xref: /dragonfly/contrib/less/command.c (revision 7485684f)
1 /*
2  * Copyright (C) 1984-2023  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 squished;
28 extern int sc_width;
29 extern int sc_height;
30 extern char *kent;
31 extern int swindow;
32 extern int jump_sline;
33 extern int quitting;
34 extern int wscroll;
35 extern int top_scroll;
36 extern int ignore_eoi;
37 extern int secure;
38 extern int hshift;
39 extern int bs_mode;
40 extern int proc_backspace;
41 extern int show_attn;
42 extern int status_col;
43 extern POSITION highest_hilite;
44 extern POSITION start_attnpos;
45 extern POSITION end_attnpos;
46 extern char *every_first_cmd;
47 extern char version[];
48 extern struct scrpos initial_scrpos;
49 extern IFILE curr_ifile;
50 extern void *ml_search;
51 extern void *ml_examine;
52 extern int wheel_lines;
53 extern int header_lines;
54 extern int def_search_type;
55 extern int updown_match;
56 #if SHELL_ESCAPE || PIPEC
57 extern void *ml_shell;
58 #endif
59 #if EDITOR
60 extern char *editor;
61 extern char *editproto;
62 #endif
63 extern int screen_trashed;      /* The screen has been overwritten */
64 extern int shift_count;
65 extern int oldbot;
66 extern int forw_prompt;
67 extern int incr_search;
68 extern int full_screen;
69 #if MSDOS_COMPILER==WIN32C
70 extern int utf_mode;
71 #endif
72 
73 #if SHELL_ESCAPE
74 static char *shellcmd = NULL;   /* For holding last shell command for "!!" */
75 #endif
76 static int mca;                 /* The multicharacter command (action) */
77 static int search_type;         /* The previous type of search */
78 static int last_search_type;    /* Type of last executed search */
79 static LINENUM number;          /* The number typed by the user */
80 static long fraction;           /* The fractional part of the number */
81 static struct loption *curropt;
82 static int opt_lower;
83 static int optflag;
84 static int optgetname;
85 static POSITION bottompos;
86 static int save_hshift;
87 static int save_bs_mode;
88 static int save_proc_backspace;
89 #if PIPEC
90 static char pipec;
91 #endif
92 
93 /* Stack of ungotten chars (via ungetcc) */
94 struct ungot {
95 	struct ungot *ug_next;
96 	LWCHAR ug_char;
97 };
98 static struct ungot* ungot = NULL;
99 
100 static void multi_search (char *pattern, int n, int silent);
101 
102 /*
103  * Move the cursor to start of prompt line before executing a command.
104  * This looks nicer if the command takes a long time before
105  * updating the screen.
106  */
107 static void cmd_exec(void)
108 {
109 	clear_attn();
110 	clear_bot();
111 	flush();
112 }
113 
114 /*
115  * Indicate we are reading a multi-character command.
116  */
117 static void set_mca(int action)
118 {
119 	mca = action;
120 	clear_bot();
121 	clear_cmd();
122 }
123 
124 /*
125  * Indicate we are not reading a multi-character command.
126  */
127 static void clear_mca(void)
128 {
129 	if (mca == 0)
130 		return;
131 	mca = 0;
132 }
133 
134 /*
135  * Set up the display to start a new multi-character command.
136  */
137 static void start_mca(int action, constant char *prompt, void *mlist, int cmdflags)
138 {
139 	set_mca(action);
140 	cmd_putstr(prompt);
141 	set_mlist(mlist, cmdflags);
142 }
143 
144 public int in_mca(void)
145 {
146 	return (mca != 0 && mca != A_PREFIX);
147 }
148 
149 /*
150  * Set up the display to start a new search command.
151  */
152 static void mca_search1(void)
153 {
154 	int i;
155 
156 #if HILITE_SEARCH
157 	if (search_type & SRCH_FILTER)
158 		set_mca(A_FILTER);
159 	else
160 #endif
161 	if (search_type & SRCH_FORW)
162 		set_mca(A_F_SEARCH);
163 	else
164 		set_mca(A_B_SEARCH);
165 
166 	if (search_type & SRCH_NO_MATCH)
167 		cmd_putstr("Non-match ");
168 	if (search_type & SRCH_FIRST_FILE)
169 		cmd_putstr("First-file ");
170 	if (search_type & SRCH_PAST_EOF)
171 		cmd_putstr("EOF-ignore ");
172 	if (search_type & SRCH_NO_MOVE)
173 		cmd_putstr("Keep-pos ");
174 	if (search_type & SRCH_NO_REGEX)
175 		cmd_putstr("Regex-off ");
176 	if (search_type & SRCH_WRAP)
177 		cmd_putstr("Wrap ");
178 	for (i = 1; i <= NUM_SEARCH_COLORS; i++)
179 	{
180 		if (search_type & SRCH_SUBSEARCH(i))
181 		{
182 			char buf[INT_STRLEN_BOUND(int)+8];
183 			SNPRINTF1(buf, sizeof(buf), "Sub-%d ", i);
184 			cmd_putstr(buf);
185 		}
186 	}
187 
188 #if HILITE_SEARCH
189 	if (search_type & SRCH_FILTER)
190 		cmd_putstr("&/");
191 	else
192 #endif
193 	if (search_type & SRCH_FORW)
194 		cmd_putstr("/");
195 	else
196 		cmd_putstr("?");
197 	forw_prompt = 0;
198 }
199 
200 static void mca_search(void)
201 {
202 	mca_search1();
203 	set_mlist(ml_search, 0);
204 }
205 
206 /*
207  * Set up the display to start a new toggle-option command.
208  */
209 static void mca_opt_toggle(void)
210 {
211 	int no_prompt;
212 	int flag;
213 	char *dash;
214 
215 	no_prompt = (optflag & OPT_NO_PROMPT);
216 	flag = (optflag & ~OPT_NO_PROMPT);
217 	dash = (flag == OPT_NO_TOGGLE) ? "_" : "-";
218 
219 	set_mca(A_OPT_TOGGLE);
220 	cmd_putstr(dash);
221 	if (optgetname)
222 		cmd_putstr(dash);
223 	if (no_prompt)
224 		cmd_putstr("(P)");
225 	switch (flag)
226 	{
227 	case OPT_UNSET:
228 		cmd_putstr("+");
229 		break;
230 	case OPT_SET:
231 		cmd_putstr("!");
232 		break;
233 	}
234 	forw_prompt = 0;
235 	set_mlist(NULL, 0);
236 }
237 
238 /*
239  * Execute a multicharacter command.
240  */
241 static void exec_mca(void)
242 {
243 	char *cbuf;
244 
245 	cmd_exec();
246 	cbuf = get_cmdbuf();
247 	if (cbuf == NULL)
248 		return;
249 
250 	switch (mca)
251 	{
252 	case A_F_SEARCH:
253 	case A_B_SEARCH:
254 		multi_search(cbuf, (int) number, 0);
255 		break;
256 #if HILITE_SEARCH
257 	case A_FILTER:
258 		search_type ^= SRCH_NO_MATCH;
259 		set_filter_pattern(cbuf, search_type);
260 		break;
261 #endif
262 	case A_FIRSTCMD:
263 		/*
264 		 * Skip leading spaces or + signs in the string.
265 		 */
266 		while (*cbuf == '+' || *cbuf == ' ')
267 			cbuf++;
268 		if (every_first_cmd != NULL)
269 			free(every_first_cmd);
270 		if (*cbuf == '\0')
271 			every_first_cmd = NULL;
272 		else
273 			every_first_cmd = save(cbuf);
274 		break;
275 	case A_OPT_TOGGLE:
276 		toggle_option(curropt, opt_lower, cbuf, optflag);
277 		curropt = NULL;
278 		break;
279 	case A_F_BRACKET:
280 		match_brac(cbuf[0], cbuf[1], 1, (int) number);
281 		break;
282 	case A_B_BRACKET:
283 		match_brac(cbuf[1], cbuf[0], 0, (int) number);
284 		break;
285 #if EXAMINE
286 	case A_EXAMINE:
287 		if (secure)
288 			break;
289 		edit_list(cbuf);
290 #if TAGS
291 		/* If tag structure is loaded then clean it up. */
292 		cleantags();
293 #endif
294 		break;
295 #endif
296 #if SHELL_ESCAPE
297 	case A_SHELL:
298 		/*
299 		 * !! just uses whatever is in shellcmd.
