
1252 		 * generate SIGWINCH.
1253 		 */
1254 		check_winch();
1255 
1256 		/*
1257 		 * Display prompt and accept a character.
1258 		 */
1259 		cmd_reset();
1260 		prompt();
1261 		if (sigs)
1262 			continue;
1263 		if (newaction == A_NOACTION)
1264 			c = getcc();
1265 
1266 	again:
1267 		if (sigs)
1268 			continue;
1269 
1270 		if (newaction != A_NOACTION)
1271 		{
1272 			action = newaction;
1273 			newaction = A_NOACTION;
1274 		} else
1275 		{
1276 			/*
1277 			 * If we are in a multicharacter command, call mca_char.
1278 			 * Otherwise we call fcmd_decode to determine the
1279 			 * action to be performed.
1280 			 */
1281 			if (mca)
1282 				switch (mca_char(c))
1283 				{
1284 				case MCA_MORE:
1285 					/*
1286 					 * Need another character.
1287 					 */
1288 					c = getcc();
1289 					goto again;
1290 				case MCA_DONE:
1291 					/*
1292 					 * Command has been handled by mca_char.
1293 					 * Start clean with a prompt.
1294 					 */
1295 					continue;
1296 				case NO_MCA:
1297 					/*
1298 					 * Not a multi-char command
1299 					 * (at least, not anymore).
1300 					 */
1301 					break;
1302 				}
1303 
1304 			/*
1305 			 * Decode the command character and decide what to do.
1306 			 */
1307 			if (mca)
1308 			{
1309 				/*
1310 				 * We're in a multichar command.
1311 				 * Add the character to the command buffer
1312 				 * and display it on the screen.
1313 				 * If the user backspaces past the start
1314 				 * of the line, abort the command.
1315 				 */
1316 				if (cmd_char(c) == CC_QUIT || len_cmdbuf() == 0)
1317 					continue;
1318 				cbuf = get_cmdbuf();
1319 				if (cbuf == NULL)
1320 					continue;
1321 			} else
1322 			{
1323 				/*
1324 				 * Don't use cmd_char if we're starting fresh
1325 				 * at the beginning of a command, because we
1326 				 * don't want to echo the command until we know
1327 				 * it is a multichar command.  We also don't
1328 				 * want erase_char/kill_char to be treated
1329 				 * as line editing characters.
1330 				 */
1331 				tbuf[0] = c;
1332 				tbuf[1] = '\0';
1333 				cbuf = tbuf;
1334 			}
1335 			extra = NULL;
1336 			action = fcmd_decode(cbuf, &extra);
1337 			/*
1338 			 * If an "extra" string was returned,
1339 			 * process it as a string of command characters.
1340 			 */
1341 			if (extra != NULL)
1342 				ungetsc(extra);
1343 		}
1344 		/*
1345 		 * Clear the cmdbuf string.
1346 		 * (But not if we're in the prefix of a command,
1347 		 * because the partial command string is kept there.)
1348 		 */
1349 		if (action != A_PREFIX)
1350 			cmd_reset();
1351 
1352 		switch (action)
1353 		{
1354 		case A_DIGIT:
1355 			/*
1356 			 * First digit of a number.
1357 			 */
1358 			start_mca(A_DIGIT, ":", (void*)NULL, CF_QUIT_ON_ERASE);
1359 			goto again;
1360 
1361 		case A_F_WINDOW:
1362 			/*
1363 			 * Forward one window (and set the window size).
1364 			 */
1365 			if (number > 0)
1366 				swindow = (int) number;
1367 			/* FALLTHRU */
1368 		case A_F_SCREEN:
1369 			/*
1370 			 * Forward one screen.
1371 			 */
1372 			if (number <= 0)
1373 				number = get_swindow();
1374 			cmd_exec();
1375 			if (show_attn)
1376 				set_attnpos(bottompos);
1377 			forward((int) number, 0, 1);
1378 			break;
1379 
1380 		case A_B_WINDOW:
1381 			/*
1382 			 * Backward one window (and set the window size).
1383 			 */
1384 			if (number > 0)
1385 				swindow = (int) number;
1386 			/* FALLTHRU */
1387 		case A_B_SCREEN:
1388 			/*
1389 			 * Backward one screen.
