1static const char	elsieid[] = "@(#)zdump.c	7.31";
2
3#ifndef lint
4static const char rcsid[] =
5  "$FreeBSD: src/usr.sbin/zic/zdump.c,v 1.10 2008/02/19 07:09:19 ru Exp $";
6#endif /* not lint */
7
8/*
9** This code has been made independent of the rest of the time
10** conversion package to increase confidence in the verification it provides.
11** You can use this code to help in verifying other implementations.
12*/
13
14#include <err.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#include <limits.h>
22
23#ifndef MAX_STRING_LENGTH
24#define MAX_STRING_LENGTH	1024
25#endif /* !defined MAX_STRING_LENGTH */
26
27#ifndef TRUE
28#define TRUE		1
29#endif /* !defined TRUE */
30
31#ifndef FALSE
32#define FALSE		0
33#endif /* !defined FALSE */
34
35#ifndef EXIT_SUCCESS
36#define EXIT_SUCCESS	0
37#endif /* !defined EXIT_SUCCESS */
38
39#ifndef EXIT_FAILURE
40#define EXIT_FAILURE	1
41#endif /* !defined EXIT_FAILURE */
42
43#ifndef SECSPERMIN
44#define SECSPERMIN	60
45#endif /* !defined SECSPERMIN */
46
47#ifndef MINSPERHOUR
48#define MINSPERHOUR	60
49#endif /* !defined MINSPERHOUR */
50
51#ifndef SECSPERHOUR
52#define SECSPERHOUR	(SECSPERMIN * MINSPERHOUR)
53#endif /* !defined SECSPERHOUR */
54
55#ifndef HOURSPERDAY
56#define HOURSPERDAY	24
57#endif /* !defined HOURSPERDAY */
58
59#ifndef EPOCH_YEAR
60#define EPOCH_YEAR	1970
61#endif /* !defined EPOCH_YEAR */
62
63#ifndef TM_YEAR_BASE
64#define TM_YEAR_BASE	1900
65#endif /* !defined TM_YEAR_BASE */
66
67#ifndef DAYSPERNYEAR
68#define DAYSPERNYEAR	365
69#endif /* !defined DAYSPERNYEAR */
70
71#ifndef isleap
72#define isleap(y) ((((y) % 4) == 0 && ((y) % 100) != 0) || ((y) % 400) == 0)
73#endif /* !defined isleap */
74
75#if HAVE_GETTEXT - 0
76#include "locale.h"	/* for setlocale */
77#include "libintl.h"
78#endif /* HAVE_GETTEXT - 0 */
79
80#ifndef GNUC_or_lint
81#ifdef lint
82#define GNUC_or_lint
83#endif /* defined lint */
84#ifndef lint
85#ifdef __GNUC__
86#define GNUC_or_lint
87#endif /* defined __GNUC__ */
88#endif /* !defined lint */
89#endif /* !defined GNUC_or_lint */
90
91#ifndef INITIALIZE
92#ifdef GNUC_or_lint
93#define INITIALIZE(x)	((x) = 0)
94#endif /* defined GNUC_or_lint */
95#ifndef GNUC_or_lint
96#define INITIALIZE(x)
97#endif /* !defined GNUC_or_lint */
98#endif /* !defined INITIALIZE */
99
100/*
101** For the benefit of GNU folk...
102** `_(MSGID)' uses the current locale's message library string for MSGID.
103** The default is to use gettext if available, and use MSGID otherwise.
104*/
105
106#ifndef _
107#if HAVE_GETTEXT - 0
108#define _(msgid) gettext(msgid)
109#else /* !(HAVE_GETTEXT - 0) */
110#define _(msgid) msgid
111#endif /* !(HAVE_GETTEXT - 0) */
112#endif /* !defined _ */
113
114#ifndef TZ_DOMAIN
115#define TZ_DOMAIN "tz"
116#endif /* !defined TZ_DOMAIN */
117
118#ifndef P
119#ifdef __STDC__
120#define P(x)	x
121#endif /* defined __STDC__ */
122#ifndef __STDC__
123#define P(x)	()
124#endif /* !defined __STDC__ */
125#endif /* !defined P */
126
127extern char **	environ;
128extern char *	tzname[2];
129
130static char *	abbr P((struct tm * tmp));
131static long	delta P((struct tm * newp, struct tm * oldp));
132static time_t	hunt P((char * name, time_t lot, time_t	hit));
133static size_t	longest;
134static void	show P((char * zone, time_t t, int v));
135static void     usage(void);
136
137int
138main(argc, argv)
139int	argc;
140char *	argv[];
141{
142	register int		i;
143	register int		c;
144	register int		vflag;
145	register char *		cutoff;
146	register int		cutyear;
147	register long		cuttime;
148	char **			fakeenv;
149	time_t			now;
150	time_t			t;
151	time_t			newt;
152#ifndef __APPLE__
153// <rdar://problem/6013740>
154// The approach of walking through every day from the minimum
155// possible time_t value to the maximum possible time_t value
156// falls apart with 64-bit time_t (takes too long to iterate,
157// and causes gmtime(3) and localtime(3) to return EOVERFLOW
158// which this code does not anticipate).  Limiting the time_t
159// range to [INT_MIN:INT_MAX] even on LP64.
