xref: /freebsd/contrib/less/cmdbuf.c (revision af23369a6deaaeb612ab266eb88b8bb8d560c322)
1 /*
2  * Copyright (C) 1984-2022  Mark Nudelman
3  *
4  * You may distribute under the terms of either the GNU General Public
5  * License or the Less License, as specified in the README file.
6  *
7  * For more information, see the README file.
8  */
9 
10 
11 /*
12  * Functions which manipulate the command buffer.
13  * Used only by command() and related functions.
14  */
15 
16 #include "less.h"
17 #include "cmd.h"
18 #include "charset.h"
19 #if HAVE_STAT
20 #include <sys/stat.h>
21 #endif
22 
23 extern int sc_width;
24 extern int utf_mode;
25 extern int no_hist_dups;
26 extern int marks_modified;
27 extern int secure;
28 
29 static char cmdbuf[CMDBUF_SIZE]; /* Buffer for holding a multi-char command */
30 static int cmd_col;              /* Current column of the cursor */
31 static int prompt_col;           /* Column of cursor just after prompt */
32 static char *cp;                 /* Pointer into cmdbuf */
33 static int cmd_offset;           /* Index into cmdbuf of first displayed char */
34 static int literal;              /* Next input char should not be interpreted */
35 public int updown_match = -1;    /* Prefix length in up/down movement */
36 
37 #if TAB_COMPLETE_FILENAME
38 static int cmd_complete LESSPARAMS((int action));
39 /*
40  * These variables are statics used by cmd_complete.
41  */
42 static int in_completion = 0;
43 static char *tk_text;
44 static char *tk_original;
45 static char *tk_ipoint;
46 static char *tk_trial = NULL;
47 static struct textlist tk_tlist;
48 #endif
49 
50 static int cmd_left();
51 static int cmd_right();
52 
53 #if SPACES_IN_FILENAMES
54 public char openquote = '"';
55 public char closequote = '"';
56 #endif
57 
58 #if CMD_HISTORY
59 
60 /* History file */
61 #define HISTFILE_FIRST_LINE      ".less-history-file:"
62 #define HISTFILE_SEARCH_SECTION  ".search"
63 #define HISTFILE_SHELL_SECTION   ".shell"
64 #define HISTFILE_MARK_SECTION    ".mark"
65 
66 /*
67  * A mlist structure represents a command history.
68  */
69 struct mlist
70 {
71 	struct mlist *next;
72 	struct mlist *prev;
73 	struct mlist *curr_mp;
74 	char *string;
75 	int modified;
76 };
77 
78 /*
79  * These are the various command histories that exist.
80  */
81 struct mlist mlist_search =
82 	{ &mlist_search,  &mlist_search,  &mlist_search,  NULL, 0 };
83 public void *ml_search = (void *) &mlist_search;
84 
85 struct mlist mlist_examine =
86 	{ &mlist_examine, &mlist_examine, &mlist_examine, NULL, 0 };
87 public void *ml_examine = (void *) &mlist_examine;
88 
89 #if SHELL_ESCAPE || PIPEC
90 struct mlist mlist_shell =
91 	{ &mlist_shell,   &mlist_shell,   &mlist_shell,   NULL, 0 };
92 public void *ml_shell = (void *) &mlist_shell;
93 #endif
94 
95 #else /* CMD_HISTORY */
96 
97 /* If CMD_HISTORY is off, these are just flags. */
98 public void *ml_search = (void *)1;
99 public void *ml_examine = (void *)2;
100 #if SHELL_ESCAPE || PIPEC
101 public void *ml_shell = (void *)3;
102 #endif
103 
104 #endif /* CMD_HISTORY */
105 
106 /*
107  * History for the current command.
108  */
109 static struct mlist *curr_mlist = NULL;
110 static int curr_cmdflags;
111 
112 static char cmd_mbc_buf[MAX_UTF_CHAR_LEN];
113 static int cmd_mbc_buf_len;
114 static int cmd_mbc_buf_index;
115 
116 
117 /*
118  * Reset command buffer (to empty).
119  */
120 	public void
121 cmd_reset(VOID_PARAM)
122 {
123 	cp = cmdbuf;
124 	*cp = '\0';
125 	cmd_col = 0;
126 	cmd_offset = 0;
127 	literal = 0;
128 	cmd_mbc_buf_len = 0;
129 	updown_match = -1;
130 }
131 
132 /*
133  * Clear command line.
134  */
135 	public void
136 clear_cmd(VOID_PARAM)
137 {
138 	cmd_col = prompt_col = 0;
139 	cmd_mbc_buf_len = 0;
140 	updown_match = -1;
141 }
142 
143 /*
144  * Display a string, usually as a prompt for input into the command buffer.
145  */
146 	public void
147 cmd_putstr(s)
148 	constant char *s;
149 {
150 	LWCHAR prev_ch = 0;
151 	LWCHAR ch;
152 	constant char *endline = s + strlen(s);
153 	while (*s != '\0')
154 	{
155 		char *ns = (char *) s;
156 		int width;
157 		ch = step_char(&ns, +1, endline);
158 		while (s < ns)
159 			putchr(*s++);
160 		if (!utf_mode)
161 			width = 1;
162 		else if (is_composing_char(ch) || is_combining_char(prev_ch, ch))
163 			width = 0;
164 		else
165 			width = is_wide_char(ch) ? 2 : 1;
166 		cmd_col += width;
167 		prompt_col += width;
168 		prev_ch = ch;
169 	}
170 }
171 
172 /*
173  * How many characters are in the command buffer?
174  */
175 	public int
176 len_cmdbuf(VOID_PARAM)
177 {
178 	char *s = cmdbuf;
179 	char *endline = s + strlen(s);
180 	int len = 0;
181 
182 	while (*s != '\0')
183 	{
184 		step_char(&s, +1, endline);
185 		len++;
186 	}
187 	return (len);
188 }
189 
190 /*
191  * Common part of cmd_step_right() and cmd_step_left().
192  * {{ Returning pwidth and bswidth separately is a historical artifact
193  *    since they're always the same. Maybe clean this up someday. }}
194  */
195 	static char *
196 cmd_step_common(p, ch, len, pwidth, bswidth)
197 	char *p;
198 	LWCHAR ch;
199 	int len;
200 	int *pwidth;
201 	int *bswidth;
202 {
203 	char *pr;
204 	int width;
205 
206 	if (len == 1)
207 	{
208 		pr = prchar((int) ch);
209 		width = (int) strlen(pr);
210 	} else
211 	{
212 		pr = prutfchar(ch);
213 		if (is_composing_char(ch))
214 			width = 0;
215 		else if (is_ubin_char(ch))
216 			width = (int) strlen(pr);
217 		else
218 		{
219 			LWCHAR prev_ch = step_char(&p, -1, cmdbuf);
220 			if (is_combining_char(prev_ch, ch))
221 				width = 0;
222 			else
223 				width = is_wide_char(ch) ? 2 : 1;
224 		}
225 	}
226 	if (pwidth != NULL)
227 		*pwidth = width;
228 	if (bswidth != NULL)
229 		*bswidth = width;
230 	return (pr);
231 }
232 
233 /*
234  * Step a pointer one character right in the command buffer.