300 		 * Otherwise, copy cmdbuf to shellcmd,
301 		 * expanding any special characters ("%" or "#").
302 		 */
303 		if (*cbuf != '!')
304 		{
305 			if (shellcmd != NULL)
306 				free(shellcmd);
307 			shellcmd = fexpand(cbuf);
308 		}
309 
310 		if (secure)
311 			break;
312 		if (shellcmd == NULL)
313 			lsystem("", "!done");
314 		else
315 			lsystem(shellcmd, "!done");
316 		break;
317 	case A_PSHELL:
318 		if (secure)
319 			break;
320 		lsystem(pr_expand(cbuf), "#done");
321 		break;
322 #endif
323 #if PIPEC
324 	case A_PIPE:
325 		if (secure)
326 			break;
327 		(void) pipe_mark(pipec, cbuf);
328 		error("|done", NULL_PARG);
329 		break;
330 #endif
331 	}
332 }
333 
334 /*
335  * Is a character an erase or kill char?
336  */
337 static int is_erase_char(int c)
338 {
339 	return (c == erase_char || c == erase2_char || c == kill_char);
340 }
341 
342 /*
343  * Is a character a carriage return or newline?
344  */
345 static int is_newline_char(int c)
346 {
347 	return (c == '\n' || c == '\r');
348 }
349 
350 /*
351  * Handle the first char of an option (after the initial dash).
352  */
353 static int mca_opt_first_char(int c)
354 {
355 	int no_prompt = (optflag & OPT_NO_PROMPT);
356 	int flag = (optflag & ~OPT_NO_PROMPT);
357 	if (flag == OPT_NO_TOGGLE)
358 	{
359 		switch (c)
360 		{
361 		case '_':
362 			/* "__" = long option name. */
363 			optgetname = TRUE;
364 			mca_opt_toggle();
365 			return (MCA_MORE);
366 		}
367 	} else
368 	{
369 		switch (c)
370 		{
371 		case '+':
372 			/* "-+" = UNSET. */
373 			optflag = no_prompt | ((flag == OPT_UNSET) ?
374 				OPT_TOGGLE : OPT_UNSET);
375 			mca_opt_toggle();
376 			return (MCA_MORE);
377 		case '!':
378 			/* "-!" = SET */
379 			optflag = no_prompt | ((flag == OPT_SET) ?
380 				OPT_TOGGLE : OPT_SET);
381 			mca_opt_toggle();
382 			return (MCA_MORE);
383 		case CONTROL('P'):
384 			optflag ^= OPT_NO_PROMPT;
385 			mca_opt_toggle();
386 			return (MCA_MORE);
387 		case '-':
388 			/* "--" = long option name. */
389 			optgetname = TRUE;
390 			mca_opt_toggle();
391 			return (MCA_MORE);
392 		}
393 	}
394 	/* Char was not handled here. */
395 	return (NO_MCA);
396 }
397 
398 /*
399  * Add a char to a long option name.
400  * See if we've got a match for an option name yet.
401  * If so, display the complete name and stop
402  * accepting chars until user hits RETURN.
403  */
404 static int mca_opt_nonfirst_char(int c)
405 {
406 	char *p;
407 	char *oname;
408 	int err;
409 
410 	if (curropt != NULL)
411 	{
412 		/*
413 		 * Already have a match for the name.
414 		 * Don't accept anything but erase/kill.
415 		 */
416 		if (is_erase_char(c))
417 			return (MCA_DONE);
418 		return (MCA_MORE);
419 	}
420 	/*
421 	 * Add char to cmd buffer and try to match
422 	 * the option name.
423 	 */
424 	if (cmd_char(c) == CC_QUIT)
425 		return (MCA_DONE);
426 	p = get_cmdbuf();
427 	if (p == NULL)
428 		return (MCA_MORE);
429 	opt_lower = ASCII_IS_LOWER(p[0]);
430 	err = 0;
431 	curropt = findopt_name(&p, &oname, &err);
432 	if (curropt != NULL)
433 	{
434 		/*
435 		 * Got a match.
436 		 * Remember the option and
437 		 * display the full option name.
438 		 */
439 		cmd_reset();
440 		mca_opt_toggle();
441 		for (p = oname;  *p != '\0';  p++)
442 		{
443 			c = *p;
444 			if (!opt_lower && ASCII_IS_LOWER(c))
445 				c = ASCII_TO_UPPER(c);
446 			if (cmd_char(c) != CC_OK)
447 				return (MCA_DONE);
448 		}
449 	} else if (err != OPT_AMBIG)
450 	{
451 		bell();
452 	}
453 	return (MCA_MORE);
454 }
455 
456 /*
457  * Handle a char of an option toggle command.
458  */
459 static int mca_opt_char(int c)
460 {
461 	PARG parg;
462 
463 	/*
464 	 * This may be a short option (single char),
465 	 * or one char of a long option name,
466 	 * or one char of the option parameter.
467 	 */
468 	if (curropt == NULL && len_cmdbuf() == 0)
469 	{
470 		int ret = mca_opt_first_char(c);
471 		if (ret != NO_MCA)
472 			return (ret);
473 	}
474 	if (optgetname)
475 	{
476 		/* We're getting a long option name.  */
477 		if (!is_newline_char(c) && c != '=')
478 			return (mca_opt_nonfirst_char(c));
479 		if (curropt == NULL)
480 		{
481 			parg.p_string = get_cmdbuf();
482 			if (parg.p_string == NULL)
483 				return (MCA_MORE);
484 			error("There is no --%s option", &parg);
485 			return (MCA_DONE);
486 		}
487 		optgetname = FALSE;
488 		cmd_reset();
489 	} else
490 	{
491 		if (is_erase_char(c))
492 			return (NO_MCA);
493 		if (curropt != NULL)
494 			/* We're getting the option parameter. */
495 			return (NO_MCA);
496 		curropt = findopt(c);
497 		if (curropt == NULL)
498 		{
499 			parg.p_string = propt(c);
500 			error("There is no %s option", &parg);
501 			return (MCA_DONE);
502 		}
503 		opt_lower = ASCII_IS_LOWER(c);
504 	}
505 	/*
506 	 * If the option which was entered does not take a
507 	 * parameter, toggle the option immediately,
508 	 * so user doesn't have to hit RETURN.
509 	 */
510 	if ((optflag & ~OPT_NO_PROMPT) != OPT_TOGGLE ||
511 	    !opt_has_param(curropt))
512 	{
513 		toggle_option(curropt, opt_lower, "", optflag);
514 		return (MCA_DONE);
515 	}
516 	/*
517 	 * Display a prompt appropriate for the option parameter.
518 	 */
519 	start_mca(A_OPT_TOGGLE, opt_prompt(curropt), (void*)NULL, 0);
520 	return (MCA_MORE);
521 }
522 
523 /*
524  * Normalize search type.
525  */
526 public int norm_search_type(int st)
527 {
528 	/* WRAP and PAST_EOF are mutually exclusive. */
529 	if ((st & (SRCH_PAST_EOF|SRCH_WRAP)) == (SRCH_PAST_EOF|SRCH_WRAP))
530 		st ^= SRCH_PAST_EOF;
531 	return st;
532 }
533 
534 /*
535  * Handle a char of a search command.