1390 			 */
1391 			if (number <= 0)
1392 				number = get_swindow();
1393 			cmd_exec();
1394 			backward((int) number, 0, 1);
1395 			break;
1396 
1397 		case A_F_LINE:
1398 			/*
1399 			 * Forward N (default 1) line.
1400 			 */
1401 			if (number <= 0)
1402 				number = 1;
1403 			cmd_exec();
1404 			if (show_attn == OPT_ONPLUS && number > 1)
1405 				set_attnpos(bottompos);
1406 			forward((int) number, 0, 0);
1407 			break;
1408 
1409 		case A_B_LINE:
1410 			/*
1411 			 * Backward N (default 1) line.
1412 			 */
1413 			if (number <= 0)
1414 				number = 1;
1415 			cmd_exec();
1416 			backward((int) number, 0, 0);
1417 			break;
1418 
1419 		case A_F_MOUSE:
1420 			/*
1421 			 * Forward wheel_lines lines.
1422 			 */
1423 			cmd_exec();
1424 			forward(wheel_lines, 0, 0);
1425 			break;
1426 
1427 		case A_B_MOUSE:
1428 			/*
1429 			 * Backward wheel_lines lines.
1430 			 */
1431 			cmd_exec();
1432 			backward(wheel_lines, 0, 0);
1433 			break;
1434 
1435 		case A_FF_LINE:
1436 			/*
1437 			 * Force forward N (default 1) line.
1438 			 */
1439 			if (number <= 0)
1440 				number = 1;
1441 			cmd_exec();
1442 			if (show_attn == OPT_ONPLUS && number > 1)
1443 				set_attnpos(bottompos);
1444 			forward((int) number, 1, 0);
1445 			break;
1446 
1447 		case A_BF_LINE:
1448 			/*
1449 			 * Force backward N (default 1) line.
1450 			 */
1451 			if (number <= 0)
1452 				number = 1;
1453 			cmd_exec();
1454 			backward((int) number, 1, 0);
1455 			break;
1456 
1457 		case A_FF_SCREEN:
1458 			/*
1459 			 * Force forward one screen.
1460 			 */
1461 			if (number <= 0)
1462 				number = get_swindow();
1463 			cmd_exec();
1464 			if (show_attn == OPT_ONPLUS)
1465 				set_attnpos(bottompos);
1466 			forward((int) number, 1, 0);
1467 			break;
1468 
1469 		case A_F_FOREVER:
1470 			/*
1471 			 * Forward forever, ignoring EOF.
1472 			 */
1473 			if (show_attn)
1474 				set_attnpos(bottompos);
1475 			newaction = forw_loop(0);
1476 			break;
1477 
1478 		case A_F_UNTIL_HILITE:
1479 			newaction = forw_loop(1);
1480 			break;
1481 
1482 		case A_F_SCROLL:
1483 			/*
1484 			 * Forward N lines
1485 			 * (default same as last 'd' or 'u' command).
1486 			 */
1487 			if (number > 0)
1488 				wscroll = (int) number;
1489 			cmd_exec();
1490 			if (show_attn == OPT_ONPLUS)
1491 				set_attnpos(bottompos);
1492 			forward(wscroll, 0, 0);
1493 			break;
1494 
1495 		case A_B_SCROLL:
1496 			/*
1497 			 * Forward N lines
1498 			 * (default same as last 'd' or 'u' command).
1499 			 */
1500 			if (number > 0)
1501 				wscroll = (int) number;
1502 			cmd_exec();
1503 			backward(wscroll, 0, 0);
1504 			break;
1505 
1506 		case A_FREPAINT:
1507 			/*
1508 			 * Flush buffers, then repaint screen.
1509 			 * Don't flush the buffers on a pipe!
1510 			 */
1511 			clear_buffers();
1512 			/* FALLTHRU */
1513 		case A_REPAINT:
1514 			/*
1515 			 * Repaint screen.
1516 			 */
1517 			cmd_exec();
1518 			repaint();
1519 			break;
1520 
1521 		case A_GOLINE:
1522 			/*
1523 			 * Go to line N, default beginning of file.
1524 			 * If N <= 0, ignore jump_sline in order to avoid
1525 			 * empty lines before the beginning of the file.
1526 			 */
1527 			save_jump_sline = jump_sline;
1528 			if (number <= 0)
1529 			{
1530 				number = 1;
1531 				jump_sline = 0;
1532 			}
1533 			cmd_exec();
1534 			jump_back(number);
1535 			jump_sline = save_jump_sline;
1536 			break;
1537 
1538 		case A_PERCENT:
1539 			/*
1540 			 * Go to a specified percentage into the file.
