xref: /freebsd/contrib/less/command.c (revision ce9de47260d4edc963a94140789e4a52642c28e6)
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 
801 #if MSDOS_COMPILER==WIN32C
802 	/*
803 	 * In Win32, display the file name in the window title.
804 	 */
805 	if (!(ch_getflags() & CH_HELPFILE))
806 	{
807 		WCHAR w[MAX_PATH+16];
808 		p = pr_expand("Less?f - %f.", 0);
809 		MultiByteToWideChar(CP_ACP, 0, p, -1, w, sizeof(w)/sizeof(*w));
810 		SetConsoleTitleW(w);
811 	}
812 #endif
813 
814 	/*
815 	 * Select the proper prompt and display it.
816 	 */
817 	/*
818 	 * If the previous action was a forward movement,
819 	 * don't clear the bottom line of the display;
820 	 * just print the prompt since the forward movement guarantees
821 	 * that we're in the right position to display the prompt.
822 	 * Clearing the line could cause a problem: for example, if the last
823 	 * line displayed ended at the right screen edge without a newline,
824 	 * then clearing would clear the last displayed line rather than
825 	 * the prompt line.
826 	 */
827 	if (!forw_prompt)
828 		clear_bot();
829 	clear_cmd();
830 	forw_prompt = 0;
831 	p = pr_string();
832 #if HILITE_SEARCH
833 	if (is_filtering())
834 		putstr("& ");
835 #endif
836 	if (p == NULL || *p == '\0')
837 	{
838 		at_enter(AT_NORMAL|AT_COLOR_PROMPT);
839 		putchr(':');
840 		at_exit();
841 	} else
842 	{
843 #if MSDOS_COMPILER==WIN32C
844 		WCHAR w[MAX_PATH*2];
845 		char  a[MAX_PATH*2];
846 		MultiByteToWideChar(CP_ACP, 0, p, -1, w, sizeof(w)/sizeof(*w));
847 		WideCharToMultiByte(utf_mode ? CP_UTF8 : GetConsoleOutputCP(),
848 		                    0, w, -1, a, sizeof(a), NULL, NULL);
849 		p = a;
850 #endif
851 		at_enter(AT_STANDOUT|AT_COLOR_PROMPT);
852 		putstr(p);
853 		at_exit();
854 	}
855 	clear_eol();
856 }
857 
858 /*
859  * Display the less version message.
860  */
861 	public void
862 dispversion(VOID_PARAM)
863 {
864 	PARG parg;
865 
866 	parg.p_string = version;
867 	error("less %s", &parg);
868 }
869 
870 /*
871  * Return a character to complete a partial command, if possible.
872  */
873 	static LWCHAR
874 getcc_end_command(VOID_PARAM)
875 {
876 	switch (mca)
877 	{
878 	case A_DIGIT:
879 		/* We have a number but no command.  Treat as #g. */
880 		return ('g');
881 	case A_F_SEARCH:
882 	case A_B_SEARCH:
883 		/* We have "/string" but no newline.  Add the \n. */
884 		return ('\n');
885 	default:
886 		/* Some other incomplete command.  Let user complete it. */
887 		return ((ungot == NULL) ? getchr() : 0);
888 	}
889 }
890 
891 /*
892  * Get command character.
893  * The character normally comes from the keyboard,
894  * but may come from ungotten characters
895  * (characters previously given to ungetcc or ungetsc).
896  */
897 	static LWCHAR
898 getccu(VOID_PARAM)
899 {
900 	LWCHAR c = 0;
901 	while (c == 0)
902 	{
903 		if (ungot == NULL)
904 		{
905 			/* Normal case: no ungotten chars.
906 			 * Get char from the user. */
907 			c = getchr();
908 		} else
909 		{
910 			/* Ungotten chars available:
911 			 * Take the top of stack (most recent). */
912 			struct ungot *ug = ungot;
913 			c = ug->ug_char;
914 			ungot = ug->ug_next;
915 			free(ug);
916 
917 			if (c == CHAR_END_COMMAND)
918 				c = getcc_end_command();
919 		}
920 	}
921 	return (c);
922 }
923 
924 /*
925  * Get a command character, but if we receive the orig sequence,
926  * convert it to the repl sequence.
927  */
928 	static LWCHAR
929 getcc_repl(orig, repl, gr_getc, gr_ungetc)
930 	char const* orig;
931 	char const* repl;
932 	LWCHAR (*gr_getc)(VOID_PARAM);
933 	void (*gr_ungetc)(LWCHAR);
934 {
935 	LWCHAR c;
936 	LWCHAR keys[16];
937 	int ki = 0;
938 
939 	c = (*gr_getc)();
940 	if (orig == NULL || orig[0] == '\0')
941 		return c;
942 	for (;;)
943 	{
944 		keys[ki] = c;
945 		if (c != orig[ki] || ki >= sizeof(keys)-1)
946 		{
947 			/* This is not orig we have been receiving.
