xref: /netbsd-src/lib/libc/time/zic.c (revision dc306354b0b29af51801a7632f1e95265a68cd81)
1 /*	$NetBSD: zic.c,v 1.14 1998/10/04 19:27:55 kleink Exp $	*/
2 
3 #include <sys/cdefs.h>
4 #ifndef lint
5 #ifndef NOID
6 #if 0
7 static char	elsieid[] = "@(#)zic.c	7.95";
8 #else
9 __RCSID("$NetBSD: zic.c,v 1.14 1998/10/04 19:27:55 kleink Exp $");
10 #endif
11 #endif /* !defined NOID */
12 #endif /* !defined lint */
13 
14 #include "private.h"
15 #include "locale.h"
16 #include "tzfile.h"
17 #include "sys/stat.h"			/* for umask manifest constants */
18 #include "unistd.h"
19 
20 /*
21 ** On some ancient hosts, predicates like `isspace(C)' are defined
22 ** only if isascii(C) || C == EOF.  Modern hosts obey the C Standard,
23 ** which says they are defined only if C == ((unsigned char) C) || C == EOF.
24 ** Neither the C Standard nor Posix require that `isascii' exist.
25 ** For portability, we check both ancient and modern requirements.
26 ** If isascii is not defined, the isascii check succeeds trivially.
27 */
28 #include "ctype.h"
29 #ifndef isascii
30 #define isascii(x) 1
31 #endif
32 
33 struct rule {
34 	const char *	r_filename;
35 	int		r_linenum;
36 	const char *	r_name;
37 
38 	int		r_loyear;	/* for example, 1986 */
39 	int		r_hiyear;	/* for example, 1986 */
40 	const char *	r_yrtype;
41 
42 	int		r_month;	/* 0..11 */
43 
44 	int		r_dycode;	/* see below */
45 	int		r_dayofmonth;
46 	int		r_wday;
47 
48 	long		r_tod;		/* time from midnight */
49 	int		r_todisstd;	/* above is standard time if TRUE */
50 					/* or wall clock time if FALSE */
51 	int		r_todisgmt;	/* above is GMT if TRUE */
52 					/* or local time if FALSE */
53 	long		r_stdoff;	/* offset from standard time */
54 	const char *	r_abbrvar;	/* variable part of abbreviation */
55 
56 	int		r_todo;		/* a rule to do (used in outzone) */
57 	time_t		r_temp;		/* used in outzone */
58 };
59 
60 /*
61 **	r_dycode		r_dayofmonth	r_wday
62 */
63 
64 #define DC_DOM		0	/* 1..31 */	/* unused */
65 #define DC_DOWGEQ	1	/* 1..31 */	/* 0..6 (Sun..Sat) */
66 #define DC_DOWLEQ	2	/* 1..31 */	/* 0..6 (Sun..Sat) */
67 
68 struct zone {
69 	const char *	z_filename;
70 	int		z_linenum;
71 
72 	const char *	z_name;
73 	long		z_gmtoff;
74 	const char *	z_rule;
75 	const char *	z_format;
76 
77 	long		z_stdoff;
78 
79 	struct rule *	z_rules;
80 	int		z_nrules;
81 
82 	struct rule	z_untilrule;
83 	time_t		z_untiltime;
84 };
85 
86 extern int	getopt P((int argc, char * const argv[],
87 			const char * options));
88 extern int	link P((const char * fromname, const char * toname));
89 extern char *	optarg;
90 extern int	optind;
91 
92 static int	atcomp P((const void *, const void *));
93 static void	addtt P((time_t starttime, int type));
94 static int	addtype P((long gmtoff, const char * abbr, int isdst,
95 				int ttisstd, int ttisgmt));
96 static void	leapadd P((time_t t, int positive, int rolling, int count));
97 static void	adjleap P((void));
98 static void	associate P((void));
99 static int	ciequal P((const char * ap, const char * bp));
100 static void	convert P((long val, char * buf));
101 static void	dolink P((const char * fromfile, const char * tofile));
102 static void	doabbr P((char * abbr, int abbrlen, const char * format,
103 			const char * letters, int isdst));
104 static void	eat P((const char * name, int num));
105 static void	eats P((const char * name, int num,
106 			const char * rname, int rnum));
107 static long	eitol P((int i));
108 static void	error P((const char * message));
109 static char **	getfields P((char * buf));
110 static long	gethms P((const char * string, const char * errstrng,
111 			int signable));
112 static void	infile P((const char * filename));
113 static void	inleap P((char ** fields, int nfields));
114 static void	inlink P((char ** fields, int nfields));
115 static void	inrule P((char ** fields, int nfields));
116 static int	inzcont P((char ** fields, int nfields));
117 static int	inzone P((char ** fields, int nfields));
118 static int	inzsub P((char ** fields, int nfields, int iscont));
119 static int	itsabbr P((const char * abbr, const char * word));
120 static int	itsdir P((const char * name));
121 static int	lowerit P((int c));
122 int		main P((int, char **));
123 static char *	memcheck P((char * tocheck));
124 static int	mkdirs P((char * filename));
125 static void	newabbr P((const char * abbr));
126 static long	oadd P((long t1, long t2));
127 static void	outzone P((const struct zone * zp, int ntzones));
128 static void	puttzcode P((long code, FILE * fp));
129 static int	rcomp P((const void * leftp, const void * rightp));
130 static time_t	rpytime P((const struct rule * rp, int wantedy));
131 static void	rulesub P((struct rule * rp,
132 			const char * loyearp, const char * hiyearp,
133 			const char * typep, const char * monthp,
134 			const char * dayp, const char * timep));
135 static void	setboundaries P((void));
136 static time_t	tadd P((time_t t1, long t2));
137 static void	usage P((void));
138 static void	warning P((const char * const));
139 static void	writezone P((const char * name));
140 static int	yearistype P((int year, const char * type));
141 
142 #if !(HAVE_STRERROR - 0)
143 static char *	strerror P((int));
144 #endif /* !(HAVE_STRERROR - 0) */
145 
146 static int		charcnt;
147 static int		errors;
148 static const char *	filename;
149 static int		leapcnt;
150 static int		linenum;
151 static time_t		max_time;
152 static int		max_year;
153 static int		max_year_representable;
154 static time_t		min_time;
155 static int		min_year;
156 static int		min_year_representable;
157 static int		noise;
158 static const char *	rfilename;
159 static int		rlinenum;
160 static const char *	progname;
161 static int		timecnt;
162 static int		typecnt;
163 
164 /*
165 ** Line codes.
166 */
167 
168 #define LC_RULE		0
169 #define LC_ZONE		1
170 #define LC_LINK		2
171 #define LC_LEAP		3
172 
173 /*
174 ** Which fields are which on a Zone line.
175 */
176 
177 #define ZF_NAME		1
178 #define ZF_GMTOFF	2
179 #define ZF_RULE		3
180 #define ZF_FORMAT	4
181 #define ZF_TILYEAR	5
182 #define ZF_TILMONTH	6
183 #define ZF_TILDAY	7
184 #define ZF_TILTIME	8
185 #define ZONE_MINFIELDS	5
186 #define ZONE_MAXFIELDS	9
187 
188 /*
189 ** Which fields are which on a Zone continuation line.
190 */
191 
192 #define ZFC_GMTOFF	0
193 #define ZFC_RULE	1
194 #define ZFC_FORMAT	2
195 #define ZFC_TILYEAR	3
196 #define ZFC_TILMONTH	4
197 #define ZFC_TILDAY	5
198 #define ZFC_TILTIME	6
199 #define ZONEC_MINFIELDS	3
200 #define ZONEC_MAXFIELDS	7
201 
202 /*
203 ** Which files are which on a Rule line.
204 */
205 
206 #define RF_NAME		1
207 #define RF_LOYEAR	2
208 #define RF_HIYEAR	3
209 #define RF_COMMAND	4
210 #define RF_MONTH	5
211 #define RF_DAY		6
212 #define RF_TOD		7
213 #define RF_STDOFF	8
214 #define RF_ABBRVAR	9
215 #define RULE_FIELDS	10
216 
217 /*
218 ** Which fields are which on a Link line.
219 */
220 
221 #define LF_FROM		1
222 #define LF_TO		2
223 #define LINK_FIELDS	3
224 
225 /*
226 ** Which fields are which on a Leap line.
227 */
228 
229 #define LP_YEAR		1
230 #define LP_MONTH	2
231 #define LP_DAY		3
232 #define LP_TIME		4
233 #define LP_CORR		5
234 #define LP_ROLL		6
235 #define LEAP_FIELDS	7
236 
237 /*
238 ** Year synonyms.
