xref: /dragonfly/usr.sbin/zic/zdump.c (revision c3762235)
1 /*
2  * $FreeBSD: src/usr.sbin/zic/zdump.c,v 1.7 1999/08/28 01:21:19 peter Exp $
3  */
4 /*
5 ** This code has been made independent of the rest of the time
6 ** conversion package to increase confidence in the verification it provides.
7 ** You can use this code to help in verifying other implementations.
8 */
9 
10 #include <ctype.h>	/* for isalpha et al. */
11 #include <err.h>
12 #include <inttypes.h>
13 #include <limits.h>	/* for CHAR_BIT, LLONG_MAX */
14 #include <stdint.h>
15 #include <stdio.h>	/* for stdout, stderr */
16 #include <stdlib.h>	/* for exit, malloc, atoi */
17 #include <string.h>	/* for strcpy */
18 #include <sys/types.h>	/* for time_t */
19 #include <time.h>	/* for struct tm */
20 #include <unistd.h>
21 
22 #ifndef ZDUMP_LO_YEAR
23 #define ZDUMP_LO_YEAR	(-500)
24 #endif /* !defined ZDUMP_LO_YEAR */
25 
26 #ifndef ZDUMP_HI_YEAR
27 #define ZDUMP_HI_YEAR	2500
28 #endif /* !defined ZDUMP_HI_YEAR */
29 
30 #ifndef MAX_STRING_LENGTH
31 #define MAX_STRING_LENGTH	1024
32 #endif /* !defined MAX_STRING_LENGTH */
33 
34 #ifndef TRUE
35 #define TRUE		1
36 #endif /* !defined TRUE */
37 
38 #ifndef FALSE
39 #define FALSE		0
40 #endif /* !defined FALSE */
41 
42 #ifndef EXIT_SUCCESS
43 #define EXIT_SUCCESS	0
44 #endif /* !defined EXIT_SUCCESS */
45 
46 #ifndef EXIT_FAILURE
47 #define EXIT_FAILURE	1
48 #endif /* !defined EXIT_FAILURE */
49 
50 #ifndef SECSPERMIN
51 #define SECSPERMIN	60
52 #endif /* !defined SECSPERMIN */
53 
54 #ifndef MINSPERHOUR
55 #define MINSPERHOUR	60
56 #endif /* !defined MINSPERHOUR */
57 
58 #ifndef SECSPERHOUR
59 #define SECSPERHOUR	(SECSPERMIN * MINSPERHOUR)
60 #endif /* !defined SECSPERHOUR */
61 
62 #ifndef HOURSPERDAY
63 #define HOURSPERDAY	24
64 #endif /* !defined HOURSPERDAY */
65 
66 #ifndef EPOCH_YEAR
67 #define EPOCH_YEAR	1970
68 #endif /* !defined EPOCH_YEAR */
69 
70 #ifndef TM_YEAR_BASE
71 #define TM_YEAR_BASE	1900
72 #endif /* !defined TM_YEAR_BASE */
73 
74 #ifndef DAYSPERNYEAR
75 #define DAYSPERNYEAR	365
76 #endif /* !defined DAYSPERNYEAR */
77 
78 #ifndef isleap
79 #define isleap(y) (((y) % 4) == 0 && (((y) % 100) != 0 || ((y) % 400) == 0))
80 #endif /* !defined isleap */
81 
82 #ifndef isleap_sum
83 /*
84 ** See tzfile.h for details on isleap_sum.
85 */
86 #define isleap_sum(a, b)	isleap((a) % 400 + (b) % 400)
87 #endif /* !defined isleap_sum */
88 
89 #define SECSPERDAY	((int_fast32_t) SECSPERHOUR * HOURSPERDAY)
90 #define SECSPERNYEAR	(SECSPERDAY * DAYSPERNYEAR)
91 #define SECSPERLYEAR	(SECSPERNYEAR + SECSPERDAY)
92 #define SECSPER400YEARS	(SECSPERNYEAR * (intmax_t) (300 + 3)	\
93 			 + SECSPERLYEAR * (intmax_t) (100 - 3))
94 
95 /*
96 ** True if SECSPER400YEARS is known to be representable as an
97 ** intmax_t.  It's OK that SECSPER400YEARS_FITS can in theory be false
98 ** even if SECSPER400YEARS is representable, because when that happens
99 ** the code merely runs a bit more slowly, and this slowness doesn't
100 ** occur on any practical platform.
