zdump.c revision 130819 
1static const char	elsieid[] = "@(#)zdump.c	7.31";
2
3#ifndef lint
4static const char rcsid[] =
5  "$FreeBSD: head/usr.sbin/zic/zdump.c 130819 2004-06-20 21:41:11Z stefanf $";
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
22#ifndef MAX_STRING_LENGTH
23#define MAX_STRING_LENGTH	1024
24#endif /* !defined MAX_STRING_LENGTH */
25
26#ifndef TRUE
27#define TRUE		1
28#endif /* !defined TRUE */
29
30#ifndef FALSE
31#define FALSE		0
32#endif /* !defined FALSE */
33
34#ifndef EXIT_SUCCESS
35#define EXIT_SUCCESS	0
36#endif /* !defined EXIT_SUCCESS */
37
38#ifndef EXIT_FAILURE
39#define EXIT_FAILURE	1
40#endif /* !defined EXIT_FAILURE */
41
42#ifndef SECSPERMIN
43#define SECSPERMIN	60
44#endif /* !defined SECSPERMIN */
45
46#ifndef MINSPERHOUR
47#define MINSPERHOUR	60
48#endif /* !defined MINSPERHOUR */
49
50#ifndef SECSPERHOUR
51#define SECSPERHOUR	(SECSPERMIN * MINSPERHOUR)
52#endif /* !defined SECSPERHOUR */
53
54#ifndef HOURSPERDAY
55#define HOURSPERDAY	24
56#endif /* !defined HOURSPERDAY */
57
58#ifndef EPOCH_YEAR
59#define EPOCH_YEAR	1970
60#endif /* !defined EPOCH_YEAR */
61
62#ifndef TM_YEAR_BASE
63#define TM_YEAR_BASE	1900
64#endif /* !defined TM_YEAR_BASE */
65
66#ifndef DAYSPERNYEAR
67#define DAYSPERNYEAR	365
68#endif /* !defined DAYSPERNYEAR */
69
70#ifndef isleap
71#define isleap(y) ((((y) % 4) == 0 && ((y) % 100) != 0) || ((y) % 400) == 0)
72#endif /* !defined isleap */
73
74#if HAVE_GETTEXT - 0
75#include "locale.h"	/* for setlocale */
76#include "libintl.h"
77#endif /* HAVE_GETTEXT - 0 */
78
79#ifndef GNUC_or_lint
80#ifdef lint
81#define GNUC_or_lint
82#endif /* defined lint */
83#ifndef lint
84#ifdef __GNUC__
85#define GNUC_or_lint
86#endif /* defined __GNUC__ */
87#endif /* !defined lint */
88#endif /* !defined GNUC_or_lint */
89
90#ifndef INITIALIZE
91#ifdef GNUC_or_lint
92#define INITIALIZE(x)	((x) = 0)
93#endif /* defined GNUC_or_lint */
94#ifndef GNUC_or_lint
95#define INITIALIZE(x)
96#endif /* !defined GNUC_or_lint */
97#endif /* !defined INITIALIZE */
98
99/*
100** For the benefit of GNU folk...
101** `_(MSGID)' uses the current locale's message library string for MSGID.
102** The default is to use gettext if available, and use MSGID otherwise.