239 */
240 
241 #define YR_MINIMUM	0
242 #define YR_MAXIMUM	1
243 #define YR_ONLY		2
244 
245 static struct rule *	rules;
246 static int		nrules;	/* number of rules */
247 
248 static struct zone *	zones;
249 static int		nzones;	/* number of zones */
250 
251 struct link {
252 	const char *	l_filename;
253 	int		l_linenum;
254 	const char *	l_from;
255 	const char *	l_to;
256 };
257 
258 static struct link *	links;
259 static int		nlinks;
260 
261 struct lookup {
262 	const char *	l_word;
263 	const int	l_value;
264 };
265 
266 static struct lookup const *	byword P((const char * string,
267 					const struct lookup * lp));
268 
269 static struct lookup const	line_codes[] = {
270 	{ "Rule",	LC_RULE },
271 	{ "Zone",	LC_ZONE },
272 	{ "Link",	LC_LINK },
273 	{ "Leap",	LC_LEAP },
274 	{ NULL,		0}
275 };
276 
277 static struct lookup const	mon_names[] = {
278 	{ "January",	TM_JANUARY },
279 	{ "February",	TM_FEBRUARY },
280 	{ "March",	TM_MARCH },
281 	{ "April",	TM_APRIL },
282 	{ "May",	TM_MAY },
283 	{ "June",	TM_JUNE },
284 	{ "July",	TM_JULY },
285 	{ "August",	TM_AUGUST },
286 	{ "September",	TM_SEPTEMBER },
287 	{ "October",	TM_OCTOBER },
288 	{ "November",	TM_NOVEMBER },
289 	{ "December",	TM_DECEMBER },
290 	{ NULL,		0 }
291 };
292 
293 static struct lookup const	wday_names[] = {
294 	{ "Sunday",	TM_SUNDAY },
295 	{ "Monday",	TM_MONDAY },
296 	{ "Tuesday",	TM_TUESDAY },
297 	{ "Wednesday",	TM_WEDNESDAY },
298 	{ "Thursday",	TM_THURSDAY },
299 	{ "Friday",	TM_FRIDAY },
300 	{ "Saturday",	TM_SATURDAY },
301 	{ NULL,		0 }
302 };
303 
304 static struct lookup const	lasts[] = {
305 	{ "last-Sunday",	TM_SUNDAY },
306 	{ "last-Monday",	TM_MONDAY },
307 	{ "last-Tuesday",	TM_TUESDAY },
308 	{ "last-Wednesday",	TM_WEDNESDAY },
309 	{ "last-Thursday",	TM_THURSDAY },
310 	{ "last-Friday",	TM_FRIDAY },
311 	{ "last-Saturday",	TM_SATURDAY },
312 	{ NULL,			0 }
313 };
314 
315 static struct lookup const	begin_years[] = {
316 	{ "minimum",	YR_MINIMUM },
317 	{ "maximum",	YR_MAXIMUM },
318 	{ NULL,		0 }
319 };
320 
321 static struct lookup const	end_years[] = {
322 	{ "minimum",	YR_MINIMUM },
323 	{ "maximum",	YR_MAXIMUM },
324 	{ "only",	YR_ONLY },
325 	{ NULL,		0 }
326 };
327 
328 static struct lookup const	leap_types[] = {
329 	{ "Rolling",	TRUE },
330 	{ "Stationary",	FALSE },
331 	{ NULL,		0 }
332 };
333 
334 static const int	len_months[2][MONSPERYEAR] = {
335 	{ 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 },
336 	{ 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 }
337 };
338 
339 static const int	len_years[2] = {
340 	DAYSPERNYEAR, DAYSPERLYEAR
341 };
342 
343 static struct attype {
344 	time_t		at;
345 	unsigned char	type;
346 }			attypes[TZ_MAX_TIMES];
347 static long		gmtoffs[TZ_MAX_TYPES];
348 static char		isdsts[TZ_MAX_TYPES];
349 static unsigned char	abbrinds[TZ_MAX_TYPES];
350 static char		ttisstds[TZ_MAX_TYPES];
351 static char		ttisgmts[TZ_MAX_TYPES];
352 static char		chars[TZ_MAX_CHARS];
353 static time_t		trans[TZ_MAX_LEAPS];
354 static long		corr[TZ_MAX_LEAPS];
355 static char		roll[TZ_MAX_LEAPS];
356 
357 /*
358 ** Memory allocation.
359 */
360 
361 static char *
362 memcheck(ptr)
363 char * const	ptr;
364 {
365 	if (ptr == NULL) {
366 		const char *e = strerror(errno);
367 
368 		(void) fprintf(stderr, _("%s: Memory exhausted: %s\n"),
369 			progname, e);
370 		(void) exit(EXIT_FAILURE);
371 	}
372 	return ptr;
373 }
374 
375 #define emalloc(size)		memcheck(imalloc(size))
376 #define erealloc(ptr, size)	memcheck(irealloc((ptr), (size)))
377 #define ecpyalloc(ptr)		memcheck(icpyalloc(ptr))
378 #define ecatalloc(oldp, newp)	memcheck(icatalloc((oldp), (newp)))
379 
380 /*
381 ** Error handling.
382 */
383 
384 #if !(HAVE_STRERROR - 0)
385 static char *
386 strerror(errnum)
387 int	errnum;
388 {
389 	extern char *	sys_errlist[];
390 	extern int	sys_nerr;
391 
392 	return (errnum > 0 && errnum <= sys_nerr) ?
393 		sys_errlist[errnum] : "Unknown system error";
394 }
395 #endif /* !(HAVE_STRERROR - 0) */
396 
397 static void
398 eats(name, num, rname, rnum)
399 const char * const	name;
400 const int		num;
401 const char * const	rname;
402 const int		rnum;
403 {
404 	filename = name;
405 	linenum = num;
406 	rfilename = rname;
407 	rlinenum = rnum;
408 }
409 
410 static void
411 eat(name, num)
412 const char * const	name;
413 const int		num;
414 {
415 	eats(name, num, (char *) NULL, -1);
416 }
417 
418 static void
419 error(string)
420 const char * const	string;
421 {
422 	/*
423 	** Match the format of "cc" to allow sh users to
424 	**	zic ... 2>&1 | error -t "*" -v
425 	** on BSD systems.
426 	*/
427 	(void) fprintf(stderr, _("\"%s\", line %d: %s"),
428 		filename, linenum, string);
429 	if (rfilename != NULL)
430 		(void) fprintf(stderr, _(" (rule from \"%s\", line %d)"),
431 			rfilename, rlinenum);
432 	(void) fprintf(stderr, "\n");
433 	++errors;
434 }
435 
436 static void
437 warning(string)
438 const char * const	string;
439 {
440 	char *	cp;
441 
442 	cp = ecpyalloc("warning: ");
443 	cp = ecatalloc(cp, string);
444 	error(cp);
445 	ifree(cp);
446 	--errors;
447 }
448 
449 static void
450 usage P((void))
451 {
452 	(void) fprintf(stderr, _("%s: usage is %s [ -s ] [ -v ] [ -l localtime ] [ -p posixrules ] [ -d directory ]\n\t[ -L leapseconds ] [ -y yearistype ] [ filename ... ]\n"),
453 		progname, progname);
454 	(void) exit(EXIT_FAILURE);
455 }
456 
457 static const char *	psxrules;
458 static const char *	lcltime;
459 static const char *	directory;
460 static const char *	leapsec;
461 static const char *	yitcommand;
462 static int		sflag = FALSE;
463 
464 int
465 main(argc, argv)
466 int	argc;
467 char *	argv[];
468 {
469 	register int	i;
470 	register int	j;
471 	register int	c;
472 
473 #ifdef _POSIX_VERSION
474 	(void) umask(umask(S_IWGRP | S_IWOTH) | (S_IWGRP | S_IWOTH));
475 #endif /* defined _POSIX_VERSION */
476 #if HAVE_GETTEXT - 0
477 	(void) setlocale(LC_MESSAGES, "");
478 #ifdef TZ_DOMAINDIR
479 	(void) bindtextdomain(TZ_DOMAIN, TZ_DOMAINDIR);
480 #endif /* defined TEXTDOMAINDIR */
481 	(void) textdomain(TZ_DOMAIN);
482 #endif /* HAVE_GETTEXT - 0 */
483 	progname = argv[0];
484 	while ((c = getopt(argc, argv, "d:l:p:L:vsy:")) != EOF && c != -1)
485 		switch (c) {
486 			default:
487 				usage();
488 			case 'd':
489 				if (directory == NULL)
490 					directory = optarg;
491 				else {
492 					(void) fprintf(stderr,
493 _("%s: More than one -d option specified\n"),
494 						progname);
495 					(void) exit(EXIT_FAILURE);
496 				}
497 				break;
498 			case 'l':
499 				if (lcltime == NULL)
500 					lcltime = optarg;
501 				else {
502 					(void) fprintf(stderr,
503 _("%s: More than one -l option specified\n"),
504 						progname);
505 					(void) exit(EXIT_FAILURE);
506 				}
507 				break;
508 			case 'p':
509 				if (psxrules == NULL)
510 					psxrules = optarg;
511 				else {
512 					(void) fprintf(stderr,
513 _("%s: More than one -p option specified\n"),
514 						progname);
515 					(void) exit(EXIT_FAILURE);
516 				}
517 				break;
518 			case 'y':
519 				if (yitcommand == NULL)
520 					yitcommand = optarg;
521 				else {
522 					(void) fprintf(stderr,
523 _("%s: More than one -y option specified\n"),
524 						progname);
525 					(void) exit(EXIT_FAILURE);
526 				}
527 				break;
528 			case 'L':
529 				if (leapsec == NULL)
530 					leapsec = optarg;
531 				else {
532 					(void) fprintf(stderr,
533 _("%s: More than one -L option specified\n"),
534 						progname);
535 					(void) exit(EXIT_FAILURE);
536 				}
537 				break;
538 			case 'v':
539 				noise = TRUE;
540 				break;
541 			case 's':
542 				sflag = TRUE;
543 				break;
544 		}
545 	if (optind == argc - 1 && strcmp(argv[optind], "=") == 0)
546 		usage();	/* usage message by request */
547 	if (directory == NULL)
548 		directory = TZDIR;
549 	if (yitcommand == NULL)
550 		yitcommand = "yearistype";
551 
552 	setboundaries();
553 
554 	if (optind < argc && leapsec != NULL) {
555 		infile(leapsec);
556 		adjleap();
557 	}
558 
559 	for (i = optind; i < argc; ++i)
560 		infile(argv[i]);
561 	if (errors)
562 		(void) exit(EXIT_FAILURE);
563 	associate();
564 	for (i = 0; i < nzones; i = j) {
565 		/*
566 		** Find the next non-continuation zone entry.
567 		*/
568 		for (j = i + 1; j < nzones && zones[j].z_name == NULL; ++j)
569 			continue;
570 		outzone(&zones[i], j - i);
571 	}
572 	/*
573 	** Make links.
574 	*/
575 	for (i = 0; i < nlinks; ++i)
576 		dolink(links[i].l_from, links[i].l_to);
577 	if (lcltime != NULL)
578 		dolink(lcltime, TZDEFAULT);
579 	if (psxrules != NULL)
580 		dolink(psxrules, TZDEFRULES);
581 	return (errors == 0) ? EXIT_SUCCESS : EXIT_FAILURE;
582 }
583 
584 static void
585 dolink(fromfile, tofile)
586 const char * const	fromfile;
587 const char * const	tofile;
588 {
589 	register char *	fromname;
590 	register char *	toname;
591 
592 	if (fromfile[0] == '/')
593 		fromname = ecpyalloc(fromfile);
594 	else {
595 		fromname = ecpyalloc(directory);
596 		fromname = ecatalloc(fromname, "/");
597 		fromname = ecatalloc(fromname, fromfile);
598 	}
599 	if (tofile[0] == '/')
600 		toname = ecpyalloc(tofile);
601 	else {
602 		toname = ecpyalloc(directory);
603 		toname = ecatalloc(toname, "/");
604 		toname = ecatalloc(toname, tofile);
605 	}
606 	/*
607 	** We get to be careful here since
608 	** there's a fair chance of root running us.