536  */
537 static int mca_search_char(int c)
538 {
539 	int flag = 0;
540 
541 	/*
542 	 * Certain characters as the first char of
543 	 * the pattern have special meaning:
544 	 *      !  Toggle the NO_MATCH flag
545 	 *      *  Toggle the PAST_EOF flag
546 	 *      @  Toggle the FIRST_FILE flag
547 	 */
548 	if (len_cmdbuf() > 0)
549 		return (NO_MCA);
550 
551 	switch (c)
552 	{
553 	case CONTROL('E'): /* ignore END of file */
554 	case '*':
555 		if (mca != A_FILTER)
556 			flag = SRCH_PAST_EOF;
557 		search_type &= ~SRCH_WRAP;
558 		break;
559 	case CONTROL('F'): /* FIRST file */
560 	case '@':
561 		if (mca != A_FILTER)
562 			flag = SRCH_FIRST_FILE;
563 		break;
564 	case CONTROL('K'): /* KEEP position */
565 		if (mca != A_FILTER)
566 			flag = SRCH_NO_MOVE;
567 		break;
568 	case CONTROL('S'): { /* SUBSEARCH */
569 		char buf[INT_STRLEN_BOUND(int)+24];
570 		SNPRINTF1(buf, sizeof(buf), "Sub-pattern (1-%d):", NUM_SEARCH_COLORS);
571 		clear_bot();
572 		cmd_putstr(buf);
573 		flush();
574 		c = getcc();
575 		if (c >= '1' && c <= '0'+NUM_SEARCH_COLORS)
576 			flag = SRCH_SUBSEARCH(c-'0');
577 		else
578 			flag = -1; /* calls mca_search() below to repaint */
579 		break; }
580 	case CONTROL('W'): /* WRAP around */
581 		if (mca != A_FILTER)
582 			flag = SRCH_WRAP;
583 		break;
584 	case CONTROL('R'): /* Don't use REGULAR EXPRESSIONS */
585 		flag = SRCH_NO_REGEX;
586 		break;
587 	case CONTROL('N'): /* NOT match */
588 	case '!':
589 		flag = SRCH_NO_MATCH;
590 		break;
591 	}
592 
593 	if (flag != 0)
594 	{
595 		if (flag != -1)
596 			search_type = norm_search_type(search_type ^ flag);
597 		mca_search();
598 		return (MCA_MORE);
599 	}
600 	return (NO_MCA);
601 }
602 
603 /*
604  * Handle a character of a multi-character command.
605  */
606 static int mca_char(int c)
607 {
608 	int ret;
609 
610 	switch (mca)
611 	{
612 	case 0:
613 		/*
614 		 * We're not in a multicharacter command.
615 		 */
616 		return (NO_MCA);
617 
618 	case A_PREFIX:
619 		/*
620 		 * In the prefix of a command.
621 		 * This not considered a multichar command
622 		 * (even tho it uses cmdbuf, etc.).
623 		 * It is handled in the commands() switch.
624 		 */
625 		return (NO_MCA);
626 
627 	case A_DIGIT:
628 		/*
629 		 * Entering digits of a number.
630 		 * Terminated by a non-digit.
631 		 */
632 		if ((c >= '0' && c <= '9') || c == '.')
633 			break;
634 		switch (editchar(c, ECF_PEEK|ECF_NOHISTORY|ECF_NOCOMPLETE|ECF_NORIGHTLEFT))
635 		{
636 		case A_NOACTION:
637 			/*
638 			 * Ignore this char and get another one.
639 			 */
640 			return (MCA_MORE);
641 		case A_INVALID:
642 			/*
643 			 * Not part of the number.
644 			 * End the number and treat this char
645 			 * as a normal command character.
646 			 */
647 			number = cmd_int(&fraction);
648 			clear_mca();
649 			cmd_accept();
650 			return (NO_MCA);
651 		}
652 		break;
653 
654 	case A_OPT_TOGGLE:
655 		ret = mca_opt_char(c);
656 		if (ret != NO_MCA)
657 			return (ret);
658 		break;
659 
660 	case A_F_SEARCH:
661 	case A_B_SEARCH:
662 	case A_FILTER:
663 		ret = mca_search_char(c);
664 		if (ret != NO_MCA)
665 			return (ret);
666 		break;
667 
668 	default:
669 		/* Other multicharacter command. */
670 		break;
671 	}
672 
673 	/*
674 	 * The multichar command is terminated by a newline.
675 	 */
676 	if (is_newline_char(c))
677 	{
678 		/*
679 		 * Execute the command.
680 		 */
681 		exec_mca();
682 		return (MCA_DONE);
683 	}
684 
685 	/*
686 	 * Append the char to the command buffer.
687 	 */
688 	if (cmd_char(c) == CC_QUIT)
689 		/*
690 		 * Abort the multi-char command.
691 		 */
692 		return (MCA_DONE);
693 
694 	switch (mca)
695 	{
696 	case A_F_BRACKET:
697 	case A_B_BRACKET:
698 		if (len_cmdbuf() >= 2)
699 		{
700 			/*
701 			 * Special case for the bracket-matching commands.
702 			 * Execute the command after getting exactly two
703 			 * characters from the user.
704 			 */
705 			exec_mca();
706 			return (MCA_DONE);
707 		}
708 		break;
709 	case A_F_SEARCH:
710 	case A_B_SEARCH:
711 		if (incr_search)
712 		{
713 			/* Incremental search: do a search after every input char. */
714 			int st = (search_type & (SRCH_FORW|SRCH_BACK|SRCH_NO_MATCH|SRCH_NO_REGEX|SRCH_NO_MOVE|SRCH_WRAP|SRCH_SUBSEARCH_ALL));
715 			char *pattern = get_cmdbuf();
716 			if (pattern == NULL)
717 				return (MCA_MORE);
718 			/*
719 			 * Must save updown_match because mca_search
720 			 * reinits it. That breaks history scrolling.
721 			 * {{ This is ugly. mca_search probably shouldn't call set_mlist. }}
722 			 */
723 			int save_updown_match = updown_match;
724 			cmd_exec();
725 			if (*pattern == '\0')
726 			{
727 				/* User has backspaced to an empty pattern. */
728 				undo_search(1);
729 			} else
730 			{
731 				if (search(st | SRCH_INCR, pattern, 1) != 0)
732 					/* No match, invalid pattern, etc. */
733 					undo_search(1);
734 			}
735 			/* Redraw the search prompt and search string. */
736 			if (!full_screen)
737 			{
738 				clear();
739 				repaint();
740 			}
741 			mca_search1();
742 			updown_match = save_updown_match;
743 			cmd_repaint(NULL);
744 		}
745 		break;
746 	}
747 
748 	/*
749 	 * Need another character.
750 	 */
751 	return (MCA_MORE);
752 }
753 
754 /*
755  * Discard any buffered file data.
756  */
757 static void clear_buffers(void)
758 {
759 	if (!(ch_getflags() & CH_CANSEEK))
760 		return;
761 	ch_flush();
762 	clr_linenum();
763 #if HILITE_SEARCH
764 	clr_hilite();
765 #endif
766 }
767 
768 /*
769  * Make sure the screen is displayed.
770  */
771 static void make_display(void)
772 {
773 	/*
774 	 * If not full_screen, we can't rely on scrolling to fill the screen.
775 	 * We need to clear and repaint screen before any change.
776 	 */
777 	if (!full_screen && !(quit_if_one_screen && one_screen))
778 		clear();
779 	/*
780 	 * If nothing is displayed yet, display starting from initial_scrpos.
781 	 */
782 	if (empty_screen())
783 	{
784 		if (initial_scrpos.pos == NULL_POSITION)
785 			jump_loc(ch_zero(), 1);
786 		else
787 			jump_loc(initial_scrpos.pos, initial_scrpos.ln);
788 	} else if (screen_trashed || !full_screen)
789 	{
790 		int save_top_scroll = top_scroll;
791 		int save_ignore_eoi = ignore_eoi;
792 		top_scroll = 1;
793 		ignore_eoi = 0;
794 		if (screen_trashed == 2)
795 		{
796 			/* Special case used by ignore_eoi: re-open the input file
797 			 * and jump to the end of the file. */
798 			reopen_curr_ifile();
799 			jump_forw();
800 		}
801 		repaint();
802 		top_scroll = save_top_scroll;
803 		ignore_eoi = save_ignore_eoi;
804 	}
805 }
806 
807 /*
808  * Display the appropriate prompt.
