xref: /freebsd/contrib/less/lesskey.c (revision 7cc42f6d25ef2e19059d088fa7d4853fe9afefb5)
1 /*
2  * Copyright (C) 1984-2019  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  *	lesskey [-o output] [input]
13  *
14  * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
15  *
16  *	Make a .less file.
17  *	If no input file is specified, standard input is used.
18  *	If no output file is specified, $HOME/.less is used.
19  *
20  *	The .less file is used to specify (to "less") user-defined
21  *	key bindings.  Basically any sequence of 1 to MAX_CMDLEN
22  *	keystrokes may be bound to an existing less function.
23  *
24  * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
25  *
26  *	The input file is an ascii file consisting of a
27  *	sequence of lines of the form:
28  *		string <whitespace> action [chars] <newline>
29  *
30  *	"string" is a sequence of command characters which form
31  *		the new user-defined command.  The command
32  *		characters may be:
33  *		1. The actual character itself.
34  *		2. A character preceded by ^ to specify a
35  *		   control character (e.g. ^X means control-X).
36  *		3. A backslash followed by one to three octal digits
37  *		   to specify a character by its octal value.
38  *		4. A backslash followed by b, e, n, r or t
39  *		   to specify \b, ESC, \n, \r or \t, respectively.
40  *		5. Any character (other than those mentioned above) preceded
41  *		   by a \ to specify the character itself (characters which
42  *		   must be preceded by \ include ^, \, and whitespace.
43  *	"action" is the name of a "less" action, from the table below.
44  *	"chars" is an optional sequence of characters which is treated
45  *		as keyboard input after the command is executed.
46  *
47  *	Blank lines and lines which start with # are ignored,
48  *	except for the special control lines:
49  *		#command	Signals the beginning of the command
50  *				keys section.
51  *		#line-edit	Signals the beginning of the line-editing
52  *				keys section.
53  *		#env		Signals the beginning of the environment
54  *				variable section.
55  *		#stop		Stops command parsing in less;
56  *				causes all default keys to be disabled.
57  *
58  * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
59  *
60  *	The output file is a non-ascii file, consisting of a header,
61  *	one or more sections, and a trailer.
62  *	Each section begins with a section header, a section length word
63  *	and the section data.  Normally there are three sections:
64  *		CMD_SECTION	Definition of command keys.
65  *		EDIT_SECTION	Definition of editing keys.
66  *		END_SECTION	A special section header, with no
67  *				length word or section data.
68  *
69  *	Section data consists of zero or more byte sequences of the form:
70  *		string <0> <action>
71  *	or
72  *		string <0> <action|A_EXTRA> chars <0>
73  *
74  *	"string" is the command string.
75  *	"<0>" is one null byte.
76  *	"<action>" is one byte containing the action code (the A_xxx value).
77  *	If action is ORed with A_EXTRA, the action byte is followed
78  *		by the null-terminated "chars" string.
