xref: /freebsd/contrib/less/command.c (revision ea906c4152774dff300bb26fbfc1e4188351c89a)
1 /* $FreeBSD$ */
2 /*
3  * Copyright (C) 1984-2007  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 about less, or for information on how to
9  * contact the author, see the README file.
10  */
11 
12 
13 /*
14  * User-level command processor.
15  */
16 
17 #include "less.h"
18 #if MSDOS_COMPILER==WIN32C
19 #include <windows.h>
20 #endif
21 #include "position.h"
22 #include "option.h"
23 #include "cmd.h"
24 
25 extern int erase_char, erase2_char, kill_char;
26 extern int sigs;
27 extern int quit_if_one_screen;
28 extern int squished;
29 extern int hit_eof;
30 extern int sc_width;
31 extern int sc_height;
32 extern int swindow;
33 extern int jump_sline;
34 extern int quitting;
35 extern int wscroll;
36 extern int top_scroll;
37 extern int ignore_eoi;
38 extern int secure;
39 extern int hshift;
40 extern int show_attn;
41 extern int less_is_more;
42 extern char *every_first_cmd;
43 extern char *curr_altfilename;
44 extern char version[];
45 extern struct scrpos initial_scrpos;
46 extern IFILE curr_ifile;
47 extern void constant *ml_search;
48 extern void constant *ml_examine;
49 #if SHELL_ESCAPE || PIPEC
50 extern void constant *ml_shell;
51 #endif
52 #if EDITOR
53 extern char *editor;
54 extern char *editproto;
55 #endif
56 extern int screen_trashed;	/* The screen has been overwritten */
57 extern int shift_count;
58 extern int oldbot;
59 extern int forw_prompt;
60 
61 static char ungot[UNGOT_SIZE];
62 static char *ungotp = NULL;
63 #if SHELL_ESCAPE
64 static char *shellcmd = NULL;	/* For holding last shell command for "!!" */
65 #endif
66 static int mca;			/* The multicharacter command (action) */
67 static int search_type;		/* The previous type of search */
68 static LINENUM number;		/* The number typed by the user */
69 static long fraction;		/* The fractional part of the number */
70 static char optchar;
71 static int optflag;
72 static int optgetname;
73 static POSITION bottompos;
74 static int save_hshift;
75 #if PIPEC
76 static char pipec;
77 #endif
78 
79 static void multi_search();
80 
81 /*
82  * Move the cursor to start of prompt line before executing a command.
83  * This looks nicer if the command takes a long time before
84  * updating the screen.
85  */
86 	static void
87 cmd_exec()
88 {
89 	clear_attn();
90 	clear_bot();
91 	flush();
92 }
93 
94 /*
95  * Set up the display to start a new multi-character command.
96  */
97 	static void
98 start_mca(action, prompt, mlist, cmdflags)
99 	int action;
100 	char *prompt;
101 	void *mlist;
102 	int cmdflags;
103 {
104 	mca = action;
105 	clear_bot();
106 	clear_cmd();
107 	cmd_putstr(prompt);
108 	set_mlist(mlist, cmdflags);
109 }
110 
111 	public int
112 in_mca()
113 {
114 	return (mca != 0 && mca != A_PREFIX);
115 }
116 
117 /*
118  * Set up the display to start a new search command.
119  */
120 	static void
121 mca_search()
122 {
123 	if (search_type & SRCH_FORW)
124 		mca = A_F_SEARCH;
125 	else
126 		mca = A_B_SEARCH;
127 
128 	clear_bot();
129 	clear_cmd();
130 
131 	if (search_type & SRCH_NO_MATCH)
132 		cmd_putstr("Non-match ");
133 	if (search_type & SRCH_FIRST_FILE)
134 		cmd_putstr("First-file ");
135 	if (search_type & SRCH_PAST_EOF)
136 		cmd_putstr("EOF-ignore ");
137 	if (search_type & SRCH_NO_MOVE)
138 		cmd_putstr("Keep-pos ");
139 	if (search_type & SRCH_NO_REGEX)
140 		cmd_putstr("Regex-off ");
141 
142 	if (search_type & SRCH_FORW)
143 		cmd_putstr("/");
144 	else
145 		cmd_putstr("?");
146 	set_mlist(ml_search, 0);
147 }
148 
149 /*
150  * Set up the display to start a new toggle-option command.
151  */
152 	static void
153 mca_opt_toggle()
154 {
155 	int no_prompt;
156 	int flag;
157 	char *dash;
158 
159 	no_prompt = (optflag & OPT_NO_PROMPT);
160 	flag = (optflag & ~OPT_NO_PROMPT);
161 	dash = (flag == OPT_NO_TOGGLE) ? "_" : "-";
162 
163 	mca = A_OPT_TOGGLE;
164 	clear_bot();
165 	clear_cmd();
166 	cmd_putstr(dash);
167 	if (optgetname)
168 		cmd_putstr(dash);
169 	if (no_prompt)
170 		cmd_putstr("(P)");
171 	switch (flag)
172 	{
173 	case OPT_UNSET:
174 		cmd_putstr("+");
175 		break;
176 	case OPT_SET:
177 		cmd_putstr("!");
178 		break;
179 	}
180 	set_mlist(NULL, 0);
181 }
182 
183 /*
184  * Execute a multicharacter command.
185  */
186 	static void
187 exec_mca()
188 {
189 	register char *cbuf;
190 
191 	cmd_exec();
192 	cbuf = get_cmdbuf();
193 
194 	switch (mca)
195 	{
196 	case A_F_SEARCH:
197 	case A_B_SEARCH:
198 		multi_search(cbuf, (int) number);
199 		break;
200 	case A_FIRSTCMD:
201 		/*
202 		 * Skip leading spaces or + signs in the string.
