xref: /freebsd/contrib/less/command.c (revision 8ddb146abcdf061be9f2c0db7e391697dafad85c)
1 /* $FreeBSD$ */
2 /*
3  * Copyright (C) 1984-2021  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 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 show_attn;
41 extern int less_is_more;
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 #if SHELL_ESCAPE || PIPEC
54 extern void *ml_shell;
55 #endif
56 #if EDITOR
57 extern char *editor;
58 extern char *editproto;
59 #endif
60 extern int screen_trashed;      /* The screen has been overwritten */
61 extern int shift_count;
62 extern int oldbot;
63 extern int forw_prompt;
64 extern int incr_search;
65 #if MSDOS_COMPILER==WIN32C
66 extern int utf_mode;
67 #endif
68 
69 #if SHELL_ESCAPE
70 static char *shellcmd = NULL;   /* For holding last shell command for "!!" */
71 #endif
72 static int mca;                 /* The multicharacter command (action) */
73 static int search_type;         /* The previous type of search */
74 static LINENUM number;          /* The number typed by the user */
75 static long fraction;           /* The fractional part of the number */
76 static struct loption *curropt;
77 static int opt_lower;
78 static int optflag;
79 static int optgetname;
80 static POSITION bottompos;
81 static int save_hshift;
82 static int save_bs_mode;
83 #if PIPEC
84 static char pipec;
85 #endif
86 
87 /* Stack of ungotten chars (via ungetcc) */
88 struct ungot {
89 	struct ungot *ug_next;
90 	LWCHAR ug_char;
91 };
92 static struct ungot* ungot = NULL;
93 
94 static void multi_search LESSPARAMS((char *pattern, int n, int silent));
95 
96 /*
97  * Move the cursor to start of prompt line before executing a command.
98  * This looks nicer if the command takes a long time before
99  * updating the screen.
100  */
101 	static void
102 cmd_exec(VOID_PARAM)
103 {
104 	clear_attn();
105 	clear_bot();
106 	flush();
107 }
108 
109 /*
110  * Indicate we are reading a multi-character command.
111  */
112 	static void
113 set_mca(action)
114 	int action;
115 {
116 	mca = action;
117 	clear_bot();
118 	clear_cmd();
119 }
120 
121 /*
122  * Indicate we are not reading a multi-character command.
123  */
124 	static void
125 clear_mca(VOID_PARAM)
126 {
127 	if (mca == 0)
128 		return;
129 	mca = 0;
130 }
131 
132 /*
133  * Set up the display to start a new multi-character command.
134  */
135 	static void
136 start_mca(action, prompt, mlist, cmdflags)
137 	int action;
138 	constant char *prompt;
139 	void *mlist;
140 	int cmdflags;
141 {
142 	set_mca(action);
143 	cmd_putstr(prompt);
144 	set_mlist(mlist, cmdflags);
145 }
146 
147 	public int
148 in_mca(VOID_PARAM)
149 {
150 	return (mca != 0 && mca != A_PREFIX);
151 }
152 
153 /*
154  * Set up the display to start a new search command.
155  */
156 	static void
157 mca_search(VOID_PARAM)
158 {
159 #if HILITE_SEARCH
160 	if (search_type & SRCH_FILTER)
161 		set_mca(A_FILTER);
162 	else
163 #endif
164 	if (search_type & SRCH_FORW)
165 		set_mca(A_F_SEARCH);
166 	else
167 		set_mca(A_B_SEARCH);
168 
169 	if (search_type & SRCH_NO_MATCH)
170 		cmd_putstr("Non-match ");
171 	if (search_type & SRCH_FIRST_FILE)
172 		cmd_putstr("First-file ");
173 	if (search_type & SRCH_PAST_EOF)
174 		cmd_putstr("EOF-ignore ");
175 	if (search_type & SRCH_NO_MOVE)
176 		cmd_putstr("Keep-pos ");
177 	if (search_type & SRCH_NO_REGEX)
178 		cmd_putstr("Regex-off ");
179 	if (search_type & SRCH_WRAP)
180 		cmd_putstr("Wrap ");
181 
182 #if HILITE_SEARCH
183 	if (search_type & SRCH_FILTER)
184 		cmd_putstr("&/");
185 	else
186 #endif
187 	if (search_type & SRCH_FORW)
188 		cmd_putstr("/");
189 	else
190 		cmd_putstr("?");
191 	forw_prompt = 0;
192 	set_mlist(ml_search, 0);
193 }
194 
195 /*
196  * Set up the display to start a new toggle-option command.
197  */
198 	static void
199 mca_opt_toggle(VOID_PARAM)
200 {
201 	int no_prompt;
202 	int flag;
203 	char *dash;
204 
205 	no_prompt = (optflag & OPT_NO_PROMPT);
206 	flag = (optflag & ~OPT_NO_PROMPT);
207 	dash = (flag == OPT_NO_TOGGLE) ? "_" : "-";
208 
209 	set_mca(A_OPT_TOGGLE);
210 	cmd_putstr(dash);
211 	if (optgetname)
212 		cmd_putstr(dash);
213 	if (no_prompt)
214 		cmd_putstr("(P)");
215 	switch (flag)
216 	{
217 	case OPT_UNSET:
218 		cmd_putstr("+");
219 		break;
220 	case OPT_SET:
221 		cmd_putstr("!");
222 		break;
223 	}
224 	forw_prompt = 0;
225 	set_mlist(NULL, 0);
226 }
227 
228 /*
229  * Execute a multicharacter command.
230  */
231 	static void
232 exec_mca(VOID_PARAM)
233 {
234 	char *cbuf;
235 
236 	cmd_exec();
237 	cbuf = get_cmdbuf();
238 
239 	switch (mca)
240 	{
241 	case A_F_SEARCH:
242 	case A_B_SEARCH:
243 		multi_search(cbuf, (int) number, 0);
244 		break;
245 #if HILITE_SEARCH
246 	case A_FILTER:
247 		search_type ^= SRCH_NO_MATCH;
248 		set_filter_pattern(cbuf, search_type);
249 		break;
250 #endif
251 	case A_FIRSTCMD:
252 		/*
253 		 * Skip leading spaces or + signs in the string.
254 		 */
255 		while (*cbuf == '+' || *cbuf == ' ')
256 			cbuf++;
257 		if (every_first_cmd != NULL)
258 			free(every_first_cmd);
259 		if (*cbuf == '\0')
260 			every_first_cmd = NULL;
261 		else
262 			every_first_cmd = save(cbuf);
263 		break;
264 	case A_OPT_TOGGLE:
265 		toggle_option(curropt, opt_lower, cbuf, optflag);
266 		curropt = NULL;
267 		break;
268 	case A_F_BRACKET:
269 		match_brac(cbuf[0], cbuf[1], 1, (int) number);
270 		break;
271 	case A_B_BRACKET:
272 		match_brac(cbuf[1], cbuf[0], 0, (int) number);
273 		break;
274 #if EXAMINE
275 	case A_EXAMINE:
276 		if (secure)
277 			break;
278 		edit_list(cbuf);
279 #if TAGS
280 		/* If tag structure is loaded then clean it up. */
281 		cleantags();
282 #endif
283 		break;
284 #endif
285 #if SHELL_ESCAPE
286 	case A_SHELL:
287 		/*
288 		 * !! just uses whatever is in shellcmd.
289 		 * Otherwise, copy cmdbuf to shellcmd,
290 		 * expanding any special characters ("%" or "#").
291 		 */
292 		if (*cbuf != '!')