79  *
80  * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
81  */
82 
83 #include "less.h"
84 #include "lesskey.h"
85 #include "cmd.h"
86 
87 struct cmdname
88 {
89 	char *cn_name;
90 	int cn_action;
91 };
92 
93 struct cmdname cmdnames[] =
94 {
95 	{ "back-bracket",         A_B_BRACKET },
96 	{ "back-line",            A_B_LINE },
97 	{ "back-line-force",      A_BF_LINE },
98 	{ "back-screen",          A_B_SCREEN },
99 	{ "back-scroll",          A_B_SCROLL },
100 	{ "back-search",          A_B_SEARCH },
101 	{ "back-window",          A_B_WINDOW },
102 	{ "clear-mark",           A_CLRMARK },
103 	{ "debug",                A_DEBUG },
104 	{ "digit",                A_DIGIT },
105 	{ "display-flag",         A_DISP_OPTION },
106 	{ "display-option",       A_DISP_OPTION },
107 	{ "end",                  A_GOEND },
108 	{ "end-scroll",           A_RRSHIFT },
109 	{ "examine",              A_EXAMINE },
110 	{ "filter",               A_FILTER },
111 	{ "first-cmd",            A_FIRSTCMD },
112 	{ "firstcmd",             A_FIRSTCMD },
113 	{ "flush-repaint",        A_FREPAINT },
114 	{ "forw-bracket",         A_F_BRACKET },
115 	{ "forw-forever",         A_F_FOREVER },
116 	{ "forw-until-hilite",    A_F_UNTIL_HILITE },
117 	{ "forw-line",            A_F_LINE },
118 	{ "forw-line-force",      A_FF_LINE },
119 	{ "forw-screen",          A_F_SCREEN },
120 	{ "forw-screen-force",    A_FF_SCREEN },
121 	{ "forw-scroll",          A_F_SCROLL },
122 	{ "forw-search",          A_F_SEARCH },
123 	{ "forw-window",          A_F_WINDOW },
124 	{ "goto-end",             A_GOEND },
125 	{ "goto-end-buffered",    A_GOEND_BUF },
126 	{ "goto-line",            A_GOLINE },
127 	{ "goto-mark",            A_GOMARK },
128 	{ "help",                 A_HELP },
129 	{ "index-file",           A_INDEX_FILE },
130 	{ "invalid",              A_UINVALID },
131 	{ "left-scroll",          A_LSHIFT },
132 	{ "next-file",            A_NEXT_FILE },
133 	{ "next-tag",             A_NEXT_TAG },
134 	{ "noaction",             A_NOACTION },
135 	{ "no-scroll",            A_LLSHIFT },
136 	{ "percent",              A_PERCENT },
137 	{ "pipe",                 A_PIPE },
138 	{ "prev-file",            A_PREV_FILE },
139 	{ "prev-tag",             A_PREV_TAG },
140 	{ "quit",                 A_QUIT },
141 	{ "remove-file",          A_REMOVE_FILE },
142 	{ "repaint",              A_REPAINT },
143 	{ "repaint-flush",        A_FREPAINT },
144 	{ "repeat-search",        A_AGAIN_SEARCH },
145 	{ "repeat-search-all",    A_T_AGAIN_SEARCH },
146 	{ "reverse-search",       A_REVERSE_SEARCH },
147 	{ "reverse-search-all",   A_T_REVERSE_SEARCH },
148 	{ "right-scroll",         A_RSHIFT },
149 	{ "set-mark",             A_SETMARK },
150 	{ "set-mark-bottom",      A_SETMARKBOT },
151 	{ "shell",                A_SHELL },
152 	{ "status",               A_STAT },
153 	{ "toggle-flag",          A_OPT_TOGGLE },
154 	{ "toggle-option",        A_OPT_TOGGLE },
155 	{ "undo-hilite",          A_UNDO_SEARCH },
156 	{ "version",              A_VERSION },
157 	{ "visual",               A_VISUAL },
158 	{ NULL,   0 }
159 };
160 
161 struct cmdname editnames[] =
162 {
163 	{ "back-complete",	EC_B_COMPLETE },
164 	{ "backspace",		EC_BACKSPACE },
165 	{ "delete",		EC_DELETE },
166 	{ "down",		EC_DOWN },
167 	{ "end",		EC_END },
168 	{ "expand",		EC_EXPAND },
169 	{ "forw-complete",	EC_F_COMPLETE },
170 	{ "home",		EC_HOME },
171 	{ "insert",		EC_INSERT },
172 	{ "invalid",		EC_UINVALID },
173 	{ "kill-line",		EC_LINEKILL },