203 		 */
204 		while (*cbuf == '+' || *cbuf == ' ')
205 			cbuf++;
206 		if (every_first_cmd != NULL)
207 			free(every_first_cmd);
208 		if (*cbuf == '\0')
209 			every_first_cmd = NULL;
210 		else
211 			every_first_cmd = save(cbuf);
212 		break;
213 	case A_OPT_TOGGLE:
214 		toggle_option(optchar, cbuf, optflag);
215 		optchar = '\0';
216 		break;
217 	case A_F_BRACKET:
218 		match_brac(cbuf[0], cbuf[1], 1, (int) number);
219 		break;
220 	case A_B_BRACKET:
221 		match_brac(cbuf[1], cbuf[0], 0, (int) number);
222 		break;
223 #if EXAMINE
224 	case A_EXAMINE:
225 		if (secure)
226 			break;
227 		edit_list(cbuf);
228 #if TAGS
229 		/* If tag structure is loaded then clean it up. */
230 		cleantags();
231 #endif
232 		break;
233 #endif
234 #if SHELL_ESCAPE
235 	case A_SHELL:
236 		/*
237 		 * !! just uses whatever is in shellcmd.
238 		 * Otherwise, copy cmdbuf to shellcmd,
239 		 * expanding any special characters ("%" or "#").
240 		 */
241 		if (*cbuf != '!')
242 		{
243 			if (shellcmd != NULL)
244 				free(shellcmd);
245 			shellcmd = fexpand(cbuf);
246 		}
247 
248 		if (secure)
249 			break;
250 		if (shellcmd == NULL)
251 			lsystem("", "!done");
252 		else
253 			lsystem(shellcmd, "!done");
254 		break;
255 #endif
256 #if PIPEC
257 	case A_PIPE:
258 		if (secure)
259 			break;
260 		(void) pipe_mark(pipec, cbuf);
261 		error("|done", NULL_PARG);
262 		break;
263 #endif
264 	}
265 }
266 
267 /*
268  * Add a character to a multi-character command.
269  */
270 	static int
271 mca_char(c)
272 	int c;
273 {
274 	char *p;
275 	int flag;
276 	char buf[3];
277 	PARG parg;
278 
279 	switch (mca)
280 	{
281 	case 0:
282 		/*
283 		 * Not in a multicharacter command.
284 		 */
285 		return (NO_MCA);
286 
287 	case A_PREFIX:
288 		/*
289 		 * In the prefix of a command.
290 		 * This not considered a multichar command
291 		 * (even tho it uses cmdbuf, etc.).
292 		 * It is handled in the commands() switch.
293 		 */
294 		return (NO_MCA);
295 
296 	case A_DIGIT:
297 		/*
298 		 * Entering digits of a number.
299 		 * Terminated by a non-digit.
300 		 */
301 		if (!((c >= '0' && c <= '9') || c == '.') &&
302 		  editchar(c, EC_PEEK|EC_NOHISTORY|EC_NOCOMPLETE|EC_NORIGHTLEFT) == A_INVALID)
303 		{
304 			/*
305 			 * Not part of the number.
306 			 * Treat as a normal command character.
307 			 */
308 			number = cmd_int(&fraction);
309 			mca = 0;
310 			cmd_accept();
311 			return (NO_MCA);
312 		}
313 		break;
314 
315 	case A_OPT_TOGGLE:
316 		/*
317 		 * Special case for the TOGGLE_OPTION command.
318 		 * If the option letter which was entered is a
319 		 * single-char option, execute the command immediately,
320 		 * so user doesn't have to hit RETURN.
321 		 * If the first char is + or -, this indicates
322 		 * OPT_UNSET or OPT_SET respectively, instead of OPT_TOGGLE.
323 		 * "--" begins inputting a long option name.
324 		 */
325 		if (optchar == '\0' && len_cmdbuf() == 0)
326 		{
327 			flag = (optflag & ~OPT_NO_PROMPT);
328 			if (flag == OPT_NO_TOGGLE)
329 			{
330 				switch (c)
331 				{
332 				case '_':
333 					/* "__" = long option name. */
334 					optgetname = TRUE;
335 					mca_opt_toggle();
336 					return (MCA_MORE);
337 				}
338 			} else
339 			{
340 				switch (c)
341 				{
342 				case '+':
343 					/* "-+" = UNSET. */
344 					optflag = (flag == OPT_UNSET) ?
345 						OPT_TOGGLE : OPT_UNSET;
346 					mca_opt_toggle();
347 					return (MCA_MORE);
348 				case '!':
349 					/* "-!" = SET */
350 					optflag = (flag == OPT_SET) ?
351 						OPT_TOGGLE : OPT_SET;
352 					mca_opt_toggle();
353 					return (MCA_MORE);
354 				case CONTROL('P'):
355 					optflag ^= OPT_NO_PROMPT;
356 					mca_opt_toggle();
357 					return (MCA_MORE);
358 				case '-':
359 					/* "--" = long option name. */
360 					optgetname = TRUE;
361 					mca_opt_toggle();
362 					return (MCA_MORE);
363 				}
364 			}
365 		}
366 		if (optgetname)
367 		{
368 			/*
369 			 * We're getting a long option name.
370 			 * See if we've matched an option name yet.
371 			 * If so, display the complete name and stop
372 			 * accepting chars until user hits RETURN.
373 			 */
374 			struct loption *o;
375 			char *oname;
376 			int lc;
377 
378 			if (c == '\n' || c == '\r')
379 			{
380 				/*
381 				 * When the user hits RETURN, make sure
382 				 * we've matched an option name, then
383 				 * pretend he just entered the equivalent
384 				 * option letter.
385 				 */
386 				if (optchar == '\0')
387 				{
388 					parg.p_string = get_cmdbuf();
389 					error("There is no --%s option", &parg);
390 					return (MCA_DONE);
391 				}
392 				optgetname = FALSE;
393 				cmd_reset();
394 				c = optchar;
395 			} else
396 			{
397 				if (optchar != '\0')
398 				{
399 					/*
400 					 * Already have a match for the name.
401 					 * Don't accept anything but erase/kill.
402 					 */
403 					if (c == erase_char ||
404 					    c == erase2_char ||
405 					    c == kill_char)
406 						return (MCA_DONE);
407 					return (MCA_MORE);
408 				}
409 				/*
410 				 * Add char to cmd buffer and try to match
411 				 * the option name.
412 				 */
413 				if (cmd_char(c) == CC_QUIT)
414 					return (MCA_DONE);
415 				p = get_cmdbuf();
416 				lc = ASCII_IS_LOWER(p[0]);
417 				o = findopt_name(&p, &oname, NULL);
418 				if (o != NULL)
419 				{
420 					/*
421 					 * Got a match.