948 			 * If we have stashed chars in keys[],
949 			 * unget them and return the first one. */
950 			while (ki > 0)
951 				(*gr_ungetc)(keys[ki--]);
952 			return keys[0];
953 		}
954 		if (orig[++ki] == '\0')
955 		{
956 			/* We've received the full orig sequence.
957 			 * Return the repl sequence. */
958 			ki = strlen(repl)-1;
959 			while (ki > 0)
960 				(*gr_ungetc)(repl[ki--]);
961 			return repl[0];
962 		}
963 		/* We've received a partial orig sequence (ki chars of it).
964 		 * Get next char and see if it continues to match orig. */
965 		c = (*gr_getc)();
966 	}
967 }
968 
969 /*
970  * Get command character.
971  */
972 	public int
973 getcc(VOID_PARAM)
974 {
975 	/* Replace kent (keypad Enter) with a newline. */
976 	return getcc_repl(kent, "\n", getccu, ungetcc);
977 }
978 
979 /*
980  * "Unget" a command character.
981  * The next getcc() will return this character.
982  */
983 	public void
984 ungetcc(c)
985 	LWCHAR c;
986 {
987 	struct ungot *ug = (struct ungot *) ecalloc(1, sizeof(struct ungot));
988 
989 	ug->ug_char = c;
990 	ug->ug_next = ungot;
991 	ungot = ug;
992 }
993 
994 /*
995  * "Unget" a command character.
996  * If any other chars are already ungotten, put this one after those.
997  */
998 	public void
999 ungetcc_back(c)
1000 	LWCHAR c;
1001 {
1002 	struct ungot *ug = (struct ungot *) ecalloc(1, sizeof(struct ungot));
1003 	ug->ug_char = c;
1004 	ug->ug_next = NULL;
1005 	if (ungot == NULL)
1006 		ungot = ug;
1007 	else
1008 	{
1009 		struct ungot *pu;
1010 		for (pu = ungot; pu->ug_next != NULL; pu = pu->ug_next)
1011 			continue;
1012 		pu->ug_next = ug;
1013 	}
1014 }
1015 
1016 /*
1017  * Unget a whole string of command characters.
1018  * The next sequence of getcc()'s will return this string.
1019  */
1020 	public void
1021 ungetsc(s)
1022 	char *s;
1023 {
1024 	while (*s != '\0')
1025 		ungetcc_back(*s++);
1026 }
1027 
1028 /*
1029  * Peek the next command character, without consuming it.
1030  */
1031 	public LWCHAR
1032 peekcc(VOID_PARAM)
1033 {
1034 	LWCHAR c = getcc();
1035 	ungetcc(c);
1036 	return c;
1037 }
1038 
1039 /*
1040  * Search for a pattern, possibly in multiple files.
1041  * If SRCH_FIRST_FILE is set, begin searching at the first file.
1042  * If SRCH_PAST_EOF is set, continue the search thru multiple files.
1043  */
1044 	static void
1045 multi_search(pattern, n, silent)
1046 	char *pattern;
1047 	int n;
1048 	int silent;
1049 {
1050 	int nomore;
1051 	IFILE save_ifile;
1052 	int changed_file;
1053 
1054 	changed_file = 0;
1055 	save_ifile = save_curr_ifile();
1056 
1057 	if (search_type & SRCH_FIRST_FILE)
1058 	{
1059 		/*
1060 		 * Start at the first (or last) file
1061 		 * in the command line list.
1062 		 */
1063 		if (search_type & SRCH_FORW)
1064 			nomore = edit_first();
1065 		else
1066 			nomore = edit_last();
1067 		if (nomore)
1068 		{
1069 			unsave_ifile(save_ifile);
1070 			return;
1071 		}
1072 		changed_file = 1;
1073 		search_type &= ~SRCH_FIRST_FILE;
1074 	}
1075 
1076 	for (;;)
1077 	{
1078 		n = search(search_type, pattern, n);
1079 		/*
1080 		 * The SRCH_NO_MOVE flag doesn't "stick": it gets cleared
1081 		 * after being used once.  This allows "n" to work after
1082 		 * using a /@@ search.
1083 		 */
1084 		search_type &= ~SRCH_NO_MOVE;
1085 		if (n == 0)
1086 		{
1087 			/*
1088 			 * Found it.
1089 			 */
1090 			unsave_ifile(save_ifile);
1091 			return;
1092 		}
1093 
1094 		if (n < 0)
1095 			/*
1096 			 * Some kind of error in the search.
1097 			 * Error message has been printed by search().
1098 			 */
1099 			break;
1100 
1101 		if ((search_type & SRCH_PAST_EOF) == 0)
1102 			/*
1103 			 * We didn't find a match, but we're
1104 			 * supposed to search only one file.