235  */
236 	static char *
237 cmd_step_right(pp, pwidth, bswidth)
238 	char **pp;
239 	int *pwidth;
240 	int *bswidth;
241 {
242 	char *p = *pp;
243 	LWCHAR ch = step_char(pp, +1, p + strlen(p));
244 
245 	return cmd_step_common(p, ch, *pp - p, pwidth, bswidth);
246 }
247 
248 /*
249  * Step a pointer one character left in the command buffer.
250  */
251 	static char *
252 cmd_step_left(pp, pwidth, bswidth)
253 	char **pp;
254 	int *pwidth;
255 	int *bswidth;
256 {
257 	char *p = *pp;
258 	LWCHAR ch = step_char(pp, -1, cmdbuf);
259 
260 	return cmd_step_common(*pp, ch, p - *pp, pwidth, bswidth);
261 }
262 
263 /*
264  * Put the cursor at "home" (just after the prompt),
265  * and set cp to the corresponding char in cmdbuf.
266  */
267 	static void
268 cmd_home(VOID_PARAM)
269 {
270 	while (cmd_col > prompt_col)
271 	{
272 		int width, bswidth;
273 
274 		cmd_step_left(&cp, &width, &bswidth);
275 		while (bswidth-- > 0)
276 			putbs();
277 		cmd_col -= width;
278 	}
279 
280 	cp = &cmdbuf[cmd_offset];
281 }
282 
283 /*
284  * Repaint the line from cp onwards.
285  * Then position the cursor just after the char old_cp (a pointer into cmdbuf).
286  */
287 	public void
288 cmd_repaint(old_cp)
289 	constant char *old_cp;
290 {
291 	/*
292 	 * Repaint the line from the current position.
293 	 */
294 	if (old_cp == NULL)
295 	{
296 		old_cp = cp;
297 		cmd_home();
298 	}
299 	clear_eol();
300 	while (*cp != '\0')
301 	{
302 		char *np = cp;
303 		int width;
304 		char *pr = cmd_step_right(&np, &width, NULL);
305 		if (cmd_col + width >= sc_width)
306 			break;
307 		cp = np;
308 		putstr(pr);
309 		cmd_col += width;
310 	}
311 	while (*cp != '\0')
312 	{
313 		char *np = cp;
314 		int width;
315 		char *pr = cmd_step_right(&np, &width, NULL);
316 		if (width > 0)
317 			break;
318 		cp = np;
319 		putstr(pr);
320 	}
321 
322 	/*
323 	 * Back up the cursor to the correct position.
324 	 */
325 	while (cp > old_cp)
326 		cmd_left();
327 }
328 
329 /*
330  * Shift the cmdbuf display left a half-screen.
331  */
332 	static void
333 cmd_lshift(VOID_PARAM)
334 {
335 	char *s;
336 	char *save_cp;
337 	int cols;
338 
339 	/*
340 	 * Start at the first displayed char, count how far to the
341 	 * right we'd have to move to reach the center of the screen.
342 	 */
343 	s = cmdbuf + cmd_offset;
344 	cols = 0;
345 	while (cols < (sc_width - prompt_col) / 2 && *s != '\0')
346 	{
347 		int width;
348 		cmd_step_right(&s, &width, NULL);
349 		cols += width;
350 	}
351 	while (*s != '\0')
352 	{
353 		int width;
354 		char *ns = s;
355 		cmd_step_right(&ns, &width, NULL);
356 		if (width > 0)
357 			break;
358 		s = ns;
359 	}
360 
361 	cmd_offset = (int) (s - cmdbuf);
362 	save_cp = cp;
363 	cmd_home();
364 	cmd_repaint(save_cp);
365 }
366 
367 /*
368  * Shift the cmdbuf display right a half-screen.
369  */
370 	static void
371 cmd_rshift(VOID_PARAM)
372 {
373 	char *s;
374 	char *save_cp;
375 	int cols;
376 
377 	/*
378 	 * Start at the first displayed char, count how far to the
379 	 * left we'd have to move to traverse a half-screen width
380 	 * of displayed characters.
381 	 */
382 	s = cmdbuf + cmd_offset;
383 	cols = 0;
384 	while (cols < (sc_width - prompt_col) / 2 && s > cmdbuf)
385 	{
386 		int width;
387 		cmd_step_left(&s, &width, NULL);
388 		cols += width;
389 	}
390 
391 	cmd_offset = (int) (s - cmdbuf);
392 	save_cp = cp;
393 	cmd_home();
394 	cmd_repaint(save_cp);
395 }
396 
397 /*
398  * Move cursor right one character.
399  */
400 	static int
401 cmd_right(VOID_PARAM)
402 {
403 	char *pr;
404 	char *ncp;
405 	int width;
406 
407 	if (*cp == '\0')
408 	{
409 		/* Already at the end of the line. */
410 		return (CC_OK);
411 	}
412 	ncp = cp;
413 	pr = cmd_step_right(&ncp, &width, NULL);
414 	if (cmd_col + width >= sc_width)
415 		cmd_lshift();
416 	else if (cmd_col + width == sc_width - 1 && cp[1] != '\0')
417 		cmd_lshift();
418 	cp = ncp;
419 	cmd_col += width;
420 	putstr(pr);
421 	while (*cp != '\0')
422 	{
423 		pr = cmd_step_right(&ncp, &width, NULL);
424 		if (width > 0)
425 			break;
426 		putstr(pr);
427 		cp = ncp;
428 	}
429 	return (CC_OK);
430 }
431 
432 /*
433  * Move cursor left one character.
434  */
435 	static int
436 cmd_left(VOID_PARAM)
437 {
438 	char *ncp;
439 	int width = 0;
440 	int bswidth = 0;
441 
442 	if (cp <= cmdbuf)
443 	{
444 		/* Already at the beginning of the line */
445 		return (CC_OK);
446 	}
447 	ncp = cp;
448 	while (ncp > cmdbuf)
449 	{
450 		cmd_step_left(&ncp, &width, &bswidth);
451 		if (width > 0)
452 			break;
453 	}
454 	if (cmd_col < prompt_col + width)
455 		cmd_rshift();
456 	cp = ncp;
457 	cmd_col -= width;
458 	while (bswidth-- > 0)
459 		putbs();
460 	return (CC_OK);
461 }
462 
463 /*
464  * Insert a char into the command buffer, at the current position.