103*/
104
105#ifndef _
106#if HAVE_GETTEXT - 0
107#define _(msgid) gettext(msgid)
108#else /* !(HAVE_GETTEXT - 0) */
109#define _(msgid) msgid
110#endif /* !(HAVE_GETTEXT - 0) */
111#endif /* !defined _ */
112
113#ifndef TZ_DOMAIN
114#define TZ_DOMAIN "tz"
115#endif /* !defined TZ_DOMAIN */
116
117#ifndef P
118#ifdef __STDC__
119#define P(x)	x
120#endif /* defined __STDC__ */
121#ifndef __STDC__
122#define P(x)	()
123#endif /* !defined __STDC__ */
124#endif /* !defined P */
125
126extern char **	environ;
127extern char *	tzname[2];
128
129static char *	abbr P((struct tm * tmp));
130static long	delta P((struct tm * newp, struct tm * oldp));
131static time_t	hunt P((char * name, time_t lot, time_t	hit));
132static size_t	longest;
133static void	show P((char * zone, time_t t, int v));
134static void     usage(void);
135
136int
137main(argc, argv)
138int	argc;
139char *	argv[];
140{
141	register int		i;
142	register int		c;
143	register int		vflag;
144	register char *		cutoff;
145	register int		cutyear;
146	register long		cuttime;
147	char **			fakeenv;
148	time_t			now;
149	time_t			t;
150	time_t			newt;
151	time_t			hibit;
152	struct tm		tm;
153	struct tm		newtm;
154
155	INITIALIZE(cuttime);
156#if HAVE_GETTEXT - 0
157	(void) setlocale(LC_MESSAGES, "");
158#ifdef TZ_DOMAINDIR
159	(void) bindtextdomain(TZ_DOMAIN, TZ_DOMAINDIR);
160#endif /* defined(TEXTDOMAINDIR) */
161	(void) textdomain(TZ_DOMAIN);
162#endif /* HAVE_GETTEXT - 0 */
163	for (i = 1; i < argc; ++i)
164		if (strcmp(argv[i], "--version") == 0) {
165			errx(EXIT_SUCCESS, "%s", elsieid);
166		}
167	vflag = 0;
168	cutoff = NULL;
169	while ((c = getopt(argc, argv, "c:v")) == 'c' || c == 'v')
170		if (c == 'v')
171			vflag = 1;
172		else	cutoff = optarg;
173	if ((c != EOF && c != -1) ||
174		(optind == argc - 1 && strcmp(argv[optind], "=") == 0)) {
175			usage();
176	}
177	if (cutoff != NULL) {
178		int	y;
179
180		cutyear = atoi(cutoff);
181		cuttime = 0;
182		for (y = EPOCH_YEAR; y < cutyear; ++y)
183			cuttime += DAYSPERNYEAR + isleap(y);
184		cuttime *= SECSPERHOUR * HOURSPERDAY;
185	}
186	(void) time(&now);
187	longest = 0;
188	for (i = optind; i < argc; ++i)
189		if (strlen(argv[i]) > longest)
190			longest = strlen(argv[i]);
191	for (hibit = 1; (hibit << 1) != 0; hibit <<= 1)
192		continue;
193	{
194		register int	from;
195		register int	to;
196
197		for (i = 0;  environ[i] != NULL;  ++i)
198			continue;
199		fakeenv = (char **) malloc((size_t) ((i + 2) *
200			sizeof *fakeenv));
201		if (fakeenv == NULL ||
202			(fakeenv[0] = (char *) malloc((size_t) (longest +
203				4))) == NULL)
204					errx(EXIT_FAILURE,
205					     _("malloc() failed"));
206		to = 0;
207		(void) strcpy(fakeenv[to++], "TZ=");
208		for (from = 0; environ[from] != NULL; ++from)
209			if (strncmp(environ[from], "TZ=", 3) != 0)
210				fakeenv[to++] = environ[from];
211		fakeenv[to] = NULL;
212		environ = fakeenv;
213	}
214	for (i = optind; i < argc; ++i) {
215		static char	buf[MAX_STRING_LENGTH];
216
217		(void) strcpy(&fakeenv[0][3], argv[i]);
218		if (!vflag) {
219			show(argv[i], now, FALSE);
220			continue;
221		}
222		/*
223		** Get lowest value of t.
224		*/
225		t = hibit;
226		if (t > 0)		/* time_t is unsigned */
227			t = 0;
228		show(argv[i], t, TRUE);
229		t += SECSPERHOUR * HOURSPERDAY;
230		show(argv[i], t, TRUE);
231		tm = *localtime(&t);
232		(void) strncpy(buf, abbr(&tm), (sizeof buf) - 1);
233		for ( ; ; ) {
234			if (cutoff != NULL && t >= cuttime)
235				break;
236			newt = t + SECSPERHOUR * 12;
237			if (cutoff != NULL && newt >= cuttime)
238				break;
239			if (newt <= t)
240				break;
241			newtm = *localtime(&newt);
242			if (delta(&newtm, &tm) != (newt - t) ||
243				newtm.tm_isdst != tm.tm_isdst ||
244				strcmp(abbr(&newtm), buf) != 0) {
245					newt = hunt(argv[i], t, newt);
246					newtm = *localtime(&newt);
247					(void) strncpy(buf, abbr(&newtm),
248						(sizeof buf) - 1);
249			}
250			t = newt;
251			tm = newtm;
252		}
253		/*
254		** Get highest value of t.