174 	{ "abort",		EC_ABORT },
175 	{ "left",		EC_LEFT },
176 	{ "literal",		EC_LITERAL },
177 	{ "right",		EC_RIGHT },
178 	{ "up",			EC_UP },
179 	{ "word-backspace",	EC_W_BACKSPACE },
180 	{ "word-delete",	EC_W_DELETE },
181 	{ "word-left",		EC_W_LEFT },
182 	{ "word-right",		EC_W_RIGHT },
183 	{ NULL, 0 }
184 };
185 
186 struct table
187 {
188 	struct cmdname *names;
189 	char *pbuffer;
190 	char buffer[MAX_USERCMD];
191 };
192 
193 struct table cmdtable;
194 struct table edittable;
195 struct table vartable;
196 struct table *currtable = &cmdtable;
197 
198 char fileheader[] = {
199 	C0_LESSKEY_MAGIC,
200 	C1_LESSKEY_MAGIC,
201 	C2_LESSKEY_MAGIC,
202 	C3_LESSKEY_MAGIC
203 };
204 char filetrailer[] = {
205 	C0_END_LESSKEY_MAGIC,
206 	C1_END_LESSKEY_MAGIC,
207 	C2_END_LESSKEY_MAGIC
208 };
209 char cmdsection[1] =	{ CMD_SECTION };
210 char editsection[1] =	{ EDIT_SECTION };
211 char varsection[1] =	{ VAR_SECTION };
212 char endsection[1] =	{ END_SECTION };
213 
214 char *infile = NULL;
215 char *outfile = NULL ;
216 
217 int linenum;
218 int errors;
219 
220 extern char version[];
221 
222 	void
223 usage(VOID_PARAM)
224 {
225 	fprintf(stderr, "usage: lesskey [-o output] [input]\n");
226 	exit(1);
227 }
228 
229 	char *
230 mkpathname(dirname, filename)
231 	char *dirname;
232 	char *filename;
233 {
234 	char *pathname;
235 
236 	pathname = calloc(strlen(dirname) + strlen(filename) + 2, sizeof(char));
237 	strcpy(pathname, dirname);
238 	strcat(pathname, PATHNAME_SEP);
239 	strcat(pathname, filename);
240 	return (pathname);
241 }
242 
243 /*
244  * Figure out the name of a default file (in the user's HOME directory).
245  */
246 	char *
247 homefile(filename)
248 	char *filename;
249 {
250 	char *p;
251 	char *pathname;
252 
253 	if ((p = getenv("HOME")) != NULL && *p != '\0')
254 		pathname = mkpathname(p, filename);
255 #if OS2
256 	else if ((p = getenv("INIT")) != NULL && *p != '\0')
257 		pathname = mkpathname(p, filename);
258 #endif
259 	else
260 	{
261 		fprintf(stderr, "cannot find $HOME - using current directory\n");
262 		pathname = mkpathname(".", filename);
263 	}
264 	return (pathname);
265 }
266 
267 /*
268  * Parse command line arguments.
269  */
270 	void
271 parse_args(argc, argv)
272 	int argc;
273 	char **argv;
274 {
275 	char *arg;
276 
277 	outfile = NULL;
278 	while (--argc > 0)
279 	{
280 		arg = *++argv;
281 		if (arg[0] != '-')
282 			/* Arg does not start with "-"; it's not an option. */
283 			break;
284 		if (arg[1] == '\0')
285 			/* "-" means standard input. */
286 			break;
287 		if (arg[1] == '-' && arg[2] == '\0')
288 		{
289 			/* "--" means end of options. */
290 			argc--;
291 			argv++;
292 			break;
293 		}
294 		switch (arg[1])
295 		{
296 		case '-':
297 			if (strncmp(arg, "--output", 8) == 0)
298 			{
299 				if (arg[8] == '\0')
300 					outfile = &arg[8];
301 				else if (arg[8] == '=')
302 					outfile = &arg[9];
303 				else
304 					usage();
305 				goto opt_o;
306 			}
307 			if (strcmp(arg, "--version") == 0)
308 			{
309 				goto opt_V;
310 			}
311 			usage();
312 			break;
313 		case 'o':
314 			outfile = &argv[0][2];
315 		opt_o:
316 			if (*outfile == '\0')
317 			{
318 				if (--argc <= 0)
319 					usage();
320 				outfile = *(++argv);
321 			}
322 			break;
323 		case 'V':
324 		opt_V:
325 			printf("lesskey  version %s\n", version);
326 			exit(0);
327 		default:
328 			usage();
329 		}
330 	}
331 	if (argc > 1)
332 		usage();
333 	/*
334 	 * Open the input file, or use DEF_LESSKEYINFILE if none specified.