1541 			 */
1542 			if (number < 0)
1543 			{
1544 				number = 0;
1545 				fraction = 0;
1546 			}
1547 			if (number > 100 || (number == 100 && fraction != 0))
1548 			{
1549 				number = 100;
1550 				fraction = 0;
1551 			}
1552 			cmd_exec();
1553 			jump_percent((int) number, fraction);
1554 			break;
1555 
1556 		case A_GOEND:
1557 			/*
1558 			 * Go to line N, default end of file.
1559 			 */
1560 			cmd_exec();
1561 			if (number <= 0)
1562 				jump_forw();
1563 			else
1564 				jump_back(number);
1565 			break;
1566 
1567 		case A_GOEND_BUF:
1568 			/*
1569 			 * Go to line N, default last buffered byte.
1570 			 */
1571 			cmd_exec();
1572 			if (number <= 0)
1573 				jump_forw_buffered();
1574 			else
1575 				jump_back(number);
1576 			break;
1577 
1578 		case A_GOPOS:
1579 			/*
1580 			 * Go to a specified byte position in the file.
1581 			 */
1582 			cmd_exec();
1583 			if (number < 0)
1584 				number = 0;
1585 			jump_line_loc((POSITION) number, jump_sline);
1586 			break;
1587 
1588 		case A_STAT:
1589 			/*
1590 			 * Print file name, etc.
1591 			 */
1592 			if (ch_getflags() & CH_HELPFILE)
1593 				break;
1594 			cmd_exec();
1595 			parg.p_string = eq_message();
1596 			error("%s", &parg);
1597 			break;
1598 
1599 		case A_VERSION:
1600 			/*
1601 			 * Print version number.
1602 			 */
1603 			cmd_exec();
1604 			dispversion();
1605 			break;
1606 
1607 		case A_QUIT:
1608 			/*
1609 			 * Exit.
1610 			 */
1611 			if (curr_ifile != NULL_IFILE &&
1612 			    ch_getflags() & CH_HELPFILE)
1613 			{
1614 				/*
1615 				 * Quit while viewing the help file
1616 				 * just means return to viewing the
1617 				 * previous file.
1618 				 */
1619 				hshift = save_hshift;
1620 				bs_mode = save_bs_mode;
1621 				proc_backspace = save_proc_backspace;
1622 				if (edit_prev(1) == 0)
1623 					break;
1624 			}
1625 			if (extra != NULL)
1626 				quit(*extra);
1627 			quit(QUIT_OK);
1628 			break;
1629 
1630 /*
1631  * Define abbreviation for a commonly used sequence below.
1632  */
1633 #define DO_SEARCH() \
1634 			if (number <= 0) number = 1;    \
1635 			mca_search();                   \
1636 			cmd_exec();                     \
1637 			multi_search((char *)NULL, (int) number, 0);
1638 
1639 		case A_F_SEARCH:
1640 			/*
1641 			 * Search forward for a pattern.
1642 			 * Get the first char of the pattern.
1643 			 */
1644 			search_type = SRCH_FORW | def_search_type;
1645 			if (number <= 0)
1646 				number = 1;
1647 			mca_search();
1648 			c = getcc();
1649 			goto again;
1650 
1651 		case A_B_SEARCH:
1652 			/*
1653 			 * Search backward for a pattern.
1654 			 * Get the first char of the pattern.
1655 			 */
1656 			search_type = SRCH_BACK | def_search_type;
1657 			if (number <= 0)
1658 				number = 1;
1659 			mca_search();
1660 			c = getcc();
1661 			goto again;
1662 
1663 		case A_FILTER:
1664 #if HILITE_SEARCH
1665 			search_type = SRCH_FORW | SRCH_FILTER;
1666 			mca_search();
1667 			c = getcc();
1668 			goto again;
1669 #else
1670 			error("Command not available", NULL_PARG);
1671 			break;
1672 #endif
1673 
1674 		case A_AGAIN_SEARCH:
1675 			/*
1676 			 * Repeat previous search.
1677 			 */
1678 			search_type = last_search_type;
1679 			DO_SEARCH();
1680 			break;
1681 
1682 		case A_T_AGAIN_SEARCH:
1683 			/*
1684 			 * Repeat previous search, multiple files.