422 					 * Remember the option letter and
423 					 * display the full option name.
424 					 */
425 					optchar = o->oletter;
426 					if (!lc && ASCII_IS_LOWER(optchar))
427 						optchar = ASCII_TO_UPPER(optchar);
428 					cmd_reset();
429 					mca_opt_toggle();
430 					for (p = oname;  *p != '\0';  p++)
431 					{
432 						c = *p;
433 						if (!lc && ASCII_IS_LOWER(c))
434 							c = ASCII_TO_UPPER(c);
435 						if (cmd_char(c) != CC_OK)
436 							return (MCA_DONE);
437 					}
438 				}
439 				return (MCA_MORE);
440 			}
441 		} else
442 		{
443 			if (c == erase_char || c == erase2_char || c == kill_char)
444 				break;
445 			if (optchar != '\0')
446 				/* We already have the option letter. */
447 				break;
448 		}
449 
450 		optchar = c;
451 		if ((optflag & ~OPT_NO_PROMPT) != OPT_TOGGLE ||
452 		    single_char_option(c))
453 		{
454 			toggle_option(c, "", optflag);
455 			return (MCA_DONE);
456 		}
457 		/*
458 		 * Display a prompt appropriate for the option letter.
459 		 */
460 		if ((p = opt_prompt(c)) == NULL)
461 		{
462 			buf[0] = '-';
463 			buf[1] = c;
464 			buf[2] = '\0';
465 			p = buf;
466 		}
467 		start_mca(A_OPT_TOGGLE, p, (void*)NULL, 0);
468 		return (MCA_MORE);
469 
470 	case A_F_SEARCH:
471 	case A_B_SEARCH:
472 		/*
473 		 * Special case for search commands.
474 		 * Certain characters as the first char of
475 		 * the pattern have special meaning:
476 		 *	!  Toggle the NO_MATCH flag
477 		 *	*  Toggle the PAST_EOF flag
478 		 *	@  Toggle the FIRST_FILE flag
479 		 */
480 		if (len_cmdbuf() > 0)
481 			/*
482 			 * Only works for the first char of the pattern.
483 			 */
484 			break;
485 
486 		flag = 0;
487 		switch (c)
488 		{
489 		case '*':
490 			if (less_is_more)
491 				break;
492 		case CONTROL('E'): /* ignore END of file */
493 			flag = SRCH_PAST_EOF;
494 			break;
495 		case '@':
496 			if (less_is_more)
497 				break;
498 		case CONTROL('F'): /* FIRST file */
499 			flag = SRCH_FIRST_FILE;
500 			break;
501 		case CONTROL('K'): /* KEEP position */
502 			flag = SRCH_NO_MOVE;
503 			break;
504 		case CONTROL('R'): /* Don't use REGULAR EXPRESSIONS */
505 			flag = SRCH_NO_REGEX;
506 			break;
507 		case CONTROL('N'): /* NOT match */
508 		case '!':
509 			flag = SRCH_NO_MATCH;
510 			break;
511 		}
512 		if (flag != 0)
513 		{
514 			search_type ^= flag;
515 			mca_search();
516 			return (MCA_MORE);
517 		}
518 		break;
519 	}
520 
521 	/*
522 	 * Any other multicharacter command
523 	 * is terminated by a newline.
524 	 */
525 	if (c == '\n' || c == '\r')
526 	{
527 		/*
528 		 * Execute the command.
529 		 */
530 		exec_mca();
531 		return (MCA_DONE);
532 	}
533 
534 	/*
535 	 * Append the char to the command buffer.
536 	 */
537 	if (cmd_char(c) == CC_QUIT)
538 		/*
539 		 * Abort the multi-char command.
540 		 */
541 		return (MCA_DONE);
542 
543 	if ((mca == A_F_BRACKET || mca == A_B_BRACKET) && len_cmdbuf() >= 2)
544 	{
545 		/*
546 		 * Special case for the bracket-matching commands.
547 		 * Execute the command after getting exactly two
548 		 * characters from the user.
549 		 */
550 		exec_mca();
551 		return (MCA_DONE);
552 	}
553 
554 	/*
555 	 * Need another character.
556 	 */
557 	return (MCA_MORE);
558 }
559 
560 /*
561  * Discard any buffered file data.
562  */
563 	static void
564 clear_buffers()
565 {
566 	if (!(ch_getflags() & CH_CANSEEK))
567 		return;
568 	ch_flush();
569 	clr_linenum();
570 #if HILITE_SEARCH
571 	clr_hilite();
572 #endif
573 }
574 
575 /*
576  * Make sure the screen is displayed.
577  */
578 	static void
579 make_display()
580 {
581 	/*
582 	 * If nothing is displayed yet, display starting from initial_scrpos.
583 	 */
584 	if (empty_screen())
585 	{
586 		if (initial_scrpos.pos == NULL_POSITION)
587 			/*
588 			 * {{ Maybe this should be:
589 			 *    jump_loc(ch_zero(), jump_sline);
590 			 *    but this behavior seems rather unexpected
591 			 *    on the first screen. }}
592 			 */
593 			jump_loc(ch_zero(), 1);
594 		else
595 			jump_loc(initial_scrpos.pos, initial_scrpos.ln);
596 	} else if (screen_trashed)
597 	{
598 		int save_top_scroll = top_scroll;
599 		int save_ignore_eoi = ignore_eoi;
600 		top_scroll = 1;
601 		ignore_eoi = 0;
602 		if (screen_trashed == 2)
603 		{
604 			/* Special case used by ignore_eoi: re-open the input file
605 			 * and jump to the end of the file. */
606 			reopen_curr_ifile();
607 			jump_forw();
608 		}
609 		repaint();
610 		top_scroll = save_top_scroll;
611 		ignore_eoi = save_ignore_eoi;
612 	}
613 }
614 
615 /*
616  * Display the appropriate prompt.
617  */
618 	static void
619 prompt()
620 {
621 	register char *p;
622 
623 	if (ungotp != NULL && ungotp > ungot)
624 	{
625 		/*
626 		 * No prompt necessary if commands are from
627 		 * ungotten chars rather than from the user.
628 		 */
629 		return;
630 	}
631 
632 	/*
633 	 * Make sure the screen is displayed.