809  */
810 static void prompt(void)
811 {
812 	constant char *p;
813 
814 	if (ungot != NULL && ungot->ug_char != CHAR_END_COMMAND)
815 	{
816 		/*
817 		 * No prompt necessary if commands are from
818 		 * ungotten chars rather than from the user.
819 		 */
820 		return;
821 	}
822 
823 	/*
824 	 * Make sure the screen is displayed.
825 	 */
826 	make_display();
827 	bottompos = position(BOTTOM_PLUS_ONE);
828 
829 	/*
830 	 * If we've hit EOF on the last file and the -E flag is set, quit.
831 	 */
832 	if (get_quit_at_eof() == OPT_ONPLUS &&
833 	    eof_displayed() && !(ch_getflags() & CH_HELPFILE) &&
834 	    next_ifile(curr_ifile) == NULL_IFILE)
835 		quit(QUIT_OK);
836 
837 	/*
838 	 * If the entire file is displayed and the -F flag is set, quit.
839 	 */
840 	if (quit_if_one_screen &&
841 	    entire_file_displayed() && !(ch_getflags() & CH_HELPFILE) &&
842 	    next_ifile(curr_ifile) == NULL_IFILE)
843 		quit(QUIT_OK);
844 	quit_if_one_screen = FALSE; /* only get one chance at this */
845 
846 #if MSDOS_COMPILER==WIN32C
847 	/*
848 	 * In Win32, display the file name in the window title.
849 	 */
850 	if (!(ch_getflags() & CH_HELPFILE))
851 	{
852 		WCHAR w[MAX_PATH+16];
853 		p = pr_expand("Less?f - %f.");
854 		MultiByteToWideChar(CP_ACP, 0, p, -1, w, sizeof(w)/sizeof(*w));
855 		SetConsoleTitleW(w);
856 	}
857 #endif
858 
859 	/*
860 	 * Select the proper prompt and display it.
861 	 */
862 	/*
863 	 * If the previous action was a forward movement,
864 	 * don't clear the bottom line of the display;
865 	 * just print the prompt since the forward movement guarantees
866 	 * that we're in the right position to display the prompt.
867 	 * Clearing the line could cause a problem: for example, if the last
868 	 * line displayed ended at the right screen edge without a newline,
869 	 * then clearing would clear the last displayed line rather than
870 	 * the prompt line.
871 	 */
872 	if (!forw_prompt)
873 		clear_bot();
874 	clear_cmd();
875 	forw_prompt = 0;
876 	p = pr_string();
877 #if HILITE_SEARCH
878 	if (is_filtering())
879 		putstr("& ");
880 #endif
881 	if (p == NULL || *p == '\0')
882 	{
883 		at_enter(AT_NORMAL|AT_COLOR_PROMPT);
884 		putchr(':');
885 		at_exit();
886 	} else
887 	{
888 #if MSDOS_COMPILER==WIN32C
889 		WCHAR w[MAX_PATH*2];
890 		char  a[MAX_PATH*2];
891 		MultiByteToWideChar(CP_ACP, 0, p, -1, w, sizeof(w)/sizeof(*w));
892 		WideCharToMultiByte(utf_mode ? CP_UTF8 : GetConsoleOutputCP(),
893 		                    0, w, -1, a, sizeof(a), NULL, NULL);
894 		p = a;
895 #endif
896 		load_line(p);
897 		put_line();
898 	}
899 	clear_eol();
900 }
901 
902 /*
903  * Display the less version message.
904  */
905 public void dispversion(void)
906 {
907 	PARG parg;
908 
909 	parg.p_string = version;
910 	error("less %s", &parg);
911 }
912 
913 /*
914  * Return a character to complete a partial command, if possible.
915  */
916 static LWCHAR getcc_end_command(void)
917 {
918 	switch (mca)
919 	{
920 	case A_DIGIT:
921 		/* We have a number but no command.  Treat as #g. */
922 		return ('g');
923 	case A_F_SEARCH:
924 	case A_B_SEARCH:
925 	case A_FILTER:
926 		/* We have "/string" but no newline.  Add the \n. */
927 		return ('\n');
928 	default:
929 		/* Some other incomplete command.  Let user complete it. */
930 		return ((ungot == NULL) ? getchr() : 0);
931 	}
932 }
933 
934 /*
935  * Get command character.
936  * The character normally comes from the keyboard,
937  * but may come from ungotten characters
938  * (characters previously given to ungetcc or ungetsc).
939  */
940 static LWCHAR getccu(void)
941 {
942 	LWCHAR c = 0;
943 	while (c == 0)
944 	{
945 		if (ungot == NULL)
946 		{
947 			/* Normal case: no ungotten chars.
948 			 * Get char from the user. */
949 			c = getchr();
950 		} else
951 		{
952 			/* Ungotten chars available:
953 			 * Take the top of stack (most recent). */
954 			struct ungot *ug = ungot;
955 			c = ug->ug_char;
956 			ungot = ug->ug_next;
957 			free(ug);
958 
959 			if (c == CHAR_END_COMMAND)
960 				c = getcc_end_command();
961 		}
962 	}
963 	return (c);
964 }
965 
966 /*
967  * Get a command character, but if we receive the orig sequence,
968  * convert it to the repl sequence.
969  */
970 static LWCHAR getcc_repl(char constant *orig, char constant *repl, LWCHAR (*gr_getc)(void), void (*gr_ungetc)(LWCHAR))
971 {
972 	LWCHAR c;
973 	LWCHAR keys[16];
974 	int ki = 0;
975 
976 	c = (*gr_getc)();
977 	if (orig == NULL || orig[0] == '\0')
978 		return c;
979 	for (;;)
980 	{
981 		keys[ki] = c;
982 		if (c != orig[ki] || ki >= sizeof(keys)-1)
983 		{
984 			/* This is not orig we have been receiving.
985 			 * If we have stashed chars in keys[],
986 			 * unget them and return the first one. */
987 			while (ki > 0)
988 				(*gr_ungetc)(keys[ki--]);
989 			return keys[0];
990 		}
991 		if (orig[++ki] == '\0')
992 		{
993 			/* We've received the full orig sequence.
994 			 * Return the repl sequence. */
995 			ki = strlen(repl)-1;
996 			while (ki > 0)
997 				(*gr_ungetc)(repl[ki--]);
998 			return repl[0];
999 		}
1000 		/* We've received a partial orig sequence (ki chars of it).
1001 		 * Get next char and see if it continues to match orig. */
1002 		c = (*gr_getc)();
1003 	}
1004 }
1005 
1006 /*
1007  * Get command character.
1008  */
1009 public int getcc(void)
1010 {
1011 	/* Replace kent (keypad Enter) with a newline. */
1012 	return getcc_repl(kent, "\n", getccu, ungetcc);
1013 }
1014 
1015 /*
1016  * "Unget" a command character.
1017  * The next getcc() will return this character.
1018  */
1019 public void ungetcc(LWCHAR c)
1020 {
1021 	struct ungot *ug = (struct ungot *) ecalloc(1, sizeof(struct ungot));
1022 
1023 	ug->ug_char = c;
1024 	ug->ug_next = ungot;
1025 	ungot = ug;
1026 }
1027 
1028 /*
1029  * "Unget" a command character.
1030  * If any other chars are already ungotten, put this one after those.
1031  */
1032 public void ungetcc_back(LWCHAR c)
1033 {
1034 	struct ungot *ug = (struct ungot *) ecalloc(1, sizeof(struct ungot));
1035 	ug->ug_char = c;
1036 	ug->ug_next = NULL;
1037 	if (ungot == NULL)
1038 		ungot = ug;
1039 	else
1040 	{
1041 		struct ungot *pu;
1042 		for (pu = ungot; pu->ug_next != NULL; pu = pu->ug_next)
1043 			continue;
1044 		pu->ug_next = ug;
1045 	}
1046 }
1047 
1048 /*
1049  * Unget a whole string of command characters.