101 */
102 enum { SECSPER400YEARS_FITS = SECSPERLYEAR <= INTMAX_MAX / 400 };
103 
104 /*
105 ** For the benefit of GNU folk...
106 ** `_(MSGID)' uses the current locale's message library string for MSGID.
107 ** The default is to use gettext if available, and use MSGID otherwise.
108 */
109 
110 #ifndef _
111 #define _(msgid) msgid
112 #endif /* !defined _ */
113 
114 #ifndef TZ_DOMAIN
115 #define TZ_DOMAIN "tz"
116 #endif /* !defined TZ_DOMAIN */
117 
118 extern char **	environ;
119 extern char *	tzname[2];
120 
121 /* The minimum and maximum finite time values.  */
122 static time_t const absolute_min_time =
123   ((time_t) -1 < 0
124    ? (time_t) -1 << (CHAR_BIT * sizeof (time_t) - 1)
125    : 0);
126 static time_t const absolute_max_time =
127   ((time_t) -1 < 0
128    ? - (~ 0 < 0) - ((time_t) -1 << (CHAR_BIT * sizeof (time_t) - 1))
129    : -1);
130 static size_t	 longest;
131 static int	 warned;
132 
133 static char	*abbr(struct tm *tmp);
134 static void	 abbrok(const char *abbrp, const char *zone);
135 static intmax_t	 delta(struct tm * newp, struct tm * oldp) __pure;
136 static void	 dumptime(const struct tm *tmp);
137 static time_t	 hunt(char *name, time_t lot, time_t hit);
138 static void	 show(char *zone, time_t t, int v);
139 static const char *tformat(void);
140 static time_t	 yeartot(intmax_t y) __pure;
141 static void	 usage(void);
142 
143 #ifndef TYPECHECK
144 #define my_localtime	localtime
145 #else /* !defined TYPECHECK */
146 static struct tm *
147 my_localtime(time_t *tp)
148 {
149 	struct tm *	tmp;
150 
151 	tmp = localtime(tp);
152 	if (tp != NULL && tmp != NULL) {
153 		struct tm	tm;
154 		time_t		t;
155 
156 		tm = *tmp;
157 		t = mktime(&tm);
158 		if (t != *tp) {
159 			fflush(stdout);
160 			fprintf(stderr, "\n%s: ", progname);
161 			fprintf(stderr, tformat(), *tp);
162 			fprintf(stderr, " ->");
163 			fprintf(stderr, " year=%d", tmp->tm_year);
164 			fprintf(stderr, " mon=%d", tmp->tm_mon);
165 			fprintf(stderr, " mday=%d", tmp->tm_mday);
166 			fprintf(stderr, " hour=%d", tmp->tm_hour);
167 			fprintf(stderr, " min=%d", tmp->tm_min);
168 			fprintf(stderr, " sec=%d", tmp->tm_sec);
169 			fprintf(stderr, " isdst=%d", tmp->tm_isdst);
170 			fprintf(stderr, " -> ");
171 			fprintf(stderr, tformat(), t);
172 			fprintf(stderr, "\n");
173 		}
174 	}
175 	return tmp;
176 }
177 #endif /* !defined TYPECHECK */
178 
179 static void
180 abbrok(const char * const abbrp, const char * const zone)
181 {
182 	const char *cp;
183 	const char *wp;
184 
185 	if (warned)
186 		return;
187 	cp = abbrp;
188 	wp = NULL;
189 	while (isascii((unsigned char) *cp) && isalpha((unsigned char) *cp))
190 		++cp;
191 	if (cp - abbrp == 0)
192 		wp = _("lacks alphabetic at start");
193 	else if (cp - abbrp < 3)
194 		wp = _("has fewer than 3 alphabetics");
195 	else if (cp - abbrp > 6)
196 		wp = _("has more than 6 alphabetics");
197 	if (wp == NULL && (*cp == '+' || *cp == '-')) {
198 		++cp;
199 		if (isascii((unsigned char) *cp) &&
200 			isdigit((unsigned char) *cp))
201 				if (*cp++ == '1' && *cp >= '0' && *cp <= '4')
202 					++cp;