609 	*/
610 	if (!itsdir(toname))
611 		(void) remove(toname);
612 	if (link(fromname, toname) != 0) {
613 		int	result;
614 
615 		if (mkdirs(toname) != 0)
616 			(void) exit(EXIT_FAILURE);
617 		result = link(fromname, toname);
618 #if (HAVE_SYMLINK - 0)
619 		if (result != 0) {
620 			result = symlink(fromname, toname);
621 			if (result == 0)
622 warning(_("hard link failed, symbolic link used"));
623 		}
624 #endif
625 		if (result != 0) {
626 			const char *e = strerror(errno);
627 
628 			(void) fprintf(stderr,
629 				_("%s: Can't link from %s to %s: %s\n"),
630 				progname, fromname, toname, e);
631 			(void) exit(EXIT_FAILURE);
632 		}
633 	}
634 	ifree(fromname);
635 	ifree(toname);
636 }
637 
638 #ifndef INT_MAX
639 #define INT_MAX	((int) (((unsigned)~0)>>1))
640 #endif /* !defined INT_MAX */
641 
642 #ifndef INT_MIN
643 #define INT_MIN	((int) ~(((unsigned)~0)>>1))
644 #endif /* !defined INT_MIN */
645 
646 /*
647 ** The tz file format currently allows at most 32-bit quantities.
648 ** This restriction should be removed before signed 32-bit values
649 ** wrap around in 2038, but unfortunately this will require a
650 ** change to the tz file format.
651 */
652 
653 #define MAX_BITS_IN_FILE	32
654 #define TIME_T_BITS_IN_FILE	((TYPE_BIT(time_t) < MAX_BITS_IN_FILE) ? TYPE_BIT(time_t) : MAX_BITS_IN_FILE)
655 
656 static void
657 setboundaries P((void))
658 {
659 	if (TYPE_SIGNED(time_t)) {
660 		min_time = ~ (time_t) 0;
661 		min_time <<= TIME_T_BITS_IN_FILE - 1;
662 		max_time = ~ (time_t) 0 - min_time;
663 		if (sflag)
664 			min_time = 0;
665 	} else {
666 		min_time = 0;
667 		max_time = 2 - sflag;
668 		max_time <<= TIME_T_BITS_IN_FILE - 1;
669 		--max_time;
670 	}
671 	min_year = TM_YEAR_BASE + gmtime(&min_time)->tm_year;
672 	max_year = TM_YEAR_BASE + gmtime(&max_time)->tm_year;
673 	min_year_representable = min_year;
674 	max_year_representable = max_year;
675 }
676 
677 static int
678 itsdir(name)
679 const char * const	name;
680 {
681 	register char *	myname;
682 	register int	accres;
683 
684 	myname = ecpyalloc(name);
685 	myname = ecatalloc(myname, "/.");
686 	accres = access(myname, F_OK);
687 	ifree(myname);
688 	return accres == 0;
689 }
690 
691 /*
692 ** Associate sets of rules with zones.
693 */
694 
695 /*
696 ** Sort by rule name.
697 */
698 
699 static int
700 rcomp(cp1, cp2)
701 const void *	cp1;
702 const void *	cp2;
703 {
704 	return strcmp(((const struct rule *) cp1)->r_name,
705 		((const struct rule *) cp2)->r_name);
706 }
707 
708 static void
709 associate P((void))
710 {
711 	register struct zone *	zp;
712 	register struct rule *	rp;
713 	register int		base, out;
714 	register int		i, j;
715 
716 	if (nrules != 0) {
717 		(void) qsort((void *) rules, (size_t) nrules,
718 			(size_t) sizeof *rules, rcomp);
719 		for (i = 0; i < nrules - 1; ++i) {
720 			if (strcmp(rules[i].r_name,
721 				rules[i + 1].r_name) != 0)
722 					continue;
723 			if (strcmp(rules[i].r_filename,
724 				rules[i + 1].r_filename) == 0)
725 					continue;
726 			eat(rules[i].r_filename, rules[i].r_linenum);
727 			warning(_("same rule name in multiple files"));
728 			eat(rules[i + 1].r_filename, rules[i + 1].r_linenum);
729 			warning(_("same rule name in multiple files"));
730 			for (j = i + 2; j < nrules; ++j) {
731 				if (strcmp(rules[i].r_name,
732 					rules[j].r_name) != 0)
733 						break;
734 				if (strcmp(rules[i].r_filename,
735 					rules[j].r_filename) == 0)
736 						continue;
737 				if (strcmp(rules[i + 1].r_filename,
738 					rules[j].r_filename) == 0)
739 						continue;
740 				break;
741 			}
742 			i = j - 1;
743 		}
744 	}
745 	for (i = 0; i < nzones; ++i) {
746 		zp = &zones[i];
747 		zp->z_rules = NULL;
748 		zp->z_nrules = 0;
749 	}
750 	for (base = 0; base < nrules; base = out) {
751 		rp = &rules[base];
752 		for (out = base + 1; out < nrules; ++out)
753 			if (strcmp(rp->r_name, rules[out].r_name) != 0)
754 				break;
755 		for (i = 0; i < nzones; ++i) {
756 			zp = &zones[i];
757 			if (strcmp(zp->z_rule, rp->r_name) != 0)
758 				continue;
759 			zp->z_rules = rp;
760 			zp->z_nrules = out - base;
761 		}
762 	}
763 	for (i = 0; i < nzones; ++i) {
764 		zp = &zones[i];
765 		if (zp->z_nrules == 0) {
766 			/*
767 			** Maybe we have a local standard time offset.
768 			*/
769 			eat(zp->z_filename, zp->z_linenum);
770 			zp->z_stdoff = gethms(zp->z_rule, _("unruly zone"),
771 					      TRUE);
772 			/*
773 			** Note, though, that if there's no rule,
774 			** a '%s' in the format is a bad thing.
775 			*/
776 			if (strchr(zp->z_format, '%') != 0)
777 				error(_("%s in ruleless zone"));
778 		}
779 	}
780 	if (errors)
781 		(void) exit(EXIT_FAILURE);
782 }
783 
784 static void
785 infile(name)
786 const char *	name;
787 {
788 	register FILE *			fp;
789 	register char **		fields;
790 	register char *			cp;
791 	register const struct lookup *	lp;
792 	register int			nfields;
793 	register int			wantcont;
794 	register int			num;
795 	char				buf[BUFSIZ];
796 
797 	if (strcmp(name, "-") == 0) {
798 		name = _("standard input");
799 		fp = stdin;
800 	} else if ((fp = fopen(name, "r")) == NULL) {
801 		const char *e = strerror(errno);
802 
803 		(void) fprintf(stderr, _("%s: Can't open %s: %s\n"),
804 			progname, name, e);
805 		(void) exit(EXIT_FAILURE);
806 	}
807 	wantcont = FALSE;
808 	for (num = 1; ; ++num) {
809 		eat(name, num);
810 		if (fgets(buf, (int) sizeof buf, fp) != buf)
811 			break;
812 		cp = strchr(buf, '\n');
813 		if (cp == NULL) {
814 			error(_("line too long"));
815 			(void) exit(EXIT_FAILURE);
816 		}
817 		*cp = '\0';
818 		fields = getfields(buf);
819 		nfields = 0;
820 		while (fields[nfields] != NULL) {
821 			static char	nada;
822 
823 			if (strcmp(fields[nfields], "-") == 0)
824 				fields[nfields] = &nada;
825 			++nfields;
826 		}
827 		if (nfields == 0) {
828 			/* nothing to do */
829 		} else if (wantcont) {
830 			wantcont = inzcont(fields, nfields);
831 		} else {
832 			lp = byword(fields[0], line_codes);
833 			if (lp == NULL)
834 				error(_("input line of unknown type"));
835 			else switch ((int) (lp->l_value)) {
836 				case LC_RULE:
837 					inrule(fields, nfields);
838 					wantcont = FALSE;
839 					break;
840 				case LC_ZONE:
841 					wantcont = inzone(fields, nfields);
842 					break;
843 				case LC_LINK:
844 					inlink(fields, nfields);
845 					wantcont = FALSE;
846 					break;
847 				case LC_LEAP:
848 					if (name != leapsec)
849 						(void) fprintf(stderr,
850 _("%s: Leap line in non leap seconds file %s\n"),
851 							progname, name);
852 					else	inleap(fields, nfields);
853 					wantcont = FALSE;
854 					break;
855 				default:	/* "cannot happen" */
856 					(void) fprintf(stderr,
857 _("%s: panic: Invalid l_value %d\n"),
858 						progname, lp->l_value);
859 					(void) exit(EXIT_FAILURE);
860 			}
861 		}
862 		ifree((char *) fields);
863 	}
864 	if (ferror(fp)) {
865 		(void) fprintf(stderr, _("%s: Error reading %s\n"),
866 			progname, filename);
867 		(void) exit(EXIT_FAILURE);
868 	}
869 	if (fp != stdin && fclose(fp)) {
870 		const char *e = strerror(errno);
871 
872 		(void) fprintf(stderr, _("%s: Error closing %s: %s\n"),
873 			progname, filename, e);
874 		(void) exit(EXIT_FAILURE);
875 	}
876 	if (wantcont)
877 		error(_("expected continuation line not found"));
878 }
879 
880 /*
881 ** Convert a string of one of the forms
882 **	h	-h	hh:mm	-hh:mm	hh:mm:ss	-hh:mm:ss
883 ** into a number of seconds.
884 ** A null string maps to zero.
885 ** Call error with errstring and return zero on errors.