1050  * The next sequence of getcc()'s will return this string.
1051  */
1052 public void ungetsc(char *s)
1053 {
1054 	while (*s != '\0')
1055 		ungetcc_back(*s++);
1056 }
1057 
1058 /*
1059  * Peek the next command character, without consuming it.
1060  */
1061 public LWCHAR peekcc(void)
1062 {
1063 	LWCHAR c = getcc();
1064 	ungetcc(c);
1065 	return c;
1066 }
1067 
1068 /*
1069  * Search for a pattern, possibly in multiple files.
1070  * If SRCH_FIRST_FILE is set, begin searching at the first file.
1071  * If SRCH_PAST_EOF is set, continue the search thru multiple files.
1072  */
1073 static void multi_search(char *pattern, int n, int silent)
1074 {
1075 	int nomore;
1076 	IFILE save_ifile;
1077 	int changed_file;
1078 
1079 	changed_file = 0;
1080 	save_ifile = save_curr_ifile();
1081 
1082 	if ((search_type & (SRCH_FORW|SRCH_BACK)) == 0)
1083 		search_type |= SRCH_FORW;
1084 	if (search_type & SRCH_FIRST_FILE)
1085 	{
1086 		/*
1087 		 * Start at the first (or last) file
1088 		 * in the command line list.
1089 		 */
1090 		if (search_type & SRCH_FORW)
1091 			nomore = edit_first();
1092 		else
1093 			nomore = edit_last();
1094 		if (nomore)
1095 		{
1096 			unsave_ifile(save_ifile);
1097 			return;
1098 		}
1099 		changed_file = 1;
1100 		search_type &= ~SRCH_FIRST_FILE;
1101 	}
1102 
1103 	for (;;)
1104 	{
1105 		n = search(search_type, pattern, n);
1106 		/*
1107 		 * The SRCH_NO_MOVE flag doesn't "stick": it gets cleared
1108 		 * after being used once.  This allows "n" to work after
1109 		 * using a /@@ search.
1110 		 */
1111 		search_type &= ~SRCH_NO_MOVE;
1112 		last_search_type = search_type;
1113 		if (n == 0)
1114 		{
1115 			/*
1116 			 * Found it.
1117 			 */
1118 			unsave_ifile(save_ifile);
1119 			return;
1120 		}
1121 
1122 		if (n < 0)
1123 			/*
1124 			 * Some kind of error in the search.
1125 			 * Error message has been printed by search().
1126 			 */
1127 			break;
1128 
1129 		if ((search_type & SRCH_PAST_EOF) == 0)
1130 			/*
1131 			 * We didn't find a match, but we're
1132 			 * supposed to search only one file.
1133 			 */
1134 			break;
1135 		/*
1136 		 * Move on to the next file.
1137 		 */
1138 		if (search_type & SRCH_FORW)
1139 			nomore = edit_next(1);
1140 		else
1141 			nomore = edit_prev(1);
1142 		if (nomore)
1143 			break;
1144 		changed_file = 1;
1145 	}
1146 
1147 	/*
1148 	 * Didn't find it.
1149 	 * Print an error message if we haven't already.
1150 	 */
1151 	if (n > 0 && !silent)
1152 		error("Pattern not found", NULL_PARG);
1153 
1154 	if (changed_file)
1155 	{
1156 		/*
1157 		 * Restore the file we were originally viewing.
1158 		 */
1159 		reedit_ifile(save_ifile);
1160 	} else
1161 	{
1162 		unsave_ifile(save_ifile);
1163 	}
1164 }
1165 
1166 /*
1167  * Forward forever, or until a highlighted line appears.
1168  */
1169 static int forw_loop(int until_hilite)
1170 {
1171 	POSITION curr_len;
1172 
1173 	if (ch_getflags() & CH_HELPFILE)
1174 		return (A_NOACTION);
1175 
1176 	cmd_exec();
1177 	jump_forw_buffered();
1178 	curr_len = ch_length();
1179 	highest_hilite = until_hilite ? curr_len : NULL_POSITION;
1180 	ignore_eoi = 1;
1181 	while (!sigs)
1182 	{
1183 		if (until_hilite && highest_hilite > curr_len)
1184 		{
1185 			bell();
1186 			break;
1187 		}
1188 		make_display();
1189 		forward(1, 0, 0);
1190 	}
1191 	ignore_eoi = 0;
1192 	ch_set_eof();
1193 
1194 	/*
1195 	 * This gets us back in "F mode" after processing
1196 	 * a non-abort signal (e.g. window-change).
1197 	 */
1198 	if (sigs && !ABORT_SIGS())
1199 		return (until_hilite ? A_F_UNTIL_HILITE : A_F_FOREVER);
1200 
1201 	return (A_NOACTION);
1202 }
1203 
1204 /*
1205  * Main command processor.
1206  * Accept and execute commands until a quit command.
1207  */
1208 public void commands(void)
1209 {
1210 	int c;
1211 	int action;
1212 	char *cbuf;
1213 	int newaction;
1214 	int save_jump_sline;
1215 	int save_search_type;
1216 	char *extra;
1217 	char tbuf[2];
1218 	PARG parg;
1219 	IFILE old_ifile;
1220 	IFILE new_ifile;
1221 	char *tagfile;
1222 
1223 	search_type = SRCH_FORW;
1224 	wscroll = (sc_height + 1) / 2;
1225 	newaction = A_NOACTION;
1226 
1227 	for (;;)
1228 	{
1229 		clear_mca();
1230 		cmd_accept();
1231 		number = 0;
1232 		curropt = NULL;
1233 
1234 		/*
1235 		 * See if any signals need processing.
1236 		 */
1237 		if (sigs)
1238 		{
1239 			psignals();
1240 			if (quitting)
1241 				quit(QUIT_SAVED_STATUS);
1242 		}
1243 
1244 		/*
1245 		 * See if window size changed, for systems that don't
1246 		 * generate SIGWINCH.
1247 		 */
1248 		check_winch();
1249 
1250 		/*
1251 		 * Display prompt and accept a character.
1252 		 */
1253 		cmd_reset();
1254 		prompt();
1255 		if (sigs)
1256 			continue;
1257 		if (newaction == A_NOACTION)
1258 			c = getcc();
1259 
1260 	again:
1261 		if (sigs)
1262 			continue;
1263 
1264 		if (newaction != A_NOACTION)
1265 		{
1266 			action = newaction;
1267 			newaction = A_NOACTION;
1268 		} else
1269 		{
1270 			/*
1271 			 * If we are in a multicharacter command, call mca_char.
1272 			 * Otherwise we call fcmd_decode to determine the
1273 			 * action to be performed.
1274 			 */
1275 			if (mca)
1276 				switch (mca_char(c))
1277 				{
1278 				case MCA_MORE:
1279 					/*
1280 					 * Need another character.
1281 					 */
1282 					c = getcc();
1283 					goto again;
1284 				case MCA_DONE:
1285 					/*
1286 					 * Command has been handled by mca_char.
1287 					 * Start clean with a prompt.
1288 					 */
1289 					continue;
1290 				case NO_MCA:
1291 					/*
1292 					 * Not a multi-char command
1293 					 * (at least, not anymore).
1294 					 */
1295 					break;
1296 				}
1297 
1298 			/*
1299 			 * Decode the command character and decide what to do.
1300 			 */
1301 			if (mca)
1302 			{
1303 				/*
1304 				 * We're in a multichar command.
1305 				 * Add the character to the command buffer
1306 				 * and display it on the screen.
1307 				 * If the user backspaces past the start
1308 				 * of the line, abort the command.