1685 			 */
1686 			search_type = last_search_type | SRCH_PAST_EOF;
1687 			DO_SEARCH();
1688 			break;
1689 
1690 		case A_REVERSE_SEARCH:
1691 			/*
1692 			 * Repeat previous search, in reverse direction.
1693 			 */
1694 			save_search_type = search_type = last_search_type;
1695 			search_type = SRCH_REVERSE(search_type);
1696 			DO_SEARCH();
1697 			last_search_type = save_search_type;
1698 			break;
1699 
1700 		case A_T_REVERSE_SEARCH:
1701 			/*
1702 			 * Repeat previous search,
1703 			 * multiple files in reverse direction.
1704 			 */
1705 			save_search_type = search_type = last_search_type;
1706 			search_type = SRCH_REVERSE(search_type) | SRCH_PAST_EOF;
1707 			DO_SEARCH();
1708 			last_search_type = save_search_type;
1709 			break;
1710 
1711 		case A_UNDO_SEARCH:
1712 		case A_CLR_SEARCH:
1713 			/*
1714 			 * Clear search string highlighting.
1715 			 */
1716 			undo_search(action == A_CLR_SEARCH);
1717 			break;
1718 
1719 		case A_HELP:
1720 			/*
1721 			 * Help.
1722 			 */
1723 			if (ch_getflags() & CH_HELPFILE)
1724 				break;
1725 			cmd_exec();
1726 			save_hshift = hshift;
1727 			hshift = 0;
1728 			save_bs_mode = bs_mode;
1729 			bs_mode = BS_SPECIAL;
1730 			save_proc_backspace = proc_backspace;
1731 			proc_backspace = OPT_OFF;
1732 			(void) edit(FAKE_HELPFILE);
1733 			break;
1734 
1735 		case A_EXAMINE:
1736 			/*
1737 			 * Edit a new file.  Get the filename.
1738 			 */
1739 #if EXAMINE
1740 			if (!secure)
1741 			{
1742 				start_mca(A_EXAMINE, "Examine: ", ml_examine, 0);
1743 				c = getcc();
1744 				goto again;
1745 			}
1746 #endif
1747 			error("Command not available", NULL_PARG);
1748 			break;
1749 
1750 		case A_VISUAL:
1751 			/*
1752 			 * Invoke an editor on the input file.
1753 			 */
1754 #if EDITOR
1755 			if (!secure)
1756 			{
1757 				if (ch_getflags() & CH_HELPFILE)
1758 					break;
1759 				if (strcmp(get_filename(curr_ifile), "-") == 0)
1760 				{
1761 					error("Cannot edit standard input", NULL_PARG);
1762 					break;
1763 				}
1764 				if (get_altfilename(curr_ifile) != NULL)
1765 				{
1766 					error("WARNING: This file was viewed via LESSOPEN",
1767 						NULL_PARG);
1768 				}
1769 				start_mca(A_SHELL, "!", ml_shell, 0);
1770 				/*
1771 				 * Expand the editor prototype string
1772 				 * and pass it to the system to execute.
1773 				 * (Make sure the screen is displayed so the
1774 				 * expansion of "+%lm" works.)
1775 				 */
1776 				make_display();
1777 				cmd_exec();
1778 				lsystem(pr_expand(editproto), (char*)NULL);
1779 				break;
1780 			}
1781 #endif
1782 			error("Command not available", NULL_PARG);
1783 			break;
1784 
1785 		case A_NEXT_FILE:
1786 			/*
1787 			 * Examine next file.
1788 			 */
1789 #if TAGS
1790 			if (ntags())
1791 			{
1792 				error("No next file", NULL_PARG);
1793 				break;
1794 			}
1795 #endif
1796 			if (number <= 0)
1797 				number = 1;
1798 			if (edit_next((int) number))
1799 			{
1800 				if (get_quit_at_eof() && eof_displayed() &&
1801 				    !(ch_getflags() & CH_HELPFILE))
1802 					quit(QUIT_OK);
1803 				parg.p_string = (number > 1) ? "(N-th) " : "";
1804 				error("No %snext file", &parg);
1805 			}
1806 			break;
1807 
1808 		case A_PREV_FILE:
1809 			/*
1810 			 * Examine previous file.