634 	 */
635 	make_display();
636 	bottompos = position(BOTTOM_PLUS_ONE);
637 
638 	/*
639 	 * If we've hit EOF on the last file, and the -E flag is set
640 	 * (or -F is set and this is the first prompt), then quit.
641 	 * {{ Relying on "first prompt" to detect a single-screen file
642 	 * fails if +G is used, for example. }}
643 	 */
644 	if ((get_quit_at_eof() == OPT_ONPLUS || quit_if_one_screen) &&
645 	    hit_eof && !(ch_getflags() & CH_HELPFILE) &&
646 	    next_ifile(curr_ifile) == NULL_IFILE)
647 		quit(QUIT_OK);
648 	quit_if_one_screen = FALSE;
649 #if 0 /* This doesn't work well because some "te"s clear the screen. */
650 	/*
651 	 * If the -e flag is set and we've hit EOF on the last file,
652 	 * and the file is squished (shorter than the screen), quit.
653 	 */
654 	if (get_quit_at_eof() && squished &&
655 	    next_ifile(curr_ifile) == NULL_IFILE)
656 		quit(QUIT_OK);
657 #endif
658 
659 #if MSDOS_COMPILER==WIN32C
660 	/*
661 	 * In Win32, display the file name in the window title.
662 	 */
663 	if (!(ch_getflags() & CH_HELPFILE))
664 		SetConsoleTitle(pr_expand("Less?f - %f.", 0));
665 #endif
666 	/*
667 	 * Select the proper prompt and display it.
668 	 */
669 	/*
670 	 * If the previous action was a forward movement,
671 	 * don't clear the bottom line of the display;
672 	 * just print the prompt since the forward movement guarantees
673 	 * that we're in the right position to display the prompt.
674 	 * Clearing the line could cause a problem: for example, if the last
675 	 * line displayed ended at the right screen edge without a newline,
676 	 * then clearing would clear the last displayed line rather than
677 	 * the prompt line.
678 	 */
679 	if (!forw_prompt)
680 		clear_bot();
681 	clear_cmd();
682 	forw_prompt = 0;
683 	p = pr_string();
684 	if (p == NULL || *p == '\0')
685 		putchr(':');
686 	else
687 	{
688 		at_enter(AT_STANDOUT);
689 		putstr(p);
690 		at_exit();
691 	}
692 	clear_eol();
693 }
694 
695 /*
696  * Display the less version message.
697  */
698 	public void
699 dispversion()
700 {
701 	PARG parg;
702 
703 	parg.p_string = version;
704 	error("less %s", &parg);
705 }
706 
707 /*
708  * Get command character.
709  * The character normally comes from the keyboard,
710  * but may come from ungotten characters
711  * (characters previously given to ungetcc or ungetsc).
712  */
713 	public int
714 getcc()
715 {
716 	if (ungotp == NULL)
717 		/*
718 		 * Normal case: no ungotten chars, so get one from the user.
719 		 */
720 		return (getchr());
721 
722 	if (ungotp > ungot)
723 		/*
724 		 * Return the next ungotten char.
725 		 */
726 		return (*--ungotp);
727 
728 	/*
729 	 * We have just run out of ungotten chars.
730 	 */
731 	ungotp = NULL;
732 	if (len_cmdbuf() == 0 || !empty_screen())
733 		return (getchr());
734 	/*
735 	 * Command is incomplete, so try to complete it.
736 	 */
737 	switch (mca)
738 	{
739 	case A_DIGIT:
740 		/*
741 		 * We have a number but no command.  Treat as #g.
742 		 */
743 		return ('g');
744 
745 	case A_F_SEARCH:
746 	case A_B_SEARCH:
747 		/*
748 		 * We have "/string" but no newline.  Add the \n.
749 		 */
750 		return ('\n');
751 
752 	default:
753 		/*
754 		 * Some other incomplete command.  Let user complete it.
755 		 */
756 		return (getchr());
757 	}
758 }
759 
760 /*
761  * "Unget" a command character.
762  * The next getcc() will return this character.
763  */
764 	public void
765 ungetcc(c)
766 	int c;
767 {
768 	if (ungotp == NULL)
769 		ungotp = ungot;
770 	if (ungotp >= ungot + sizeof(ungot))
771 	{
772 		error("ungetcc overflow", NULL_PARG);
773 		quit(QUIT_ERROR);
774 	}
775 	*ungotp++ = c;
776 }
777 
778 /*
779  * Unget a whole string of command characters.
780  * The next sequence of getcc()'s will return this string.
781  */
782 	public void
783 ungetsc(s)
784 	char *s;
785 {
786 	register char *p;
787 
788 	for (p = s + strlen(s) - 1;  p >= s;  p--)
789 		ungetcc(*p);
790 }
791 
792 /*
793  * Search for a pattern, possibly in multiple files.
794  * If SRCH_FIRST_FILE is set, begin searching at the first file.
795  * If SRCH_PAST_EOF is set, continue the search thru multiple files.
796  */
797 	static void
798 multi_search(pattern, n)
799 	char *pattern;
800 	int n;
801 {
802 	register int nomore;
803 	IFILE save_ifile;
804 	int changed_file;
805 
806 	changed_file = 0;
807 	save_ifile = save_curr_ifile();
808 
809 	if (search_type & SRCH_FIRST_FILE)
810 	{
811 		/*
812 		 * Start at the first (or last) file
813 		 * in the command line list.
814 		 */
815 		if (search_type & SRCH_FORW)
816 			nomore = edit_first();
817 		else
818 			nomore = edit_last();
819 		if (nomore)
820 		{
821 			unsave_ifile(save_ifile);
822 			return;
823 		}
824 		changed_file = 1;
825 		search_type &= ~SRCH_FIRST_FILE;
826 	}
827 
828 	for (;;)
829 	{
830 		n = search(search_type, pattern, n);
831 		/*
832 		 * The SRCH_NO_MOVE flag doesn't "stick": it gets cleared
833 		 * after being used once.  This allows "n" to work after
834 		 * using a /@@ search.
835 		 */
836 		search_type &= ~SRCH_NO_MOVE;
837 		if (n == 0)
838 		{
839 			/*
840 			 * Found it.