293 		{
294 			if (shellcmd != NULL)
295 				free(shellcmd);
296 			shellcmd = fexpand(cbuf);
297 		}
298 
299 		if (secure)
300 			break;
301 		if (shellcmd == NULL)
302 			lsystem("", "!done");
303 		else
304 			lsystem(shellcmd, "!done");
305 		break;
306 #endif
307 #if PIPEC
308 	case A_PIPE:
309 		if (secure)
310 			break;
311 		(void) pipe_mark(pipec, cbuf);
312 		error("|done", NULL_PARG);
313 		break;
314 #endif
315 	}
316 }
317 
318 /*
319  * Is a character an erase or kill char?
320  */
321 	static int
322 is_erase_char(c)
323 	int c;
324 {
325 	return (c == erase_char || c == erase2_char || c == kill_char);
326 }
327 
328 /*
329  * Is a character a carriage return or newline?
330  */
331 	static int
332 is_newline_char(c)
333 	int c;
334 {
335 	return (c == '\n' || c == '\r');
336 }
337 
338 /*
339  * Handle the first char of an option (after the initial dash).
340  */
341 	static int
342 mca_opt_first_char(c)
343 	int c;
344 {
345 	int flag = (optflag & ~OPT_NO_PROMPT);
346 	if (flag == OPT_NO_TOGGLE)
347 	{
348 		switch (c)
349 		{
350 		case '_':
351 			/* "__" = long option name. */
352 			optgetname = TRUE;
353 			mca_opt_toggle();
354 			return (MCA_MORE);
355 		}
356 	} else
357 	{
358 		switch (c)
359 		{
360 		case '+':
361 			/* "-+" = UNSET. */
362 			optflag = (flag == OPT_UNSET) ?
363 				OPT_TOGGLE : OPT_UNSET;
364 			mca_opt_toggle();
365 			return (MCA_MORE);
366 		case '!':
367 			/* "-!" = SET */
368 			optflag = (flag == OPT_SET) ?
369 				OPT_TOGGLE : OPT_SET;
370 			mca_opt_toggle();
371 			return (MCA_MORE);
372 		case CONTROL('P'):
373 			optflag ^= OPT_NO_PROMPT;
374 			mca_opt_toggle();
375 			return (MCA_MORE);
376 		case '-':
377 			/* "--" = long option name. */
378 			optgetname = TRUE;
379 			mca_opt_toggle();
380 			return (MCA_MORE);
381 		}
382 	}
383 	/* Char was not handled here. */
384 	return (NO_MCA);
385 }
386 
387 /*
388  * Add a char to a long option name.
389  * See if we've got a match for an option name yet.
390  * If so, display the complete name and stop
391  * accepting chars until user hits RETURN.
392  */
393 	static int
394 mca_opt_nonfirst_char(c)
395 	int c;
396 {
397 	char *p;
398 	char *oname;
399 	int err;
400 
401 	if (curropt != NULL)
402 	{
403 		/*
404 		 * Already have a match for the name.
405 		 * Don't accept anything but erase/kill.
406 		 */
407 		if (is_erase_char(c))
408 			return (MCA_DONE);
409 		return (MCA_MORE);
410 	}
411 	/*
412 	 * Add char to cmd buffer and try to match
413 	 * the option name.
414 	 */
415 	if (cmd_char(c) == CC_QUIT)
416 		return (MCA_DONE);
417 	p = get_cmdbuf();
418 	opt_lower = ASCII_IS_LOWER(p[0]);
419 	err = 0;
420 	curropt = findopt_name(&p, &oname, &err);
421 	if (curropt != NULL)
422 	{
423 		/*
424 		 * Got a match.
425 		 * Remember the option and
426 		 * display the full option name.
427 		 */
428 		cmd_reset();
429 		mca_opt_toggle();
430 		for (p = oname;  *p != '\0';  p++)
431 		{
432 			c = *p;
433 			if (!opt_lower && ASCII_IS_LOWER(c))
434 				c = ASCII_TO_UPPER(c);
435 			if (cmd_char(c) != CC_OK)
436 				return (MCA_DONE);
437 		}
438 	} else if (err != OPT_AMBIG)
439 	{
440 		bell();
441 	}
442 	return (MCA_MORE);
443 }
444 
445 /*
446  * Handle a char of an option toggle command.
447  */
448 	static int
449 mca_opt_char(c)
450 	int c;
451 {
452 	PARG parg;
453 
454 	/*
455 	 * This may be a short option (single char),
456 	 * or one char of a long option name,
457 	 * or one char of the option parameter.
458 	 */
459 	if (curropt == NULL && len_cmdbuf() == 0)
460 	{
461 		int ret = mca_opt_first_char(c);
462 		if (ret != NO_MCA)
463 			return (ret);
464 	}
465 	if (optgetname)
466 	{
467 		/* We're getting a long option name.  */
468 		if (!is_newline_char(c))
469 			return (mca_opt_nonfirst_char(c));
470 		if (curropt == NULL)
471 		{
472 			parg.p_string = get_cmdbuf();
473 			error("There is no --%s option", &parg);
474 			return (MCA_DONE);
475 		}
476 		optgetname = FALSE;
477 		cmd_reset();
478 	} else
479 	{
480 		if (is_erase_char(c))
481 			return (NO_MCA);
482 		if (curropt != NULL)
483 			/* We're getting the option parameter. */
484 			return (NO_MCA);
485 		curropt = findopt(c);
486 		if (curropt == NULL)
487 		{
488 			parg.p_string = propt(c);
489 			error("There is no %s option", &parg);
490 			return (MCA_DONE);
491 		}
492 		opt_lower = ASCII_IS_LOWER(c);
493 	}
494 	/*
495 	 * If the option which was entered does not take a
496 	 * parameter, toggle the option immediately,
497 	 * so user doesn't have to hit RETURN.
498 	 */
499 	if ((optflag & ~OPT_NO_PROMPT) != OPT_TOGGLE ||
500 	    !opt_has_param(curropt))
501 	{
502 		toggle_option(curropt, opt_lower, "", optflag);
503 		return (MCA_DONE);
504 	}
505 	/*
506 	 * Display a prompt appropriate for the option parameter.
507 	 */
508 	start_mca(A_OPT_TOGGLE, opt_prompt(curropt), (void*)NULL, 0);
509 	return (MCA_MORE);
510 }
511 
512 /*
513  * Handle a char of a search command.
514  */
515 	static int
516 mca_search_char(c)
517 	int c;
518 {
519 	int flag = 0;
520 
521 	/*
522 	 * Certain characters as the first char of
523 	 * the pattern have special meaning:
524 	 *      !  Toggle the NO_MATCH flag
525 	 *      *  Toggle the PAST_EOF flag
526 	 *      @  Toggle the FIRST_FILE flag
527 	 */
528 	if (len_cmdbuf() > 0)
529 		return (NO_MCA);
530 
531 	switch (c)
532 	{
533 	case '*':
534 		if (less_is_more)
535 			break;
536 	case CONTROL('E'): /* ignore END of file */
537 		if (mca != A_FILTER)
538 			flag = SRCH_PAST_EOF;
539 		break;
540 	case '@':
541 		if (less_is_more)
542 			break;
543 	case CONTROL('F'): /* FIRST file */
544 		if (mca != A_FILTER)
545 			flag = SRCH_FIRST_FILE;
546 		break;
547 	case CONTROL('K'): /* KEEP position */
548 		if (mca != A_FILTER)
549 			flag = SRCH_NO_MOVE;
550 		break;
551 	case CONTROL('W'): /* WRAP around */
552 		if (mca != A_FILTER)
553 			flag = SRCH_WRAP;
554 		break;
555 	case CONTROL('R'): /* Don't use REGULAR EXPRESSIONS */
556 		flag = SRCH_NO_REGEX;
557 		break;
558 	case CONTROL('N'): /* NOT match */
559 	case '!':
560 		flag = SRCH_NO_MATCH;
561 		break;
562 	}
563 
564 	if (flag != 0)
565 	{
566 		/* Toggle flag, but keep PAST_EOF and WRAP mutually exclusive. */
567 		search_type ^= flag | (search_type & (SRCH_PAST_EOF|SRCH_WRAP));
568 		mca_search();
569 		return (MCA_MORE);
570 	}
571 	return (NO_MCA);
572 }
573 
574 /*
575  * Handle a character of a multi-character command.