886 */
887 
888 static long
889 gethms(string, errstring, signable)
890 const char *		string;
891 const char * const	errstring;
892 const int		signable;
893 {
894 	int	hh, mm, ss, sign;
895 
896 	if (string == NULL || *string == '\0')
897 		return 0;
898 	if (!signable)
899 		sign = 1;
900 	else if (*string == '-') {
901 		sign = -1;
902 		++string;
903 	} else	sign = 1;
904 	if (sscanf(string, scheck(string, "%d"), &hh) == 1)
905 		mm = ss = 0;
906 	else if (sscanf(string, scheck(string, "%d:%d"), &hh, &mm) == 2)
907 		ss = 0;
908 	else if (sscanf(string, scheck(string, "%d:%d:%d"),
909 		&hh, &mm, &ss) != 3) {
910 			error(errstring);
911 			return 0;
912 	}
913 	if ((hh < 0 || hh >= HOURSPERDAY ||
914 		mm < 0 || mm >= MINSPERHOUR ||
915 		ss < 0 || ss > SECSPERMIN) &&
916 		!(hh == HOURSPERDAY && mm == 0 && ss == 0)) {
917 			error(errstring);
918 			return 0;
919 	}
920 	return eitol(sign) *
921 		(eitol(hh * MINSPERHOUR + mm) *
922 		eitol(SECSPERMIN) + eitol(ss));
923 }
924 
925 static void
926 inrule(fields, nfields)
927 register char ** const	fields;
928 const int		nfields;
929 {
930 	static struct rule	r;
931 
932 	if (nfields != RULE_FIELDS) {
933 		error(_("wrong number of fields on Rule line"));
934 		return;
935 	}
936 	if (*fields[RF_NAME] == '\0') {
937 		error(_("nameless rule"));
938 		return;
939 	}
940 	r.r_filename = filename;
941 	r.r_linenum = linenum;
942 	r.r_stdoff = gethms(fields[RF_STDOFF], _("invalid saved time"), TRUE);
943 	rulesub(&r, fields[RF_LOYEAR], fields[RF_HIYEAR], fields[RF_COMMAND],
944 		fields[RF_MONTH], fields[RF_DAY], fields[RF_TOD]);
945 	r.r_name = ecpyalloc(fields[RF_NAME]);
946 	r.r_abbrvar = ecpyalloc(fields[RF_ABBRVAR]);
947 	rules = (struct rule *) (void *) erealloc((char *) rules,
948 		(int) ((nrules + 1) * sizeof *rules));
949 	rules[nrules++] = r;
950 }
951 
952 static int
953 inzone(fields, nfields)
954 register char ** const	fields;
955 const int		nfields;
956 {
957 	register int	i;
958 	static char *	buf;
959 
960 	if (nfields < ZONE_MINFIELDS || nfields > ZONE_MAXFIELDS) {
961 		error(_("wrong number of fields on Zone line"));
962 		return FALSE;
963 	}
964 	if (strcmp(fields[ZF_NAME], TZDEFAULT) == 0 && lcltime != NULL) {
965 		buf = erealloc(buf, (int) (132 + strlen(TZDEFAULT)));
966 		(void)sprintf(buf,	/* XXX: sprintf is safe */
967 _("\"Zone %s\" line and -l option are mutually exclusive"),
968 			TZDEFAULT);
969 		error(buf);
970 		return FALSE;
971 	}
972 	if (strcmp(fields[ZF_NAME], TZDEFRULES) == 0 && psxrules != NULL) {
973 		buf = erealloc(buf, (int) (132 + strlen(TZDEFRULES)));
974 		(void)sprintf(buf,	/* XXX: sprintf is safe */
975 _("\"Zone %s\" line and -p option are mutually exclusive"),
976 			TZDEFRULES);
977 		error(buf);
978 		return FALSE;
979 	}
980 	for (i = 0; i < nzones; ++i)
981 		if (zones[i].z_name != NULL &&
982 			strcmp(zones[i].z_name, fields[ZF_NAME]) == 0) {
983 				buf = erealloc(buf, (int) (132 +
984 					strlen(fields[ZF_NAME]) +
985 					strlen(zones[i].z_filename)));
986 				(void)sprintf(buf,	/* XXX: sprintf is safe */
987 _("duplicate zone name %s (file \"%s\", line %d)"),
988 					fields[ZF_NAME],
989 					zones[i].z_filename,
990 					zones[i].z_linenum);
991 				error(buf);
992 				return FALSE;
993 		}
994 	return inzsub(fields, nfields, FALSE);
995 }
996 
997 static int
998 inzcont(fields, nfields)
999 register char ** const	fields;
1000 const int		nfields;
1001 {
1002 	if (nfields < ZONEC_MINFIELDS || nfields > ZONEC_MAXFIELDS) {
1003 		error(_("wrong number of fields on Zone continuation line"));
1004 		return FALSE;
1005 	}
1006 	return inzsub(fields, nfields, TRUE);
1007 }
1008 
1009 static int
1010 inzsub(fields, nfields, iscont)
1011 register char ** const	fields;
1012 const int		nfields;
1013 const int		iscont;
1014 {
1015 	register char *		cp;
1016 	static struct zone	z;
1017 	register int		i_gmtoff, i_rule, i_format;
1018 	register int		i_untilyear, i_untilmonth;
1019 	register int		i_untilday, i_untiltime;
1020 	register int		hasuntil;
1021 
1022 	if (iscont) {
1023 		i_gmtoff = ZFC_GMTOFF;
1024 		i_rule = ZFC_RULE;
1025 		i_format = ZFC_FORMAT;
1026 		i_untilyear = ZFC_TILYEAR;
1027 		i_untilmonth = ZFC_TILMONTH;
1028 		i_untilday = ZFC_TILDAY;
1029 		i_untiltime = ZFC_TILTIME;
1030 		z.z_name = NULL;
1031 	} else {
1032 		i_gmtoff = ZF_GMTOFF;
1033 		i_rule = ZF_RULE;
1034 		i_format = ZF_FORMAT;
1035 		i_untilyear = ZF_TILYEAR;
1036 		i_untilmonth = ZF_TILMONTH;
1037 		i_untilday = ZF_TILDAY;
1038 		i_untiltime = ZF_TILTIME;
1039 		z.z_name = ecpyalloc(fields[ZF_NAME]);
1040 	}
1041 	z.z_filename = filename;
1042 	z.z_linenum = linenum;
1043 	z.z_gmtoff = gethms(fields[i_gmtoff], _("invalid UTC offset"), TRUE);
1044 	if ((cp = strchr(fields[i_format], '%')) != 0) {
1045 		if (*++cp != 's' || strchr(cp, '%') != 0) {
1046 			error(_("invalid abbreviation format"));
1047 			return FALSE;
1048 		}
1049 	}
1050 	z.z_rule = ecpyalloc(fields[i_rule]);
1051 	z.z_format = ecpyalloc(fields[i_format]);
1052 	hasuntil = nfields > i_untilyear;
1053 	if (hasuntil) {
1054 		z.z_untilrule.r_filename = filename;
1055 		z.z_untilrule.r_linenum = linenum;
1056 		rulesub(&z.z_untilrule,
1057 			fields[i_untilyear],
1058 			"only",
1059 			"",
1060 			(nfields > i_untilmonth) ?
1061 			fields[i_untilmonth] : "Jan",
1062 			(nfields > i_untilday) ? fields[i_untilday] : "1",
1063 			(nfields > i_untiltime) ? fields[i_untiltime] : "0");
1064 		z.z_untiltime = rpytime(&z.z_untilrule,
1065 			z.z_untilrule.r_loyear);
1066 		if (iscont && nzones > 0 &&
1067 			z.z_untiltime > min_time &&
1068 			z.z_untiltime < max_time &&
1069 			zones[nzones - 1].z_untiltime > min_time &&
1070 			zones[nzones - 1].z_untiltime < max_time &&
1071 			zones[nzones - 1].z_untiltime >= z.z_untiltime) {
1072 				error(_("Zone continuation line end time is not after end time of previous line"));
1073 				return FALSE;
1074 		}
1075 	}
1076 	zones = (struct zone *) (void *) erealloc((char *) zones,
1077 		(int) ((nzones + 1) * sizeof *zones));
1078 	zones[nzones++] = z;
1079 	/*
1080 	** If there was an UNTIL field on this line,
1081 	** there's more information about the zone on the next line.
1082 	*/
1083 	return hasuntil;
1084 }
1085 
1086 static void
1087 inleap(fields, nfields)
1088 register char ** const	fields;
1089 const int		nfields;
1090 {
1091 	register const char *		cp;
1092 	register const struct lookup *	lp;
1093 	register int			i, j;
1094 	int				year, month, day;
1095 	long				dayoff, tod;
1096 	time_t				t;
1097 
1098 	if (nfields != LEAP_FIELDS) {
1099 		error(_("wrong number of fields on Leap line"));
1100 		return;
1101 	}
1102 	dayoff = 0;
1103 	cp = fields[LP_YEAR];
1104 	if (sscanf(cp, scheck(cp, "%d"), &year) != 1) {
1105 			/*
1106 			 * Leapin' Lizards!
1107 			 */
1108 			error(_("invalid leaping year"));
1109 			return;
1110 	}
1111 	j = EPOCH_YEAR;
1112 	while (j != year) {
1113 		if (year > j) {
1114 			i = len_years[isleap(j)];
1115 			++j;
1116 		} else {
1117 			--j;
1118 			i = -len_years[isleap(j)];
1119 		}
1120 		dayoff = oadd(dayoff, eitol(i));
1121 	}
1122 	if ((lp = byword(fields[LP_MONTH], mon_names)) == NULL) {
1123 		error(_("invalid month name"));
1124 		return;
1125 	}
1126 	month = lp->l_value;
1127 	j = TM_JANUARY;
1128 	while (j != month) {
1129 		i = len_months[isleap(year)][j];
1130 		dayoff = oadd(dayoff, eitol(i));
1131 		++j;
1132 	}
1133 	cp = fields[LP_DAY];
1134 	if (sscanf(cp, scheck(cp, "%d"), &day) != 1 ||
1135 		day <= 0 || day > len_months[isleap(year)][month]) {
1136 			error(_("invalid day of month"));
1137 			return;
1138 	}
1139 	dayoff = oadd(dayoff, eitol(day - 1));
1140 	if (dayoff < 0 && !TYPE_SIGNED(time_t)) {
1141 		error(_("time before zero"));
1142 		return;
1143 	}
1144 	t = (time_t) dayoff * SECSPERDAY;
1145 	/*
1146 	** Cheap overflow check.