203 		if (*cp != '\0')
204 			wp = _("differs from POSIX standard");
205 	}
206 	if (wp == NULL)
207 		return;
208 	fflush(stdout);
209 	warnx(_("warning: zone \"%s\" abbreviation \"%s\" %s\n"),
210 		zone, abbrp, wp);
211 	warned = TRUE;
212 }
213 
214 int
215 main(int argc, char *argv[])
216 {
217 	int i;
218 	int vflag;
219 	int Vflag;
220 	char *cutarg;
221 	char *cuttimes;
222 	time_t cutlotime;
223 	time_t cuthitime;
224 	char **fakeenv;
225 	time_t now;
226 	time_t t;
227 	time_t newt;
228 	struct tm tm;
229 	struct tm newtm;
230 	struct tm *tmp;
231 	struct tm *newtmp;
232 
233 	cutlotime = absolute_min_time;
234 	cuthitime = absolute_max_time;
235 	vflag = Vflag = 0;
236 	cutarg = cuttimes = NULL;
237 	for (;;)
238 	  switch (getopt(argc, argv, "c:t:vV")) {
239 	  case 'c': cutarg = optarg; break;
240 	  case 't': cuttimes = optarg; break;
241 	  case 'v': vflag = 1; break;
242 	  case 'V': Vflag = 1; break;
243 	  case -1:
244 	    if (! (optind == argc - 1 && strcmp(argv[optind], "=") == 0))
245 	      goto arg_processing_done;
246 	    /* Fall through.  */
247 	  default:
248 	    usage();
249 	  }
250  arg_processing_done:;
251 
252 	if (vflag | Vflag) {
253 		intmax_t	lo;
254 		intmax_t	hi;
255 		char *loend, *hiend;
256 		intmax_t cutloyear = ZDUMP_LO_YEAR;
257 		intmax_t cuthiyear = ZDUMP_HI_YEAR;
258 		if (cutarg != NULL) {
259 			lo = strtoimax(cutarg, &loend, 10);
260 			if (cutarg != loend && !*loend) {
261 				hi = lo;
262 				cuthiyear = hi;
263 			} else if (cutarg != loend && *loend == ','
264 				   && (hi = strtoimax(loend + 1, &hiend, 10),
265 				       loend + 1 != hiend && !*hiend)) {
266 				cutloyear = lo;
267 				cuthiyear = hi;
268 			} else {
269 				errx(EXIT_FAILURE,
270 					_("wild -c argument %s\n"),
271 					cutarg);
272 			}
273 		}
274 		if (cutarg != NULL || cuttimes == NULL) {
275 			cutlotime = yeartot(cutloyear);
276 			cuthitime = yeartot(cuthiyear);
277 		}
278 		if (cuttimes != NULL) {
279 			lo = strtoimax(cuttimes, &loend, 10);
280 			if (cuttimes != loend && !*loend) {
281 				hi = lo;
282 				if (hi < cuthitime) {
283 					if (hi < absolute_min_time)
284 						hi = absolute_min_time;
285 					cuthitime = hi;
286 				}
287 			} else if (cuttimes != loend && *loend == ','
288 				   && (hi = strtoimax(loend + 1, &hiend, 10),
289 				       loend + 1 != hiend && !*hiend)) {
290 				if (cutlotime < lo) {
291 					if (absolute_max_time < lo)
292 						lo = absolute_max_time;
293 					cutlotime = lo;
294 				}
295 				if (hi < cuthitime) {
296 					if (hi < absolute_min_time)
297 						hi = absolute_min_time;
298 					cuthitime = hi;
299 				}
300 			} else {
301 				errx(EXIT_FAILURE,
302 					_("wild -t argument %s\n"),
303 					cuttimes);
304 			}
305 		}
306 	}
307 	time(&now);
308 	longest = 0;
309 	for (i = optind; i < argc; ++i)
310 		if (strlen(argv[i]) > longest)
311 			longest = strlen(argv[i]);
312 	{
313 		int from;
314 		int to;
315 
316 		for (i = 0; environ[i] != NULL;  ++i)
317 			continue;
318 		fakeenv = malloc((i + 2) * sizeof *fakeenv);
319 		if (fakeenv == NULL