576  */
577 	static int
578 mca_char(c)
579 	int c;
580 {
581 	int ret;
582 
583 	switch (mca)
584 	{
585 	case 0:
586 		/*
587 		 * We're not in a multicharacter command.
588 		 */
589 		return (NO_MCA);
590 
591 	case A_PREFIX:
592 		/*
593 		 * In the prefix of a command.
594 		 * This not considered a multichar command
595 		 * (even tho it uses cmdbuf, etc.).
596 		 * It is handled in the commands() switch.
597 		 */
598 		return (NO_MCA);
599 
600 	case A_DIGIT:
601 		/*
602 		 * Entering digits of a number.
603 		 * Terminated by a non-digit.
604 		 */
605 		if ((c >= '0' && c <= '9') || c == '.')
606 			break;
607 		switch (editchar(c, ECF_PEEK|ECF_NOHISTORY|ECF_NOCOMPLETE|ECF_NORIGHTLEFT))
608 		{
609 		case A_NOACTION:
610 			/*
611 			 * Ignore this char and get another one.
612 			 */
613 			return (MCA_MORE);
614 		case A_INVALID:
615 			/*
616 			 * Not part of the number.
617 			 * End the number and treat this char
618 			 * as a normal command character.
619 			 */
620 			number = cmd_int(&fraction);
621 			clear_mca();
622 			cmd_accept();
623 			return (NO_MCA);
624 		}
625 		break;
626 
627 	case A_OPT_TOGGLE:
628 		ret = mca_opt_char(c);
629 		if (ret != NO_MCA)
630 			return (ret);
631 		break;
632 
633 	case A_F_SEARCH:
634 	case A_B_SEARCH:
635 	case A_FILTER:
636 		ret = mca_search_char(c);
637 		if (ret != NO_MCA)
638 			return (ret);
639 		break;
640 
641 	default:
642 		/* Other multicharacter command. */
643 		break;
644 	}
645 
646 	/*
647 	 * The multichar command is terminated by a newline.
648 	 */
649 	if (is_newline_char(c))
650 	{
651 		/*
652 		 * Execute the command.
653 		 */
654 		exec_mca();
655 		return (MCA_DONE);
656 	}
657 
658 	/*
659 	 * Append the char to the command buffer.
660 	 */
661 	if (cmd_char(c) == CC_QUIT)
662 		/*
663 		 * Abort the multi-char command.
664 		 */
665 		return (MCA_DONE);
666 
667 	switch (mca)
668 	{
669 	case A_F_BRACKET:
670 	case A_B_BRACKET:
671 		if (len_cmdbuf() >= 2)
672 		{
673 			/*
674 			 * Special case for the bracket-matching commands.
675 			 * Execute the command after getting exactly two
676 			 * characters from the user.
677 			 */
678 			exec_mca();
679 			return (MCA_DONE);
680 		}
681 		break;
682 	case A_F_SEARCH:
683 	case A_B_SEARCH:
684 		if (incr_search)
685 		{
686 			/* Incremental search: do a search after every input char. */
687 			int st = (search_type & (SRCH_FORW|SRCH_BACK|SRCH_NO_MATCH|SRCH_NO_REGEX|SRCH_NO_MOVE|SRCH_WRAP));
688 			char *pattern = get_cmdbuf();
689 			cmd_exec();
690 			if (*pattern == '\0')
691 			{
692 				/* User has backspaced to an empty pattern. */
693 				undo_search(1);
694 			} else
695 			{
696 				if (search(st | SRCH_INCR, pattern, 1) != 0)
697 					/* No match, invalid pattern, etc. */
698 					undo_search(1);
699 			}
700 			/* Redraw the search prompt and search string. */
701 			mca_search();
702 			cmd_repaint(NULL);
703 		}
704 		break;
705 	}
706 
707 	/*
708 	 * Need another character.
709 	 */
710 	return (MCA_MORE);
711 }
712 
713 /*
714  * Discard any buffered file data.
715  */
716 	static void
717 clear_buffers(VOID_PARAM)
718 {
719 	if (!(ch_getflags() & CH_CANSEEK))
720 		return;
721 	ch_flush();
722 	clr_linenum();
723 #if HILITE_SEARCH
724 	clr_hilite();
725 #endif
726 }
727 
728 /*
729  * Make sure the screen is displayed.
730  */
731 	static void
732 make_display(VOID_PARAM)
733 {
734 	/*
735 	 * If nothing is displayed yet, display starting from initial_scrpos.
736 	 */
737 	if (empty_screen())
738 	{
739 		if (initial_scrpos.pos == NULL_POSITION)
740 			jump_loc(ch_zero(), 1);
741 		else
742 			jump_loc(initial_scrpos.pos, initial_scrpos.ln);
743 	} else if (screen_trashed)
744 	{
745 		int save_top_scroll = top_scroll;
746 		int save_ignore_eoi = ignore_eoi;
747 		top_scroll = 1;
748 		ignore_eoi = 0;
749 		if (screen_trashed == 2)
750 		{
751 			/* Special case used by ignore_eoi: re-open the input file
752 			 * and jump to the end of the file. */
753 			reopen_curr_ifile();
754 			jump_forw();
755 		}
756 		repaint();
757 		top_scroll = save_top_scroll;
758 		ignore_eoi = save_ignore_eoi;
759 	}
760 }
761 
762 /*
763  * Display the appropriate prompt.
764  */
765 	static void
766 prompt(VOID_PARAM)
767 {
768 	constant char *p;
769 
770 	if (ungot != NULL && ungot->ug_char != CHAR_END_COMMAND)
771 	{
772 		/*
773 		 * No prompt necessary if commands are from
774 		 * ungotten chars rather than from the user.
775 		 */
776 		return;
777 	}
778 
779 	/*
780 	 * Make sure the screen is displayed.
781 	 */
782 	make_display();
783 	bottompos = position(BOTTOM_PLUS_ONE);
784 
785 	/*
786 	 * If we've hit EOF on the last file and the -E flag is set, quit.
787 	 */
788 	if (get_quit_at_eof() == OPT_ONPLUS &&
789 	    eof_displayed() && !(ch_getflags() & CH_HELPFILE) &&
790 	    next_ifile(curr_ifile) == NULL_IFILE)
791 		quit(QUIT_OK);
792 
793 	/*
794 	 * If the entire file is displayed and the -F flag is set, quit.
795 	 */
796 	if (quit_if_one_screen &&
797 	    entire_file_displayed() && !(ch_getflags() & CH_HELPFILE) &&
798 	    next_ifile(curr_ifile) == NULL_IFILE)
799 		quit(QUIT_OK);
800 	quit_if_one_screen = FALSE; /* only get one chance at this */
801 
802 #if MSDOS_COMPILER==WIN32C
803 	/*
804 	 * In Win32, display the file name in the window title.