1147 	*/
1148 	if (t / SECSPERDAY != dayoff) {
1149 		error(_("time overflow"));
1150 		return;
1151 	}
1152 	tod = gethms(fields[LP_TIME], _("invalid time of day"), FALSE);
1153 	cp = fields[LP_CORR];
1154 	{
1155 		register int	positive;
1156 		int		count;
1157 
1158 		if (strcmp(cp, "") == 0) { /* infile() turns "-" into "" */
1159 			positive = FALSE;
1160 			count = 1;
1161 		} else if (strcmp(cp, "--") == 0) {
1162 			positive = FALSE;
1163 			count = 2;
1164 		} else if (strcmp(cp, "+") == 0) {
1165 			positive = TRUE;
1166 			count = 1;
1167 		} else if (strcmp(cp, "++") == 0) {
1168 			positive = TRUE;
1169 			count = 2;
1170 		} else {
1171 			error(_("illegal CORRECTION field on Leap line"));
1172 			return;
1173 		}
1174 		if ((lp = byword(fields[LP_ROLL], leap_types)) == NULL) {
1175 			error(_("illegal Rolling/Stationary field on Leap line"));
1176 			return;
1177 		}
1178 		leapadd(tadd(t, tod), positive, lp->l_value, count);
1179 	}
1180 }
1181 
1182 static void
1183 inlink(fields, nfields)
1184 register char ** const	fields;
1185 const int		nfields;
1186 {
1187 	struct link	l;
1188 
1189 	if (nfields != LINK_FIELDS) {
1190 		error(_("wrong number of fields on Link line"));
1191 		return;
1192 	}
1193 	if (*fields[LF_FROM] == '\0') {
1194 		error(_("blank FROM field on Link line"));
1195 		return;
1196 	}
1197 	if (*fields[LF_TO] == '\0') {
1198 		error(_("blank TO field on Link line"));
1199 		return;
1200 	}
1201 	l.l_filename = filename;
1202 	l.l_linenum = linenum;
1203 	l.l_from = ecpyalloc(fields[LF_FROM]);
1204 	l.l_to = ecpyalloc(fields[LF_TO]);
1205 	links = (struct link *) (void *) erealloc((char *) links,
1206 		(int) ((nlinks + 1) * sizeof *links));
1207 	links[nlinks++] = l;
1208 }
1209 
1210 static void
1211 rulesub(rp, loyearp, hiyearp, typep, monthp, dayp, timep)
1212 register struct rule * const	rp;
1213 const char * const		loyearp;
1214 const char * const		hiyearp;
1215 const char * const		typep;
1216 const char * const		monthp;
1217 const char * const		dayp;
1218 const char * const		timep;
1219 {
1220 	register const struct lookup *	lp;
1221 	register const char *		cp;
1222 	register char *			dp;
1223 	register char *			ep;
1224 
1225 	if ((lp = byword(monthp, mon_names)) == NULL) {
1226 		error(_("invalid month name"));
1227 		return;
1228 	}
1229 	rp->r_month = lp->l_value;
1230 	rp->r_todisstd = FALSE;
1231 	rp->r_todisgmt = FALSE;
1232 	dp = ecpyalloc(timep);
1233 	if (*dp != '\0') {
1234 		ep = dp + strlen(dp) - 1;
1235 		switch (lowerit(*ep)) {
1236 			case 's':	/* Standard */
1237 				rp->r_todisstd = TRUE;
1238 				rp->r_todisgmt = FALSE;
1239 				*ep = '\0';
1240 				break;
1241 			case 'w':	/* Wall */
1242 				rp->r_todisstd = FALSE;
1243 				rp->r_todisgmt = FALSE;
1244 				*ep = '\0';
1245 				break;
1246 			case 'g':	/* Greenwich */
1247 			case 'u':	/* Universal */
1248 			case 'z':	/* Zulu */
1249 				rp->r_todisstd = TRUE;
1250 				rp->r_todisgmt = TRUE;
1251 				*ep = '\0';
1252 				break;
1253 		}
1254 	}
1255 	rp->r_tod = gethms(dp, _("invalid time of day"), FALSE);
1256 	ifree(dp);
1257 	/*
1258 	** Year work.
1259 	*/
1260 	cp = loyearp;
1261 	lp = byword(cp, begin_years);
1262 	if (lp != NULL) switch ((int) lp->l_value) {
1263 		case YR_MINIMUM:
1264 			rp->r_loyear = INT_MIN;
1265 			break;
1266 		case YR_MAXIMUM:
1267 			rp->r_loyear = INT_MAX;
1268 			break;
1269 		default:	/* "cannot happen" */
1270 			(void) fprintf(stderr,
1271 				_("%s: panic: Invalid l_value %d\n"),
1272 				progname, lp->l_value);
1273 			(void) exit(EXIT_FAILURE);
1274 	} else if (sscanf(cp, scheck(cp, "%d"), &rp->r_loyear) != 1) {
1275 		error(_("invalid starting year"));
1276 		return;
1277 	} else if (noise) {
1278 		if (rp->r_loyear < min_year_representable)
1279 			warning(_("starting year too low to be represented"));
1280 		else if (rp->r_loyear > max_year_representable)
1281 			warning(_("starting year too high to be represented"));
1282 	}
1283 	cp = hiyearp;
1284 	if ((lp = byword(cp, end_years)) != NULL) switch ((int) lp->l_value) {
1285 		case YR_MINIMUM:
1286 			rp->r_hiyear = INT_MIN;
1287 			break;
1288 		case YR_MAXIMUM:
1289 			rp->r_hiyear = INT_MAX;
1290 			break;
1291 		case YR_ONLY:
1292 			rp->r_hiyear = rp->r_loyear;
1293 			break;
1294 		default:	/* "cannot happen" */
1295 			(void) fprintf(stderr,
1296 				_("%s: panic: Invalid l_value %d\n"),
1297 				progname, lp->l_value);
1298 			(void) exit(EXIT_FAILURE);
1299 	} else if (sscanf(cp, scheck(cp, "%d"), &rp->r_hiyear) != 1) {
1300 		error(_("invalid ending year"));
1301 		return;
1302 	} else if (noise) {
1303 		if (rp->r_loyear < min_year_representable)
1304 			warning(_("starting year too low to be represented"));
1305 		else if (rp->r_loyear > max_year_representable)
1306 			warning(_("starting year too high to be represented"));
1307 	}
1308 	if (rp->r_loyear > rp->r_hiyear) {
1309 		error(_("starting year greater than ending year"));
1310 		return;
1311 	}
1312 	if (*typep == '\0')
1313 		rp->r_yrtype = NULL;
1314 	else {
1315 		if (rp->r_loyear == rp->r_hiyear) {
1316 			error(_("typed single year"));
1317 			return;
1318 		}
1319 		rp->r_yrtype = ecpyalloc(typep);
1320 	}
1321 	if (rp->r_loyear < min_year && rp->r_loyear > 0)
1322 		min_year = rp->r_loyear;
1323 	/*
1324 	** Day work.
1325 	** Accept things such as:
1326 	**	1
1327 	**	last-Sunday
1328 	**	Sun<=20
1329 	**	Sun>=7
1330 	*/
1331 	dp = ecpyalloc(dayp);
1332 	if ((lp = byword(dp, lasts)) != NULL) {
1333 		rp->r_dycode = DC_DOWLEQ;
1334 		rp->r_wday = lp->l_value;
1335 		rp->r_dayofmonth = len_months[1][rp->r_month];
1336 	} else {
1337 		if ((ep = strchr(dp, '<')) != 0)
1338 			rp->r_dycode = DC_DOWLEQ;
1339 		else if ((ep = strchr(dp, '>')) != 0)
1340 			rp->r_dycode = DC_DOWGEQ;
1341 		else {
1342 			ep = dp;
1343 			rp->r_dycode = DC_DOM;
1344 		}
1345 		if (rp->r_dycode != DC_DOM) {
1346 			*ep++ = 0;
1347 			if (*ep++ != '=') {
1348 				error(_("invalid day of month"));
1349 				ifree(dp);
1350 				return;
1351 			}
1352 			if ((lp = byword(dp, wday_names)) == NULL) {
1353 				error(_("invalid weekday name"));
1354 				ifree(dp);
1355 				return;
1356 			}
1357 			rp->r_wday = lp->l_value;
1358 		}
1359 		if (sscanf(ep, scheck(ep, "%d"), &rp->r_dayofmonth) != 1 ||
1360 			rp->r_dayofmonth <= 0 ||
1361 			(rp->r_dayofmonth > len_months[1][rp->r_month])) {
1362 				error(_("invalid day of month"));
1363 				ifree(dp);
1364 				return;
1365 		}
1366 	}
1367 	ifree(dp);
1368 }
1369 
1370 static void
1371 convert(val, buf)
1372 const long	val;
1373 char * const	buf;
1374 {
1375 	register int	i;
1376 	register long	shift;
1377 
1378 	for (i = 0, shift = 24; i < 4; ++i, shift -= 8)
1379 		buf[i] = val >> shift;
1380 }
1381 
1382 static void
1383 puttzcode(val, fp)
1384 const long	val;
1385 FILE * const	fp;
1386 {
1387 	char	buf[4];
1388 
1389 	convert(val, buf);
1390 	(void) fwrite((void *) buf, (size_t) sizeof buf, (size_t) 1, fp);
1391 }
1392 
1393 static int
1394 atcomp(avp, bvp)
1395 const void *	avp;
1396 const void *	bvp;
1397 {
1398 	if (((struct attype *) avp)->at < ((struct attype *) bvp)->at)
1399 		return -1;
1400 	else if (((struct attype *) avp)->at > ((struct attype *) bvp)->at)
1401 		return 1;
1402 	else	return 0;
1403 }
1404 
1405 static void
1406 writezone(name)
1407 const char * const	name;
1408 {
1409 	register FILE *		fp;
1410 	register int		i, j;
1411 	static char *		fullname;
1412 	static struct tzhead	tzh;
1413 	time_t			ats[TZ_MAX_TIMES];
1414 	unsigned char		types[TZ_MAX_TIMES];
1415 
1416 	/*
1417 	** Sort.
1418 	*/
1419 	if (timecnt > 1)
1420 		(void) qsort((void *) attypes, (size_t) timecnt,
1421 			(size_t) sizeof *attypes, atcomp);
1422 	/*
1423 	** Optimize.