320 		    || (fakeenv[0] = malloc(longest + 4)) == NULL) {
321 					errx(EXIT_FAILURE,
322 					     _("malloc() failed"));
323 		}
324 		to = 0;
325 		strcpy(fakeenv[to++], "TZ=");
326 		for (from = 0; environ[from] != NULL; ++from)
327 			if (strncmp(environ[from], "TZ=", 3) != 0)
328 				fakeenv[to++] = environ[from];
329 		fakeenv[to] = NULL;
330 		environ = fakeenv;
331 	}
332 	for (i = optind; i < argc; ++i) {
333 		static char	buf[MAX_STRING_LENGTH];
334 
335 		strcpy(&fakeenv[0][3], argv[i]);
336 		if (! (vflag | Vflag)) {
337 			show(argv[i], now, FALSE);
338 			continue;
339 		}
340 		warned = FALSE;
341 		t = absolute_min_time;
342 		if (!Vflag) {
343 			show(argv[i], t, TRUE);
344 			t += SECSPERDAY;
345 			show(argv[i], t, TRUE);
346 		}
347 		if (t < cutlotime)
348 			t = cutlotime;
349 		tmp = my_localtime(&t);
350 		if (tmp != NULL) {
351 			tm = *tmp;
352 			strncpy(buf, abbr(&tm), (sizeof buf) - 1);
353 		}
354 		for ( ; ; ) {
355 			newt = (t < absolute_max_time - SECSPERDAY / 2
356 				? t + SECSPERDAY / 2
357 				: absolute_max_time);
358 			if (cuthitime <= newt)
359 				break;
360 			newtmp = localtime(&newt);
361 			if (newtmp != NULL)
362 				newtm = *newtmp;
363 			if ((tmp == NULL || newtmp == NULL) ? (tmp != newtmp) :
364 				(delta(&newtm, &tm) != (newt - t) ||
365 				newtm.tm_isdst != tm.tm_isdst ||
366 				strcmp(abbr(&newtm), buf) != 0)) {
367 					newt = hunt(argv[i], t, newt);
368 					newtmp = localtime(&newt);
369 					if (newtmp != NULL) {
370 						newtm = *newtmp;
371 						strncpy(buf,
372 							abbr(&newtm),
373 							(sizeof buf) - 1);
374 					}
375 			}
376 			t = newt;
377 			tm = newtm;
378 			tmp = newtmp;
379 		}
380 		if (!Vflag) {
381 			t = absolute_max_time;
382 			t -= SECSPERDAY;
383 			show(argv[i], t, TRUE);
384 			t += SECSPERDAY;
385 			show(argv[i], t, TRUE);
386 		}
387 	}
388 	if (fflush(stdout) || ferror(stdout))
389 		errx(EXIT_FAILURE, _("error writing standard output"));
390 	exit(EXIT_SUCCESS);
391 	/* If exit fails to exit... */
392 	return EXIT_FAILURE;
393 }
394 
395 static void
396 usage(void)
397 {
398 	fprintf(stderr, _("usage: zdump [-vV] [-c [loyear,]hiyear] [-t [lotime,]hitime] zonename ...\n"));
399 	exit(EXIT_FAILURE);
400 }
401 
402 static time_t
403 yeartot(const intmax_t y)
404 {
405 	intmax_t	myy, seconds, years;
406 	time_t		t;
407 
408 	myy = EPOCH_YEAR;
409 	t = 0;
410 	while (myy < y) {
411 		if (SECSPER400YEARS_FITS && 400 <= y - myy) {
412 			intmax_t diff400 = (y - myy) / 400;
413 			if (INTMAX_MAX / SECSPER400YEARS < diff400)
414 				return absolute_max_time;
415 			seconds = diff400 * SECSPER400YEARS;
416 			years = diff400 * 400;
417                 } else {
418 			seconds = isleap(myy) ? SECSPERLYEAR : SECSPERNYEAR;
419 			years = 1;
420 		}
421 		myy += years;
422 		if (t > absolute_max_time - seconds)
423 			return absolute_max_time;
424 		t += seconds;
425 	}
426 	while (y < myy) {
427 		if (SECSPER400YEARS_FITS && y + 400 <= myy && myy < 0) {
428 			intmax_t diff400 = (myy - y) / 400;
429 			if (INTMAX_MAX / SECSPER400YEARS < diff400)
430 				return absolute_min_time;