841 			 */
842 			unsave_ifile(save_ifile);
843 			return;
844 		}
845 
846 		if (n < 0)
847 			/*
848 			 * Some kind of error in the search.
849 			 * Error message has been printed by search().
850 			 */
851 			break;
852 
853 		if ((search_type & SRCH_PAST_EOF) == 0)
854 			/*
855 			 * We didn't find a match, but we're
856 			 * supposed to search only one file.
857 			 */
858 			break;
859 		/*
860 		 * Move on to the next file.
861 		 */
862 		if (search_type & SRCH_FORW)
863 			nomore = edit_next(1);
864 		else
865 			nomore = edit_prev(1);
866 		if (nomore)
867 			break;
868 		changed_file = 1;
869 	}
870 
871 	/*
872 	 * Didn't find it.
873 	 * Print an error message if we haven't already.
874 	 */
875 	if (n > 0)
876 		error("Pattern not found", NULL_PARG);
877 
878 	if (changed_file)
879 	{
880 		/*
881 		 * Restore the file we were originally viewing.
882 		 */
883 		reedit_ifile(save_ifile);
884 	} else
885 	{
886 		unsave_ifile(save_ifile);
887 	}
888 }
889 
890 /*
891  * Main command processor.
892  * Accept and execute commands until a quit command.
893  */
894 	public void
895 commands()
896 {
897 	register int c;
898 	register int action;
899 	register char *cbuf;
900 	int newaction;
901 	int save_search_type;
902 	char *extra;
903 	char tbuf[2];
904 	PARG parg;
905 	IFILE old_ifile;
906 	IFILE new_ifile;
907 	char *tagfile;
908 
909 	search_type = SRCH_FORW;
910 	wscroll = (sc_height + 1) / 2;
911 	newaction = A_NOACTION;
912 
913 	for (;;)
914 	{
915 		mca = 0;
916 		cmd_accept();
917 		number = 0;
918 		optchar = '\0';
919 
920 		/*
921 		 * See if any signals need processing.
922 		 */
923 		if (sigs)
924 		{
925 			psignals();
926 			if (quitting)
927 				quit(QUIT_SAVED_STATUS);
928 		}
929 
930 		/*
931 		 * See if window size changed, for systems that don't
932 		 * generate SIGWINCH.
933 		 */
934 		check_winch();
935 
936 		/*
937 		 * Display prompt and accept a character.
938 		 */
939 		cmd_reset();
940 		prompt();
941 		if (sigs)
942 			continue;
943 		if (newaction == A_NOACTION)
944 			c = getcc();
945 
946 	again:
947 		if (sigs)
948 			continue;
949 
950 		if (newaction != A_NOACTION)
951 		{
952 			action = newaction;
953 			newaction = A_NOACTION;
954 		} else
955 		{
956 			/*
957 			 * If we are in a multicharacter command, call mca_char.
958 			 * Otherwise we call fcmd_decode to determine the
959 			 * action to be performed.
960 			 */
961 			if (mca)
962 				switch (mca_char(c))
963 				{
964 				case MCA_MORE:
965 					/*
966 					 * Need another character.
967 					 */
968 					c = getcc();
969 					goto again;
970 				case MCA_DONE:
971 					/*
972 					 * Command has been handled by mca_char.
973 					 * Start clean with a prompt.
974 					 */
975 					continue;
976 				case NO_MCA:
977 					/*
978 					 * Not a multi-char command
979 					 * (at least, not anymore).
980 					 */
981 					break;
982 				}
983 
984 			/*
985 			 * Decode the command character and decide what to do.
986 			 */
987 			if (mca)
988 			{
989 				/*
990 				 * We're in a multichar command.
991 				 * Add the character to the command buffer
992 				 * and display it on the screen.
993 				 * If the user backspaces past the start
994 				 * of the line, abort the command.
995 				 */
996 				if (cmd_char(c) == CC_QUIT || len_cmdbuf() == 0)
997 					continue;
998 				cbuf = get_cmdbuf();
999 			} else
1000 			{
1001 				/*
1002 				 * Don't use cmd_char if we're starting fresh
1003 				 * at the beginning of a command, because we
1004 				 * don't want to echo the command until we know
1005 				 * it is a multichar command.  We also don't
1006 				 * want erase_char/kill_char to be treated
1007 				 * as line editing characters.
1008 				 */
1009 				tbuf[0] = c;
1010 				tbuf[1] = '\0';
1011 				cbuf = tbuf;
1012 			}
1013 			extra = NULL;
1014 			action = fcmd_decode(cbuf, &extra);
1015 			/*
1016 			 * If an "extra" string was returned,
1017 			 * process it as a string of command characters.
1018 			 */
1019 			if (extra != NULL)
1020 				ungetsc(extra);
1021 		}
1022 		/*
1023 		 * Clear the cmdbuf string.
1024 		 * (But not if we're in the prefix of a command,
1025 		 * because the partial command string is kept there.)
1026 		 */
1027 		if (action != A_PREFIX)
1028 			cmd_reset();
1029 
1030 		switch (action)
1031 		{
1032 		case A_DIGIT:
1033 			/*
1034 			 * First digit of a number.
1035 			 */
1036 			start_mca(A_DIGIT, ":", (void*)NULL, CF_QUIT_ON_ERASE);
1037 			goto again;
1038 
1039 		case A_F_WINDOW:
1040 			/*
1041 			 * Forward one window (and set the window size).
1042 			 */
1043 			if (number > 0)
1044 				swindow = (int) number;
1045 			/* FALLTHRU */
1046 		case A_F_SCREEN:
1047 			/*
1048 			 * Forward one screen.
1049 			 */
1050 			if (number <= 0)
1051 				number = get_swindow();
1052 			cmd_exec();
1053 			if (show_attn)
1054 				set_attnpos(bottompos);
1055 			forward((int) number, 0, 1);
1056 			break;
1057 
1058 		case A_B_WINDOW:
1059 			/*
1060 			 * Backward one window (and set the window size).
1061 			 */
1062 			if (number > 0)
1063 				swindow = (int) number;
1064 			/* FALLTHRU */
1065 		case A_B_SCREEN:
1066 			/*
1067 			 * Backward one screen.