1424 	*/
1425 	{
1426 		int	fromi;
1427 		int	toi;
1428 
1429 		toi = 0;
1430 		fromi = 0;
1431 		while (fromi < timecnt && attypes[fromi].at < min_time)
1432 			++fromi;
1433 		if (isdsts[0] == 0)
1434 			while (fromi < timecnt && attypes[fromi].type == 0)
1435 				++fromi;	/* handled by default rule */
1436 		for ( ; fromi < timecnt; ++fromi) {
1437 			if (toi != 0
1438 			    && ((attypes[fromi].at
1439 				 + gmtoffs[attypes[toi - 1].type])
1440 				<= (attypes[toi - 1].at
1441 				    + gmtoffs[toi == 1 ? 0
1442 					      : attypes[toi - 2].type]))) {
1443 				attypes[toi - 1].type = attypes[fromi].type;
1444 				continue;
1445 			}
1446 			if (toi == 0 ||
1447 				attypes[toi - 1].type != attypes[fromi].type)
1448 					attypes[toi++] = attypes[fromi];
1449 		}
1450 		timecnt = toi;
1451 	}
1452 	/*
1453 	** Transfer.
1454 	*/
1455 	for (i = 0; i < timecnt; ++i) {
1456 		ats[i] = attypes[i].at;
1457 		types[i] = attypes[i].type;
1458 	}
1459 	fullname = erealloc(fullname,
1460 		(int) (strlen(directory) + 1 + strlen(name) + 1));
1461 	(void) sprintf(fullname, "%s/%s", directory, name);	/* XXX: sprintf is safe */
1462 	/*
1463 	** Remove old file, if any, to snap links.
1464 	*/
1465 	if (!itsdir(fullname) && remove(fullname) != 0 && errno != ENOENT) {
1466 		const char *e = strerror(errno);
1467 
1468 		(void) fprintf(stderr, _("%s: Can't remove %s: %s\n"),
1469 			progname, fullname, e);
1470 		(void) exit(EXIT_FAILURE);
1471 	}
1472 	if ((fp = fopen(fullname, "wb")) == NULL) {
1473 		if (mkdirs(fullname) != 0)
1474 			(void) exit(EXIT_FAILURE);
1475 		if ((fp = fopen(fullname, "wb")) == NULL) {
1476 			const char *e = strerror(errno);
1477 
1478 			(void) fprintf(stderr, _("%s: Can't create %s: %s\n"),
1479 				progname, fullname, e);
1480 			(void) exit(EXIT_FAILURE);
1481 		}
1482 	}
1483 	convert(eitol(typecnt), tzh.tzh_ttisgmtcnt);
1484 	convert(eitol(typecnt), tzh.tzh_ttisstdcnt);
1485 	convert(eitol(leapcnt), tzh.tzh_leapcnt);
1486 	convert(eitol(timecnt), tzh.tzh_timecnt);
1487 	convert(eitol(typecnt), tzh.tzh_typecnt);
1488 	convert(eitol(charcnt), tzh.tzh_charcnt);
1489 	(void) strncpy(tzh.tzh_magic, TZ_MAGIC, sizeof tzh.tzh_magic);
1490 #define DO(field)	(void) fwrite((void *) tzh.field, (size_t) sizeof tzh.field, (size_t) 1, fp)
1491 	DO(tzh_magic);
1492 	DO(tzh_reserved);
1493 	DO(tzh_ttisgmtcnt);
1494 	DO(tzh_ttisstdcnt);
1495 	DO(tzh_leapcnt);
1496 	DO(tzh_timecnt);
1497 	DO(tzh_typecnt);
1498 	DO(tzh_charcnt);
1499 #undef DO
1500 	for (i = 0; i < timecnt; ++i) {
1501 		j = leapcnt;
1502 		while (--j >= 0)
1503 			if (ats[i] >= trans[j]) {
1504 				ats[i] = tadd(ats[i], corr[j]);
1505 				break;
1506 			}
1507 		puttzcode((long) ats[i], fp);
1508 	}
1509 	if (timecnt > 0)
1510 		(void) fwrite((void *) types, (size_t) sizeof types[0],
1511 			(size_t) timecnt, fp);
1512 	for (i = 0; i < typecnt; ++i) {
1513 		puttzcode((long) gmtoffs[i], fp);
1514 		(void) putc(isdsts[i], fp);
1515 		(void) putc(abbrinds[i], fp);
1516 	}
1517 	if (charcnt != 0)
1518 		(void) fwrite((void *) chars, (size_t) sizeof chars[0],
1519 			(size_t) charcnt, fp);
1520 	for (i = 0; i < leapcnt; ++i) {
1521 		if (roll[i]) {
1522 			if (timecnt == 0 || trans[i] < ats[0]) {
1523 				j = 0;
1524 				while (isdsts[j])
1525 					if (++j >= typecnt) {
1526 						j = 0;
1527 						break;
1528 					}
1529 			} else {
1530 				j = 1;
1531 				while (j < timecnt && trans[i] >= ats[j])
1532 					++j;
1533 				j = types[j - 1];
1534 			}
1535 			puttzcode((long) tadd(trans[i], -gmtoffs[j]), fp);
1536 		} else	puttzcode((long) trans[i], fp);
1537 		puttzcode((long) corr[i], fp);
1538 	}
1539 	for (i = 0; i < typecnt; ++i)
1540 		(void) putc(ttisstds[i], fp);
1541 	for (i = 0; i < typecnt; ++i)
1542 		(void) putc(ttisgmts[i], fp);
1543 	if (ferror(fp) || fclose(fp)) {
1544 		(void) fprintf(stderr, _("%s: Error writing %s\n"),
1545 			progname, fullname);
1546 		(void) exit(EXIT_FAILURE);
1547 	}
1548 }
1549 
1550 static void
1551 doabbr(abbr, abbrlen, format, letters, isdst)
1552 char * const		abbr;
1553 const int		abbrlen;
1554 const char * const	format;
1555 const char * const	letters;
1556 const int		isdst;
1557 {
1558 	if (strchr(format, '/') == NULL) {
1559 		if (letters == NULL)
1560 			(void)strncpy(abbr, format, abbrlen - 1);
1561 		else
1562 			(void)snprintf(abbr, abbrlen, format, letters);
1563 	} else if (isdst)
1564 		(void)strncpy(abbr, strchr(format, '/') + 1, abbrlen - 1);
1565 	else {
1566 		(void)strncpy(abbr, format, abbrlen - 1);
1567 		*strchr(abbr, '/') = '\0';
1568 	}
1569 }
1570 
1571 static void
1572 outzone(zpfirst, zonecount)
1573 const struct zone * const	zpfirst;
1574 const int			zonecount;
1575 {
1576 	register const struct zone *	zp;
1577 	register struct rule *		rp;
1578 	register int			i, j;
1579 	register int			usestart, useuntil;
1580 	register time_t			starttime, untiltime;
1581 	register long			gmtoff;
1582 	register long			stdoff;
1583 	register int			year;
1584 	register long			startoff;
1585 	register int			startttisstd;
1586 	register int			startttisgmt;
1587 	register int			type;
1588 	char				startbuf[BUFSIZ];
1589 
1590 	INITIALIZE(untiltime);
1591 	INITIALIZE(starttime);
1592 	/*
1593 	** Now. . .finally. . .generate some useful data!
1594 	*/
1595 	timecnt = 0;
1596 	typecnt = 0;
1597 	charcnt = 0;
1598 	/*
1599 	** A guess that may well be corrected later.
1600 	*/
1601 	stdoff = 0;
1602 	/*
1603 	** Thanks to Earl Chew (earl@dnd.icp.nec.com.au)
1604 	** for noting the need to unconditionally initialize startttisstd.
1605 	*/
1606 	startttisstd = FALSE;
1607 	startttisgmt = FALSE;
1608 	for (i = 0; i < zonecount; ++i) {
1609 		zp = &zpfirst[i];
1610 		usestart = i > 0 && (zp - 1)->z_untiltime > min_time;
1611 		useuntil = i < (zonecount - 1);
1612 		if (useuntil && zp->z_untiltime <= min_time)
1613 			continue;
1614 		gmtoff = zp->z_gmtoff;
1615 		eat(zp->z_filename, zp->z_linenum);
1616 		*startbuf = '\0';
1617 		startoff = zp->z_gmtoff;
1618 		if (zp->z_nrules == 0) {
1619 			stdoff = zp->z_stdoff;
1620 			doabbr(startbuf, sizeof startbuf, zp->z_format,
1621 				(char *) NULL, stdoff != 0);
1622 			type = addtype(oadd(zp->z_gmtoff, stdoff),
1623 				startbuf, stdoff != 0, startttisstd,
1624 				startttisgmt);
1625 			if (usestart) {
1626 				addtt(starttime, type);
1627 				usestart = FALSE;
1628 			}
1629 			else if (stdoff != 0)
1630 				addtt(min_time, type);
1631 		} else for (year = min_year; year <= max_year; ++year) {
1632 			if (useuntil && year > zp->z_untilrule.r_hiyear)
1633 				break;
1634 			/*
1635 			** Mark which rules to do in the current year.
1636 			** For those to do, calculate rpytime(rp, year);
1637 			*/
1638 			for (j = 0; j < zp->z_nrules; ++j) {
1639 				rp = &zp->z_rules[j];
1640 				eats(zp->z_filename, zp->z_linenum,
1641 					rp->r_filename, rp->r_linenum);
1642 				rp->r_todo = year >= rp->r_loyear &&
1643 						year <= rp->r_hiyear &&
1644 						yearistype(year, rp->r_yrtype);
1645 				if (rp->r_todo)
1646 					rp->r_temp = rpytime(rp, year);
1647 			}
1648 			for ( ; ; ) {
1649 				register int	k;
1650 				register time_t	jtime, ktime;
1651 				register long	offset;
1652 				char		buf[BUFSIZ];
1653 
1654 				INITIALIZE(ktime);
1655 				if (useuntil) {
1656 					/*
1657 					** Turn untiltime into UTC
1658 					** assuming the current gmtoff and
1659 					** stdoff values.