335 	 */
336 	if (argc > 0)
337 		infile = *argv;
338 	else
339 		infile = homefile(DEF_LESSKEYINFILE);
340 }
341 
342 /*
343  * Initialize data structures.
344  */
345 	void
346 init_tables(VOID_PARAM)
347 {
348 	cmdtable.names = cmdnames;
349 	cmdtable.pbuffer = cmdtable.buffer;
350 
351 	edittable.names = editnames;
352 	edittable.pbuffer = edittable.buffer;
353 
354 	vartable.names = NULL;
355 	vartable.pbuffer = vartable.buffer;
356 }
357 
358 /*
359  * Parse one character of a string.
360  */
361 	char *
362 tstr(pp, xlate)
363 	char **pp;
364 	int xlate;
365 {
366 	char *p;
367 	char ch;
368 	int i;
369 	static char buf[10];
370 	static char tstr_control_k[] =
371 		{ SK_SPECIAL_KEY, SK_CONTROL_K, 6, 1, 1, 1, '\0' };
372 
373 	p = *pp;
374 	switch (*p)
375 	{
376 	case '\\':
377 		++p;
378 		switch (*p)
379 		{
380 		case '0': case '1': case '2': case '3':
381 		case '4': case '5': case '6': case '7':
382 			/*
383 			 * Parse an octal number.
384 			 */
385 			ch = 0;
386 			i = 0;
387 			do
388 				ch = 8*ch + (*p - '0');
389 			while (*++p >= '0' && *p <= '7' && ++i < 3);
390 			*pp = p;
391 			if (xlate && ch == CONTROL('K'))
392 				return tstr_control_k;
393 			buf[0] = ch;
394 			buf[1] = '\0';
395 			return (buf);
396 		case 'b':
397 			*pp = p+1;
398 			return ("\b");
399 		case 'e':
400 			*pp = p+1;
401 			buf[0] = ESC;
402 			buf[1] = '\0';
403 			return (buf);
404 		case 'n':
405 			*pp = p+1;
406 			return ("\n");
407 		case 'r':
408 			*pp = p+1;
409 			return ("\r");
410 		case 't':
411 			*pp = p+1;
412 			return ("\t");
413 		case 'k':
414 			if (xlate)
415 			{
416 				switch (*++p)
417 				{
418 				case 'u': ch = SK_UP_ARROW; break;
419 				case 'd': ch = SK_DOWN_ARROW; break;
420 				case 'r': ch = SK_RIGHT_ARROW; break;
421 				case 'l': ch = SK_LEFT_ARROW; break;
422 				case 'U': ch = SK_PAGE_UP; break;
423 				case 'D': ch = SK_PAGE_DOWN; break;
424 				case 'h': ch = SK_HOME; break;
425 				case 'e': ch = SK_END; break;
426 				case 'x': ch = SK_DELETE; break;
427 				default:
428 					error("illegal char after \\k", NULL_PARG);
429 					*pp = p+1;
430 					return ("");
431 				}
432 				*pp = p+1;
433 				buf[0] = SK_SPECIAL_KEY;
434 				buf[1] = ch;
435 				buf[2] = 6;
436 				buf[3] = 1;
437 				buf[4] = 1;
438 				buf[5] = 1;
439 				buf[6] = '\0';
440 				return (buf);
441 			}
442 			/* FALLTHRU */
443 		default:
444 			/*
445 			 * Backslash followed by any other char
446 			 * just means that char.
447 			 */
448 			*pp = p+1;
449 			buf[0] = *p;
450 			buf[1] = '\0';
451 			if (xlate && buf[0] == CONTROL('K'))
452 				return tstr_control_k;
453 			return (buf);
454 		}
455 	case '^':
456 		/*
457 		 * Caret means CONTROL.