1811 			 */
1812 #if TAGS
1813 			if (ntags())
1814 			{
1815 				error("No previous file", NULL_PARG);
1816 				break;
1817 			}
1818 #endif
1819 			if (number <= 0)
1820 				number = 1;
1821 			if (edit_prev((int) number))
1822 			{
1823 				parg.p_string = (number > 1) ? "(N-th) " : "";
1824 				error("No %sprevious file", &parg);
1825 			}
1826 			break;
1827 
1828 		case A_NEXT_TAG:
1829 			/*
1830 			 * Jump to the next tag in the current tag list.
1831 			 */
1832 #if TAGS
1833 			if (number <= 0)
1834 				number = 1;
1835 			tagfile = nexttag((int) number);
1836 			if (tagfile == NULL)
1837 			{
1838 				error("No next tag", NULL_PARG);
1839 				break;
1840 			}
1841 			cmd_exec();
1842 			if (edit(tagfile) == 0)
1843 			{
1844 				POSITION pos = tagsearch();
1845 				if (pos != NULL_POSITION)
1846 					jump_loc(pos, jump_sline);
1847 			}
1848 #else
1849 			error("Command not available", NULL_PARG);
1850 #endif
1851 			break;
1852 
1853 		case A_PREV_TAG:
1854 			/*
1855 			 * Jump to the previous tag in the current tag list.
1856 			 */
1857 #if TAGS
1858 			if (number <= 0)
1859 				number = 1;
1860 			tagfile = prevtag((int) number);
1861 			if (tagfile == NULL)
1862 			{
1863 				error("No previous tag", NULL_PARG);
1864 				break;
1865 			}
1866 			cmd_exec();
1867 			if (edit(tagfile) == 0)
1868 			{
1869 				POSITION pos = tagsearch();
1870 				if (pos != NULL_POSITION)
1871 					jump_loc(pos, jump_sline);
1872 			}
1873 #else
1874 			error("Command not available", NULL_PARG);
1875 #endif
1876 			break;
1877 
1878 		case A_INDEX_FILE:
1879 			/*
1880 			 * Examine a particular file.
1881 			 */
1882 			if (number <= 0)
1883 				number = 1;
1884 			if (edit_index((int) number))
1885 				error("No such file", NULL_PARG);
1886 			break;
1887 
1888 		case A_REMOVE_FILE:
1889 			/*
1890 			 * Remove a file from the input file list.
1891 			 */
1892 			if (ch_getflags() & CH_HELPFILE)
1893 				break;
1894 			old_ifile = curr_ifile;
1895 			new_ifile = getoff_ifile(curr_ifile);
1896 			if (new_ifile == NULL_IFILE)
1897 			{
1898 				bell();
1899 				break;
1900 			}
1901 			if (edit_ifile(new_ifile) != 0)
1902 			{
1903 				reedit_ifile(old_ifile);
1904 				break;
1905 			}
1906 			del_ifile(old_ifile);
1907 			break;
1908 
1909 		case A_OPT_TOGGLE:
1910 			/*
1911 			 * Change the setting of an  option.
1912 			 */
1913 			optflag = OPT_TOGGLE;
1914 			optgetname = FALSE;
1915 			mca_opt_toggle();
1916 			c = getcc();
1917 			cbuf = opt_toggle_disallowed(c);
1918 			if (cbuf != NULL)
1919 			{
1920 				error(cbuf, NULL_PARG);
1921 				break;
1922 			}
1923 			goto again;
1924 
1925 		case A_DISP_OPTION:
1926 			/*
1927 			 * Report the setting of an option.
1928 			 */
1929 			optflag = OPT_NO_TOGGLE;
1930 			optgetname = FALSE;
1931 			mca_opt_toggle();
1932 			c = getcc();
1933 			goto again;
1934 
1935 		case A_FIRSTCMD:
1936 			/*
1937 			 * Set an initial command for new files.
1938 			 */
1939 			start_mca(A_FIRSTCMD, "+", (void*)NULL, 0);
1940 			c = getcc();
1941 			goto again;
1942 
1943 		case A_SHELL:
1944 		case A_PSHELL:
1945 			/*
1946 			 * Shell escape.
1947 			 */
1948 #if SHELL_ESCAPE
1949 			if (!secure)
1950 			{
1951 				start_mca(action, (action == A_SHELL) ? "!" : "#", ml_shell, 0);
1952 				c = getcc();
1953 				goto again;
1954 			}
1955 #endif
1956 			error("Command not available", NULL_PARG);
1957 			break;
1958 
1959 		case A_SETMARK:
1960 		case A_SETMARKBOT:
1961 			/*
1962 			 * Set a mark.