1660 					*/
1661 					untiltime = zp->z_untiltime;
1662 					if (!zp->z_untilrule.r_todisgmt)
1663 						untiltime = tadd(untiltime,
1664 							-gmtoff);
1665 					if (!zp->z_untilrule.r_todisstd)
1666 						untiltime = tadd(untiltime,
1667 							-stdoff);
1668 				}
1669 				/*
1670 				** Find the rule (of those to do, if any)
1671 				** that takes effect earliest in the year.
1672 				*/
1673 				k = -1;
1674 				for (j = 0; j < zp->z_nrules; ++j) {
1675 					rp = &zp->z_rules[j];
1676 					if (!rp->r_todo)
1677 						continue;
1678 					eats(zp->z_filename, zp->z_linenum,
1679 						rp->r_filename, rp->r_linenum);
1680 					offset = rp->r_todisgmt ? 0 : gmtoff;
1681 					if (!rp->r_todisstd)
1682 						offset = oadd(offset, stdoff);
1683 					jtime = rp->r_temp;
1684 					if (jtime == min_time ||
1685 						jtime == max_time)
1686 							continue;
1687 					jtime = tadd(jtime, -offset);
1688 					if (k < 0 || jtime < ktime) {
1689 						k = j;
1690 						ktime = jtime;
1691 					}
1692 				}
1693 				if (k < 0)
1694 					break;	/* go on to next year */
1695 				rp = &zp->z_rules[k];
1696 				rp->r_todo = FALSE;
1697 				if (useuntil && ktime >= untiltime)
1698 					break;
1699 				stdoff = rp->r_stdoff;
1700 				if (usestart && ktime == starttime)
1701 					usestart = FALSE;
1702 				if (usestart) {
1703 					if (ktime < starttime) {
1704 						startoff = oadd(zp->z_gmtoff,
1705 							stdoff);
1706 						doabbr(startbuf,sizeof startbuf,
1707 							zp->z_format,
1708 							rp->r_abbrvar,
1709 							rp->r_stdoff != 0);
1710 						continue;
1711 					}
1712 					if (*startbuf == '\0' &&
1713 					    startoff == oadd(zp->z_gmtoff,
1714 					    stdoff)) {
1715 						doabbr(startbuf,sizeof startbuf,
1716 							zp->z_format,
1717 							rp->r_abbrvar,
1718 							rp->r_stdoff != 0);
1719 					}
1720 				}
1721 				eats(zp->z_filename, zp->z_linenum,
1722 					rp->r_filename, rp->r_linenum);
1723 				doabbr(buf, sizeof buf, zp->z_format,
1724 					rp->r_abbrvar, rp->r_stdoff != 0);
1725 				offset = oadd(zp->z_gmtoff, rp->r_stdoff);
1726 				type = addtype(offset, buf, rp->r_stdoff != 0,
1727 					rp->r_todisstd, rp->r_todisgmt);
1728 				addtt(ktime, type);
1729 			}
1730 		}
1731 		if (usestart) {
1732 			if (*startbuf == '\0' &&
1733 				zp->z_format != NULL &&
1734 				strchr(zp->z_format, '%') == NULL &&
1735 				strchr(zp->z_format, '/') == NULL)
1736 					(void)strncpy(startbuf, zp->z_format,
1737 					    sizeof(startbuf) - 1);
1738 			eat(zp->z_filename, zp->z_linenum);
1739 			if (*startbuf == '\0')
1740 error(_("can't determine time zone abbreviation to use just after until time"));
1741 			else	addtt(starttime,
1742 					addtype(startoff, startbuf,
1743 						startoff != zp->z_gmtoff,
1744 						startttisstd,
1745 						startttisgmt));
1746 		}
1747 		/*
1748 		** Now we may get to set starttime for the next zone line.
1749 		*/
1750 		if (useuntil) {
1751 			startttisstd = zp->z_untilrule.r_todisstd;
1752 			startttisgmt = zp->z_untilrule.r_todisgmt;
1753 			starttime = zp->z_untiltime;
1754 			if (!startttisstd)
1755 				starttime = tadd(starttime, -stdoff);
1756 			if (!startttisgmt)
1757 				starttime = tadd(starttime, -gmtoff);
1758 		}
1759 	}
1760 	writezone(zpfirst->z_name);
1761 }
1762 
1763 static void
1764 addtt(starttime, type)
1765 const time_t	starttime;
1766 int		type;
1767 {
1768 	if (starttime <= min_time ||
1769 		(timecnt == 1 && attypes[0].at < min_time)) {
1770 		gmtoffs[0] = gmtoffs[type];
1771 		isdsts[0] = isdsts[type];
1772 		ttisstds[0] = ttisstds[type];
1773 		ttisgmts[0] = ttisgmts[type];
1774 		if (abbrinds[type] != 0)
1775 			(void) strcpy(chars, &chars[abbrinds[type]]);
1776 		abbrinds[0] = 0;
1777 		charcnt = strlen(chars) + 1;
1778 		typecnt = 1;
1779 		timecnt = 0;
1780 		type = 0;
1781 	}
1782 	if (timecnt >= TZ_MAX_TIMES) {
1783 		error(_("too many transitions?!"));
1784 		(void) exit(EXIT_FAILURE);
1785 	}
1786 	attypes[timecnt].at = starttime;
1787 	attypes[timecnt].type = type;
1788 	++timecnt;
1789 }
1790 
1791 static int
1792 addtype(gmtoff, abbr, isdst, ttisstd, ttisgmt)
1793 const long		gmtoff;
1794 const char * const	abbr;
1795 const int		isdst;
1796 const int		ttisstd;
1797 const int		ttisgmt;
1798 {
1799 	register int	i, j;
1800 
1801 	if (isdst != TRUE && isdst != FALSE) {
1802 		error(_("internal error - addtype called with bad isdst"));
1803 		(void) exit(EXIT_FAILURE);
1804 	}
1805 	if (ttisstd != TRUE && ttisstd != FALSE) {
1806 		error(_("internal error - addtype called with bad ttisstd"));
1807 		(void) exit(EXIT_FAILURE);
1808 	}
1809 	if (ttisgmt != TRUE && ttisgmt != FALSE) {
1810 		error(_("internal error - addtype called with bad ttisgmt"));
1811 		(void) exit(EXIT_FAILURE);
1812 	}
1813 	/*
1814 	** See if there's already an entry for this zone type.
1815 	** If so, just return its index.
1816 	*/
1817 	for (i = 0; i < typecnt; ++i) {
1818 		if (gmtoff == gmtoffs[i] && isdst == isdsts[i] &&
1819 			strcmp(abbr, &chars[abbrinds[i]]) == 0 &&
1820 			ttisstd == ttisstds[i] &&
1821 			ttisgmt == ttisgmts[i])
1822 				return i;
1823 	}
1824 	/*
1825 	** There isn't one; add a new one, unless there are already too
1826 	** many.
1827 	*/
1828 	if (typecnt >= TZ_MAX_TYPES) {
1829 		error(_("too many local time types"));
1830 		(void) exit(EXIT_FAILURE);
1831 	}
1832 	gmtoffs[i] = gmtoff;
1833 	isdsts[i] = isdst;
1834 	ttisstds[i] = ttisstd;
1835 	ttisgmts[i] = ttisgmt;
1836 
1837 	for (j = 0; j < charcnt; ++j)
1838 		if (strcmp(&chars[j], abbr) == 0)
1839 			break;
1840 	if (j == charcnt)
1841 		newabbr(abbr);
1842 	abbrinds[i] = j;
1843 	++typecnt;
1844 	return i;
1845 }
1846 
1847 static void
1848 leapadd(t, positive, rolling, count)
1849 const time_t	t;
1850 const int	positive;
1851 const int	rolling;
1852 int		count;
1853 {
1854 	register int	i, j;
1855 
1856 	if (leapcnt + (positive ? count : 1) > TZ_MAX_LEAPS) {
1857 		error(_("too many leap seconds"));
1858 		(void) exit(EXIT_FAILURE);
1859 	}
1860 	for (i = 0; i < leapcnt; ++i)
1861 		if (t <= trans[i]) {
1862 			if (t == trans[i]) {
1863 				error(_("repeated leap second moment"));
1864 				(void) exit(EXIT_FAILURE);
1865 			}
1866 			break;
1867 		}
1868 	do {
1869 		for (j = leapcnt; j > i; --j) {
1870 			trans[j] = trans[j - 1];
1871 			corr[j] = corr[j - 1];
1872 			roll[j] = roll[j - 1];
1873 		}
1874 		trans[i] = t;
1875 		corr[i] = positive ? 1L : eitol(-count);
1876 		roll[i] = rolling;
1877 		++leapcnt;
1878 	} while (positive && --count != 0);
1879 }
1880 
1881 static void
1882 adjleap P((void))
1883 {
1884 	register int	i;
1885 	register long	last = 0;
1886 
1887 	/*
1888 	** propagate leap seconds forward
1889 	*/
1890 	for (i = 0; i < leapcnt; ++i) {
1891 		trans[i] = tadd(trans[i], last);
1892 		last = corr[i] += last;
1893 	}
1894 }
1895 
1896 static int
1897 yearistype(year, type)
1898 const int		year;
1899 const char * const	type;
1900 {
1901 	static char *	buf;
1902 	int		result;
1903 
1904 	if (type == NULL || *type == '\0')
1905 		return TRUE;
1906 	buf = erealloc(buf, (int) (132 + strlen(yitcommand) + strlen(type)));
1907 	(void)sprintf(buf, "%s %d %s", yitcommand, year, type); /* XXX: sprintf is safe */
1908 	result = system(buf);
1909 	if (result == 0)
1910 		return TRUE;
1911 	if (result == (1 << 8))
1912 		return FALSE;
1913 	error(_("Wild result from command execution"));
1914 	(void) fprintf(stderr, _("%s: command was '%s', result was %d\n"),
1915 		progname, buf, result);
1916 	for ( ; ; )
1917 		(void) exit(EXIT_FAILURE);
1918 }
1919 
1920 static int
1921 lowerit(a)
1922 int	a;
1923 {
1924 	a = (unsigned char) a;
1925 	return (isascii(a) && isupper(a)) ? tolower(a) : a;
1926 }
1927 
1928 static int
1929 ciequal(ap, bp)		/* case-insensitive equality */
1930 register const char *	ap;
1931 register const char *	bp;
1932 {
1933 	while (lowerit(*ap) == lowerit(*bp++))
1934 		if (*ap++ == '\0')
1935 			return TRUE;
1936 	return FALSE;
1937 }
1938 
1939 static int
1940 itsabbr(abbr, word)
1941 register const char *	abbr;
1942 register const char *	word;
1943 {
1944 	if (lowerit(*abbr) != lowerit(*word))
1945 		return FALSE;
1946 	++word;
1947 	while (*++abbr != '\0')
1948 		do {
1949 			if (*word == '\0')
1950 				return FALSE;
1951 		} while (lowerit(*word++) != lowerit(*abbr));
1952 	return TRUE;
1953 }
1954 
1955 static const struct lookup *
1956 byword(word, table)
1957 register const char * const		word;
1958 register const struct lookup * const	table;
1959 {
1960 	register const struct lookup *	foundlp;
1961 	register const struct lookup *	lp;
1962 
1963 	if (word == NULL || table == NULL)
1964 		return NULL;
1965 	/*
1966 	** Look for exact match.