805 	 */
806 	if (!(ch_getflags() & CH_HELPFILE))
807 	{
808 		WCHAR w[MAX_PATH+16];
809 		p = pr_expand("Less?f - %f.", 0);
810 		MultiByteToWideChar(CP_ACP, 0, p, -1, w, sizeof(w)/sizeof(*w));
811 		SetConsoleTitleW(w);
812 	}
813 #endif
814 
815 	/*
816 	 * Select the proper prompt and display it.
817 	 */
818 	/*
819 	 * If the previous action was a forward movement,
820 	 * don't clear the bottom line of the display;
821 	 * just print the prompt since the forward movement guarantees
822 	 * that we're in the right position to display the prompt.
823 	 * Clearing the line could cause a problem: for example, if the last
824 	 * line displayed ended at the right screen edge without a newline,
825 	 * then clearing would clear the last displayed line rather than
826 	 * the prompt line.
827 	 */
828 	if (!forw_prompt)
829 		clear_bot();
830 	clear_cmd();
831 	forw_prompt = 0;
832 	p = pr_string();
833 #if HILITE_SEARCH
834 	if (is_filtering())
835 		putstr("& ");
836 #endif
837 	if (p == NULL || *p == '\0')
838 	{
839 		at_enter(AT_NORMAL|AT_COLOR_PROMPT);
840 		putchr(':');
841 		at_exit();
842 	} else
843 	{
844 #if MSDOS_COMPILER==WIN32C
845 		WCHAR w[MAX_PATH*2];
846 		char  a[MAX_PATH*2];
847 		MultiByteToWideChar(CP_ACP, 0, p, -1, w, sizeof(w)/sizeof(*w));
848 		WideCharToMultiByte(utf_mode ? CP_UTF8 : GetConsoleOutputCP(),
849 		                    0, w, -1, a, sizeof(a), NULL, NULL);
850 		p = a;
851 #endif
852 		at_enter(AT_STANDOUT|AT_COLOR_PROMPT);
853 		putstr(p);
854 		at_exit();
855 	}
856 	clear_eol();
857 }
858 
859 /*
860  * Display the less version message.
861  */
862 	public void
863 dispversion(VOID_PARAM)
864 {
865 	PARG parg;
866 
867 	parg.p_string = version;
868 	error("less %s", &parg);
869 }
870 
871 /*
872  * Return a character to complete a partial command, if possible.
873  */
874 	static LWCHAR
875 getcc_end_command(VOID_PARAM)
876 {
877 	switch (mca)
878 	{
879 	case A_DIGIT:
880 		/* We have a number but no command.  Treat as #g. */
881 		return ('g');
882 	case A_F_SEARCH:
883 	case A_B_SEARCH:
884 		/* We have "/string" but no newline.  Add the \n. */
885 		return ('\n');
886 	default:
887 		/* Some other incomplete command.  Let user complete it. */
888 		return ((ungot == NULL) ? getchr() : 0);
889 	}
890 }
891 
892 /*
893  * Get command character.
894  * The character normally comes from the keyboard,
895  * but may come from ungotten characters
896  * (characters previously given to ungetcc or ungetsc).
897  */
898 	static LWCHAR
899 getccu(VOID_PARAM)
900 {
901 	LWCHAR c = 0;
902 	while (c == 0)
903 	{
904 		if (ungot == NULL)
905 		{
906 			/* Normal case: no ungotten chars.
907 			 * Get char from the user. */
908 			c = getchr();
909 		} else
910 		{
911 			/* Ungotten chars available:
912 			 * Take the top of stack (most recent). */
913 			struct ungot *ug = ungot;
914 			c = ug->ug_char;
915 			ungot = ug->ug_next;
916 			free(ug);
917 
918 			if (c == CHAR_END_COMMAND)
919 				c = getcc_end_command();
920 		}
921 	}
922 	return (c);
923 }
924 
925 /*
926  * Get a command character, but if we receive the orig sequence,
927  * convert it to the repl sequence.
928  */
929 	static LWCHAR
930 getcc_repl(orig, repl, gr_getc, gr_ungetc)
931 	char const* orig;
932 	char const* repl;
933 	LWCHAR (*gr_getc)(VOID_PARAM);
934 	void (*gr_ungetc)(LWCHAR);
935 {
936 	LWCHAR c;
937 	LWCHAR keys[16];
938 	int ki = 0;
939 
940 	c = (*gr_getc)();
941 	if (orig == NULL || orig[0] == '\0')
942 		return c;
943 	for (;;)
944 	{
945 		keys[ki] = c;
946 		if (c != orig[ki] || ki >= sizeof(keys)-1)
947 		{
948 			/* This is not orig we have been receiving.
949 			 * If we have stashed chars in keys[],
950 			 * unget them and return the first one. */
951 			while (ki > 0)
952 				(*gr_ungetc)(keys[ki--]);
953 			return keys[0];
954 		}
955 		if (orig[++ki] == '\0')
956 		{
957 			/* We've received the full orig sequence.
958 			 * Return the repl sequence. */
959 			ki = strlen(repl)-1;
960 			while (ki > 0)
961 				(*gr_ungetc)(repl[ki--]);
962 			return repl[0];
963 		}
964 		/* We've received a partial orig sequence (ki chars of it).
965 		 * Get next char and see if it continues to match orig. */
966 		c = (*gr_getc)();
967 	}
968 }
969 
970 /*
971  * Get command character.
972  */
973 	public int
974 getcc(VOID_PARAM)
975 {
976 	/* Replace kent (keypad Enter) with a newline. */
977 	return getcc_repl(kent, "\n", getccu, ungetcc);
978 }
979 
980 /*
981  * "Unget" a command character.
982  * The next getcc() will return this character.
983  */
984 	public void
985 ungetcc(c)
986 	LWCHAR c;
987 {
988 	struct ungot *ug = (struct ungot *) ecalloc(1, sizeof(struct ungot));
989 
990 	ug->ug_char = c;
991 	ug->ug_next = ungot;
992 	ungot = ug;
993 }
994 
995 /*
996  * "Unget" a command character.
997  * If any other chars are already ungotten, put this one after those.
998  */
999 	public void
1000 ungetcc_back(c)
1001 	LWCHAR c;
1002 {
1003 	struct ungot *ug = (struct ungot *) ecalloc(1, sizeof(struct ungot));
1004 	ug->ug_char = c;
1005 	ug->ug_next = NULL;
1006 	if (ungot == NULL)
1007 		ungot = ug;
1008 	else
1009 	{
1010 		struct ungot *pu;
1011 		for (pu = ungot; pu->ug_next != NULL; pu = pu->ug_next)
1012 			continue;
1013 		pu->ug_next = ug;
1014 	}
1015 }
1016 
1017 /*
1018  * Unget a whole string of command characters.
1019  * The next sequence of getcc()'s will return this string.
1020  */
1021 	public void
1022 ungetsc(s)
1023 	char *s;
1024 {
1025 	while (*s != '\0')
1026 		ungetcc_back(*s++);
1027 }
1028 
1029 /*
1030  * Peek the next command character, without consuming it.
1031  */
1032 	public LWCHAR
1033 peekcc(VOID_PARAM)
1034 {
1035 	LWCHAR c = getcc();
1036 	ungetcc(c);
1037 	return c;
1038 }
1039 
1040 /*
1041  * Search for a pattern, possibly in multiple files.
1042  * If SRCH_FIRST_FILE is set, begin searching at the first file.
1043  * If SRCH_PAST_EOF is set, continue the search thru multiple files.