1309 				 */
1310 				if (cmd_char(c) == CC_QUIT || len_cmdbuf() == 0)
1311 					continue;
1312 				cbuf = get_cmdbuf();
1313 				if (cbuf == NULL)
1314 					continue;
1315 			} else
1316 			{
1317 				/*
1318 				 * Don't use cmd_char if we're starting fresh
1319 				 * at the beginning of a command, because we
1320 				 * don't want to echo the command until we know
1321 				 * it is a multichar command.  We also don't
1322 				 * want erase_char/kill_char to be treated
1323 				 * as line editing characters.
1324 				 */
1325 				tbuf[0] = c;
1326 				tbuf[1] = '\0';
1327 				cbuf = tbuf;
1328 			}
1329 			extra = NULL;
1330 			action = fcmd_decode(cbuf, &extra);
1331 			/*
1332 			 * If an "extra" string was returned,
1333 			 * process it as a string of command characters.
1334 			 */
1335 			if (extra != NULL)
1336 				ungetsc(extra);
1337 		}
1338 		/*
1339 		 * Clear the cmdbuf string.
1340 		 * (But not if we're in the prefix of a command,
1341 		 * because the partial command string is kept there.)
1342 		 */
1343 		if (action != A_PREFIX)
1344 			cmd_reset();
1345 
1346 		switch (action)
1347 		{
1348 		case A_DIGIT:
1349 			/*
1350 			 * First digit of a number.
1351 			 */
1352 			start_mca(A_DIGIT, ":", (void*)NULL, CF_QUIT_ON_ERASE);
1353 			goto again;
1354 
1355 		case A_F_WINDOW:
1356 			/*
1357 			 * Forward one window (and set the window size).
1358 			 */
1359 			if (number > 0)
1360 				swindow = (int) number;
1361 			/* FALLTHRU */
1362 		case A_F_SCREEN:
1363 			/*
1364 			 * Forward one screen.
1365 			 */
1366 			if (number <= 0)
1367 				number = get_swindow();
1368 			cmd_exec();
1369 			if (show_attn)
1370 				set_attnpos(bottompos);
1371 			forward((int) number, 0, 1);
1372 			break;
1373 
1374 		case A_B_WINDOW:
1375 			/*
1376 			 * Backward one window (and set the window size).
1377 			 */
1378 			if (number > 0)
1379 				swindow = (int) number;
1380 			/* FALLTHRU */
1381 		case A_B_SCREEN:
1382 			/*
1383 			 * Backward one screen.
1384 			 */
1385 			if (number <= 0)
1386 				number = get_swindow();
1387 			cmd_exec();
1388 			backward((int) number, 0, 1);
1389 			break;
1390 
1391 		case A_F_LINE:
1392 			/*
1393 			 * Forward N (default 1) line.
1394 			 */
1395 			if (number <= 0)
1396 				number = 1;
1397 			cmd_exec();
1398 			if (show_attn == OPT_ONPLUS && number > 1)
1399 				set_attnpos(bottompos);
1400 			forward((int) number, 0, 0);
1401 			break;
1402 
1403 		case A_B_LINE:
1404 			/*
1405 			 * Backward N (default 1) line.
1406 			 */
1407 			if (number <= 0)
1408 				number = 1;
1409 			cmd_exec();
1410 			backward((int) number, 0, 0);
1411 			break;
1412 
1413 		case A_F_MOUSE:
1414 			/*
1415 			 * Forward wheel_lines lines.
1416 			 */
1417 			cmd_exec();
1418 			forward(wheel_lines, 0, 0);
1419 			break;
1420 
1421 		case A_B_MOUSE:
1422 			/*
1423 			 * Backward wheel_lines lines.
1424 			 */
1425 			cmd_exec();
1426 			backward(wheel_lines, 0, 0);
1427 			break;
1428 
1429 		case A_FF_LINE:
1430 			/*
1431 			 * Force forward N (default 1) line.
1432 			 */
1433 			if (number <= 0)
1434 				number = 1;
1435 			cmd_exec();
1436 			if (show_attn == OPT_ONPLUS && number > 1)
1437 				set_attnpos(bottompos);
1438 			forward((int) number, 1, 0);
1439 			break;
1440 
1441 		case A_BF_LINE:
1442 			/*
1443 			 * Force backward N (default 1) line.
1444 			 */
1445 			if (number <= 0)
1446 				number = 1;
1447 			cmd_exec();
1448 			backward((int) number, 1, 0);
1449 			break;
1450 
1451 		case A_FF_SCREEN:
1452 			/*
1453 			 * Force forward one screen.
1454 			 */
1455 			if (number <= 0)
1456 				number = get_swindow();
1457 			cmd_exec();
1458 			if (show_attn == OPT_ONPLUS)
1459 				set_attnpos(bottompos);
1460 			forward((int) number, 1, 0);
1461 			break;
1462 
1463 		case A_F_FOREVER:
1464 			/*
1465 			 * Forward forever, ignoring EOF.
1466 			 */
1467 			if (show_attn)
1468 				set_attnpos(bottompos);
1469 			newaction = forw_loop(0);
1470 			break;
1471 
1472 		case A_F_UNTIL_HILITE:
1473 			newaction = forw_loop(1);
1474 			break;
1475 
1476 		case A_F_SCROLL:
1477 			/*
1478 			 * Forward N lines
1479 			 * (default same as last 'd' or 'u' command).
1480 			 */
1481 			if (number > 0)
1482 				wscroll = (int) number;
1483 			cmd_exec();
1484 			if (show_attn == OPT_ONPLUS)
1485 				set_attnpos(bottompos);
1486 			forward(wscroll, 0, 0);
1487 			break;
1488 
1489 		case A_B_SCROLL:
1490 			/*
1491 			 * Forward N lines
1492 			 * (default same as last 'd' or 'u' command).
1493 			 */
1494 			if (number > 0)
1495 				wscroll = (int) number;
1496 			cmd_exec();
1497 			backward(wscroll, 0, 0);
1498 			break;
1499 
1500 		case A_FREPAINT:
1501 			/*
1502 			 * Flush buffers, then repaint screen.
1503 			 * Don't flush the buffers on a pipe!
1504 			 */
1505 			clear_buffers();
1506 			/* FALLTHRU */
1507 		case A_REPAINT:
1508 			/*
1509 			 * Repaint screen.
1510 			 */
1511 			cmd_exec();
1512 			repaint();
1513 			break;
1514 
1515 		case A_GOLINE:
1516 			/*
1517 			 * Go to line N, default beginning of file.
1518 			 * If N <= 0, ignore jump_sline in order to avoid
1519 			 * empty lines before the beginning of the file.
1520 			 */
1521 			save_jump_sline = jump_sline;
1522 			if (number <= 0)
1523 			{
1524 				number = 1;
1525 				jump_sline = 0;
1526 			}
1527 			cmd_exec();
1528 			jump_back(number);
1529 			jump_sline = save_jump_sline;
1530 			break;
1531 
1532 		case A_PERCENT:
1533 			/*
1534 			 * Go to a specified percentage into the file.
1535 			 */
1536 			if (number < 0)
1537 			{
1538 				number = 0;
1539 				fraction = 0;
1540 			}
1541 			if (number > 100 || (number == 100 && fraction != 0))
1542 			{
1543 				number = 100;
1544 				fraction = 0;
1545 			}
1546 			cmd_exec();
1547 			jump_percent((int) number, fraction);
1548 			break;
1549 
1550 		case A_GOEND:
1551 			/*
1552 			 * Go to line N, default end of file.
1553 			 */
1554 			cmd_exec();
1555 			if (number <= 0)
1556 				jump_forw();
1557 			else
1558 				jump_back(number);
1559 			break;
1560 
1561 		case A_GOEND_BUF:
1562 			/*
1563 			 * Go to line N, default last buffered byte.
1564 			 */
1565 			cmd_exec();
1566 			if (number <= 0)
1567 				jump_forw_buffered();
1568 			else
1569 				jump_back(number);
1570 			break;
1571 
1572 		case A_GOPOS:
1573 			/*
1574 			 * Go to a specified byte position in the file.