458 		 */
459 		*pp = p+2;
460 		buf[0] = CONTROL(p[1]);
461 		buf[1] = '\0';
462 		if (buf[0] == CONTROL('K'))
463 			return tstr_control_k;
464 		return (buf);
465 	}
466 	*pp = p+1;
467 	buf[0] = *p;
468 	buf[1] = '\0';
469 	if (xlate && buf[0] == CONTROL('K'))
470 		return tstr_control_k;
471 	return (buf);
472 }
473 
474 /*
475  * Skip leading spaces in a string.
476  */
477 	public char *
478 skipsp(s)
479 	char *s;
480 {
481 	while (*s == ' ' || *s == '\t')
482 		s++;
483 	return (s);
484 }
485 
486 /*
487  * Skip non-space characters in a string.
488  */
489 	public char *
490 skipnsp(s)
491 	char *s;
492 {
493 	while (*s != '\0' && *s != ' ' && *s != '\t')
494 		s++;
495 	return (s);
496 }
497 
498 /*
499  * Clean up an input line:
500  * strip off the trailing newline & any trailing # comment.
501  */
502 	char *
503 clean_line(s)
504 	char *s;
505 {
506 	int i;
507 
508 	s = skipsp(s);
509 	for (i = 0;  s[i] != '\n' && s[i] != '\r' && s[i] != '\0';  i++)
510 		if (s[i] == '#' && (i == 0 || s[i-1] != '\\'))
511 			break;
512 	s[i] = '\0';
513 	return (s);
514 }
515 
516 /*
517  * Add a byte to the output command table.
518  */
519 	void
520 add_cmd_char(c)
521 	int c;
522 {
523 	if (currtable->pbuffer >= currtable->buffer + MAX_USERCMD)
524 	{
525 		error("too many commands", NULL_PARG);
526 		exit(1);
527 	}
528 	*(currtable->pbuffer)++ = c;
529 }
530 
531 /*
532  * Add a string to the output command table.
533  */
534 	void
535 add_cmd_str(s)
536 	char *s;
537 {
538 	for ( ;  *s != '\0';  s++)
539 		add_cmd_char(*s);
540 }
541 
542 /*
543  * See if we have a special "control" line.
544  */
545 	int
546 control_line(s)
547 	char *s;
548 {
549 #define	PREFIX(str,pat)	(strncmp(str,pat,strlen(pat)) == 0)
550 
551 	if (PREFIX(s, "#line-edit"))
552 	{
553 		currtable = &edittable;
554 		return (1);
555 	}
556 	if (PREFIX(s, "#command"))
557 	{
558 		currtable = &cmdtable;
559 		return (1);
560 	}
561 	if (PREFIX(s, "#env"))
562 	{
563 		currtable = &vartable;
564 		return (1);
565 	}
566 	if (PREFIX(s, "#stop"))
567 	{
568 		add_cmd_char('\0');
569 		add_cmd_char(A_END_LIST);
570 		return (1);
571 	}
572 	return (0);
573 }
574 
575 /*
576  * Output some bytes.
577  */
578 	void
579 fputbytes(fd, buf, len)
580 	FILE *fd;
581 	char *buf;
582 	int len;
583 {
584 	while (len-- > 0)
585 	{
586 		fwrite(buf, sizeof(char), 1, fd);
587 		buf++;
588 	}
589 }
590 
591 /*
592  * Output an integer, in special KRADIX form.
593  */
594 	void
595 fputint(fd, val)
596 	FILE *fd;
597 	unsigned int val;
598 {
599 	char c;
600 
601 	if (val >= KRADIX*KRADIX)
602 	{
603 		fprintf(stderr, "error: integer too big (%d > %d)\n",
604 			val, KRADIX*KRADIX);
605 		exit(1);
606 	}
607 	c = val % KRADIX;
608 	fwrite(&c, sizeof(char), 1, fd);
609 	c = val / KRADIX;
610 	fwrite(&c, sizeof(char), 1, fd);
611 }
612 
613 /*
614  * Find an action, given the name of the action.