255		*/
256		t = ~((time_t) 0);
257		if (t < 0)		/* time_t is signed */
258			t &= ~hibit;
259		t -= SECSPERHOUR * HOURSPERDAY;
260		show(argv[i], t, TRUE);
261		t += SECSPERHOUR * HOURSPERDAY;
262		show(argv[i], t, TRUE);
263	}
264	if (fflush(stdout) || ferror(stdout))
265		errx(EXIT_FAILURE, _("error writing standard output"));
266	exit(EXIT_SUCCESS);
267
268	/* gcc -Wall pacifier */
269	for ( ; ; )
270		continue;
271}
272
273static void
274usage(void)
275{
276	fprintf(stderr,
277_("usage: zdump [--version] [-v] [-c cutoff] zonename ...\n"));
278	exit(EXIT_FAILURE);
279}
280
281static time_t
282hunt(name, lot, hit)
283char *	name;
284time_t	lot;
285time_t	hit;
286{
287	time_t		t;
288	struct tm	lotm;
289	struct tm	tm;
290	static char	loab[MAX_STRING_LENGTH];
291
292	lotm = *localtime(&lot);
293	(void) strncpy(loab, abbr(&lotm), (sizeof loab) - 1);
294	while ((hit - lot) >= 2) {
295		t = lot / 2 + hit / 2;
296		if (t <= lot)
297			++t;
298		else if (t >= hit)
299			--t;
300		tm = *localtime(&t);
301		if (delta(&tm, &lotm) == (t - lot) &&
302			tm.tm_isdst == lotm.tm_isdst &&
303			strcmp(abbr(&tm), loab) == 0) {
304				lot = t;
305				lotm = tm;
306		} else	hit = t;
307	}
308	show(name, lot, TRUE);
309	show(name, hit, TRUE);
310	return hit;
311}
312
313/*
314** Thanks to Paul Eggert (eggert@twinsun.com) for logic used in delta.
315*/
316
317static long
318delta(newp, oldp)
319struct tm *	newp;
320struct tm *	oldp;
321{
322	long	result;
323	int	tmy;
324
325	if (newp->tm_year < oldp->tm_year)
326		return -delta(oldp, newp);
327	result = 0;
328	for (tmy = oldp->tm_year; tmy < newp->tm_year; ++tmy)
329		result += DAYSPERNYEAR + isleap(tmy + TM_YEAR_BASE);
330	result += newp->tm_yday - oldp->tm_yday;
331	result *= HOURSPERDAY;
332	result += newp->tm_hour - oldp->tm_hour;
333	result *= MINSPERHOUR;
334	result += newp->tm_min - oldp->tm_min;
335	result *= SECSPERMIN;
336	result += newp->tm_sec - oldp->tm_sec;
337	return result;
338}
339
340static void
341show(zone, t, v)
342char *	zone;
343time_t	t;
344int	v;
345{
346	struct tm *	tmp;
347
348	(void) printf("%-*s  ", (int) longest, zone);
349	if (v)
350		(void) printf("%.24s UTC = ", asctime(gmtime(&t)));
351	tmp = localtime(&t);
352	(void) printf("%.24s", asctime(tmp));
353	if (*abbr(tmp) != '\0')
354		(void) printf(" %s", abbr(tmp));
355	if (v) {
356		(void) printf(" isdst=%d", tmp->tm_isdst);
357#ifdef TM_GMTOFF
358		(void) printf(" gmtoff=%ld", tmp->TM_GMTOFF);
359#endif /* defined TM_GMTOFF */
360	}
361	(void) printf("\n");
362}
363
364static char *
365abbr(tmp)
366struct tm *	tmp;
367{
368	register char *	result;
369	static char	nada;
370
371	if (tmp->tm_isdst != 0 && tmp->tm_isdst != 1)
372		return &nada;
373	result = tzname[tmp->tm_isdst];
374	return (result == NULL) ? &nada : result;
375}
376