1575 			 */
1576 			cmd_exec();
1577 			if (number < 0)
1578 				number = 0;
1579 			jump_line_loc((POSITION) number, jump_sline);
1580 			break;
1581 
1582 		case A_STAT:
1583 			/*
1584 			 * Print file name, etc.
1585 			 */
1586 			if (ch_getflags() & CH_HELPFILE)
1587 				break;
1588 			cmd_exec();
1589 			parg.p_string = eq_message();
1590 			error("%s", &parg);
1591 			break;
1592 
1593 		case A_VERSION:
1594 			/*
1595 			 * Print version number.
1596 			 */
1597 			cmd_exec();
1598 			dispversion();
1599 			break;
1600 
1601 		case A_QUIT:
1602 			/*
1603 			 * Exit.
1604 			 */
1605 			if (curr_ifile != NULL_IFILE &&
1606 			    ch_getflags() & CH_HELPFILE)
1607 			{
1608 				/*
1609 				 * Quit while viewing the help file
1610 				 * just means return to viewing the
1611 				 * previous file.
1612 				 */
1613 				hshift = save_hshift;
1614 				bs_mode = save_bs_mode;
1615 				proc_backspace = save_proc_backspace;
1616 				if (edit_prev(1) == 0)
1617 					break;
1618 			}
1619 			if (extra != NULL)
1620 				quit(*extra);
1621 			quit(QUIT_OK);
1622 			break;
1623 
1624 /*
1625  * Define abbreviation for a commonly used sequence below.
1626  */
1627 #define DO_SEARCH() \
1628 			if (number <= 0) number = 1;    \
1629 			mca_search();                   \
1630 			cmd_exec();                     \
1631 			multi_search((char *)NULL, (int) number, 0);
1632 
1633 		case A_F_SEARCH:
1634 			/*
1635 			 * Search forward for a pattern.
1636 			 * Get the first char of the pattern.
1637 			 */
1638 			search_type = SRCH_FORW | def_search_type;
1639 			if (number <= 0)
1640 				number = 1;
1641 			mca_search();
1642 			c = getcc();
1643 			goto again;
1644 
1645 		case A_B_SEARCH:
1646 			/*
1647 			 * Search backward for a pattern.
1648 			 * Get the first char of the pattern.
1649 			 */
1650 			search_type = SRCH_BACK | def_search_type;
1651 			if (number <= 0)
1652 				number = 1;
1653 			mca_search();
1654 			c = getcc();
1655 			goto again;
1656 
1657 		case A_FILTER:
1658 #if HILITE_SEARCH
1659 			search_type = SRCH_FORW | SRCH_FILTER;
1660 			mca_search();
1661 			c = getcc();
1662 			goto again;
1663 #else
1664 			error("Command not available", NULL_PARG);
1665 			break;
1666 #endif
1667 
1668 		case A_AGAIN_SEARCH:
1669 			/*
1670 			 * Repeat previous search.
1671 			 */
1672 			search_type = last_search_type;
1673 			DO_SEARCH();
1674 			break;
1675 
1676 		case A_T_AGAIN_SEARCH:
1677 			/*
1678 			 * Repeat previous search, multiple files.
1679 			 */
1680 			search_type = last_search_type | SRCH_PAST_EOF;
1681 			DO_SEARCH();
1682 			break;
1683 
1684 		case A_REVERSE_SEARCH:
1685 			/*
1686 			 * Repeat previous search, in reverse direction.
1687 			 */
1688 			save_search_type = search_type = last_search_type;
1689 			search_type = SRCH_REVERSE(search_type);
1690 			DO_SEARCH();
1691 			last_search_type = save_search_type;
1692 			break;
1693 
1694 		case A_T_REVERSE_SEARCH:
1695 			/*
1696 			 * Repeat previous search,
1697 			 * multiple files in reverse direction.
1698 			 */
1699 			save_search_type = search_type = last_search_type;
1700 			search_type = SRCH_REVERSE(search_type) | SRCH_PAST_EOF;
1701 			DO_SEARCH();
1702 			last_search_type = save_search_type;
1703 			break;
1704 
1705 		case A_UNDO_SEARCH:
1706 		case A_CLR_SEARCH:
1707 			/*
1708 			 * Clear search string highlighting.
1709 			 */
1710 			undo_search(action == A_CLR_SEARCH);
1711 			break;
1712 
1713 		case A_HELP:
1714 			/*
1715 			 * Help.
1716 			 */
1717 			if (ch_getflags() & CH_HELPFILE)
1718 				break;
1719 			cmd_exec();
1720 			save_hshift = hshift;
1721 			hshift = 0;
1722 			save_bs_mode = bs_mode;
1723 			bs_mode = BS_SPECIAL;
1724 			save_proc_backspace = proc_backspace;
1725 			proc_backspace = OPT_OFF;
1726 			(void) edit(FAKE_HELPFILE);
1727 			break;
1728 
1729 		case A_EXAMINE:
1730 			/*
1731 			 * Edit a new file.  Get the filename.
1732 			 */
1733 #if EXAMINE
1734 			if (!secure)
1735 			{
1736 				start_mca(A_EXAMINE, "Examine: ", ml_examine, 0);
1737 				c = getcc();
1738 				goto again;
1739 			}
1740 #endif
1741 			error("Command not available", NULL_PARG);
1742 			break;
1743 
1744 		case A_VISUAL:
1745 			/*
1746 			 * Invoke an editor on the input file.
1747 			 */
1748 #if EDITOR
1749 			if (!secure)
1750 			{
1751 				if (ch_getflags() & CH_HELPFILE)
1752 					break;
1753 				if (strcmp(get_filename(curr_ifile), "-") == 0)
1754 				{
1755 					error("Cannot edit standard input", NULL_PARG);
1756 					break;
1757 				}
1758 				if (get_altfilename(curr_ifile) != NULL)
1759 				{
1760 					error("WARNING: This file was viewed via LESSOPEN",
1761 						NULL_PARG);
1762 				}
1763 				start_mca(A_SHELL, "!", ml_shell, 0);
1764 				/*
1765 				 * Expand the editor prototype string
1766 				 * and pass it to the system to execute.
1767 				 * (Make sure the screen is displayed so the
1768 				 * expansion of "+%lm" works.)
1769 				 */
1770 				make_display();
1771 				cmd_exec();
1772 				lsystem(pr_expand(editproto), (char*)NULL);
1773 				break;
1774 			}
1775 #endif
1776 			error("Command not available", NULL_PARG);
1777 			break;
1778 
1779 		case A_NEXT_FILE:
1780 			/*
1781 			 * Examine next file.
1782 			 */
1783 #if TAGS
1784 			if (ntags())
1785 			{
1786 				error("No next file", NULL_PARG);
1787 				break;
1788 			}
1789 #endif
1790 			if (number <= 0)
1791 				number = 1;
1792 			if (edit_next((int) number))
1793 			{
1794 				if (get_quit_at_eof() && eof_displayed() &&
1795 				    !(ch_getflags() & CH_HELPFILE))
1796 					quit(QUIT_OK);
1797 				parg.p_string = (number > 1) ? "(N-th) " : "";
1798 				error("No %snext file", &parg);
1799 			}
1800 			break;
1801 
1802 		case A_PREV_FILE:
1803 			/*
1804 			 * Examine previous file.
1805 			 */
1806 #if TAGS
1807 			if (ntags())
1808 			{
1809 				error("No previous file", NULL_PARG);
1810 				break;
1811 			}
1812 #endif
1813 			if (number <= 0)
1814 				number = 1;
1815 			if (edit_prev((int) number))
1816 			{
1817 				parg.p_string = (number > 1) ? "(N-th) " : "";
1818 				error("No %sprevious file", &parg);
1819 			}
1820 			break;
1821 
1822 		case A_NEXT_TAG:
1823 			/*
1824 			 * Jump to the next tag in the current tag list.