1044  */
1045 	static void
1046 multi_search(pattern, n, silent)
1047 	char *pattern;
1048 	int n;
1049 	int silent;
1050 {
1051 	int nomore;
1052 	IFILE save_ifile;
1053 	int changed_file;
1054 
1055 	changed_file = 0;
1056 	save_ifile = save_curr_ifile();
1057 
1058 	if (search_type & SRCH_FIRST_FILE)
1059 	{
1060 		/*
1061 		 * Start at the first (or last) file
1062 		 * in the command line list.
1063 		 */
1064 		if (search_type & SRCH_FORW)
1065 			nomore = edit_first();
1066 		else
1067 			nomore = edit_last();
1068 		if (nomore)
1069 		{
1070 			unsave_ifile(save_ifile);
1071 			return;
1072 		}
1073 		changed_file = 1;
1074 		search_type &= ~SRCH_FIRST_FILE;
1075 	}
1076 
1077 	for (;;)
1078 	{
1079 		n = search(search_type, pattern, n);
1080 		/*
1081 		 * The SRCH_NO_MOVE flag doesn't "stick": it gets cleared
1082 		 * after being used once.  This allows "n" to work after
1083 		 * using a /@@ search.
1084 		 */
1085 		search_type &= ~SRCH_NO_MOVE;
1086 		if (n == 0)
1087 		{
1088 			/*
1089 			 * Found it.
1090 			 */
1091 			unsave_ifile(save_ifile);
1092 			return;
1093 		}
1094 
1095 		if (n < 0)
1096 			/*
1097 			 * Some kind of error in the search.
1098 			 * Error message has been printed by search().
1099 			 */
1100 			break;
1101 
1102 		if ((search_type & SRCH_PAST_EOF) == 0)
1103 			/*
1104 			 * We didn't find a match, but we're
1105 			 * supposed to search only one file.
1106 			 */
1107 			break;
1108 		/*
1109 		 * Move on to the next file.
1110 		 */
1111 		if (search_type & SRCH_FORW)
1112 			nomore = edit_next(1);
1113 		else
1114 			nomore = edit_prev(1);
1115 		if (nomore)
1116 			break;
1117 		changed_file = 1;
1118 	}
1119 
1120 	/*
1121 	 * Didn't find it.
1122 	 * Print an error message if we haven't already.
1123 	 */
1124 	if (n > 0 && !silent)
1125 		error("Pattern not found", NULL_PARG);
1126 
1127 	if (changed_file)
1128 	{
1129 		/*
1130 		 * Restore the file we were originally viewing.
1131 		 */
1132 		reedit_ifile(save_ifile);
1133 	} else
1134 	{
1135 		unsave_ifile(save_ifile);
1136 	}
1137 }
1138 
1139 /*
1140  * Forward forever, or until a highlighted line appears.
1141  */
1142 	static int
1143 forw_loop(until_hilite)
1144 	int until_hilite;
1145 {
1146 	POSITION curr_len;
1147 
1148 	if (ch_getflags() & CH_HELPFILE)
1149 		return (A_NOACTION);
1150 
1151 	cmd_exec();
1152 	jump_forw_buffered();
1153 	curr_len = ch_length();
1154 	highest_hilite = until_hilite ? curr_len : NULL_POSITION;
1155 	ignore_eoi = 1;
1156 	while (!sigs)
1157 	{
1158 		if (until_hilite && highest_hilite > curr_len)
1159 		{
1160 			bell();
1161 			break;
1162 		}
1163 		make_display();
1164 		forward(1, 0, 0);
1165 	}
1166 	ignore_eoi = 0;
1167 	ch_set_eof();
1168 
1169 	/*
1170 	 * This gets us back in "F mode" after processing
1171 	 * a non-abort signal (e.g. window-change).
1172 	 */
1173 	if (sigs && !ABORT_SIGS())
1174 		return (until_hilite ? A_F_UNTIL_HILITE : A_F_FOREVER);
1175 
1176 	return (A_NOACTION);
1177 }
1178 
1179 /*
1180  * Main command processor.
1181  * Accept and execute commands until a quit command.
1182  */
1183 	public void
1184 commands(VOID_PARAM)
1185 {
1186 	int c;
1187 	int action;
1188 	char *cbuf;
1189 	int newaction;
1190 	int save_jump_sline;
1191 	int save_search_type;
1192 	char *extra;
1193 	char tbuf[2];
1194 	PARG parg;
1195 	IFILE old_ifile;
1196 	IFILE new_ifile;
1197 	char *tagfile;
1198 
1199 	search_type = SRCH_FORW;
1200 	wscroll = (sc_height + 1) / 2;
1201 	newaction = A_NOACTION;
1202 
1203 	for (;;)
1204 	{
1205 		clear_mca();
1206 		cmd_accept();
1207 		number = 0;
1208 		curropt = NULL;
1209 
1210 		/*
1211 		 * See if any signals need processing.
1212 		 */
1213 		if (sigs)
1214 		{
1215 			psignals();
1216 			if (quitting)
1217 				quit(QUIT_SAVED_STATUS);
1218 		}
1219 
1220 		/*
1221 		 * See if window size changed, for systems that don't
1222 		 * generate SIGWINCH.
1223 		 */
1224 		check_winch();
1225 
1226 		/*
1227 		 * Display prompt and accept a character.
1228 		 */
1229 		cmd_reset();
1230 		prompt();
1231 		if (sigs)
1232 			continue;
1233 		if (newaction == A_NOACTION)
1234 			c = getcc();
1235 
1236 	again:
1237 		if (sigs)
1238 			continue;
1239 
1240 		if (newaction != A_NOACTION)
1241 		{
1242 			action = newaction;
1243 			newaction = A_NOACTION;
1244 		} else
1245 		{
1246 			/*
1247 			 * If we are in a multicharacter command, call mca_char.
1248 			 * Otherwise we call fcmd_decode to determine the
1249 			 * action to be performed.
1250 			 */
1251 			if (mca)
1252 				switch (mca_char(c))
1253 				{
1254 				case MCA_MORE:
1255 					/*
1256 					 * Need another character.
1257 					 */
1258 					c = getcc();
1259 					goto again;
1260 				case MCA_DONE:
1261 					/*
1262 					 * Command has been handled by mca_char.
1263 					 * Start clean with a prompt.
1264 					 */
1265 					continue;
1266 				case NO_MCA:
1267 					/*
1268 					 * Not a multi-char command
1269 					 * (at least, not anymore).
1270 					 */
1271 					break;
1272 				}
1273 
1274 			/*
1275 			 * Decode the command character and decide what to do.
1276 			 */
1277 			if (mca)
1278 			{
1279 				/*
1280 				 * We're in a multichar command.
1281 				 * Add the character to the command buffer
1282 				 * and display it on the screen.
1283 				 * If the user backspaces past the start
1284 				 * of the line, abort the command.
1285 				 */
1286 				if (cmd_char(c) == CC_QUIT || len_cmdbuf() == 0)
1287 					continue;
1288 				cbuf = get_cmdbuf();
1289 			} else
1290 			{
1291 				/*
1292 				 * Don't use cmd_char if we're starting fresh
1293 				 * at the beginning of a command, because we
1294 				 * don't want to echo the command until we know
1295 				 * it is a multichar command.  We also don't
1296 				 * want erase_char/kill_char to be treated
1297 				 * as line editing characters.
1298 				 */
1299 				tbuf[0] = c;
1300 				tbuf[1] = '\0';
1301 				cbuf = tbuf;
1302 			}
1303 			extra = NULL;
1304 			action = fcmd_decode(cbuf, &extra);
1305 			/*
1306 			 * If an "extra" string was returned,
1307 			 * process it as a string of command characters.
1308 			 */
1309 			if (extra != NULL)
1310 				ungetsc(extra);
1311 		}
1312 		/*
1313 		 * Clear the cmdbuf string.