160	time_t			hibit;
161#endif
162	struct tm		tm;
163	struct tm		newtm;
164
165	INITIALIZE(cuttime);
166#if HAVE_GETTEXT - 0
167	(void) setlocale(LC_MESSAGES, "");
168#ifdef TZ_DOMAINDIR
169	(void) bindtextdomain(TZ_DOMAIN, TZ_DOMAINDIR);
170#endif /* defined(TEXTDOMAINDIR) */
171	(void) textdomain(TZ_DOMAIN);
172#endif /* HAVE_GETTEXT - 0 */
173	for (i = 1; i < argc; ++i)
174		if (strcmp(argv[i], "--version") == 0) {
175			errx(EXIT_SUCCESS, "%s", elsieid);
176		}
177	vflag = 0;
178	cutoff = NULL;
179	while ((c = getopt(argc, argv, "c:v")) == 'c' || c == 'v')
180		if (c == 'v')
181			vflag = 1;
182		else	cutoff = optarg;
183	if ((c != -1) ||
184		(optind == argc - 1 && strcmp(argv[optind], "=") == 0)) {
185			usage();
186	}
187	if (cutoff != NULL) {
188		int	y;
189
190		cutyear = atoi(cutoff);
191		cuttime = 0;
192		for (y = EPOCH_YEAR; y < cutyear; ++y)
193			cuttime += DAYSPERNYEAR + isleap(y);
194		cuttime *= SECSPERHOUR * HOURSPERDAY;
195	}
196	(void) time(&now);
197	longest = 0;
198	for (i = optind; i < argc; ++i)
199		if (strlen(argv[i]) > longest)
200			longest = strlen(argv[i]);
201#ifndef __APPLE__
202	for (hibit = 1; (hibit << 1) != 0; hibit <<= 1)
203		continue;
204#endif
205	{
206		register int	from;
207		register int	to;
208
209		for (i = 0;  environ[i] != NULL;  ++i)
210			continue;
211		fakeenv = (char **) malloc((size_t) ((i + 2) *
212			sizeof *fakeenv));
213		if (fakeenv == NULL ||
214			(fakeenv[0] = (char *) malloc((size_t) (longest +
215				4))) == NULL)
216					errx(EXIT_FAILURE,
217					     _("malloc() failed"));
218		to = 0;
219		(void) strcpy(fakeenv[to++], "TZ=");
220		for (from = 0; environ[from] != NULL; ++from)
221			if (strncmp(environ[from], "TZ=", 3) != 0)
222				fakeenv[to++] = environ[from];
223		fakeenv[to] = NULL;
224		environ = fakeenv;
225	}
226	for (i = optind; i < argc; ++i) {
227		static char	buf[MAX_STRING_LENGTH];
228
229		(void) strcpy(&fakeenv[0][3], argv[i]);
230		if (!vflag) {
231			show(argv[i], now, FALSE);
232			continue;
233		}
234		/*
235		** Get lowest value of t.
236		*/
237#ifdef __APPLE__
238		t = INT_MIN;
239#else
240		t = hibit;
241		if (t > 0)		/* time_t is unsigned */
242			t = 0;
243#endif
244		show(argv[i], t, TRUE);
245		t += SECSPERHOUR * HOURSPERDAY;
246		show(argv[i], t, TRUE);
247		tm = *localtime(&t);
248		(void) strncpy(buf, abbr(&tm), (sizeof buf) - 1);
249		for ( ; ; ) {
250			if (cutoff != NULL && t >= cuttime)
251				break;
252			newt = t + SECSPERHOUR * 12;
253			if (cutoff != NULL && newt >= cuttime)
254				break;
255#ifdef __APPLE__
256			if (newt > INT_MAX)
257				break;
258#else
259			if (newt <= t)
260				break;
261#endif
262			newtm = *localtime(&newt);
263			if (delta(&newtm, &tm) != (newt - t) ||
264				newtm.tm_isdst != tm.tm_isdst ||
265				strcmp(abbr(&newtm), buf) != 0) {
266					newt = hunt(argv[i], t, newt);
267					newtm = *localtime(&newt);
268					(void) strncpy(buf, abbr(&newtm),
269						(sizeof buf) - 1);
270			}
271			t = newt;
272			tm = newtm;
273		}
274		/*
275		** Get highest value of t.