615  */
616 	int
617 findaction(actname)
618 	char *actname;
619 {
620 	int i;
621 
622 	for (i = 0;  currtable->names[i].cn_name != NULL;  i++)
623 		if (strcmp(currtable->names[i].cn_name, actname) == 0)
624 			return (currtable->names[i].cn_action);
625 	error("unknown action", NULL_PARG);
626 	return (A_INVALID);
627 }
628 
629 	void
630 error(s, parg)
631 	char *s;
632 	PARG *parg;
633 {
634 	fprintf(stderr, "line %d: %s\n", linenum, s);
635 	errors++;
636 	(void) parg;
637 }
638 
639 
640 	void
641 parse_cmdline(p)
642 	char *p;
643 {
644 	int cmdlen;
645 	char *actname;
646 	int action;
647 	char *s;
648 	char c;
649 
650 	/*
651 	 * Parse the command string and store it in the current table.
652 	 */
653 	cmdlen = 0;
654 	do
655 	{
656 		s = tstr(&p, 1);
657 		cmdlen += (int) strlen(s);
658 		if (cmdlen > MAX_CMDLEN)
659 			error("command too long", NULL_PARG);
660 		else
661 			add_cmd_str(s);
662 	} while (*p != ' ' && *p != '\t' && *p != '\0');
663 	/*
664 	 * Terminate the command string with a null byte.
665 	 */
666 	add_cmd_char('\0');
667 
668 	/*
669 	 * Skip white space between the command string
670 	 * and the action name.
671 	 * Terminate the action name with a null byte.
672 	 */
673 	p = skipsp(p);
674 	if (*p == '\0')
675 	{
676 		error("missing action", NULL_PARG);
677 		return;
678 	}
679 	actname = p;
680 	p = skipnsp(p);
681 	c = *p;
682 	*p = '\0';
683 
684 	/*
685 	 * Parse the action name and store it in the current table.
686 	 */
687 	action = findaction(actname);
688 
689 	/*
690 	 * See if an extra string follows the action name.
691 	 */
692 	*p = c;
693 	p = skipsp(p);
694 	if (*p == '\0')
695 	{
696 		add_cmd_char(action);
697 	} else
698 	{
699 		/*
700 		 * OR the special value A_EXTRA into the action byte.
701 		 * Put the extra string after the action byte.
702 		 */
703 		add_cmd_char(action | A_EXTRA);
704 		while (*p != '\0')
705 			add_cmd_str(tstr(&p, 0));
706 		add_cmd_char('\0');
707 	}
708 }
709 
710 	void
711 parse_varline(p)
712 	char *p;
713 {
714 	char *s;
715 
716 	do
717 	{
718 		s = tstr(&p, 0);
719 		add_cmd_str(s);
720 	} while (*p != ' ' && *p != '\t' && *p != '=' && *p != '\0');
721 	/*
722 	 * Terminate the variable name with a null byte.
723 	 */
724 	add_cmd_char('\0');
725 
726 	p = skipsp(p);
727 	if (*p++ != '=')
728 	{
729 		error("missing =", NULL_PARG);
730 		return;
731 	}
732 
733 	add_cmd_char(EV_OK|A_EXTRA);
734 
735 	p = skipsp(p);
736 	while (*p != '\0')
737 	{
738 		s = tstr(&p, 0);
739 		add_cmd_str(s);
740 	}
741 	add_cmd_char('\0');
742 }
743 
744 /*
745  * Parse a line from the lesskey file.
746  */
747 	void
748 parse_line(line)
749 	char *line;
750 {
751 	char *p;
752 
753 	/*
754 	 * See if it is a control line.
755 	 */
756 	if (control_line(line))
757 		return;
758 	/*
759 	 * Skip leading white space.