465  */
466 	static int
467 cmd_ichar(cs, clen)
468 	char *cs;
469 	int clen;
470 {
471 	char *s;
472 
473 	if (strlen(cmdbuf) + clen >= sizeof(cmdbuf)-1)
474 	{
475 		/* No room in the command buffer for another char. */
476 		bell();
477 		return (CC_ERROR);
478 	}
479 
480 	/*
481 	 * Make room for the new character (shift the tail of the buffer right).
482 	 */
483 	for (s = &cmdbuf[strlen(cmdbuf)];  s >= cp;  s--)
484 		s[clen] = s[0];
485 	/*
486 	 * Insert the character into the buffer.
487 	 */
488 	for (s = cp;  s < cp + clen;  s++)
489 		*s = *cs++;
490 	/*
491 	 * Reprint the tail of the line from the inserted char.
492 	 */
493 	updown_match = -1;
494 	cmd_repaint(cp);
495 	cmd_right();
496 	return (CC_OK);
497 }
498 
499 /*
500  * Backspace in the command buffer.
501  * Delete the char to the left of the cursor.
502  */
503 	static int
504 cmd_erase(VOID_PARAM)
505 {
506 	char *s;
507 	int clen;
508 
509 	if (cp == cmdbuf)
510 	{
511 		/*
512 		 * Backspace past beginning of the buffer:
513 		 * this usually means abort the command.
514 		 */
515 		return (CC_QUIT);
516 	}
517 	/*
518 	 * Move cursor left (to the char being erased).
519 	 */
520 	s = cp;
521 	cmd_left();
522 	clen = (int) (s - cp);
523 
524 	/*
525 	 * Remove the char from the buffer (shift the buffer left).
526 	 */
527 	for (s = cp;  ;  s++)
528 	{
529 		s[0] = s[clen];
530 		if (s[0] == '\0')
531 			break;
532 	}
533 
534 	/*
535 	 * Repaint the buffer after the erased char.
536 	 */
537 	updown_match = -1;
538 	cmd_repaint(cp);
539 
540 	/*
541 	 * We say that erasing the entire command string causes us
542 	 * to abort the current command, if CF_QUIT_ON_ERASE is set.
543 	 */
544 	if ((curr_cmdflags & CF_QUIT_ON_ERASE) && cp == cmdbuf && *cp == '\0')
545 		return (CC_QUIT);
546 	return (CC_OK);
547 }
548 
549 /*
550  * Delete the char under the cursor.
551  */
552 	static int
553 cmd_delete(VOID_PARAM)
554 {
555 	if (*cp == '\0')
556 	{
557 		/* At end of string; there is no char under the cursor. */
558 		return (CC_OK);
559 	}
560 	/*
561 	 * Move right, then use cmd_erase.
562 	 */
563 	cmd_right();
564 	cmd_erase();
565 	return (CC_OK);
566 }
567 
568 /*
569  * Delete the "word" to the left of the cursor.
570  */
571 	static int
572 cmd_werase(VOID_PARAM)
573 {
574 	if (cp > cmdbuf && cp[-1] == ' ')
575 	{
576 		/*
577 		 * If the char left of cursor is a space,
578 		 * erase all the spaces left of cursor (to the first non-space).
579 		 */
580 		while (cp > cmdbuf && cp[-1] == ' ')
581 			(void) cmd_erase();
582 	} else
583 	{
584 		/*
585 		 * If the char left of cursor is not a space,
586 		 * erase all the nonspaces left of cursor (the whole "word").
587 		 */
588 		while (cp > cmdbuf && cp[-1] != ' ')
589 			(void) cmd_erase();
590 	}
591 	return (CC_OK);
592 }
593 
594 /*
595  * Delete the "word" under the cursor.
596  */
597 	static int
598 cmd_wdelete(VOID_PARAM)
599 {
600 	if (*cp == ' ')
601 	{
602 		/*
603 		 * If the char under the cursor is a space,
604 		 * delete it and all the spaces right of cursor.
605 		 */
606 		while (*cp == ' ')
607 			(void) cmd_delete();
608 	} else
609 	{
610 		/*
611 		 * If the char under the cursor is not a space,
612 		 * delete it and all nonspaces right of cursor (the whole word).
613 		 */
614 		while (*cp != ' ' && *cp != '\0')
615 			(void) cmd_delete();
616 	}
617 	return (CC_OK);
618 }
619 
620 /*
621  * Delete all chars in the command buffer.
622  */
623 	static int
624 cmd_kill(VOID_PARAM)
625 {
626 	if (cmdbuf[0] == '\0')
627 	{
628 		/* Buffer is already empty; abort the current command. */
629 		return (CC_QUIT);
630 	}
631 	cmd_offset = 0;
632 	cmd_home();
633 	*cp = '\0';
634 	updown_match = -1;
635 	cmd_repaint(cp);
636 
637 	/*
638 	 * We say that erasing the entire command string causes us
639 	 * to abort the current command, if CF_QUIT_ON_ERASE is set.
640 	 */
641 	if (curr_cmdflags & CF_QUIT_ON_ERASE)
642 		return (CC_QUIT);
643 	return (CC_OK);
644 }
645 
646 /*
647  * Select an mlist structure to be the current command history.
648  */
649 	public void
650 set_mlist(mlist, cmdflags)
651 	void *mlist;
652 	int cmdflags;
653 {
654 #if CMD_HISTORY
655 	curr_mlist = (struct mlist *) mlist;
656 	curr_cmdflags = cmdflags;
657 
658 	/* Make sure the next up-arrow moves to the last string in the mlist. */
659 	if (curr_mlist != NULL)
660 		curr_mlist->curr_mp = curr_mlist;
661 #endif
662 }
663 
664 #if CMD_HISTORY
665 /*
666  * Move up or down in the currently selected command history list.
667  * Only consider entries whose first updown_match chars are equal to
668  * cmdbuf's corresponding chars.
669  */
670 	static int
671 cmd_updown(action)
672 	int action;
673 {
674 	constant char *s;
675 	struct mlist *ml;
676 
677 	if (curr_mlist == NULL)
678 	{
679 		/*
680 		 * The current command has no history list.
681 		 */
682 		bell();
683 		return (CC_OK);
684 	}
685 
686 	if (updown_match < 0)
687 	{
688 		updown_match = (int) (cp - cmdbuf);
689 	}
690 
691 	/*
692 	 * Find the next history entry which matches.
693 	 */
694 	for (ml = curr_mlist->curr_mp;;)
695 	{
696 		ml = (action == EC_UP) ? ml->prev : ml->next;
697 		if (ml == curr_mlist)
698 		{
699 			/*
700 			 * We reached the end (or beginning) of the list.
701 			 */
702 			break;
703 		}
704 		if (strncmp(cmdbuf, ml->string, updown_match) == 0)
705 		{
706 			/*
707 			 * This entry matches; stop here.