1068 			 */
1069 			if (number <= 0)
1070 				number = get_swindow();
1071 			cmd_exec();
1072 			backward((int) number, 0, 1);
1073 			break;
1074 
1075 		case A_F_LINE:
1076 			/*
1077 			 * Forward N (default 1) line.
1078 			 */
1079 			if (number <= 0)
1080 				number = 1;
1081 			cmd_exec();
1082 			if (show_attn == OPT_ONPLUS && number > 1)
1083 				set_attnpos(bottompos);
1084 			forward((int) number, 0, 0);
1085 			break;
1086 
1087 		case A_B_LINE:
1088 			/*
1089 			 * Backward N (default 1) line.
1090 			 */
1091 			if (number <= 0)
1092 				number = 1;
1093 			cmd_exec();
1094 			backward((int) number, 0, 0);
1095 			break;
1096 
1097 		case A_FF_LINE:
1098 			/*
1099 			 * Force forward N (default 1) line.
1100 			 */
1101 			if (number <= 0)
1102 				number = 1;
1103 			cmd_exec();
1104 			if (show_attn == OPT_ONPLUS && number > 1)
1105 				set_attnpos(bottompos);
1106 			forward((int) number, 1, 0);
1107 			break;
1108 
1109 		case A_BF_LINE:
1110 			/*
1111 			 * Force backward N (default 1) line.
1112 			 */
1113 			if (number <= 0)
1114 				number = 1;
1115 			cmd_exec();
1116 			backward((int) number, 1, 0);
1117 			break;
1118 
1119 		case A_FF_SCREEN:
1120 			/*
1121 			 * Force forward one screen.
1122 			 */
1123 			if (number <= 0)
1124 				number = get_swindow();
1125 			cmd_exec();
1126 			if (show_attn == OPT_ONPLUS)
1127 				set_attnpos(bottompos);
1128 			forward((int) number, 1, 0);
1129 			break;
1130 
1131 		case A_F_FOREVER:
1132 			/*
1133 			 * Forward forever, ignoring EOF.
1134 			 */
1135 			if (ch_getflags() & CH_HELPFILE)
1136 				break;
1137 			cmd_exec();
1138 			jump_forw();
1139 			ignore_eoi = 1;
1140 			hit_eof = 0;
1141 			while (!sigs)
1142 			{
1143 				make_display();
1144 				forward(1, 0, 0);
1145 			}
1146 			ignore_eoi = 0;
1147 			/*
1148 			 * This gets us back in "F mode" after processing
1149 			 * a non-abort signal (e.g. window-change).
1150 			 */
1151 			if (sigs && !ABORT_SIGS())
1152 				newaction = A_F_FOREVER;
1153 			break;
1154 
1155 		case A_F_SCROLL:
1156 			/*
1157 			 * Forward N lines
1158 			 * (default same as last 'd' or 'u' command).
1159 			 */
1160 			if (number > 0)
1161 				wscroll = (int) number;
1162 			cmd_exec();
1163 			if (show_attn == OPT_ONPLUS)
1164 				set_attnpos(bottompos);
1165 			forward(wscroll, 0, 0);
1166 			break;
1167 
1168 		case A_B_SCROLL:
1169 			/*
1170 			 * Forward N lines
1171 			 * (default same as last 'd' or 'u' command).
1172 			 */
1173 			if (number > 0)
1174 				wscroll = (int) number;
1175 			cmd_exec();
1176 			backward(wscroll, 0, 0);
1177 			break;
1178 
1179 		case A_FREPAINT:
1180 			/*
1181 			 * Flush buffers, then repaint screen.
1182 			 * Don't flush the buffers on a pipe!
1183 			 */
1184 			clear_buffers();
1185 			/* FALLTHRU */
1186 		case A_REPAINT:
1187 			/*
1188 			 * Repaint screen.
1189 			 */
1190 			cmd_exec();
1191 			repaint();
1192 			break;
1193 
1194 		case A_GOLINE:
1195 			/*
1196 			 * Go to line N, default beginning of file.
1197 			 */
1198 			if (number <= 0)
1199 				number = 1;
1200 			cmd_exec();
1201 			jump_back(number);
1202 			break;
1203 
1204 		case A_PERCENT:
1205 			/*
1206 			 * Go to a specified percentage into the file.
1207 			 */
1208 			if (number < 0)
1209 			{
1210 				number = 0;
1211 				fraction = 0;
1212 			}
1213 			if (number > 100)
1214 			{
1215 				number = 100;
1216 				fraction = 0;
1217 			}
1218 			cmd_exec();
1219 			jump_percent((int) number, fraction);
1220 			break;
1221 
1222 		case A_GOEND:
1223 			/*
1224 			 * Go to line N, default end of file.
1225 			 */
1226 			cmd_exec();
1227 			if (number <= 0)
1228 				jump_forw();
1229 			else
1230 				jump_back(number);
1231 			break;
1232 
1233 		case A_GOPOS:
1234 			/*
1235 			 * Go to a specified byte position in the file.
1236 			 */
1237 			cmd_exec();
1238 			if (number < 0)
1239 				number = 0;
1240 			jump_line_loc((POSITION) number, jump_sline);
1241 			break;
1242 
1243 		case A_STAT:
1244 			/*
1245 			 * Print file name, etc.
1246 			 */
1247 			if (ch_getflags() & CH_HELPFILE)
1248 				break;
1249 			cmd_exec();
1250 			parg.p_string = eq_message();
1251 			error("%s", &parg);
1252 			break;
1253 
1254 		case A_VERSION:
1255 			/*
1256 			 * Print version number, without the "@(#)".
1257 			 */
1258 			cmd_exec();
1259 			dispversion();
1260 			break;
1261 
1262 		case A_QUIT:
1263 			/*
1264 			 * Exit.
1265 			 */
1266 			if (curr_ifile != NULL_IFILE &&
1267 			    ch_getflags() & CH_HELPFILE)
1268 			{
1269 				/*
1270 				 * Quit while viewing the help file
1271 				 * just means return to viewing the
1272 				 * previous file.
1273 				 */
1274 				hshift = save_hshift;
1275 				if (edit_prev(1) == 0)
1276 					break;
1277 			}
1278 			if (extra != NULL)
1279 				quit(*extra);
1280 			quit(QUIT_OK);
1281 			break;
1282 
1283 /*
1284  * Define abbreviation for a commonly used sequence below.