1825 			 */
1826 #if TAGS
1827 			if (number <= 0)
1828 				number = 1;
1829 			tagfile = nexttag((int) number);
1830 			if (tagfile == NULL)
1831 			{
1832 				error("No next tag", NULL_PARG);
1833 				break;
1834 			}
1835 			cmd_exec();
1836 			if (edit(tagfile) == 0)
1837 			{
1838 				POSITION pos = tagsearch();
1839 				if (pos != NULL_POSITION)
1840 					jump_loc(pos, jump_sline);
1841 			}
1842 #else
1843 			error("Command not available", NULL_PARG);
1844 #endif
1845 			break;
1846 
1847 		case A_PREV_TAG:
1848 			/*
1849 			 * Jump to the previous tag in the current tag list.
1850 			 */
1851 #if TAGS
1852 			if (number <= 0)
1853 				number = 1;
1854 			tagfile = prevtag((int) number);
1855 			if (tagfile == NULL)
1856 			{
1857 				error("No previous tag", NULL_PARG);
1858 				break;
1859 			}
1860 			cmd_exec();
1861 			if (edit(tagfile) == 0)
1862 			{
1863 				POSITION pos = tagsearch();
1864 				if (pos != NULL_POSITION)
1865 					jump_loc(pos, jump_sline);
1866 			}
1867 #else
1868 			error("Command not available", NULL_PARG);
1869 #endif
1870 			break;
1871 
1872 		case A_INDEX_FILE:
1873 			/*
1874 			 * Examine a particular file.
1875 			 */
1876 			if (number <= 0)
1877 				number = 1;
1878 			if (edit_index((int) number))
1879 				error("No such file", NULL_PARG);
1880 			break;
1881 
1882 		case A_REMOVE_FILE:
1883 			/*
1884 			 * Remove a file from the input file list.
1885 			 */
1886 			if (ch_getflags() & CH_HELPFILE)
1887 				break;
1888 			old_ifile = curr_ifile;
1889 			new_ifile = getoff_ifile(curr_ifile);
1890 			if (new_ifile == NULL_IFILE)
1891 			{
1892 				bell();
1893 				break;
1894 			}
1895 			if (edit_ifile(new_ifile) != 0)
1896 			{
1897 				reedit_ifile(old_ifile);
1898 				break;
1899 			}
1900 			del_ifile(old_ifile);
1901 			break;
1902 
1903 		case A_OPT_TOGGLE:
1904 			/*
1905 			 * Change the setting of an  option.
1906 			 */
1907 			optflag = OPT_TOGGLE;
1908 			optgetname = FALSE;
1909 			mca_opt_toggle();
1910 			c = getcc();
1911 			cbuf = opt_toggle_disallowed(c);
1912 			if (cbuf != NULL)
1913 			{
1914 				error(cbuf, NULL_PARG);
1915 				break;
1916 			}
1917 			goto again;
1918 
1919 		case A_DISP_OPTION:
1920 			/*
1921 			 * Report the setting of an option.
1922 			 */
1923 			optflag = OPT_NO_TOGGLE;
1924 			optgetname = FALSE;
1925 			mca_opt_toggle();
1926 			c = getcc();
1927 			goto again;
1928 
1929 		case A_FIRSTCMD:
1930 			/*
1931 			 * Set an initial command for new files.
1932 			 */
1933 			start_mca(A_FIRSTCMD, "+", (void*)NULL, 0);
1934 			c = getcc();
1935 			goto again;
1936 
1937 		case A_SHELL:
1938 		case A_PSHELL:
1939 			/*
1940 			 * Shell escape.
1941 			 */
1942 #if SHELL_ESCAPE
1943 			if (!secure)
1944 			{
1945 				start_mca(action, (action == A_SHELL) ? "!" : "#", ml_shell, 0);
1946 				c = getcc();
1947 				goto again;
1948 			}
1949 #endif
1950 			error("Command not available", NULL_PARG);
1951 			break;
1952 
1953 		case A_SETMARK:
1954 		case A_SETMARKBOT:
1955 			/*
1956 			 * Set a mark.
1957 			 */
1958 			if (ch_getflags() & CH_HELPFILE)
1959 				break;
1960 			start_mca(A_SETMARK, "set mark: ", (void*)NULL, 0);
1961 			c = getcc();
1962 			if (is_erase_char(c) || is_newline_char(c))
1963 				break;
1964 			setmark(c, action == A_SETMARKBOT ? BOTTOM : TOP);
1965 			repaint();
1966 			break;
1967 
1968 		case A_CLRMARK:
1969 			/*
1970 			 * Clear a mark.
1971 			 */
1972 			start_mca(A_CLRMARK, "clear mark: ", (void*)NULL, 0);
1973 			c = getcc();
1974 			if (is_erase_char(c) || is_newline_char(c))
1975 				break;
1976 			clrmark(c);
1977 			repaint();
1978 			break;
1979 
1980 		case A_GOMARK:
1981 			/*
1982 			 * Jump to a marked position.
1983 			 */
1984 			start_mca(A_GOMARK, "goto mark: ", (void*)NULL, 0);
1985 			c = getcc();
1986 			if (is_erase_char(c) || is_newline_char(c))
1987 				break;
1988 			cmd_exec();
1989 			gomark(c);
1990 			break;
1991 
1992 		case A_PIPE:
1993 			/*
1994 			 * Write part of the input to a pipe to a shell command.
1995 			 */
1996 #if PIPEC
1997 			if (!secure)
1998 			{
1999 				start_mca(A_PIPE, "|mark: ", (void*)NULL, 0);
2000 				c = getcc();
2001 				if (is_erase_char(c))
2002 					break;
2003 				if (is_newline_char(c))
2004 					c = '.';
2005 				if (badmark(c))
2006 					break;
2007 				pipec = c;
2008 				start_mca(A_PIPE, "!", ml_shell, 0);
2009 				c = getcc();
2010 				goto again;
2011 			}
2012 #endif
2013 			error("Command not available", NULL_PARG);
2014 			break;
2015 
2016 		case A_B_BRACKET:
2017 		case A_F_BRACKET:
2018 			start_mca(action, "Brackets: ", (void*)NULL, 0);
2019 			c = getcc();
2020 			goto again;
2021 
2022 		case A_LSHIFT:
2023 			/*
2024 			 * Shift view left.
2025 			 */
2026 			if (number > 0)
2027 				shift_count = number;
2028 			else
2029 				number = (shift_count > 0) ?
2030 					shift_count : sc_width / 2;
2031 			if (number > hshift)
2032 				number = hshift;
2033 			hshift -= number;
2034 			screen_trashed = 1;
2035 			break;
2036 
2037 		case A_RSHIFT:
2038 			/*
2039 			 * Shift view right.
2040 			 */
2041 			if (number > 0)
2042 				shift_count = number;
2043 			else
2044 				number = (shift_count > 0) ?
2045 					shift_count : sc_width / 2;
2046 			hshift += number;
2047 			screen_trashed = 1;
2048 			break;
2049 
2050 		case A_LLSHIFT:
2051 			/*
2052 			 * Shift view left to margin.
2053 			 */
2054 			hshift = 0;
2055 			screen_trashed = 1;
2056 			break;
2057 
2058 		case A_RRSHIFT:
2059 			/*
2060 			 * Shift view right to view rightmost char on screen.
2061 			 */
2062 			hshift = rrshift();
2063 			screen_trashed = 1;
2064 			break;
2065 
2066 		case A_PREFIX:
2067 			/*
2068 			 * The command is incomplete (more chars are needed).
2069 			 * Display the current char, so the user knows
2070 			 * what's going on, and get another character.
2071 			 */
2072 			if (mca != A_PREFIX)
2073 			{
2074 				cmd_reset();
2075 				start_mca(A_PREFIX, " ", (void*)NULL,
2076 					CF_QUIT_ON_ERASE);
2077 				(void) cmd_char(c);
2078 			}
2079 			c = getcc();
2080 			goto again;
2081 
2082 		case A_NOACTION:
2083 			break;
2084 
2085 		default:
2086 			bell();
2087 			break;
2088 		}
2089 	}
2090 }
2091