760 	 * Replace the final newline with a null byte.
761 	 * Ignore blank lines and comments.
762 	 */
763 	p = clean_line(line);
764 	if (*p == '\0')
765 		return;
766 
767 	if (currtable == &vartable)
768 		parse_varline(p);
769 	else
770 		parse_cmdline(p);
771 }
772 
773 	int
774 main(argc, argv)
775 	int argc;
776 	char *argv[];
777 {
778 	FILE *desc;
779 	FILE *out;
780 	char line[1024];
781 
782 #ifdef WIN32
783 	if (getenv("HOME") == NULL)
784 	{
785 		/*
786 		 * If there is no HOME environment variable,
787 		 * try the concatenation of HOMEDRIVE + HOMEPATH.
788 		 */
789 		char *drive = getenv("HOMEDRIVE");
790 		char *path  = getenv("HOMEPATH");
791 		if (drive != NULL && path != NULL)
792 		{
793 			char *env = (char *) calloc(strlen(drive) +
794 					strlen(path) + 6, sizeof(char));
795 			strcpy(env, "HOME=");
796 			strcat(env, drive);
797 			strcat(env, path);
798 			putenv(env);
799 		}
800 	}
801 #endif /* WIN32 */
802 
803 	/*
804 	 * Process command line arguments.
805 	 */
806 	parse_args(argc, argv);
807 	init_tables();
808 
809 	/*
810 	 * Open the input file.
811 	 */
812 	if (strcmp(infile, "-") == 0)
813 		desc = stdin;
814 	else if ((desc = fopen(infile, "r")) == NULL)
815 	{
816 #if HAVE_PERROR
817 		perror(infile);
818 #else
819 		fprintf(stderr, "Cannot open %s\n", infile);
820 #endif
821 		usage();
822 	}
823 
824 	/*
825 	 * Read and parse the input file, one line at a time.
826 	 */
827 	errors = 0;
828 	linenum = 0;
829 	while (fgets(line, sizeof(line), desc) != NULL)
830 	{
831 		++linenum;
832 		parse_line(line);
833 	}
834 
835 	/*
836 	 * Write the output file.
837 	 * If no output file was specified, use "$HOME/.less"
838 	 */
839 	if (errors > 0)
840 	{
841 		fprintf(stderr, "%d errors; no output produced\n", errors);
842 		exit(1);
843 	}
844 
845 	if (outfile == NULL)
846 		outfile = getenv("LESSKEY");
847 	if (outfile == NULL)
848 		outfile = homefile(LESSKEYFILE);
849 	if ((out = fopen(outfile, "wb")) == NULL)
850 	{
851 #if HAVE_PERROR
852 		perror(outfile);
853 #else
854 		fprintf(stderr, "Cannot open %s\n", outfile);
855 #endif
856 		exit(1);
857 	}
858 
859 	/* File header */
860 	fputbytes(out, fileheader, sizeof(fileheader));
861 
862 	/* Command key section */
863 	fputbytes(out, cmdsection, sizeof(cmdsection));
864 	fputint(out, cmdtable.pbuffer - cmdtable.buffer);
865 	fputbytes(out, (char *)cmdtable.buffer, cmdtable.pbuffer-cmdtable.buffer);
866 	/* Edit key section */
867 	fputbytes(out, editsection, sizeof(editsection));
868 	fputint(out, edittable.pbuffer - edittable.buffer);
869 	fputbytes(out, (char *)edittable.buffer, edittable.pbuffer-edittable.buffer);
870 
871 	/* Environment variable section */
872 	fputbytes(out, varsection, sizeof(varsection));
873 	fputint(out, vartable.pbuffer - vartable.buffer);
874 	fputbytes(out, (char *)vartable.buffer, vartable.pbuffer-vartable.buffer);
875 
876 	/* File trailer */
877 	fputbytes(out, endsection, sizeof(endsection));
878 	fputbytes(out, filetrailer, sizeof(filetrailer));
879 	return (0);
880 }
881