1285  */
1286 #define	DO_SEARCH() \
1287 			if (number <= 0) number = 1;	\
1288 			mca_search();			\
1289 			cmd_exec();			\
1290 			multi_search((char *)NULL, (int) number);
1291 
1292 
1293 		case A_F_SEARCH:
1294 			/*
1295 			 * Search forward for a pattern.
1296 			 * Get the first char of the pattern.
1297 			 */
1298 			search_type = SRCH_FORW;
1299 			if (number <= 0)
1300 				number = 1;
1301 			mca_search();
1302 			c = getcc();
1303 			goto again;
1304 
1305 		case A_B_SEARCH:
1306 			/*
1307 			 * Search backward for a pattern.
1308 			 * Get the first char of the pattern.
1309 			 */
1310 			search_type = SRCH_BACK;
1311 			if (number <= 0)
1312 				number = 1;
1313 			mca_search();
1314 			c = getcc();
1315 			goto again;
1316 
1317 		case A_AGAIN_SEARCH:
1318 			/*
1319 			 * Repeat previous search.
1320 			 */
1321 			DO_SEARCH();
1322 			break;
1323 
1324 		case A_T_AGAIN_SEARCH:
1325 			/*
1326 			 * Repeat previous search, multiple files.
1327 			 */
1328 			search_type |= SRCH_PAST_EOF;
1329 			DO_SEARCH();
1330 			break;
1331 
1332 		case A_REVERSE_SEARCH:
1333 			/*
1334 			 * Repeat previous search, in reverse direction.
1335 			 */
1336 			save_search_type = search_type;
1337 			search_type = SRCH_REVERSE(search_type);
1338 			DO_SEARCH();
1339 			search_type = save_search_type;
1340 			break;
1341 
1342 		case A_T_REVERSE_SEARCH:
1343 			/*
1344 			 * Repeat previous search,
1345 			 * multiple files in reverse direction.
1346 			 */
1347 			save_search_type = search_type;
1348 			search_type = SRCH_REVERSE(search_type);
1349 			search_type |= SRCH_PAST_EOF;
1350 			DO_SEARCH();
1351 			search_type = save_search_type;
1352 			break;
1353 
1354 		case A_UNDO_SEARCH:
1355 			undo_search();
1356 			break;
1357 
1358 		case A_HELP:
1359 			/*
1360 			 * Help.
1361 			 */
1362 			if (ch_getflags() & CH_HELPFILE)
1363 				break;
1364 			cmd_exec();
1365 			save_hshift = hshift;
1366 			hshift = 0;
1367 			(void) edit(FAKE_HELPFILE);
1368 			break;
1369 
1370 		case A_EXAMINE:
1371 #if EXAMINE
1372 			/*
1373 			 * Edit a new file.  Get the filename.
1374 			 */
1375 			if (secure)
1376 			{
1377 				error("Command not available", NULL_PARG);
1378 				break;
1379 			}
1380 			start_mca(A_EXAMINE, "Examine: ", ml_examine, 0);
1381 			c = getcc();
1382 			goto again;
1383 #else
1384 			error("Command not available", NULL_PARG);
1385 			break;
1386 #endif
1387 
1388 		case A_VISUAL:
1389 			/*
1390 			 * Invoke an editor on the input file.
1391 			 */
1392 #if EDITOR
1393 			if (secure)
1394 			{
1395 				error("Command not available", NULL_PARG);
1396 				break;
1397 			}
1398 			if (ch_getflags() & CH_HELPFILE)
1399 				break;
1400 			if (strcmp(get_filename(curr_ifile), "-") == 0)
1401 			{
1402 				error("Cannot edit standard input", NULL_PARG);
1403 				break;
1404 			}
1405 			if (curr_altfilename != NULL)
1406 			{
1407 				error("WARNING: This file was viewed via LESSOPEN",
1408 					NULL_PARG);
1409 			}
1410 			start_mca(A_SHELL, "!", ml_shell, 0);
1411 			/*
1412 			 * Expand the editor prototype string
1413 			 * and pass it to the system to execute.
1414 			 * (Make sure the screen is displayed so the
1415 			 * expansion of "+%lm" works.)
1416 			 */
1417 			make_display();
1418 			cmd_exec();
1419 			lsystem(pr_expand(editproto, 0), (char*)NULL);
1420 			break;
1421 #else
1422 			error("Command not available", NULL_PARG);
1423 			break;
1424 #endif
1425 
1426 		case A_NEXT_FILE:
1427 			/*
1428 			 * Examine next file.
1429 			 */
1430 #if TAGS
1431 			if (ntags())
1432 			{
1433 				error("No next file", NULL_PARG);
1434 				break;
1435 			}
1436 #endif
1437 			if (number <= 0)
1438 				number = 1;
1439 			if (edit_next((int) number))
1440 			{
1441 				if (get_quit_at_eof() && hit_eof &&
1442 				    !(ch_getflags() & CH_HELPFILE))
1443 					quit(QUIT_OK);
1444 				parg.p_string = (number > 1) ? "(N-th) " : "";
1445 				error("No %snext file", &parg);
1446 			}
1447 			break;
1448 
1449 		case A_PREV_FILE:
1450 			/*
1451 			 * Examine previous file.
1452 			 */
1453 #if TAGS
1454 			if (ntags())
1455 			{
1456 				error("No previous file", NULL_PARG);
1457 				break;
1458 			}
1459 #endif
1460 			if (number <= 0)
1461 				number = 1;
1462 			if (edit_prev((int) number))
1463 			{
1464 				parg.p_string = (number > 1) ? "(N-th) " : "";
1465 				error("No %sprevious file", &parg);
1466 			}
1467 			break;
1468 
1469 		case A_NEXT_TAG:
1470 #if TAGS
1471 			if (number <= 0)
1472 				number = 1;
1473 			tagfile = nexttag((int) number);
1474 			if (tagfile == NULL)
1475 			{
1476 				error("No next tag", NULL_PARG);
1477 				break;
1478 			}
1479 			if (edit(tagfile) == 0)
1480 			{
1481 				POSITION pos = tagsearch();
1482 				if (pos != NULL_POSITION)
1483 					jump_loc(pos, jump_sline);
1484 			}
1485 #else
1486 			error("Command not available", NULL_PARG);
1487 #endif
1488 			break;
1489 
1490 		case A_PREV_TAG:
1491 #if TAGS
1492 			if (number <= 0)
1493 				number = 1;
1494 			tagfile = prevtag((int) number);
1495 			if (tagfile == NULL)
1496 			{
1497 				error("No previous tag", NULL_PARG);
1498 				break;
1499 			}
1500 			if (edit(tagfile) == 0)
1501 			{
1502 				POSITION pos = tagsearch();
1503 				if (pos != NULL_POSITION)
1504 					jump_loc(pos, jump_sline);
1505 			}
1506 #else
1507 			error("Command not available", NULL_PARG);
1508 #endif
1509 			break;
1510 
1511 		case A_INDEX_FILE:
1512 			/*
1513 			 * Examine a particular file.