708 			 * Copy the entry into cmdbuf and echo it on the screen.
709 			 */
710 			curr_mlist->curr_mp = ml;
711 			s = ml->string;
712 			if (s == NULL)
713 				s = "";
714 			cmd_offset = 0;
715 			cmd_home();
716 			clear_eol();
717 			strcpy(cmdbuf, s);
718 			for (cp = cmdbuf;  *cp != '\0';  )
719 				cmd_right();
720 			return (CC_OK);
721 		}
722 	}
723 	/*
724 	 * We didn't find a history entry that matches.
725 	 */
726 	bell();
727 	return (CC_OK);
728 }
729 #endif
730 
731 /*
732  *
733  */
734 	static void
735 ml_link(mlist, ml)
736 	struct mlist *mlist;
737 	struct mlist *ml;
738 {
739 	ml->next = mlist;
740 	ml->prev = mlist->prev;
741 	mlist->prev->next = ml;
742 	mlist->prev = ml;
743 }
744 
745 /*
746  *
747  */
748 	static void
749 ml_unlink(ml)
750 	struct mlist *ml;
751 {
752 	ml->prev->next = ml->next;
753 	ml->next->prev = ml->prev;
754 }
755 
756 /*
757  * Add a string to an mlist.
758  */
759 	public void
760 cmd_addhist(mlist, cmd, modified)
761 	struct mlist *mlist;
762 	constant char *cmd;
763 	int modified;
764 {
765 #if CMD_HISTORY
766 	struct mlist *ml;
767 
768 	/*
769 	 * Don't save a trivial command.
770 	 */
771 	if (strlen(cmd) == 0)
772 		return;
773 
774 	if (no_hist_dups)
775 	{
776 		struct mlist *next = NULL;
777 		for (ml = mlist->next;  ml->string != NULL;  ml = next)
778 		{
779 			next = ml->next;
780 			if (strcmp(ml->string, cmd) == 0)
781 			{
782 				ml_unlink(ml);
783 				free(ml->string);
784 				free(ml);
785 			}
786 		}
787 	}
788 
789 	/*
790 	 * Save the command unless it's a duplicate of the
791 	 * last command in the history.
792 	 */
793 	ml = mlist->prev;
794 	if (ml == mlist || strcmp(ml->string, cmd) != 0)
795 	{
796 		/*
797 		 * Did not find command in history.
798 		 * Save the command and put it at the end of the history list.
799 		 */
800 		ml = (struct mlist *) ecalloc(1, sizeof(struct mlist));
801 		ml->string = save(cmd);
802 		ml->modified = modified;
803 		ml_link(mlist, ml);
804 	}
805 	/*
806 	 * Point to the cmd just after the just-accepted command.
807 	 * Thus, an UPARROW will always retrieve the previous command.
808 	 */
809 	mlist->curr_mp = ml->next;
810 #endif
811 }
812 
813 /*
814  * Accept the command in the command buffer.
815  * Add it to the currently selected history list.
816  */
817 	public void
818 cmd_accept(VOID_PARAM)
819 {
820 #if CMD_HISTORY
821 	/*
822 	 * Nothing to do if there is no currently selected history list.
823 	 */
824 	if (curr_mlist == NULL || curr_mlist == ml_examine)
825 		return;
826 	cmd_addhist(curr_mlist, cmdbuf, 1);
827 	curr_mlist->modified = 1;
828 #endif
829 }
830 
831 /*
832  * Try to perform a line-edit function on the command buffer,
833  * using a specified char as a line-editing command.
834  * Returns:
835  *      CC_PASS The char does not invoke a line edit function.
836  *      CC_OK   Line edit function done.
837  *      CC_QUIT The char requests the current command to be aborted.
838  */
839 	static int
840 cmd_edit(c)
841 	int c;
842 {
843 	int action;
844 	int flags;
845 
846 #if TAB_COMPLETE_FILENAME
847 #define not_in_completion()     in_completion = 0
848 #else
849 #define not_in_completion(VOID_PARAM)
850 #endif
851 
852 	/*
853 	 * See if the char is indeed a line-editing command.
854 	 */
855 	flags = 0;
856 #if CMD_HISTORY
857 	if (curr_mlist == NULL)
858 		/*
859 		 * No current history; don't accept history manipulation cmds.
860 		 */
861 		flags |= ECF_NOHISTORY;
862 #endif
863 #if TAB_COMPLETE_FILENAME
864 	if (curr_mlist == ml_search || curr_mlist == NULL)
865 		/*
866 		 * Don't accept file-completion cmds in contexts
867 		 * such as search pattern, digits, long option name, etc.
868 		 */
869 		flags |= ECF_NOCOMPLETE;
870 #endif
871 
872 	action = editchar(c, flags);
873 
874 	switch (action)
875 	{
876 	case A_NOACTION:
877 		return (CC_OK);
878 	case EC_RIGHT:
879 		not_in_completion();
880 		return (cmd_right());
881 	case EC_LEFT:
882 		not_in_completion();
883 		return (cmd_left());
884 	case EC_W_RIGHT:
885 		not_in_completion();
886 		while (*cp != '\0' && *cp != ' ')
887 			cmd_right();
888 		while (*cp == ' ')
889 			cmd_right();
890 		return (CC_OK);
891 	case EC_W_LEFT:
892 		not_in_completion();
893 		while (cp > cmdbuf && cp[-1] == ' ')
894 			cmd_left();
895 		while (cp > cmdbuf && cp[-1] != ' ')
896 			cmd_left();
897 		return (CC_OK);
898 	case EC_HOME:
899 		not_in_completion();
900 		cmd_offset = 0;
901 		cmd_home();
902 		cmd_repaint(cp);
903 		return (CC_OK);
904 	case EC_END:
905 		not_in_completion();
906 		while (*cp != '\0')
907 			cmd_right();
908 		return (CC_OK);
909 	case EC_INSERT:
910 		not_in_completion();
911 		return (CC_OK);
912 	case EC_BACKSPACE:
913 		not_in_completion();
914 		return (cmd_erase());
915 	case EC_LINEKILL:
916 		not_in_completion();
917 		return (cmd_kill());
918 	case EC_ABORT:
919 		not_in_completion();
920 		(void) cmd_kill();
921 		return (CC_QUIT);
922 	case EC_W_BACKSPACE:
923 		not_in_completion();
924 		return (cmd_werase());
925 	case EC_DELETE:
926 		not_in_completion();
927 		return (cmd_delete());
928 	case EC_W_DELETE:
929 		not_in_completion();
930 		return (cmd_wdelete());
931 	case EC_LITERAL:
932 		literal = 1;
933 		return (CC_OK);
934 #if CMD_HISTORY
935 	case EC_UP:
936 	case EC_DOWN:
937 		not_in_completion();
938 		return (cmd_updown(action));
939 #endif
940 #if TAB_COMPLETE_FILENAME
941 	case EC_F_COMPLETE:
942 	case EC_B_COMPLETE:
943 	case EC_EXPAND:
944 		return (cmd_complete(action));
945 #endif
946 	default:
947 		not_in_completion();
948 		return (CC_PASS);
949 	}
950 }
951 
952 #if TAB_COMPLETE_FILENAME
953 /*
954  * Insert a string into the command buffer, at the current position.