1105 			 */
1106 			break;
1107 		/*
1108 		 * Move on to the next file.
1109 		 */
1110 		if (search_type & SRCH_FORW)
1111 			nomore = edit_next(1);
1112 		else
1113 			nomore = edit_prev(1);
1114 		if (nomore)
1115 			break;
1116 		changed_file = 1;
1117 	}
1118 
1119 	/*
1120 	 * Didn't find it.
1121 	 * Print an error message if we haven't already.
1122 	 */
1123 	if (n > 0 && !silent)
1124 		error("Pattern not found", NULL_PARG);
1125 
1126 	if (changed_file)
1127 	{
1128 		/*
1129 		 * Restore the file we were originally viewing.
1130 		 */
1131 		reedit_ifile(save_ifile);
1132 	} else
1133 	{
1134 		unsave_ifile(save_ifile);
1135 	}
1136 }
1137 
1138 /*
1139  * Forward forever, or until a highlighted line appears.
1140  */
1141 	static int
1142 forw_loop(until_hilite)
1143 	int until_hilite;
1144 {
1145 	POSITION curr_len;
1146 
1147 	if (ch_getflags() & CH_HELPFILE)
1148 		return (A_NOACTION);
1149 
1150 	cmd_exec();
1151 	jump_forw_buffered();
1152 	curr_len = ch_length();
1153 	highest_hilite = until_hilite ? curr_len : NULL_POSITION;
1154 	ignore_eoi = 1;
1155 	while (!sigs)
1156 	{
1157 		if (until_hilite && highest_hilite > curr_len)
1158 		{
1159 			bell();
1160 			break;
1161 		}
1162 		make_display();
1163 		forward(1, 0, 0);
1164 	}
1165 	ignore_eoi = 0;
1166 	ch_set_eof();
1167 
1168 	/*
1169 	 * This gets us back in "F mode" after processing
1170 	 * a non-abort signal (e.g. window-change).
1171 	 */
1172 	if (sigs && !ABORT_SIGS())
1173 		return (until_hilite ? A_F_UNTIL_HILITE : A_F_FOREVER);
1174 
1175 	return (A_NOACTION);
1176 }
1177 
1178 /*
1179  * Main command processor.
1180  * Accept and execute commands until a quit command.
1181  */
1182 	public void
1183 commands(VOID_PARAM)
1184 {
1185 	int c;
1186 	int action;
1187 	char *cbuf;
1188 	int newaction;
1189 	int save_jump_sline;
1190 	int save_search_type;
1191 	char *extra;
1192 	char tbuf[2];
1193 	PARG parg;
1194 	IFILE old_ifile;
1195 	IFILE new_ifile;
1196 	char *tagfile;
1197 
1198 	search_type = SRCH_FORW;
1199 	wscroll = (sc_height + 1) / 2;
1200 	newaction = A_NOACTION;
1201 
1202 	for (;;)
1203 	{
1204 		clear_mca();
1205 		cmd_accept();
1206 		number = 0;
1207 		curropt = NULL;
1208 
1209 		/*
1210 		 * See if any signals need processing.
1211 		 */
1212 		if (sigs)
1213 		{
1214 			psignals();
1215 			if (quitting)
1216 				quit(QUIT_SAVED_STATUS);
1217 		}
1218 
1219 		/*
1220 		 * See if window size changed, for systems that don't
1221 		 * generate SIGWINCH.
1222 		 */
1223 		check_winch();
1224 
1225 		/*
1226 		 * Display prompt and accept a character.
1227 		 */
1228 		cmd_reset();
1229 		prompt();
1230 		if (sigs)
1231 			continue;
1232 		if (newaction == A_NOACTION)
1233 			c = getcc();
1234 
1235 	again:
1236 		if (sigs)
1237 			continue;
1238 
1239 		if (newaction != A_NOACTION)
1240 		{
1241 			action = newaction;
1242 			newaction = A_NOACTION;
1243 		} else
1244 		{
1245 			/*
1246 			 * If we are in a multicharacter command, call mca_char.
1247 			 * Otherwise we call fcmd_decode to determine the
1248 			 * action to be performed.
1249 			 */
1250 			if (mca)
1251 				switch (mca_char(c))
1252 				{
1253 				case MCA_MORE:
1254 					/*
1255 					 * Need another character.
1256 					 */
1257 					c = getcc();
1258 					goto again;
1259 				case MCA_DONE:
1260 					/*
1261 					 * Command has been handled by mca_char.
1262 					 * Start clean with a prompt.
1263 					 */
1264 					continue;
1265 				case NO_MCA:
1266 					/*
1267 					 * Not a multi-char command
1268 					 * (at least, not anymore).
1269 					 */
1270 					break;
1271 				}
1272 
1273 			/*
1274 			 * Decode the command character and decide what to do.
1275 			 */
1276 			if (mca)
1277 			{
1278 				/*
1279 				 * We're in a multichar command.