431 			seconds = diff400 * SECSPER400YEARS;
432 			years = diff400 * 400;
433 		} else {
434 			seconds = isleap(myy - 1) ? SECSPERLYEAR : SECSPERNYEAR;
435 			years = 1;
436 		}
437 		myy -= years;
438 		if (t < absolute_min_time + seconds)
439 			return absolute_min_time;
440 		t -= seconds;
441 	}
442 	return t;
443 }
444 
445 static time_t
446 hunt(char *name, time_t lot, time_t hit)
447 {
448 	time_t		t;
449 	struct tm	lotm;
450 	struct tm *	lotmp;
451 	struct tm	tm;
452 	struct tm *	tmp;
453 	char			loab[MAX_STRING_LENGTH];
454 
455 	lotmp = my_localtime(&lot);
456 	if (lotmp != NULL) {
457 		lotm = *lotmp;
458 		strncpy(loab, abbr(&lotm), (sizeof loab) - 1);
459 	}
460 	for ( ; ; ) {
461 		time_t diff = hit - lot;
462 		if (diff < 2)
463 			break;
464 		t = lot;
465 		t += diff / 2;
466 		if (t <= lot)
467 			++t;
468 		else if (t >= hit)
469 			--t;
470 		tmp = my_localtime(&t);
471 		if (tmp != NULL)
472 			tm = *tmp;
473 		if ((lotmp == NULL || tmp == NULL) ? (lotmp == tmp) :
474 			(delta(&tm, &lotm) == (t - lot) &&
475 			tm.tm_isdst == lotm.tm_isdst &&
476 			strcmp(abbr(&tm), loab) == 0)) {
477 				lot = t;
478 				lotm = tm;
479 				lotmp = tmp;
480 		} else	hit = t;
481 	}
482 	show(name, lot, TRUE);
483 	show(name, hit, TRUE);
484 	return hit;
485 }
486 
487 /*
488 ** Thanks to Paul Eggert for logic used in delta.
489 */
490 
491 static intmax_t
492 delta(struct tm *newp, struct tm *oldp)
493 {
494 	intmax_t	result;
495 	int		tmy;
496 
497 	if (newp->tm_year < oldp->tm_year)
498 		return -delta(oldp, newp);
499 	result = 0;
500 	for (tmy = oldp->tm_year; tmy < newp->tm_year; ++tmy)
501 		result += DAYSPERNYEAR + isleap_sum(tmy, TM_YEAR_BASE);
502 	result += newp->tm_yday - oldp->tm_yday;
503 	result *= HOURSPERDAY;
504 	result += newp->tm_hour - oldp->tm_hour;
505 	result *= MINSPERHOUR;
506 	result += newp->tm_min - oldp->tm_min;
507 	result *= SECSPERMIN;
508 	result += newp->tm_sec - oldp->tm_sec;
509 	return result;
510 }
511 
512 static void
513 show(char *zone, time_t t, int v)
514 {
515 	struct tm *	tmp;
516 
517 	printf("%-*s  ", (int) longest, zone);
518 	if (v) {
519 		tmp = gmtime(&t);
520 		if (tmp == NULL) {
521 			printf(tformat(), t);
522 		} else {
523 			dumptime(tmp);
524 			printf(" UT");
525 		}
526 		printf(" = ");
527 	}
528 	tmp = my_localtime(&t);
529 	dumptime(tmp);
530 	if (tmp != NULL) {
531 		if (*abbr(tmp) != '\0')
532 			printf(" %s", abbr(tmp));
533 		if (v) {
534 			printf(" isdst=%d", tmp->tm_isdst);
535 #ifdef TM_GMTOFF
536 			printf(" gmtoff=%ld", tmp->TM_GMTOFF);
537 #endif /* defined TM_GMTOFF */
538 		}
539 	}
540 	printf("\n");
541 	if (tmp != NULL && *abbr(tmp) != '\0')
542 		abbrok(abbr(tmp), zone);
543 }
544 
545 static char *
546 abbr(struct tm *tmp)
547 {
548 	char * result;
549 	static char nada;
550 
551 	if (tmp->tm_isdst != 0 && tmp->tm_isdst != 1)
552 		return &nada;
553 	result = tzname[tmp->tm_isdst];
554 	return (result == NULL) ? &nada : result;
555 }
556 
557 /*
558 ** The code below can fail on certain theoretical systems;
559 ** it works on all known real-world systems as of 2004-12-30.