955  */
956 	static int
957 cmd_istr(str)
958 	char *str;
959 {
960 	char *s;
961 	int action;
962 	char *endline = str + strlen(str);
963 
964 	for (s = str;  *s != '\0';  )
965 	{
966 		char *os = s;
967 		step_char(&s, +1, endline);
968 		action = cmd_ichar(os, s - os);
969 		if (action != CC_OK)
970 			return (action);
971 	}
972 	return (CC_OK);
973 }
974 
975 /*
976  * Find the beginning and end of the "current" word.
977  * This is the word which the cursor (cp) is inside or at the end of.
978  * Return pointer to the beginning of the word and put the
979  * cursor at the end of the word.
980  */
981 	static char *
982 delimit_word(VOID_PARAM)
983 {
984 	char *word;
985 #if SPACES_IN_FILENAMES
986 	char *p;
987 	int delim_quoted = 0;
988 	int meta_quoted = 0;
989 	constant char *esc = get_meta_escape();
990 	int esclen = (int) strlen(esc);
991 #endif
992 
993 	/*
994 	 * Move cursor to end of word.
995 	 */
996 	if (*cp != ' ' && *cp != '\0')
997 	{
998 		/*
999 		 * Cursor is on a nonspace.
1000 		 * Move cursor right to the next space.
1001 		 */
1002 		while (*cp != ' ' && *cp != '\0')
1003 			cmd_right();
1004 	} else if (cp > cmdbuf && cp[-1] != ' ')
1005 	{
1006 		/*
1007 		 * Cursor is on a space, and char to the left is a nonspace.
1008 		 * We're already at the end of the word.
1009 		 */
1010 		;
1011 #if 0
1012 	} else
1013 	{
1014 		/*
1015 		 * Cursor is on a space and char to the left is a space.
1016 		 * Huh? There's no word here.
1017 		 */
1018 		return (NULL);
1019 #endif
1020 	}
1021 	/*
1022 	 * Find the beginning of the word which the cursor is in.
1023 	 */
1024 	if (cp == cmdbuf)
1025 		return (NULL);
1026 #if SPACES_IN_FILENAMES
1027 	/*
1028 	 * If we have an unbalanced quote (that is, an open quote
1029 	 * without a corresponding close quote), we return everything
1030 	 * from the open quote, including spaces.
1031 	 */
1032 	for (word = cmdbuf;  word < cp;  word++)
1033 		if (*word != ' ')
1034 			break;
1035 	if (word >= cp)
1036 		return (cp);
1037 	for (p = cmdbuf;  p < cp;  p++)
1038 	{
1039 		if (meta_quoted)
1040 		{
1041 			meta_quoted = 0;
1042 		} else if (esclen > 0 && p + esclen < cp &&
1043 		           strncmp(p, esc, esclen) == 0)
1044 		{
1045 			meta_quoted = 1;
1046 			p += esclen - 1;
1047 		} else if (delim_quoted)
1048 		{
1049 			if (*p == closequote)
1050 				delim_quoted = 0;
1051 		} else /* (!delim_quoted) */
1052 		{
1053 			if (*p == openquote)
1054 				delim_quoted = 1;
1055 			else if (*p == ' ')
1056 				word = p+1;
1057 		}
1058 	}
1059 #endif
1060 	return (word);
1061 }
1062 
1063 /*
1064  * Set things up to enter completion mode.
1065  * Expand the word under the cursor into a list of filenames
1066  * which start with that word, and set tk_text to that list.
1067  */
1068 	static void
1069 init_compl(VOID_PARAM)
1070 {
1071 	char *word;
1072 	char c;
1073 
1074 	/*
1075 	 * Get rid of any previous tk_text.
1076 	 */
1077 	if (tk_text != NULL)
1078 	{
1079 		free(tk_text);
1080 		tk_text = NULL;
1081 	}
1082 	/*
1083 	 * Find the original (uncompleted) word in the command buffer.
1084 	 */
1085 	word = delimit_word();
1086 	if (word == NULL)
1087 		return;
1088 	/*
1089 	 * Set the insertion point to the point in the command buffer
1090 	 * where the original (uncompleted) word now sits.
1091 	 */
1092 	tk_ipoint = word;
1093 	/*
1094 	 * Save the original (uncompleted) word
1095 	 */
1096 	if (tk_original != NULL)
1097 		free(tk_original);
1098 	tk_original = (char *) ecalloc(cp-word+1, sizeof(char));
1099 	strncpy(tk_original, word, cp-word);
1100 	/*
1101 	 * Get the expanded filename.
1102 	 * This may result in a single filename, or
1103 	 * a blank-separated list of filenames.
1104 	 */
1105 	c = *cp;
1106 	*cp = '\0';
1107 	if (*word != openquote)
1108 	{
1109 		tk_text = fcomplete(word);
1110 	} else
1111 	{
1112 #if MSDOS_COMPILER
1113 		char *qword = NULL;
1114 #else
1115 		char *qword = shell_quote(word+1);
1116 #endif
1117 		if (qword == NULL)
1118 			tk_text = fcomplete(word+1);
1119 		else
1120 		{
1121 			tk_text = fcomplete(qword);
1122 			free(qword);
1123 		}
1124 	}
1125 	*cp = c;
1126 }
1127 
1128 /*
1129  * Return the next word in the current completion list.
1130  */
1131 	static char *
1132 next_compl(action, prev)
1133 	int action;
1134 	char *prev;
1135 {
1136 	switch (action)
1137 	{
1138 	case EC_F_COMPLETE:
1139 		return (forw_textlist(&tk_tlist, prev));
1140 	case EC_B_COMPLETE:
1141 		return (back_textlist(&tk_tlist, prev));
1142 	}
1143 	/* Cannot happen */
1144 	return ("?");
1145 }
1146 
1147 /*
1148  * Complete the filename before (or under) the cursor.
1149  * cmd_complete may be called multiple times.  The global in_completion
1150  * remembers whether this call is the first time (create the list),
1151  * or a subsequent time (step thru the list).
1152  */
1153 	static int
1154 cmd_complete(action)
1155 	int action;
1156 {
1157 	char *s;
1158 
1159 	if (!in_completion || action == EC_EXPAND)
1160 	{
1161 		/*
1162 		 * Expand the word under the cursor and
1163 		 * use the first word in the expansion
1164 		 * (or the entire expansion if we're doing EC_EXPAND).