1280 				 * Add the character to the command buffer
1281 				 * and display it on the screen.
1282 				 * If the user backspaces past the start
1283 				 * of the line, abort the command.
1284 				 */
1285 				if (cmd_char(c) == CC_QUIT || len_cmdbuf() == 0)
1286 					continue;
1287 				cbuf = get_cmdbuf();
1288 			} else
1289 			{
1290 				/*
1291 				 * Don't use cmd_char if we're starting fresh
1292 				 * at the beginning of a command, because we
1293 				 * don't want to echo the command until we know
1294 				 * it is a multichar command.  We also don't
1295 				 * want erase_char/kill_char to be treated
1296 				 * as line editing characters.
1297 				 */
1298 				tbuf[0] = c;
1299 				tbuf[1] = '\0';
1300 				cbuf = tbuf;
1301 			}
1302 			extra = NULL;
1303 			action = fcmd_decode(cbuf, &extra);
1304 			/*
1305 			 * If an "extra" string was returned,
1306 			 * process it as a string of command characters.
1307 			 */
1308 			if (extra != NULL)
1309 				ungetsc(extra);
1310 		}
1311 		/*
1312 		 * Clear the cmdbuf string.
1313 		 * (But not if we're in the prefix of a command,
1314 		 * because the partial command string is kept there.)
1315 		 */
1316 		if (action != A_PREFIX)
1317 			cmd_reset();
1318 
1319 		switch (action)
1320 		{
1321 		case A_DIGIT:
1322 			/*
1323 			 * First digit of a number.
1324 			 */
1325 			start_mca(A_DIGIT, ":", (void*)NULL, CF_QUIT_ON_ERASE);
1326 			goto again;
1327 
1328 		case A_F_WINDOW:
1329 			/*
1330 			 * Forward one window (and set the window size).
1331 			 */
1332 			if (number > 0)
1333 				swindow = (int) number;
1334 			/* FALLTHRU */
1335 		case A_F_SCREEN:
1336 			/*
1337 			 * Forward one screen.
1338 			 */
1339 			if (number <= 0)
1340 				number = get_swindow();
1341 			cmd_exec();
1342 			if (show_attn)
1343 				set_attnpos(bottompos);
1344 			forward((int) number, 0, 1);
1345 			break;
1346 
1347 		case A_B_WINDOW:
1348 			/*
1349 			 * Backward one window (and set the window size).
1350 			 */
1351 			if (number > 0)
1352 				swindow = (int) number;
1353 			/* FALLTHRU */
1354 		case A_B_SCREEN:
1355 			/*
1356 			 * Backward one screen.
1357 			 */
1358 			if (number <= 0)
1359 				number = get_swindow();
1360 			cmd_exec();
1361 			backward((int) number, 0, 1);
1362 			break;
1363 
1364 		case A_F_LINE:
1365 			/*
1366 			 * Forward N (default 1) line.
1367 			 */
1368 			if (number <= 0)
1369 				number = 1;
1370 			cmd_exec();
1371 			if (show_attn == OPT_ONPLUS && number > 1)
1372 				set_attnpos(bottompos);
1373 			forward((int) number, 0, 0);
1374 			break;
1375 
1376 		case A_B_LINE:
1377 			/*
1378 			 * Backward N (default 1) line.
1379 			 */
1380 			if (number <= 0)
1381 				number = 1;
1382 			cmd_exec();
1383 			backward((int) number, 0, 0);
1384 			break;
1385 
1386 		case A_F_MOUSE:
1387 			/*
1388 			 * Forward wheel_lines lines.
1389 			 */
1390 			cmd_exec();
1391 			forward(wheel_lines, 0, 0);
1392 			break;
1393 
1394 		case A_B_MOUSE:
1395 			/*
1396 			 * Backward wheel_lines lines.
1397 			 */
1398 			cmd_exec();
1399 			backward(wheel_lines, 0, 0);
1400 			break;
1401 
1402 		case A_FF_LINE:
1403 			/*
1404 			 * Force forward N (default 1) line.
1405 			 */
1406 			if (number <= 0)
1407 				number = 1;
1408 			cmd_exec();
1409 			if (show_attn == OPT_ONPLUS && number > 1)
1410 				set_attnpos(bottompos);
1411 			forward((int) number, 1, 0);
1412 			break;
1413 
1414 		case A_BF_LINE:
1415 			/*
1416 			 * Force backward N (default 1) line.
1417 			 */
1418 			if (number <= 0)
1419 				number = 1;
1420 			cmd_exec();
1421 			backward((int) number, 1, 0);
1422 			break;
1423 
1424 		case A_FF_SCREEN:
1425 			/*
1426 			 * Force forward one screen.