1514 			 */
1515 			if (number <= 0)
1516 				number = 1;
1517 			if (edit_index((int) number))
1518 				error("No such file", NULL_PARG);
1519 			break;
1520 
1521 		case A_REMOVE_FILE:
1522 			if (ch_getflags() & CH_HELPFILE)
1523 				break;
1524 			old_ifile = curr_ifile;
1525 			new_ifile = getoff_ifile(curr_ifile);
1526 			if (new_ifile == NULL_IFILE)
1527 			{
1528 				bell();
1529 				break;
1530 			}
1531 			if (edit_ifile(new_ifile) != 0)
1532 			{
1533 				reedit_ifile(old_ifile);
1534 				break;
1535 			}
1536 			del_ifile(old_ifile);
1537 			break;
1538 
1539 		case A_OPT_TOGGLE:
1540 			optflag = OPT_TOGGLE;
1541 			optgetname = FALSE;
1542 			mca_opt_toggle();
1543 			c = getcc();
1544 			goto again;
1545 
1546 		case A_DISP_OPTION:
1547 			/*
1548 			 * Report a flag setting.
1549 			 */
1550 			optflag = OPT_NO_TOGGLE;
1551 			optgetname = FALSE;
1552 			mca_opt_toggle();
1553 			c = getcc();
1554 			goto again;
1555 
1556 		case A_FIRSTCMD:
1557 			/*
1558 			 * Set an initial command for new files.
1559 			 */
1560 			start_mca(A_FIRSTCMD, "+", (void*)NULL, 0);
1561 			c = getcc();
1562 			goto again;
1563 
1564 		case A_SHELL:
1565 			/*
1566 			 * Shell escape.
1567 			 */
1568 #if SHELL_ESCAPE
1569 			if (secure)
1570 			{
1571 				error("Command not available", NULL_PARG);
1572 				break;
1573 			}
1574 			start_mca(A_SHELL, "!", ml_shell, 0);
1575 			c = getcc();
1576 			goto again;
1577 #else
1578 			error("Command not available", NULL_PARG);
1579 			break;
1580 #endif
1581 
1582 		case A_SETMARK:
1583 			/*
1584 			 * Set a mark.
1585 			 */
1586 			if (ch_getflags() & CH_HELPFILE)
1587 				break;
1588 			start_mca(A_SETMARK, "mark: ", (void*)NULL, 0);
1589 			c = getcc();
1590 			if (c == erase_char || c == erase2_char ||
1591 			    c == kill_char || c == '\n' || c == '\r')
1592 				break;
1593 			setmark(c);
1594 			break;
1595 
1596 		case A_GOMARK:
1597 			/*
1598 			 * Go to a mark.
1599 			 */
1600 			start_mca(A_GOMARK, "goto mark: ", (void*)NULL, 0);
1601 			c = getcc();
1602 			if (c == erase_char || c == erase2_char ||
1603 			    c == kill_char || c == '\n' || c == '\r')
1604 				break;
1605 			gomark(c);
1606 			break;
1607 
1608 		case A_PIPE:
1609 #if PIPEC
1610 			if (secure)
1611 			{
1612 				error("Command not available", NULL_PARG);
1613 				break;
1614 			}
1615 			start_mca(A_PIPE, "|mark: ", (void*)NULL, 0);
1616 			c = getcc();
1617 			if (c == erase_char || c == erase2_char || c == kill_char)
1618 				break;
1619 			if (c == '\n' || c == '\r')
1620 				c = '.';
1621 			if (badmark(c))
1622 				break;
1623 			pipec = c;
1624 			start_mca(A_PIPE, "!", ml_shell, 0);
1625 			c = getcc();
1626 			goto again;
1627 #else
1628 			error("Command not available", NULL_PARG);
1629 			break;
1630 #endif
1631 
1632 		case A_B_BRACKET:
1633 		case A_F_BRACKET:
1634 			start_mca(action, "Brackets: ", (void*)NULL, 0);
1635 			c = getcc();
1636 			goto again;
1637 
1638 		case A_LSHIFT:
1639 			if (number > 0)
1640 				shift_count = number;
1641 			else
1642 				number = (shift_count > 0) ?
1643 					shift_count : sc_width / 2;
1644 			if (number > hshift)
1645 				number = hshift;
1646 			hshift -= number;
1647 			screen_trashed = 1;
1648 			break;
1649 
1650 		case A_RSHIFT:
1651 			if (number > 0)
1652 				shift_count = number;
1653 			else
1654 				number = (shift_count > 0) ?
1655 					shift_count : sc_width / 2;
1656 			hshift += number;
1657 			screen_trashed = 1;
1658 			break;
1659 
1660 		case A_PREFIX:
1661 			/*
1662 			 * The command is incomplete (more chars are needed).
1663 			 * Display the current char, so the user knows
1664 			 * what's going on, and get another character.
1665 			 */
1666 			if (mca != A_PREFIX)
1667 			{
1668 				cmd_reset();
1669 				start_mca(A_PREFIX, " ", (void*)NULL,
1670 					CF_QUIT_ON_ERASE);
1671 				(void) cmd_char(c);
1672 			}
1673 			c = getcc();
1674 			goto again;
1675 
1676 		case A_NOACTION:
1677 			break;
1678 
1679 		default:
1680 			bell();
1681 			break;
1682 		}
1683 	}
1684 }
1685