1314 		 * (But not if we're in the prefix of a command,
1315 		 * because the partial command string is kept there.)
1316 		 */
1317 		if (action != A_PREFIX)
1318 			cmd_reset();
1319 
1320 		switch (action)
1321 		{
1322 		case A_DIGIT:
1323 			/*
1324 			 * First digit of a number.
1325 			 */
1326 			start_mca(A_DIGIT, ":", (void*)NULL, CF_QUIT_ON_ERASE);
1327 			goto again;
1328 
1329 		case A_F_WINDOW:
1330 			/*
1331 			 * Forward one window (and set the window size).
1332 			 */
1333 			if (number > 0)
1334 				swindow = (int) number;
1335 			/* FALLTHRU */
1336 		case A_F_SCREEN:
1337 			/*
1338 			 * Forward one screen.
1339 			 */
1340 			if (number <= 0)
1341 				number = get_swindow();
1342 			cmd_exec();
1343 			if (show_attn)
1344 				set_attnpos(bottompos);
1345 			forward((int) number, 0, 1);
1346 			break;
1347 
1348 		case A_B_WINDOW:
1349 			/*
1350 			 * Backward one window (and set the window size).
1351 			 */
1352 			if (number > 0)
1353 				swindow = (int) number;
1354 			/* FALLTHRU */
1355 		case A_B_SCREEN:
1356 			/*
1357 			 * Backward one screen.
1358 			 */
1359 			if (number <= 0)
1360 				number = get_swindow();
1361 			cmd_exec();
1362 			backward((int) number, 0, 1);
1363 			break;
1364 
1365 		case A_F_LINE:
1366 			/*
1367 			 * Forward N (default 1) line.
1368 			 */
1369 			if (number <= 0)
1370 				number = 1;
1371 			cmd_exec();
1372 			if (show_attn == OPT_ONPLUS && number > 1)
1373 				set_attnpos(bottompos);
1374 			forward((int) number, 0, 0);
1375 			break;
1376 
1377 		case A_B_LINE:
1378 			/*
1379 			 * Backward N (default 1) line.
1380 			 */
1381 			if (number <= 0)
1382 				number = 1;
1383 			cmd_exec();
1384 			backward((int) number, 0, 0);
1385 			break;
1386 
1387 		case A_F_MOUSE:
1388 			/*
1389 			 * Forward wheel_lines lines.
1390 			 */
1391 			cmd_exec();
1392 			forward(wheel_lines, 0, 0);
1393 			break;
1394 
1395 		case A_B_MOUSE:
1396 			/*
1397 			 * Backward wheel_lines lines.
1398 			 */
1399 			cmd_exec();
1400 			backward(wheel_lines, 0, 0);
1401 			break;
1402 
1403 		case A_FF_LINE:
1404 			/*
1405 			 * Force forward N (default 1) line.
1406 			 */
1407 			if (number <= 0)
1408 				number = 1;
1409 			cmd_exec();
1410 			if (show_attn == OPT_ONPLUS && number > 1)
1411 				set_attnpos(bottompos);
1412 			forward((int) number, 1, 0);
1413 			break;
1414 
1415 		case A_BF_LINE:
1416 			/*
1417 			 * Force backward N (default 1) line.
1418 			 */
1419 			if (number <= 0)
1420 				number = 1;
1421 			cmd_exec();
1422 			backward((int) number, 1, 0);
1423 			break;
1424 
1425 		case A_FF_SCREEN:
1426 			/*
1427 			 * Force forward one screen.
1428 			 */
1429 			if (number <= 0)
1430 				number = get_swindow();
1431 			cmd_exec();
1432 			if (show_attn == OPT_ONPLUS)
1433 				set_attnpos(bottompos);
1434 			forward((int) number, 1, 0);
1435 			break;
1436 
1437 		case A_F_FOREVER:
1438 			/*
1439 			 * Forward forever, ignoring EOF.
1440 			 */
1441 			if (show_attn)
1442 				set_attnpos(bottompos);
1443 			newaction = forw_loop(0);
1444 			break;
1445 
1446 		case A_F_UNTIL_HILITE:
1447 			newaction = forw_loop(1);
1448 			break;
1449 
1450 		case A_F_SCROLL:
1451 			/*
1452 			 * Forward N lines
1453 			 * (default same as last 'd' or 'u' command).
1454 			 */
1455 			if (number > 0)
1456 				wscroll = (int) number;
1457 			cmd_exec();
1458 			if (show_attn == OPT_ONPLUS)
1459 				set_attnpos(bottompos);
1460 			forward(wscroll, 0, 0);
1461 			break;
1462 
1463 		case A_B_SCROLL:
1464 			/*
1465 			 * Forward N lines
1466 			 * (default same as last 'd' or 'u' command).
1467 			 */
1468 			if (number > 0)
1469 				wscroll = (int) number;
1470 			cmd_exec();
1471 			backward(wscroll, 0, 0);
1472 			break;
1473 
1474 		case A_FREPAINT:
1475 			/*
1476 			 * Flush buffers, then repaint screen.
1477 			 * Don't flush the buffers on a pipe!
1478 			 */
1479 			clear_buffers();
1480 			/* FALLTHRU */
1481 		case A_REPAINT:
1482 			/*
1483 			 * Repaint screen.
1484 			 */
1485 			cmd_exec();
1486 			repaint();
1487 			break;
1488 
1489 		case A_GOLINE:
1490 			/*
1491 			 * Go to line N, default beginning of file.
1492 			 * If N <= 0, ignore jump_sline in order to avoid
1493 			 * empty lines before the beginning of the file.
1494 			 */
1495 			save_jump_sline = jump_sline;
1496 			if (number <= 0)
1497 			{
1498 				number = 1;
1499 				jump_sline = 0;
1500 			}
1501 			cmd_exec();
1502 			jump_back(number);
1503 			jump_sline = save_jump_sline;
1504 			break;
1505 
1506 		case A_PERCENT:
1507 			/*
1508 			 * Go to a specified percentage into the file.
1509 			 */
1510 			if (number < 0)
1511 			{
1512 				number = 0;
1513 				fraction = 0;
1514 			}
1515 			if (number > 100 || (number == 100 && fraction != 0))
1516 			{
1517 				number = 100;
1518 				fraction = 0;
1519 			}
1520 			cmd_exec();
1521 			jump_percent((int) number, fraction);
1522 			break;
1523 
1524 		case A_GOEND:
1525 			/*
1526 			 * Go to line N, default end of file.
1527 			 */
1528 			cmd_exec();
1529 			if (number <= 0)
1530 				jump_forw();
1531 			else
1532 				jump_back(number);
1533 			break;
1534 
1535 		case A_GOEND_BUF:
1536 			/*
1537 			 * Go to line N, default last buffered byte.
1538 			 */
1539 			cmd_exec();
1540 			if (number <= 0)
1541 				jump_forw_buffered();
1542 			else
1543 				jump_back(number);
1544 			break;
1545 
1546 		case A_GOPOS:
1547 			/*
1548 			 * Go to a specified byte position in the file.
1549 			 */
1550 			cmd_exec();
1551 			if (number < 0)
1552 				number = 0;
1553 			jump_line_loc((POSITION) number, jump_sline);
1554 			break;
1555 
1556 		case A_STAT:
1557 			/*
1558 			 * Print file name, etc.
1559 			 */
1560 			if (ch_getflags() & CH_HELPFILE)
1561 				break;
1562 			cmd_exec();
1563 			parg.p_string = eq_message();
1564 			error("%s", &parg);
1565 			break;
1566 
1567 		case A_VERSION:
1568 			/*
1569 			 * Print version number.