1427 			 */
1428 			if (number <= 0)
1429 				number = get_swindow();
1430 			cmd_exec();
1431 			if (show_attn == OPT_ONPLUS)
1432 				set_attnpos(bottompos);
1433 			forward((int) number, 1, 0);
1434 			break;
1435 
1436 		case A_F_FOREVER:
1437 			/*
1438 			 * Forward forever, ignoring EOF.
1439 			 */
1440 			if (show_attn)
1441 				set_attnpos(bottompos);
1442 			newaction = forw_loop(0);
1443 			break;
1444 
1445 		case A_F_UNTIL_HILITE:
1446 			newaction = forw_loop(1);
1447 			break;
1448 
1449 		case A_F_SCROLL:
1450 			/*
1451 			 * Forward N lines
1452 			 * (default same as last 'd' or 'u' command).
1453 			 */
1454 			if (number > 0)
1455 				wscroll = (int) number;
1456 			cmd_exec();
1457 			if (show_attn == OPT_ONPLUS)
1458 				set_attnpos(bottompos);
1459 			forward(wscroll, 0, 0);
1460 			break;
1461 
1462 		case A_B_SCROLL:
1463 			/*
1464 			 * Forward N lines
1465 			 * (default same as last 'd' or 'u' command).
1466 			 */
1467 			if (number > 0)
1468 				wscroll = (int) number;
1469 			cmd_exec();
1470 			backward(wscroll, 0, 0);
1471 			break;
1472 
1473 		case A_FREPAINT:
1474 			/*
1475 			 * Flush buffers, then repaint screen.
1476 			 * Don't flush the buffers on a pipe!
1477 			 */
1478 			clear_buffers();
1479 			/* FALLTHRU */
1480 		case A_REPAINT:
1481 			/*
1482 			 * Repaint screen.
1483 			 */
1484 			cmd_exec();
1485 			repaint();
1486 			break;
1487 
1488 		case A_GOLINE:
1489 			/*
1490 			 * Go to line N, default beginning of file.
1491 			 * If N <= 0, ignore jump_sline in order to avoid
1492 			 * empty lines before the beginning of the file.
1493 			 */
1494 			save_jump_sline = jump_sline;
1495 			if (number <= 0)
1496 			{
1497 				number = 1;
1498 				jump_sline = 0;
1499 			}
1500 			cmd_exec();
1501 			jump_back(number);
1502 			jump_sline = save_jump_sline;
1503 			break;
1504 
1505 		case A_PERCENT:
1506 			/*
1507 			 * Go to a specified percentage into the file.
1508 			 */
1509 			if (number < 0)
1510 			{
1511 				number = 0;
1512 				fraction = 0;
1513 			}
1514 			if (number > 100 || (number == 100 && fraction != 0))
1515 			{
1516 				number = 100;
1517 				fraction = 0;
1518 			}
1519 			cmd_exec();
1520 			jump_percent((int) number, fraction);
1521 			break;
1522 
1523 		case A_GOEND:
1524 			/*
1525 			 * Go to line N, default end of file.
1526 			 */
1527 			cmd_exec();
1528 			if (number <= 0)
1529 				jump_forw();
1530 			else
1531 				jump_back(number);
1532 			break;
1533 
1534 		case A_GOEND_BUF:
1535 			/*
1536 			 * Go to line N, default last buffered byte.
1537 			 */
1538 			cmd_exec();
1539 			if (number <= 0)
1540 				jump_forw_buffered();
1541 			else
1542 				jump_back(number);
1543 			break;
1544 
1545 		case A_GOPOS:
1546 			/*
1547 			 * Go to a specified byte position in the file.
1548 			 */
1549 			cmd_exec();
1550 			if (number < 0)
1551 				number = 0;
1552 			jump_line_loc((POSITION) number, jump_sline);
1553 			break;
1554 
1555 		case A_STAT:
1556 			/*
1557 			 * Print file name, etc.
1558 			 */
1559 			if (ch_getflags() & CH_HELPFILE)
1560 				break;
1561 			cmd_exec();
1562 			parg.p_string = eq_message();
1563 			error("%s", &parg);
1564 			break;
1565 
1566 		case A_VERSION:
1567 			/*
1568 			 * Print version number.
1569 			 */
1570 			cmd_exec();
1571 			dispversion();
1572 			break;
1573 
1574 		case A_QUIT:
1575 			/*
1576 			 * Exit.
1577 			 */
1578 			if (curr_ifile != NULL_IFILE &&
1579 			    ch_getflags() & CH_HELPFILE)
1580 			{
1581 				/*
1582 				 * Quit while viewing the help file
1583 				 * just means return to viewing the
1584 				 * previous file.
1585 				 */
1586 				hshift = save_hshift;
1587 				bs_mode = save_bs_mode;
1588 				if (edit_prev(1) == 0)
1589 					break;
1590 			}
1591 			if (extra != NULL)
1592 				quit(*extra);
1593 			quit(QUIT_OK);
1594 			break;
1595 
1596 /*
1597  * Define abbreviation for a commonly used sequence below.