1967 	*/
1968 	for (lp = table; lp->l_word != NULL; ++lp)
1969 		if (ciequal(word, lp->l_word))
1970 			return lp;
1971 	/*
1972 	** Look for inexact match.
1973 	*/
1974 	foundlp = NULL;
1975 	for (lp = table; lp->l_word != NULL; ++lp)
1976 		if (itsabbr(word, lp->l_word)) {
1977 			if (foundlp == NULL)
1978 				foundlp = lp;
1979 			else	return NULL;	/* multiple inexact matches */
1980 		}
1981 	return foundlp;
1982 }
1983 
1984 static char **
1985 getfields(cp)
1986 register char *	cp;
1987 {
1988 	register char *		dp;
1989 	register char **	array;
1990 	register int		nsubs;
1991 
1992 	if (cp == NULL)
1993 		return NULL;
1994 	array = (char **) (void *)
1995 		emalloc((int) ((strlen(cp) + 1) * sizeof *array));
1996 	nsubs = 0;
1997 	for ( ; ; ) {
1998 		while (isascii(*cp) && isspace((unsigned char) *cp))
1999 			++cp;
2000 		if (*cp == '\0' || *cp == '#')
2001 			break;
2002 		array[nsubs++] = dp = cp;
2003 		do {
2004 			if ((*dp = *cp++) != '"')
2005 				++dp;
2006 			else while ((*dp = *cp++) != '"')
2007 				if (*dp != '\0')
2008 					++dp;
2009 				else	error(_("Odd number of quotation marks"));
2010 		} while (*cp != '\0' && *cp != '#' &&
2011 			(!isascii(*cp) || !isspace((unsigned char) *cp)));
2012 		if (isascii(*cp) && isspace((unsigned char) *cp))
2013 			++cp;
2014 		*dp = '\0';
2015 	}
2016 	array[nsubs] = NULL;
2017 	return array;
2018 }
2019 
2020 static long
2021 oadd(t1, t2)
2022 const long	t1;
2023 const long	t2;
2024 {
2025 	register long	t;
2026 
2027 	t = t1 + t2;
2028 	if ((t2 > 0 && t <= t1) || (t2 < 0 && t >= t1)) {
2029 		error(_("time overflow"));
2030 		(void) exit(EXIT_FAILURE);
2031 	}
2032 	return t;
2033 }
2034 
2035 static time_t
2036 tadd(t1, t2)
2037 const time_t	t1;
2038 const long	t2;
2039 {
2040 	register time_t	t;
2041 
2042 	if (t1 == max_time && t2 > 0)
2043 		return max_time;
2044 	if (t1 == min_time && t2 < 0)
2045 		return min_time;
2046 	t = t1 + t2;
2047 	if ((t2 > 0 && t <= t1) || (t2 < 0 && t >= t1)) {
2048 		error(_("time overflow"));
2049 		(void) exit(EXIT_FAILURE);
2050 	}
2051 	return t;
2052 }
2053 
2054 /*
2055 ** Given a rule, and a year, compute the date - in seconds since January 1,
2056 ** 1970, 00:00 LOCAL time - in that year that the rule refers to.
2057 */
2058 
2059 static time_t
2060 rpytime(rp, wantedy)
2061 register const struct rule * const	rp;
2062 register const int			wantedy;
2063 {
2064 	register int	y, m, i;
2065 	register long	dayoff;			/* with a nod to Margaret O. */
2066 	register time_t	t;
2067 
2068 	if (wantedy == INT_MIN)
2069 		return min_time;
2070 	if (wantedy == INT_MAX)
2071 		return max_time;
2072 	dayoff = 0;
2073 	m = TM_JANUARY;
2074 	y = EPOCH_YEAR;
2075 	while (wantedy != y) {
2076 		if (wantedy > y) {
2077 			i = len_years[isleap(y)];
2078 			++y;
2079 		} else {
2080 			--y;
2081 			i = -len_years[isleap(y)];
2082 		}
2083 		dayoff = oadd(dayoff, eitol(i));
2084 	}
2085 	while (m != rp->r_month) {
2086 		i = len_months[isleap(y)][m];
2087 		dayoff = oadd(dayoff, eitol(i));
2088 		++m;
2089 	}
2090 	i = rp->r_dayofmonth;
2091 	if (m == TM_FEBRUARY && i == 29 && !isleap(y)) {
2092 		if (rp->r_dycode == DC_DOWLEQ)
2093 			--i;
2094 		else {
2095 			error(_("use of 2/29 in non leap-year"));
2096 			(void) exit(EXIT_FAILURE);
2097 		}
2098 	}
2099 	--i;
2100 	dayoff = oadd(dayoff, eitol(i));
2101 	if (rp->r_dycode == DC_DOWGEQ || rp->r_dycode == DC_DOWLEQ) {
2102 		register long	wday;
2103 
2104 #define LDAYSPERWEEK	((long) DAYSPERWEEK)
2105 		wday = eitol(EPOCH_WDAY);
2106 		/*
2107 		** Don't trust mod of negative numbers.
2108 		*/
2109 		if (dayoff >= 0)
2110 			wday = (wday + dayoff) % LDAYSPERWEEK;
2111 		else {
2112 			wday -= ((-dayoff) % LDAYSPERWEEK);
2113 			if (wday < 0)
2114 				wday += LDAYSPERWEEK;
2115 		}
2116 		while (wday != eitol(rp->r_wday))
2117 			if (rp->r_dycode == DC_DOWGEQ) {
2118 				dayoff = oadd(dayoff, (long) 1);
2119 				if (++wday >= LDAYSPERWEEK)
2120 					wday = 0;
2121 				++i;
2122 			} else {
2123 				dayoff = oadd(dayoff, (long) -1);
2124 				if (--wday < 0)
2125 					wday = LDAYSPERWEEK - 1;
2126 				--i;
2127 			}
2128 		if (i < 0 || i >= len_months[isleap(y)][m]) {
2129 			error(_("no day in month matches rule"));
2130 			(void) exit(EXIT_FAILURE);
2131 		}
2132 	}
2133 	if (dayoff < 0 && !TYPE_SIGNED(time_t))
2134 		return min_time;
2135 	t = (time_t) dayoff * SECSPERDAY;
2136 	/*
2137 	** Cheap overflow check.
2138 	*/
2139 	if (t / SECSPERDAY != dayoff)
2140 		return (dayoff > 0) ? max_time : min_time;
2141 	return tadd(t, rp->r_tod);
2142 }
2143 
2144 static void
2145 newabbr(string)
2146 const char * const	string;
2147 {
2148 	register int	i;
2149 
2150 	i = strlen(string) + 1;
2151 	if (charcnt + i > TZ_MAX_CHARS) {
2152 		error(_("too many, or too long, time zone abbreviations"));
2153 		(void) exit(EXIT_FAILURE);
2154 	}
2155 	(void)strncpy(&chars[charcnt], string, sizeof(chars) - charcnt - 1);
2156 	charcnt += eitol(i);
2157 }
2158 
2159 static int
2160 mkdirs(argname)
2161 char * const	argname;
2162 {
2163 	register char *	name;
2164 	register char *	cp;
2165 
2166 	if (argname == NULL || *argname == '\0')
2167 		return 0;
2168 	cp = name = ecpyalloc(argname);
2169 	while ((cp = strchr(cp + 1, '/')) != 0) {
2170 		*cp = '\0';
2171 #ifndef __NetBSD__
2172 		/*
2173 		** DOS drive specifier?
2174 		*/
2175 		if (isalpha((unsigned char) name[0]) &&
2176 			name[1] == ':' && name[2] == '\0') {
2177 				*cp = '/';
2178 				continue;
2179 		}
2180 #endif /* !defined __NetBSD__ */
2181 		if (!itsdir(name)) {
2182 			/*
2183 			** It doesn't seem to exist, so we try to create it.
2184 			** Creation may fail because of the directory being
2185 			** created by some other multiprocessor, so we get
2186 			** to do extra checking.
2187 			*/
2188 			if (mkdir(name, S_IRUSR|S_IWUSR|S_IXUSR|S_IRGRP|S_IXGRP|S_IROTH|S_IXOTH) != 0) {
2189 				const char *e = strerror(errno);
2190 
2191 				if (errno != EEXIST || !itsdir(name)) {
2192 					(void) fprintf(stderr,
2193 _("%s: Can't create directory %s: %s\n"),
2194 						progname, name, e);
2195 					ifree(name);
2196 					return -1;
2197 				}
2198 			}
2199 		}
2200 		*cp = '/';
2201 	}
2202 	ifree(name);
2203 	return 0;
2204 }
2205 
2206 static long
2207 eitol(i)
2208 const int	i;
2209 {
2210 	long	l;
2211 
2212 	l = i;
2213 	if ((i < 0 && l >= 0) || (i == 0 && l != 0) || (i > 0 && l <= 0)) {
2214 		(void) fprintf(stderr,
2215 			_("%s: %d did not sign extend correctly\n"),
2216 			progname, i);
2217 		(void) exit(EXIT_FAILURE);
2218 	}
2219 	return l;
2220 }
2221 
2222 /*
2223 ** UNIX was a registered trademark of UNIX System Laboratories in 1993.
2224 */
2225