1570 			 */
1571 			cmd_exec();
1572 			dispversion();
1573 			break;
1574 
1575 		case A_QUIT:
1576 			/*
1577 			 * Exit.
1578 			 */
1579 			if (curr_ifile != NULL_IFILE &&
1580 			    ch_getflags() & CH_HELPFILE)
1581 			{
1582 				/*
1583 				 * Quit while viewing the help file
1584 				 * just means return to viewing the
1585 				 * previous file.
1586 				 */
1587 				hshift = save_hshift;
1588 				bs_mode = save_bs_mode;
1589 				if (edit_prev(1) == 0)
1590 					break;
1591 			}
1592 			if (extra != NULL)
1593 				quit(*extra);
1594 			quit(QUIT_OK);
1595 			break;
1596 
1597 /*
1598  * Define abbreviation for a commonly used sequence below.
1599  */
1600 #define DO_SEARCH() \
1601 			if (number <= 0) number = 1;    \
1602 			mca_search();                   \
1603 			cmd_exec();                     \
1604 			multi_search((char *)NULL, (int) number, 0);
1605 
1606 
1607 		case A_F_SEARCH:
1608 			/*
1609 			 * Search forward for a pattern.
1610 			 * Get the first char of the pattern.
1611 			 */
1612 			search_type = SRCH_FORW;
1613 			if (number <= 0)
1614 				number = 1;
1615 			mca_search();
1616 			c = getcc();
1617 			goto again;
1618 
1619 		case A_B_SEARCH:
1620 			/*
1621 			 * Search backward for a pattern.
1622 			 * Get the first char of the pattern.
1623 			 */
1624 			search_type = SRCH_BACK;
1625 			if (number <= 0)
1626 				number = 1;
1627 			mca_search();
1628 			c = getcc();
1629 			goto again;
1630 
1631 		case A_FILTER:
1632 #if HILITE_SEARCH
1633 			search_type = SRCH_FORW | SRCH_FILTER;
1634 			mca_search();
1635 			c = getcc();
1636 			goto again;
1637 #else
1638 			error("Command not available", NULL_PARG);
1639 			break;
1640 #endif
1641 
1642 		case A_AGAIN_SEARCH:
1643 			/*
1644 			 * Repeat previous search.
1645 			 */
1646 			DO_SEARCH();
1647 			break;
1648 
1649 		case A_T_AGAIN_SEARCH:
1650 			/*
1651 			 * Repeat previous search, multiple files.
1652 			 */
1653 			search_type |= SRCH_PAST_EOF;
1654 			DO_SEARCH();
1655 			break;
1656 
1657 		case A_REVERSE_SEARCH:
1658 			/*
1659 			 * Repeat previous search, in reverse direction.
1660 			 */
1661 			save_search_type = search_type;
1662 			search_type = SRCH_REVERSE(search_type);
1663 			DO_SEARCH();
1664 			search_type = save_search_type;
1665 			break;
1666 
1667 		case A_T_REVERSE_SEARCH:
1668 			/*
1669 			 * Repeat previous search,
1670 			 * multiple files in reverse direction.
1671 			 */
1672 			save_search_type = search_type;
1673 			search_type = SRCH_REVERSE(search_type);
1674 			search_type |= SRCH_PAST_EOF;
1675 			DO_SEARCH();
1676 			search_type = save_search_type;
1677 			break;
1678 
1679 		case A_UNDO_SEARCH:
1680 		case A_CLR_SEARCH:
1681 			/*
1682 			 * Clear search string highlighting.
1683 			 */
1684 			undo_search(action == A_CLR_SEARCH);
1685 			break;
1686 
1687 		case A_HELP:
1688 			/*
1689 			 * Help.
1690 			 */
1691 			if (ch_getflags() & CH_HELPFILE)
1692 				break;
1693 			cmd_exec();
1694 			save_hshift = hshift;
1695 			hshift = 0;
1696 			save_bs_mode = bs_mode;
1697 			bs_mode = BS_SPECIAL;
1698 			(void) edit(FAKE_HELPFILE);
1699 			break;
1700 
1701 		case A_EXAMINE:
1702 			/*
1703 			 * Edit a new file.  Get the filename.
1704 			 */
1705 #if EXAMINE
1706 			if (!secure)
1707 			{
1708 				start_mca(A_EXAMINE, "Examine: ", ml_examine, 0);
1709 				c = getcc();
1710 				goto again;
1711 			}
1712 #endif
1713 			error("Command not available", NULL_PARG);
1714 			break;
1715 
1716 		case A_VISUAL:
1717 			/*
1718 			 * Invoke an editor on the input file.
1719 			 */
1720 #if EDITOR
1721 			if (!secure)
1722 			{
1723 				if (ch_getflags() & CH_HELPFILE)
1724 					break;
1725 				if (strcmp(get_filename(curr_ifile), "-") == 0)
1726 				{
1727 					error("Cannot edit standard input", NULL_PARG);
1728 					break;
1729 				}
1730 				if (get_altfilename(curr_ifile) != NULL)
1731 				{
1732 					error("WARNING: This file was viewed via LESSOPEN",
1733 						NULL_PARG);
1734 				}
1735 				start_mca(A_SHELL, "!", ml_shell, 0);
1736 				/*
1737 				 * Expand the editor prototype string
1738 				 * and pass it to the system to execute.
1739 				 * (Make sure the screen is displayed so the
1740 				 * expansion of "+%lm" works.)
1741 				 */
1742 				make_display();
1743 				cmd_exec();
1744 				lsystem(pr_expand(editproto, 0), (char*)NULL);
1745 				break;
1746 			}
1747 #endif
1748 			error("Command not available", NULL_PARG);
1749 			break;
1750 
1751 		case A_NEXT_FILE:
1752 			/*
1753 			 * Examine next file.
1754 			 */
1755 #if TAGS
1756 			if (ntags())
1757 			{
1758 				error("No next file", NULL_PARG);
1759 				break;
1760 			}
1761 #endif
1762 			if (number <= 0)
1763 				number = 1;
1764 			if (edit_next((int) number))
1765 			{
1766 				if (get_quit_at_eof() && eof_displayed() &&
1767 				    !(ch_getflags() & CH_HELPFILE))
1768 					quit(QUIT_OK);
1769 				parg.p_string = (number > 1) ? "(N-th) " : "";
1770 				error("No %snext file", &parg);
1771 			}
1772 			break;
1773 
1774 		case A_PREV_FILE:
1775 			/*
1776 			 * Examine previous file.
1777 			 */
1778 #if TAGS
1779 			if (ntags())
1780 			{
1781 				error("No previous file", NULL_PARG);
1782 				break;
1783 			}
1784 #endif
1785 			if (number <= 0)
1786 				number = 1;
1787 			if (edit_prev((int) number))
1788 			{
1789 				parg.p_string = (number > 1) ? "(N-th) " : "";
1790 				error("No %sprevious file", &parg);
1791 			}
1792 			break;
1793 
1794 		case A_NEXT_TAG:
1795 			/*
1796 			 * Jump to the next tag in the current tag list.
1797 			 */
1798 #if TAGS
1799 			if (number <= 0)
1800 				number = 1;
1801 			tagfile = nexttag((int) number);
1802 			if (tagfile == NULL)
1803 			{
1804 				error("No next tag", NULL_PARG);
1805 				break;
1806 			}
1807 			cmd_exec();
1808 			if (edit(tagfile) == 0)
1809 			{
1810 				POSITION pos = tagsearch();
1811 				if (pos != NULL_POSITION)
1812 					jump_loc(pos, jump_sline);
1813 			}
1814 #else
1815 			error("Command not available", NULL_PARG);
1816 #endif
1817 			break;
1818 
1819 		case A_PREV_TAG:
1820 			/*
1821 			 * Jump to the previous tag in the current tag list.