1165 		 */
1166 		init_compl();
1167 		if (tk_text == NULL)
1168 		{
1169 			bell();
1170 			return (CC_OK);
1171 		}
1172 		if (action == EC_EXPAND)
1173 		{
1174 			/*
1175 			 * Use the whole list.
1176 			 */
1177 			tk_trial = tk_text;
1178 		} else
1179 		{
1180 			/*
1181 			 * Use the first filename in the list.
1182 			 */
1183 			in_completion = 1;
1184 			init_textlist(&tk_tlist, tk_text);
1185 			tk_trial = next_compl(action, (char*)NULL);
1186 		}
1187 	} else
1188 	{
1189 		/*
1190 		 * We already have a completion list.
1191 		 * Use the next/previous filename from the list.
1192 		 */
1193 		tk_trial = next_compl(action, tk_trial);
1194 	}
1195 
1196 	/*
1197 	 * Remove the original word, or the previous trial completion.
1198 	 */
1199 	while (cp > tk_ipoint)
1200 		(void) cmd_erase();
1201 
1202 	if (tk_trial == NULL)
1203 	{
1204 		/*
1205 		 * There are no more trial completions.
1206 		 * Insert the original (uncompleted) filename.
1207 		 */
1208 		in_completion = 0;
1209 		if (cmd_istr(tk_original) != CC_OK)
1210 			goto fail;
1211 	} else
1212 	{
1213 		/*
1214 		 * Insert trial completion.
1215 		 */
1216 		if (cmd_istr(tk_trial) != CC_OK)
1217 			goto fail;
1218 		/*
1219 		 * If it is a directory, append a slash.
1220 		 */
1221 		if (is_dir(tk_trial))
1222 		{
1223 			if (cp > cmdbuf && cp[-1] == closequote)
1224 				(void) cmd_erase();
1225 			s = lgetenv("LESSSEPARATOR");
1226 			if (s == NULL)
1227 				s = PATHNAME_SEP;
1228 			if (cmd_istr(s) != CC_OK)
1229 				goto fail;
1230 		}
1231 	}
1232 
1233 	return (CC_OK);
1234 
1235 fail:
1236 	in_completion = 0;
1237 	bell();
1238 	return (CC_OK);
1239 }
1240 
1241 #endif /* TAB_COMPLETE_FILENAME */
1242 
1243 /*
1244  * Process a single character of a multi-character command, such as
1245  * a number, or the pattern of a search command.
1246  * Returns:
1247  *      CC_OK           The char was accepted.
1248  *      CC_QUIT         The char requests the command to be aborted.
1249  *      CC_ERROR        The char could not be accepted due to an error.
1250  */
1251 	public int
1252 cmd_char(c)
1253 	int c;
1254 {
1255 	int action;
1256 	int len;
1257 
1258 	if (!utf_mode)
1259 	{
1260 		cmd_mbc_buf[0] = c;
1261 		len = 1;
1262 	} else
1263 	{
1264 		/* Perform strict validation in all possible cases.  */
1265 		if (cmd_mbc_buf_len == 0)
1266 		{
1267 		 retry:
1268 			cmd_mbc_buf_index = 1;
1269 			*cmd_mbc_buf = c;
1270 			if (IS_ASCII_OCTET(c))
1271 				cmd_mbc_buf_len = 1;
1272 #if MSDOS_COMPILER || OS2
1273 			else if (c == (unsigned char) '\340' && IS_ASCII_OCTET(peekcc()))
1274 			{
1275 				/* Assume a special key. */
1276 				cmd_mbc_buf_len = 1;
1277 			}
1278 #endif
1279 			else if (IS_UTF8_LEAD(c))
1280 			{
1281 				cmd_mbc_buf_len = utf_len(c);
1282 				return (CC_OK);
1283 			} else
1284 			{
1285 				/* UTF8_INVALID or stray UTF8_TRAIL */
1286 				bell();
1287 				return (CC_ERROR);
1288 			}
1289 		} else if (IS_UTF8_TRAIL(c))
1290 		{
1291 			cmd_mbc_buf[cmd_mbc_buf_index++] = c;
1292 			if (cmd_mbc_buf_index < cmd_mbc_buf_len)
1293 				return (CC_OK);
1294 			if (!is_utf8_well_formed(cmd_mbc_buf, cmd_mbc_buf_index))
1295 			{
1296 				/* complete, but not well formed (non-shortest form), sequence */
1297 				cmd_mbc_buf_len = 0;
1298 				bell();
1299 				return (CC_ERROR);
1300 			}
1301 		} else
1302 		{
1303 			/* Flush incomplete (truncated) sequence.  */
1304 			cmd_mbc_buf_len = 0;
1305 			bell();
1306 			/* Handle new char.  */
1307 			goto retry;
1308 		}
1309 
1310 		len = cmd_mbc_buf_len;
1311 		cmd_mbc_buf_len = 0;
1312 	}
1313 
1314 	if (literal)
1315 	{
1316 		/*
1317 		 * Insert the char, even if it is a line-editing char.
1318 		 */
1319 		literal = 0;
1320 		return (cmd_ichar(cmd_mbc_buf, len));
1321 	}
1322 
1323 	/*
1324 	 * See if it is a line-editing character.
1325 	 */
1326 	if (in_mca() && len == 1)
1327 	{
1328 		action = cmd_edit(c);
1329 		switch (action)
1330 		{
1331 		case CC_OK:
1332 		case CC_QUIT:
1333 			return (action);
1334 		case CC_PASS:
1335 			break;
1336 		}
1337 	}
1338 
1339 	/*
1340 	 * Insert the char into the command buffer.
1341 	 */
1342 	return (cmd_ichar(cmd_mbc_buf, len));
1343 }
1344 
1345 /*
1346  * Return the number currently in the command buffer.
1347  */
1348 	public LINENUM
1349 cmd_int(frac)
1350 	long *frac;
1351 {
1352 	char *p;
1353 	LINENUM n = 0;
1354 	int err;
1355 
1356 	for (p = cmdbuf;  *p >= '0' && *p <= '9';  p++)
1357 	{
1358 		LINENUM nn = (n * 10) + (*p - '0');
1359 		if (nn < n)
1360 		{
1361 			error("Integer is too big", NULL_PARG);
1362 			return (0);
1363 		}
1364 		n = nn;
1365 	}
1366 	*frac = 0;
1367 	if (*p++ == '.')
1368 	{
1369 		*frac = getfraction(&p, NULL, &err);
1370 		/* {{ do something if err is set? }} */
1371 	}
1372 	return (n);
1373 }
1374 
1375 /*
1376  * Return a pointer to the command buffer.