560 */
561 
562 static const char *
563 tformat(void)
564 {
565 	if (0 > (time_t) -1) {		/* signed */
566 		if (sizeof (time_t) == sizeof (intmax_t))
567 			return "%"PRIdMAX;
568 		if (sizeof (time_t) > sizeof (long))
569 			return "%lld";
570 		if (sizeof (time_t) > sizeof (int))
571 			return "%ld";
572 		return "%d";
573 	}
574 	if (sizeof (time_t) == sizeof (uintmax_t))
575 		return "%"PRIuMAX;
576 	if (sizeof (time_t) > sizeof (unsigned long))
577 		return "%llu";
578 	if (sizeof (time_t) > sizeof (unsigned int))
579 		return "%lu";
580 	return "%u";
581 }
582 
583 static void
584 dumptime(const struct tm *timeptr)
585 {
586 	static const char	wday_name[][3] = {
587 		"Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"
588 	};
589 	static const char	mon_name[][3] = {
590 		"Jan", "Feb", "Mar", "Apr", "May", "Jun",
591 		"Jul", "Aug", "Sep", "Oct", "Nov", "Dec"
592 	};
593 	const char *	wn;
594 	const char *	mn;
595 	int		lead;
596 	int		trail;
597 
598 	if (timeptr == NULL) {
599 		printf("NULL");
600 		return;
601 	}
602 	/*
603 	** The packaged versions of localtime and gmtime never put out-of-range
604 	** values in tm_wday or tm_mon, but since this code might be compiled
605 	** with other (perhaps experimental) versions, paranoia is in order.
606 	*/
607 	if (timeptr->tm_wday < 0 || timeptr->tm_wday >=
608 		(int) (sizeof wday_name / sizeof wday_name[0]))
609 			wn = "???";
610 	else		wn = wday_name[timeptr->tm_wday];
611 	if (timeptr->tm_mon < 0 || timeptr->tm_mon >=
612 		(int) (sizeof mon_name / sizeof mon_name[0]))
613 			mn = "???";
614 	else		mn = mon_name[timeptr->tm_mon];
615 	printf("%.3s %.3s%3d %.2d:%.2d:%.2d ",
616 		wn, mn,
617 		timeptr->tm_mday, timeptr->tm_hour,
618 		timeptr->tm_min, timeptr->tm_sec);
619 #define DIVISOR	10
620 	trail = timeptr->tm_year % DIVISOR + TM_YEAR_BASE % DIVISOR;
621 	lead = timeptr->tm_year / DIVISOR + TM_YEAR_BASE / DIVISOR +
622 		trail / DIVISOR;
623 	trail %= DIVISOR;
624 	if (trail < 0 && lead > 0) {
625 		trail += DIVISOR;
626 		--lead;
627 	} else if (lead < 0 && trail > 0) {
628 		trail -= DIVISOR;
629 		++lead;
630 	}
631 	if (lead == 0)
632 		printf("%d", trail);
633 	else	printf("%d%d", lead, ((trail < 0) ? -trail : trail));
634 }
635