1822 			 */
1823 #if TAGS
1824 			if (number <= 0)
1825 				number = 1;
1826 			tagfile = prevtag((int) number);
1827 			if (tagfile == NULL)
1828 			{
1829 				error("No previous tag", NULL_PARG);
1830 				break;
1831 			}
1832 			cmd_exec();
1833 			if (edit(tagfile) == 0)
1834 			{
1835 				POSITION pos = tagsearch();
1836 				if (pos != NULL_POSITION)
1837 					jump_loc(pos, jump_sline);
1838 			}
1839 #else
1840 			error("Command not available", NULL_PARG);
1841 #endif
1842 			break;
1843 
1844 		case A_INDEX_FILE:
1845 			/*
1846 			 * Examine a particular file.
1847 			 */
1848 			if (number <= 0)
1849 				number = 1;
1850 			if (edit_index((int) number))
1851 				error("No such file", NULL_PARG);
1852 			break;
1853 
1854 		case A_REMOVE_FILE:
1855 			/*
1856 			 * Remove a file from the input file list.
1857 			 */
1858 			if (ch_getflags() & CH_HELPFILE)
1859 				break;
1860 			old_ifile = curr_ifile;
1861 			new_ifile = getoff_ifile(curr_ifile);
1862 			if (new_ifile == NULL_IFILE)
1863 			{
1864 				bell();
1865 				break;
1866 			}
1867 			if (edit_ifile(new_ifile) != 0)
1868 			{
1869 				reedit_ifile(old_ifile);
1870 				break;
1871 			}
1872 			del_ifile(old_ifile);
1873 			break;
1874 
1875 		case A_OPT_TOGGLE:
1876 			/*
1877 			 * Change the setting of an  option.
1878 			 */
1879 			optflag = OPT_TOGGLE;
1880 			optgetname = FALSE;
1881 			mca_opt_toggle();
1882 			c = getcc();
1883 			cbuf = opt_toggle_disallowed(c);
1884 			if (cbuf != NULL)
1885 			{
1886 				error(cbuf, NULL_PARG);
1887 				break;
1888 			}
1889 			goto again;
1890 
1891 		case A_DISP_OPTION:
1892 			/*
1893 			 * Report the setting of an option.
1894 			 */
1895 			optflag = OPT_NO_TOGGLE;
1896 			optgetname = FALSE;
1897 			mca_opt_toggle();
1898 			c = getcc();
1899 			goto again;
1900 
1901 		case A_FIRSTCMD:
1902 			/*
1903 			 * Set an initial command for new files.
1904 			 */
1905 			start_mca(A_FIRSTCMD, "+", (void*)NULL, 0);
1906 			c = getcc();
1907 			goto again;
1908 
1909 		case A_SHELL:
1910 			/*
1911 			 * Shell escape.
1912 			 */
1913 #if SHELL_ESCAPE
1914 			if (!secure)
1915 			{
1916 				start_mca(A_SHELL, "!", ml_shell, 0);
1917 				c = getcc();
1918 				goto again;
1919 			}
1920 #endif
1921 			error("Command not available", NULL_PARG);
1922 			break;
1923 
1924 		case A_SETMARK:
1925 		case A_SETMARKBOT:
1926 			/*
1927 			 * Set a mark.
1928 			 */
1929 			if (ch_getflags() & CH_HELPFILE)
1930 				break;
1931 			start_mca(A_SETMARK, "set mark: ", (void*)NULL, 0);
1932 			c = getcc();
1933 			if (is_erase_char(c) || is_newline_char(c))
1934 				break;
1935 			setmark(c, action == A_SETMARKBOT ? BOTTOM : TOP);
1936 			repaint();
1937 			break;
1938 
1939 		case A_CLRMARK:
1940 			/*
1941 			 * Clear a mark.
1942 			 */
1943 			start_mca(A_CLRMARK, "clear mark: ", (void*)NULL, 0);
1944 			c = getcc();
1945 			if (is_erase_char(c) || is_newline_char(c))
1946 				break;
1947 			clrmark(c);
1948 			repaint();
1949 			break;
1950 
1951 		case A_GOMARK:
1952 			/*
1953 			 * Jump to a marked position.
1954 			 */
1955 			start_mca(A_GOMARK, "goto mark: ", (void*)NULL, 0);
1956 			c = getcc();
1957 			if (is_erase_char(c) || is_newline_char(c))
1958 				break;
1959 			cmd_exec();
1960 			gomark(c);
1961 			break;
1962 
1963 		case A_PIPE:
1964 			/*
1965 			 * Write part of the input to a pipe to a shell command.
1966 			 */
1967 #if PIPEC
1968 			if (!secure)
1969 			{
1970 				start_mca(A_PIPE, "|mark: ", (void*)NULL, 0);
1971 				c = getcc();
1972 				if (is_erase_char(c))
1973 					break;
1974 				if (is_newline_char(c))
1975 					c = '.';
1976 				if (badmark(c))
1977 					break;
1978 				pipec = c;
1979 				start_mca(A_PIPE, "!", ml_shell, 0);
1980 				c = getcc();
1981 				goto again;
1982 			}
1983 #endif
1984 			error("Command not available", NULL_PARG);
1985 			break;
1986 
1987 		case A_B_BRACKET:
1988 		case A_F_BRACKET:
1989 			start_mca(action, "Brackets: ", (void*)NULL, 0);
1990 			c = getcc();
1991 			goto again;
1992 
1993 		case A_LSHIFT:
1994 			/*
1995 			 * Shift view left.
1996 			 */
1997 			if (number > 0)
1998 				shift_count = number;
1999 			else
2000 				number = (shift_count > 0) ?
2001 					shift_count : sc_width / 2;
2002 			if (number > hshift)
2003 				number = hshift;
2004 			hshift -= number;
2005 			screen_trashed = 1;
2006 			break;
2007 
2008 		case A_RSHIFT:
2009 			/*
2010 			 * Shift view right.
2011 			 */
2012 			if (number > 0)
2013 				shift_count = number;
2014 			else
2015 				number = (shift_count > 0) ?
2016 					shift_count : sc_width / 2;
2017 			hshift += number;
2018 			screen_trashed = 1;
2019 			break;
2020 
2021 		case A_LLSHIFT:
2022 			/*
2023 			 * Shift view left to margin.
2024 			 */
2025 			hshift = 0;
2026 			screen_trashed = 1;
2027 			break;
2028 
2029 		case A_RRSHIFT:
2030 			/*
2031 			 * Shift view right to view rightmost char on screen.
2032 			 */
2033 			hshift = rrshift();
2034 			screen_trashed = 1;
2035 			break;
2036 
2037 		case A_PREFIX:
2038 			/*
2039 			 * The command is incomplete (more chars are needed).
2040 			 * Display the current char, so the user knows
2041 			 * what's going on, and get another character.
2042 			 */
2043 			if (mca != A_PREFIX)
2044 			{
2045 				cmd_reset();
2046 				start_mca(A_PREFIX, " ", (void*)NULL,
2047 					CF_QUIT_ON_ERASE);
2048 				(void) cmd_char(c);
2049 			}
2050 			c = getcc();
2051 			goto again;
2052 
2053 		case A_NOACTION:
2054 			break;
2055 
2056 		default:
2057 			bell();
2058 			break;
2059 		}
2060 	}
2061 }
2062