1377  */
1378 	public char *
1379 get_cmdbuf(VOID_PARAM)
1380 {
1381 	if (cmd_mbc_buf_index < cmd_mbc_buf_len)
1382 		/* Don't return buffer containing an incomplete multibyte char. */
1383 		return (NULL);
1384 	return (cmdbuf);
1385 }
1386 
1387 #if CMD_HISTORY
1388 /*
1389  * Return the last (most recent) string in the current command history.
1390  */
1391 	public char *
1392 cmd_lastpattern(VOID_PARAM)
1393 {
1394 	if (curr_mlist == NULL)
1395 		return (NULL);
1396 	return (curr_mlist->curr_mp->prev->string);
1397 }
1398 #endif
1399 
1400 #if CMD_HISTORY
1401 /*
1402  */
1403 	static int
1404 mlist_size(ml)
1405 	struct mlist *ml;
1406 {
1407 	int size = 0;
1408 	for (ml = ml->next;  ml->string != NULL;  ml = ml->next)
1409 		++size;
1410 	return size;
1411 }
1412 
1413 /*
1414  * Get the name of the history file.
1415  */
1416 	static char *
1417 histfile_find(must_exist)
1418 	int must_exist;
1419 {
1420 	char *home = lgetenv("HOME");
1421 	char *name = NULL;
1422 
1423 	/* Try in $XDG_STATE_HOME, then in $HOME/.local/state, then in $XDG_DATA_HOME, then in $HOME. */
1424 #if OS2
1425 	if (isnullenv(home))
1426 		home = lgetenv("INIT");
1427 #endif
1428 	name = dirfile(lgetenv("XDG_STATE_HOME"), &LESSHISTFILE[1], must_exist);
1429 	if (name == NULL)
1430 	{
1431 		char *dir = dirfile(home, ".local/state", 1);
1432 		if (dir != NULL)
1433 		{
1434 			name = dirfile(dir, &LESSHISTFILE[1], must_exist);
1435 			free(dir);
1436 		}
1437 	}
1438 	if (name == NULL)
1439 		name = dirfile(lgetenv("XDG_DATA_HOME"), &LESSHISTFILE[1], must_exist);
1440 	if (name == NULL)
1441 		name = dirfile(home, LESSHISTFILE, must_exist);
1442 	return (name);
1443 }
1444 
1445 	static char *
1446 histfile_name(must_exist)
1447 	int must_exist;
1448 {
1449 	char *name;
1450 
1451 	/* See if filename is explicitly specified by $LESSHISTFILE. */
1452 	name = lgetenv("LESSHISTFILE");
1453 	if (!isnullenv(name))
1454 	{
1455 		if (strcmp(name, "-") == 0 || strcmp(name, "/dev/null") == 0)
1456 			/* $LESSHISTFILE == "-" means don't use a history file. */
1457 			return (NULL);
1458 		return (save(name));
1459 	}
1460 
1461 	/* See if history file is disabled in the build. */
1462 	if (strcmp(LESSHISTFILE, "") == 0 || strcmp(LESSHISTFILE, "-") == 0)
1463 		return (NULL);
1464 
1465 	name = NULL;
1466 	if (!must_exist)
1467 	{
1468 	 	/* If we're writing the file and the file already exists, use it. */
1469 		name = histfile_find(1);
1470 	}
1471 	if (name == NULL)
1472 		name = histfile_find(must_exist);
1473 	return (name);
1474 }
1475 
1476 /*
1477  * Read a .lesshst file and call a callback for each line in the file.
1478  */
1479 	static void
1480 read_cmdhist2(action, uparam, skip_search, skip_shell)
1481 	void (*action)(void*,struct mlist*,char*);
1482 	void *uparam;
1483 	int skip_search;
1484 	int skip_shell;
1485 {
1486 	struct mlist *ml = NULL;
1487 	char line[CMDBUF_SIZE];
1488 	char *filename;
1489 	FILE *f;
1490 	char *p;
1491 	int *skip = NULL;
1492 
1493 	filename = histfile_name(1);
1494 	if (filename == NULL)
1495 		return;
1496 	f = fopen(filename, "r");
1497 	free(filename);
1498 	if (f == NULL)
1499 		return;
1500 	if (fgets(line, sizeof(line), f) == NULL ||
1501 	    strncmp(line, HISTFILE_FIRST_LINE, strlen(HISTFILE_FIRST_LINE)) != 0)
1502 	{
1503 		fclose(f);
1504 		return;
1505 	}
1506 	while (fgets(line, sizeof(line), f) != NULL)
1507 	{
1508 		for (p = line;  *p != '\0';  p++)
1509 		{
1510 			if (*p == '\n' || *p == '\r')
1511 			{
1512 				*p = '\0';
1513 				break;
1514 			}
1515 		}
1516 		if (strcmp(line, HISTFILE_SEARCH_SECTION) == 0)
1517 		{
1518 			ml = &mlist_search;
1519 			skip = &skip_search;
1520 		} else if (strcmp(line, HISTFILE_SHELL_SECTION) == 0)
1521 		{
1522 #if SHELL_ESCAPE || PIPEC
1523 			ml = &mlist_shell;
1524 			skip = &skip_shell;
1525 #else
1526 			ml = NULL;
1527 			skip = NULL;
1528 #endif
1529 		} else if (strcmp(line, HISTFILE_MARK_SECTION) == 0)
1530 		{
1531 			ml = NULL;
1532 		} else if (*line == '"')
1533 		{
1534 			if (ml != NULL)
1535 			{
1536 				if (skip != NULL && *skip > 0)
1537 					--(*skip);
1538 				else
1539 					(*action)(uparam, ml, line+1);
1540 			}
1541 		} else if (*line == 'm')
1542 		{
1543 			(*action)(uparam, NULL, line);
1544 		}
1545 	}
1546 	fclose(f);
1547 }
1548 
1549 	static void
1550 read_cmdhist(action, uparam, skip_search, skip_shell)
1551 	void (*action)(void*,struct mlist*,char*);
1552 	void *uparam;
1553 	int skip_search;
1554 	int skip_shell;
1555 {
1556 	if (secure)
1557 		return;
1558 	read_cmdhist2(action, uparam, skip_search, skip_shell);
1559 	(*action)(uparam, NULL, NULL); /* signal end of file */
1560 }
1561 
1562 	static void
1563 addhist_init(uparam, ml, string)
1564 	void *uparam;
1565 	struct mlist *ml;
1566 	char constant *string;
1567 {
1568 	if (ml != NULL)
1569 		cmd_addhist(ml, string, 0);
1570 	else if (string != NULL)
1571 		restore_mark((char*)string); /* stupid const cast */
1572 }
1573 #endif /* CMD_HISTORY */
1574 
1575 /*
1576  * Initialize history from a .lesshist file.
1577  */
1578 	public void
1579 init_cmdhist(VOID_PARAM)
1580 {
1581 #if CMD_HISTORY
1582 	read_cmdhist(&addhist_init, NULL, 0, 0);
1583 #endif /* CMD_HISTORY */
1584 }
1585 
1586 /*
1587  * Write the header for a section of the history file.