1963 			 */
1964 			if (ch_getflags() & CH_HELPFILE)
1965 				break;
1966 			start_mca(A_SETMARK, "set mark: ", (void*)NULL, 0);
1967 			c = getcc();
1968 			if (is_erase_char(c) || is_newline_char(c))
1969 				break;
1970 			setmark(c, action == A_SETMARKBOT ? BOTTOM : TOP);
1971 			repaint();
1972 			break;
1973 
1974 		case A_CLRMARK:
1975 			/*
1976 			 * Clear a mark.
1977 			 */
1978 			start_mca(A_CLRMARK, "clear mark: ", (void*)NULL, 0);
1979 			c = getcc();
1980 			if (is_erase_char(c) || is_newline_char(c))
1981 				break;
1982 			clrmark(c);
1983 			repaint();
1984 			break;
1985 
1986 		case A_GOMARK:
1987 			/*
1988 			 * Jump to a marked position.
1989 			 */
1990 			start_mca(A_GOMARK, "goto mark: ", (void*)NULL, 0);
1991 			c = getcc();
1992 			if (is_erase_char(c) || is_newline_char(c))
1993 				break;
1994 			cmd_exec();
1995 			gomark(c);
1996 			break;
1997 
1998 		case A_PIPE:
1999 			/*
2000 			 * Write part of the input to a pipe to a shell command.
2001 			 */
2002 #if PIPEC
2003 			if (!secure)
2004 			{
2005 				start_mca(A_PIPE, "|mark: ", (void*)NULL, 0);
2006 				c = getcc();
2007 				if (is_erase_char(c))
2008 					break;
2009 				if (is_newline_char(c))
2010 					c = '.';
2011 				if (badmark(c))
2012 					break;
2013 				pipec = c;
2014 				start_mca(A_PIPE, "!", ml_shell, 0);
2015 				c = getcc();
2016 				goto again;
2017 			}
2018 #endif
2019 			error("Command not available", NULL_PARG);
2020 			break;
2021 
2022 		case A_B_BRACKET:
2023 		case A_F_BRACKET:
2024 			start_mca(action, "Brackets: ", (void*)NULL, 0);
2025 			c = getcc();
2026 			goto again;
2027 
2028 		case A_LSHIFT:
2029 			/*
2030 			 * Shift view left.
2031 			 */
2032 			if (number > 0)
2033 				shift_count = number;
2034 			else
2035 				number = (shift_count > 0) ?
2036 					shift_count : sc_width / 2;
2037 			if (number > hshift)
2038 				number = hshift;
2039 			hshift -= number;
2040 			screen_trashed = 1;
2041 			break;
2042 
2043 		case A_RSHIFT:
2044 			/*
2045 			 * Shift view right.
2046 			 */
2047 			if (number > 0)
2048 				shift_count = number;
2049 			else
2050 				number = (shift_count > 0) ?
2051 					shift_count : sc_width / 2;
2052 			hshift += number;
2053 			screen_trashed = 1;
2054 			break;
2055 
2056 		case A_LLSHIFT:
2057 			/*
2058 			 * Shift view left to margin.
2059 			 */
2060 			hshift = 0;
2061 			screen_trashed = 1;
2062 			break;
2063 
2064 		case A_RRSHIFT:
2065 			/*
2066 			 * Shift view right to view rightmost char on screen.
2067 			 */
2068 			hshift = rrshift();
2069 			screen_trashed = 1;
2070 			break;
2071 
2072 		case A_PREFIX:
2073 			/*
2074 			 * The command is incomplete (more chars are needed).
2075 			 * Display the current char, so the user knows
2076 			 * what's going on, and get another character.
2077 			 */
2078 			if (mca != A_PREFIX)
2079 			{
2080 				cmd_reset();
2081 				start_mca(A_PREFIX, " ", (void*)NULL,
2082 					CF_QUIT_ON_ERASE);
2083 				(void) cmd_char(c);
2084 			}
2085 			c = getcc();
2086 			goto again;
2087 
2088 		case A_NOACTION:
2089 			break;
2090 
2091 		default:
2092 			bell();
2093 			break;
2094 		}
2095 	}
2096 }
2097