1598  */
1599 #define DO_SEARCH() \
1600 			if (number <= 0) number = 1;    \
1601 			mca_search();                   \
1602 			cmd_exec();                     \
1603 			multi_search((char *)NULL, (int) number, 0);
1604 
1605 
1606 		case A_F_SEARCH:
1607 			/*
1608 			 * Search forward for a pattern.
1609 			 * Get the first char of the pattern.
1610 			 */
1611 			search_type = SRCH_FORW;
1612 			if (number <= 0)
1613 				number = 1;
1614 			mca_search();
1615 			c = getcc();
1616 			goto again;
1617 
1618 		case A_B_SEARCH:
1619 			/*
1620 			 * Search backward for a pattern.
1621 			 * Get the first char of the pattern.
1622 			 */
1623 			search_type = SRCH_BACK;
1624 			if (number <= 0)
1625 				number = 1;
1626 			mca_search();
1627 			c = getcc();
1628 			goto again;
1629 
1630 		case A_FILTER:
1631 #if HILITE_SEARCH
1632 			search_type = SRCH_FORW | SRCH_FILTER;
1633 			mca_search();
1634 			c = getcc();
1635 			goto again;
1636 #else
1637 			error("Command not available", NULL_PARG);
1638 			break;
1639 #endif
1640 
1641 		case A_AGAIN_SEARCH:
1642 			/*
1643 			 * Repeat previous search.
1644 			 */
1645 			DO_SEARCH();
1646 			break;
1647 
1648 		case A_T_AGAIN_SEARCH:
1649 			/*
1650 			 * Repeat previous search, multiple files.
1651 			 */
1652 			search_type |= SRCH_PAST_EOF;
1653 			DO_SEARCH();
1654 			break;
1655 
1656 		case A_REVERSE_SEARCH:
1657 			/*
1658 			 * Repeat previous search, in reverse direction.
1659 			 */
1660 			save_search_type = search_type;
1661 			search_type = SRCH_REVERSE(search_type);
1662 			DO_SEARCH();
1663 			search_type = save_search_type;
1664 			break;
1665 
1666 		case A_T_REVERSE_SEARCH:
1667 			/*
1668 			 * Repeat previous search,
1669 			 * multiple files in reverse direction.
1670 			 */
1671 			save_search_type = search_type;
1672 			search_type = SRCH_REVERSE(search_type);
1673 			search_type |= SRCH_PAST_EOF;
1674 			DO_SEARCH();
1675 			search_type = save_search_type;
1676 			break;
1677 
1678 		case A_UNDO_SEARCH:
1679 		case A_CLR_SEARCH:
1680 			/*
1681 			 * Clear search string highlighting.
1682 			 */
1683 			undo_search(action == A_CLR_SEARCH);
1684 			break;
1685 
1686 		case A_HELP:
1687 			/*
1688 			 * Help.
1689 			 */
1690 			if (ch_getflags() & CH_HELPFILE)
1691 				break;
1692 			cmd_exec();
1693 			save_hshift = hshift;
1694 			hshift = 0;
1695 			save_bs_mode = bs_mode;
1696 			bs_mode = BS_SPECIAL;
1697 			(void) edit(FAKE_HELPFILE);
1698 			break;
1699 
1700 		case A_EXAMINE:
1701 			/*
1702 			 * Edit a new file.  Get the filename.
1703 			 */
1704 #if EXAMINE
1705 			if (!secure)
1706 			{
1707 				start_mca(A_EXAMINE, "Examine: ", ml_examine, 0);
1708 				c = getcc();
1709 				goto again;
1710 			}
1711 #endif
1712 			error("Command not available", NULL_PARG);
1713 			break;
1714 
1715 		case A_VISUAL:
1716 			/*
1717 			 * Invoke an editor on the input file.
1718 			 */
1719 #if EDITOR
1720 			if (!secure)
1721 			{
1722 				if (ch_getflags() & CH_HELPFILE)
1723 					break;
1724 				if (strcmp(get_filename(curr_ifile), "-") == 0)
1725 				{
1726 					error("Cannot edit standard input", NULL_PARG);
1727 					break;
1728 				}
1729 				if (get_altfilename(curr_ifile) != NULL)
1730 				{
1731 					error("WARNING: This file was viewed via LESSOPEN",
1732 						NULL_PARG);
1733 				}
1734 				start_mca(A_SHELL, "!", ml_shell, 0);
1735 				/*
1736 				 * Expand the editor prototype string
1737 				 * and pass it to the system to execute.
1738 				 * (Make sure the screen is displayed so the
1739 				 * expansion of "+%lm" works.)