1588  */
1589 #if CMD_HISTORY
1590 	static void
1591 write_mlist_header(ml, f)
1592 	struct mlist *ml;
1593 	FILE *f;
1594 {
1595 	if (ml == &mlist_search)
1596 		fprintf(f, "%s\n", HISTFILE_SEARCH_SECTION);
1597 #if SHELL_ESCAPE || PIPEC
1598 	else if (ml == &mlist_shell)
1599 		fprintf(f, "%s\n", HISTFILE_SHELL_SECTION);
1600 #endif
1601 }
1602 
1603 /*
1604  * Write all modified entries in an mlist to the history file.
1605  */
1606 	static void
1607 write_mlist(ml, f)
1608 	struct mlist *ml;
1609 	FILE *f;
1610 {
1611 	for (ml = ml->next;  ml->string != NULL;  ml = ml->next)
1612 	{
1613 		if (!ml->modified)
1614 			continue;
1615 		fprintf(f, "\"%s\n", ml->string);
1616 		ml->modified = 0;
1617 	}
1618 	ml->modified = 0; /* entire mlist is now unmodified */
1619 }
1620 
1621 /*
1622  * Make a temp name in the same directory as filename.
1623  */
1624 	static char *
1625 make_tempname(filename)
1626 	char *filename;
1627 {
1628 	char lastch;
1629 	char *tempname = ecalloc(1, strlen(filename)+1);
1630 	strcpy(tempname, filename);
1631 	lastch = tempname[strlen(tempname)-1];
1632 	tempname[strlen(tempname)-1] = (lastch == 'Q') ? 'Z' : 'Q';
1633 	return tempname;
1634 }
1635 
1636 struct save_ctx
1637 {
1638 	struct mlist *mlist;
1639 	FILE *fout;
1640 };
1641 
1642 /*
1643  * Copy entries from the saved history file to a new file.
1644  * At the end of each mlist, append any new entries
1645  * created during this session.
1646  */
1647 	static void
1648 copy_hist(uparam, ml, string)
1649 	void *uparam;
1650 	struct mlist *ml;
1651 	char constant *string;
1652 {
1653 	struct save_ctx *ctx = (struct save_ctx *) uparam;
1654 
1655 	if (ml != NULL && ml != ctx->mlist) {
1656 		/* We're changing mlists. */
1657 		if (ctx->mlist)
1658 			/* Append any new entries to the end of the current mlist. */
1659 			write_mlist(ctx->mlist, ctx->fout);
1660 		/* Write the header for the new mlist. */
1661 		ctx->mlist = ml;
1662 		write_mlist_header(ctx->mlist, ctx->fout);
1663 	}
1664 
1665 	if (string == NULL) /* End of file */
1666 	{
1667 		/* Write any sections that were not in the original file. */
1668 		if (mlist_search.modified)
1669 		{
1670 			write_mlist_header(&mlist_search, ctx->fout);
1671 			write_mlist(&mlist_search, ctx->fout);
1672 		}
1673 #if SHELL_ESCAPE || PIPEC
1674 		if (mlist_shell.modified)
1675 		{
1676 			write_mlist_header(&mlist_shell, ctx->fout);
1677 			write_mlist(&mlist_shell, ctx->fout);
1678 		}
1679 #endif
1680 	} else if (ml != NULL)
1681 	{
1682 		/* Copy mlist entry. */
1683 		fprintf(ctx->fout, "\"%s\n", string);
1684 	}
1685 	/* Skip marks */
1686 }
1687 #endif /* CMD_HISTORY */
1688 
1689 /*
1690  * Make a file readable only by its owner.
1691  */
1692 	static void
1693 make_file_private(f)
1694 	FILE *f;
1695 {
1696 #if HAVE_FCHMOD
1697 	int do_chmod = 1;
1698 #if HAVE_STAT
1699 	struct stat statbuf;
1700 	int r = fstat(fileno(f), &statbuf);
1701 	if (r < 0 || !S_ISREG(statbuf.st_mode))
1702 		/* Don't chmod if not a regular file. */
1703 		do_chmod = 0;
1704 #endif
1705 	if (do_chmod)
1706 		fchmod(fileno(f), 0600);
1707 #endif
1708 }
1709 
1710 /*
1711  * Does the history file need to be updated?
1712  */
1713 #if CMD_HISTORY
1714 	static int
1715 histfile_modified(VOID_PARAM)
1716 {
1717 	if (mlist_search.modified)
1718 		return 1;
1719 #if SHELL_ESCAPE || PIPEC
1720 	if (mlist_shell.modified)
1721 		return 1;
1722 #endif
1723 	if (marks_modified)
1724 		return 1;
1725 	return 0;
1726 }
1727 #endif
1728 
1729 /*
1730  * Update the .lesshst file.
1731  */
1732 	public void
1733 save_cmdhist(VOID_PARAM)
1734 {
1735 #if CMD_HISTORY
1736 	char *histname;
1737 	char *tempname;
1738 	int skip_search;
1739 	int skip_shell;
1740 	struct save_ctx ctx;
1741 	char *s;
1742 	FILE *fout = NULL;
1743 	int histsize = 0;
1744 
1745 	if (secure || !histfile_modified())
1746 		return;
1747 	histname = histfile_name(0);
1748 	if (histname == NULL)
1749 		return;
1750 	tempname = make_tempname(histname);
1751 	fout = fopen(tempname, "w");
1752 	if (fout != NULL)
1753 	{
1754 		make_file_private(fout);
1755 		s = lgetenv("LESSHISTSIZE");
1756 		if (s != NULL)
1757 			histsize = atoi(s);
1758 		if (histsize <= 0)
1759 			histsize = 100;
1760 		skip_search = mlist_size(&mlist_search) - histsize;
1761 #if SHELL_ESCAPE || PIPEC
1762 		skip_shell = mlist_size(&mlist_shell) - histsize;
1763 #endif
1764 		fprintf(fout, "%s\n", HISTFILE_FIRST_LINE);
1765 		ctx.fout = fout;
1766 		ctx.mlist = NULL;
1767 		read_cmdhist(&copy_hist, &ctx, skip_search, skip_shell);
1768 		save_marks(fout, HISTFILE_MARK_SECTION);
1769 		fclose(fout);
1770 #if MSDOS_COMPILER==WIN32C
1771 		/*
1772 		 * Windows rename doesn't remove an existing file,
1773 		 * making it useless for atomic operations. Sigh.
1774 		 */
1775 		remove(histname);
1776 #endif
1777 		rename(tempname, histname);
1778 	}
1779 	free(tempname);
1780 	free(histname);
1781 #endif /* CMD_HISTORY */
1782 }
1783