276		*/
277#ifdef __APPLE__
278		t = INT_MAX;
279#else
280		t = ~((time_t) 0);
281		if (t < 0)		/* time_t is signed */
282			t &= ~hibit;
283#endif
284		t -= SECSPERHOUR * HOURSPERDAY;
285		show(argv[i], t, TRUE);
286		t += SECSPERHOUR * HOURSPERDAY;
287		show(argv[i], t, TRUE);
288	}
289	if (fflush(stdout) || ferror(stdout))
290		errx(EXIT_FAILURE, _("error writing standard output"));
291	exit(EXIT_SUCCESS);
292
293	/* gcc -Wall pacifier */
294	for ( ; ; )
295		continue;
296}
297
298static void
299usage(void)
300{
301	fprintf(stderr,
302_("usage: zdump [--version] [-v] [-c cutoff] zonename ...\n"));
303	exit(EXIT_FAILURE);
304}
305
306static time_t
307hunt(name, lot, hit)
308char *	name;
309time_t	lot;
310time_t	hit;
311{
312	time_t		t;
313	struct tm	lotm;
314	struct tm	tm;
315	static char	loab[MAX_STRING_LENGTH];
316
317	lotm = *localtime(&lot);
318	(void) strncpy(loab, abbr(&lotm), (sizeof loab) - 1);
319	while ((hit - lot) >= 2) {
320		t = lot / 2 + hit / 2;
321		if (t <= lot)
322			++t;
323		else if (t >= hit)
324			--t;
325		tm = *localtime(&t);
326		if (delta(&tm, &lotm) == (t - lot) &&
327			tm.tm_isdst == lotm.tm_isdst &&
328			strcmp(abbr(&tm), loab) == 0) {
329				lot = t;
330				lotm = tm;
331		} else	hit = t;
332	}
333	show(name, lot, TRUE);
334	show(name, hit, TRUE);
335	return hit;
336}
337
338/*
339** Thanks to Paul Eggert (eggert@twinsun.com) for logic used in delta.
340*/
341
342static long
343delta(newp, oldp)
344struct tm *	newp;
345struct tm *	oldp;
346{
347	long	result;
348	int	tmy;
349
350	if (newp->tm_year < oldp->tm_year)
351		return -delta(oldp, newp);
352	result = 0;
353	for (tmy = oldp->tm_year; tmy < newp->tm_year; ++tmy)
354		result += DAYSPERNYEAR + isleap(tmy + TM_YEAR_BASE);
355	result += newp->tm_yday - oldp->tm_yday;
356	result *= HOURSPERDAY;
357	result += newp->tm_hour - oldp->tm_hour;
358	result *= MINSPERHOUR;
359	result += newp->tm_min - oldp->tm_min;
360	result *= SECSPERMIN;
361	result += newp->tm_sec - oldp->tm_sec;
362	return result;
363}
364
365static void
366show(zone, t, v)
367char *	zone;
368time_t	t;
369int	v;
370{
371	struct tm *	tmp;
372
373	(void) printf("%-*s  ", (int) longest, zone);
374	if (v)
375		(void) printf("%.24s UTC = ", asctime(gmtime(&t)));
376	tmp = localtime(&t);
377	(void) printf("%.24s", asctime(tmp));
378	if (*abbr(tmp) != '\0')
379		(void) printf(" %s", abbr(tmp));
380	if (v) {
381		(void) printf(" isdst=%d", tmp->tm_isdst);
382#ifdef TM_GMTOFF
383		(void) printf(" gmtoff=%ld", tmp->TM_GMTOFF);
384#endif /* defined TM_GMTOFF */
385	}
386	(void) printf("\n");
387}
388
389static char *
390abbr(tmp)
391struct tm *	tmp;
392{
393	register char *	result;
394	static char	nada;
395
396	if (tmp->tm_isdst != 0 && tmp->tm_isdst != 1)
397		return &nada;
398	result = tzname[tmp->tm_isdst];
399	return (result == NULL) ? &nada : result;
400}
401