1740 				 */
1741 				make_display();
1742 				cmd_exec();
1743 				lsystem(pr_expand(editproto, 0), (char*)NULL);
1744 				break;
1745 			}
1746 #endif
1747 			error("Command not available", NULL_PARG);
1748 			break;
1749 
1750 		case A_NEXT_FILE:
1751 			/*
1752 			 * Examine next file.
1753 			 */
1754 #if TAGS
1755 			if (ntags())
1756 			{
1757 				error("No next file", NULL_PARG);
1758 				break;
1759 			}
1760 #endif
1761 			if (number <= 0)
1762 				number = 1;
1763 			if (edit_next((int) number))
1764 			{
1765 				if (get_quit_at_eof() && eof_displayed() &&
1766 				    !(ch_getflags() & CH_HELPFILE))
1767 					quit(QUIT_OK);
1768 				parg.p_string = (number > 1) ? "(N-th) " : "";
1769 				error("No %snext file", &parg);
1770 			}
1771 			break;
1772 
1773 		case A_PREV_FILE:
1774 			/*
1775 			 * Examine previous file.
1776 			 */
1777 #if TAGS
1778 			if (ntags())
1779 			{
1780 				error("No previous file", NULL_PARG);
1781 				break;
1782 			}
1783 #endif
1784 			if (number <= 0)
1785 				number = 1;
1786 			if (edit_prev((int) number))
1787 			{
1788 				parg.p_string = (number > 1) ? "(N-th) " : "";
1789 				error("No %sprevious file", &parg);
1790 			}
1791 			break;
1792 
1793 		case A_NEXT_TAG:
1794 			/*
1795 			 * Jump to the next tag in the current tag list.
1796 			 */
1797 #if TAGS
1798 			if (number <= 0)
1799 				number = 1;
1800 			tagfile = nexttag((int) number);
1801 			if (tagfile == NULL)
1802 			{
1803 				error("No next tag", NULL_PARG);
1804 				break;
1805 			}
1806 			cmd_exec();
1807 			if (edit(tagfile) == 0)
1808 			{
1809 				POSITION pos = tagsearch();
1810 				if (pos != NULL_POSITION)
1811 					jump_loc(pos, jump_sline);
1812 			}
1813 #else
1814 			error("Command not available", NULL_PARG);
1815 #endif
1816 			break;
1817 
1818 		case A_PREV_TAG:
1819 			/*
1820 			 * Jump to the previous tag in the current tag list.
1821 			 */
1822 #if TAGS
1823 			if (number <= 0)
1824 				number = 1;
1825 			tagfile = prevtag((int) number);
1826 			if (tagfile == NULL)
1827 			{
1828 				error("No previous tag", NULL_PARG);
1829 				break;
1830 			}
1831 			cmd_exec();
1832 			if (edit(tagfile) == 0)
1833 			{
1834 				POSITION pos = tagsearch();
1835 				if (pos != NULL_POSITION)
1836 					jump_loc(pos, jump_sline);
1837 			}
1838 #else
1839 			error("Command not available", NULL_PARG);
1840 #endif
1841 			break;
1842 
1843 		case A_INDEX_FILE:
1844 			/*
1845 			 * Examine a particular file.
1846 			 */
1847 			if (number <= 0)
1848 				number = 1;
1849 			if (edit_index((int) number))
1850 				error("No such file", NULL_PARG);
1851 			break;
1852 
1853 		case A_REMOVE_FILE:
1854 			/*
1855 			 * Remove a file from the input file list.
1856 			 */
1857 			if (ch_getflags() & CH_HELPFILE)
1858 				break;
1859 			old_ifile = curr_ifile;
1860 			new_ifile = getoff_ifile(curr_ifile);
1861 			if (new_ifile == NULL_IFILE)
1862 			{
1863 				bell();
1864 				break;
1865 			}
1866 			if (edit_ifile(new_ifile) != 0)
1867 			{
1868 				reedit_ifile(old_ifile);
1869 				break;
1870 			}
1871 			del_ifile(old_ifile);
1872 			break;
1873 
1874 		case A_OPT_TOGGLE:
1875 			/*
1876 			 * Change the setting of an  option.
1877 			 */
1878 			optflag = OPT_TOGGLE;
1879 			optgetname = FALSE;
1880 			mca_opt_toggle();
1881 			c = getcc();
1882 			cbuf = opt_toggle_disallowed(c);
1883 			if (cbuf != NULL)
1884 			{
1885 				error(cbuf, NULL_PARG);
1886 				break;
1887 			}
1888 			goto again;
1889 
1890 		case A_DISP_OPTION:
1891 			/*
1892 			 * Report the setting of an option.
1893 			 */
1894 			optflag = OPT_NO_TOGGLE;
1895 			optgetname = FALSE;
1896 			mca_opt_toggle();
1897 			c = getcc();
1898 			goto again;
1899 
1900 		case A_FIRSTCMD:
1901 			/*
1902 			 * Set an initial command for new files.
1903 			 */
1904 			start_mca(A_FIRSTCMD, "+", (void*)NULL, 0);
1905 			c = getcc();
1906 			goto again;
1907 
1908 		case A_SHELL:
1909 			/*
1910 			 * Shell escape.
1911 			 */
1912 #if SHELL_ESCAPE
1913 			if (!secure)
1914 			{
1915 				start_mca(A_SHELL, "!", ml_shell, 0);
1916 				c = getcc();
1917 				goto again;
1918 			}
1919 #endif
1920 			error("Command not available", NULL_PARG);
1921 			break;
1922 
1923 		case A_SETMARK:
1924 		case A_SETMARKBOT:
1925 			/*
1926 			 * Set a mark.
1927 			 */
1928 			if (ch_getflags() & CH_HELPFILE)
1929 				break;
1930 			start_mca(A_SETMARK, "set mark: ", (void*)NULL, 0);
1931 			c = getcc();
1932 			if (is_erase_char(c) || is_newline_char(c))
1933 				break;
1934 			setmark(c, action == A_SETMARKBOT ? BOTTOM : TOP);
1935 			repaint();
1936 			break;
1937 
1938 		case A_CLRMARK:
1939 			/*
1940 			 * Clear a mark.
1941 			 */
1942 			start_mca(A_CLRMARK, "clear mark: ", (void*)NULL, 0);
1943 			c = getcc();
1944 			if (is_erase_char(c) || is_newline_char(c))
1945 				break;
1946 			clrmark(c);
1947 			repaint();
1948 			break;
1949 
1950 		case A_GOMARK:
1951 			/*
1952 			 * Jump to a marked position.
1953 			 */
1954 			start_mca(A_GOMARK, "goto mark: ", (void*)NULL, 0);
1955 			c = getcc();
1956 			if (is_erase_char(c) || is_newline_char(c))
1957 				break;
1958 			cmd_exec();
1959 			gomark(c);
1960 			break;
1961 
1962 		case A_PIPE:
1963 			/*
1964 			 * Write part of the input to a pipe to a shell command.
1965 			 */
1966 #if PIPEC
1967 			if (!secure)
1968 			{
1969 				start_mca(A_PIPE, "|mark: ", (void*)NULL, 0);
1970 				c = getcc();
1971 				if (is_erase_char(c))
1972 					break;
1973 				if (is_newline_char(c))
1974 					c = '.';
1975 				if (badmark(c))
1976 					break;
1977 				pipec = c;
1978 				start_mca(A_PIPE, "!", ml_shell, 0);
1979 				c = getcc();
1980 				goto again;
1981 			}
1982 #endif
1983 			error("Command not available", NULL_PARG);
1984 			break;
1985 
1986 		case A_B_BRACKET:
1987 		case A_F_BRACKET:
1988 			start_mca(action, "Brackets: ", (void*)NULL, 0);
1989 			c = getcc();
1990 			goto again;
1991 
1992 		case A_LSHIFT:
1993 			/*
1994 			 * Shift view left.
1995 			 */
1996 			if (number > 0)
1997 				shift_count = number;
1998 			else
1999 				number = (shift_count > 0) ?
2000 					shift_count : sc_width / 2;
2001 			if (number > hshift)
2002 				number = hshift;
2003 			hshift -= number;
2004 			screen_trashed = 1;
2005 			break;
2006 
2007 		case A_RSHIFT:
2008 			/*
2009 			 * Shift view right.
2010 			 */
2011 			if (number > 0)
2012 				shift_count = number;
2013 			else
2014 				number = (shift_count > 0) ?
2015 					shift_count : sc_width / 2;
2016 			hshift += number;
2017 			screen_trashed = 1;
2018 			break;
2019 
2020 		case A_LLSHIFT:
2021 			/*
2022 			 * Shift view left to margin.
2023 			 */
2024 			hshift = 0;
2025 			screen_trashed = 1;
2026 			break;
2027 
2028 		case A_RRSHIFT:
2029 			/*
2030 			 * Shift view right to view rightmost char on screen.
2031 			 */
2032 			hshift = rrshift();
2033 			screen_trashed = 1;
2034 			break;
2035 
2036 		case A_PREFIX:
2037 			/*
2038 			 * The command is incomplete (more chars are needed).
2039 			 * Display the current char, so the user knows
2040 			 * what's going on, and get another character.
2041 			 */
2042 			if (mca != A_PREFIX)
2043 			{
2044 				cmd_reset();
2045 				start_mca(A_PREFIX, " ", (void*)NULL,
2046 					CF_QUIT_ON_ERASE);
2047 				(void) cmd_char(c);
2048 			}
2049 			c = getcc();
2050 			goto again;
2051 
2052 		case A_NOACTION:
2053 			break;
2054 
2055 		default:
2056 			bell();
2057 			break;
2058 		}
2059 	}
2060 }
2061