zdump.c revision 17214 
1#ifndef lint
2#ifndef NOID
3static char	elsieid[] = "@(#)zdump.c	7.24";
4#endif /* !defined NOID */
5#endif /* !defined lint */
6
7/*
8** This code has been made independent of the rest of the time
9** conversion package to increase confidence in the verification it provides.
10** You can use this code to help in verifying other implementations.
11*/
12
13#include "stdio.h"	/* for stdout, stderr, perror */
14#include "string.h"	/* for strcpy */
15#include "sys/types.h"	/* for time_t */
16#include "time.h"	/* for struct tm */
17#include "stdlib.h"	/* for exit, malloc, atoi */
18
19#ifndef MAX_STRING_LENGTH
20#define MAX_STRING_LENGTH	1024
21#endif /* !defined MAX_STRING_LENGTH */
22
23#ifndef TRUE
24#define TRUE		1
25#endif /* !defined TRUE */
26
27#ifndef FALSE
28#define FALSE		0
29#endif /* !defined FALSE */
30
31#ifndef EXIT_SUCCESS
32#define EXIT_SUCCESS	0
33#endif /* !defined EXIT_SUCCESS */
34
35#ifndef EXIT_FAILURE
36#define EXIT_FAILURE	1
37#endif /* !defined EXIT_FAILURE */
38
39#ifndef SECSPERMIN
40#define SECSPERMIN	60
41#endif /* !defined SECSPERMIN */
42
43#ifndef MINSPERHOUR
44#define MINSPERHOUR	60
45#endif /* !defined MINSPERHOUR */
46
47#ifndef SECSPERHOUR
48#define SECSPERHOUR	(SECSPERMIN * MINSPERHOUR)
49#endif /* !defined SECSPERHOUR */
50
51#ifndef HOURSPERDAY
52#define HOURSPERDAY	24
53#endif /* !defined HOURSPERDAY */
54
55#ifndef EPOCH_YEAR
56#define EPOCH_YEAR	1970
57#endif /* !defined EPOCH_YEAR */
58
59#ifndef TM_YEAR_BASE
60#define TM_YEAR_BASE	1900
61#endif /* !defined TM_YEAR_BASE */
62
63#ifndef DAYSPERNYEAR
64#define DAYSPERNYEAR	365
65#endif /* !defined DAYSPERNYEAR */
66
67#ifndef isleap
68#define isleap(y) ((((y) % 4) == 0 && ((y) % 100) != 0) || ((y) % 400) == 0)
69#endif /* !defined isleap */
70
71#if HAVE_GETTEXT - 0
72#include "locale.h"	/* for setlocale */
73#include "libintl.h"
74#endif /* HAVE_GETTEXT - 0 */
75
76#ifndef GNUC_or_lint
77#ifdef lint
78#define GNUC_or_lint
79#endif /* defined lint */
80#ifndef lint
81#ifdef __GNUC__
82#define GNUC_or_lint
83#endif /* defined __GNUC__ */
84#endif /* !defined lint */
85#endif /* !defined GNUC_or_lint */
86
87#ifndef INITIALIZE
88#ifdef GNUC_or_lint
89#define INITIALIZE(x)	((x) = 0)
90#endif /* defined GNUC_or_lint */
91#ifndef GNUC_or_lint
92#define INITIALIZE(x)
93#endif /* !defined GNUC_or_lint */
94#endif /* !defined INITIALIZE */
95
96/*
97** For the benefit of GNU folk...
98** `_(MSGID)' uses the current locale's message library string for MSGID.
99** The default is to use gettext if available, and use MSGID otherwise.
100*/
101
102#ifndef _
103#if HAVE_GETTEXT - 0
104#define _(msgid) gettext(msgid)
105#else /* !(HAVE_GETTEXT - 0) */
106#define _(msgid) msgid
107#endif /* !(HAVE_GETTEXT - 0) */
108#endif /* !defined _ */
109
110#ifndef TZ_DOMAIN
111#define TZ_DOMAIN "tz"
112#endif /* !defined TZ_DOMAIN */
113
114extern char **	environ;
115extern int	getopt();
116extern char *	optarg;
117extern int	optind;
118extern time_t	time();
119extern char *	tzname[2];
120
121static char *	abbr();
122static long	delta();
123static time_t	hunt();
124static int	longest;
125static char *	progname;
126static void	show();
127
128int
129main(argc, argv)
130int	argc;
131char *	argv[];
132{
133	register int		i;
134	register int		c;
135	register int		vflag;
136	register char *		cutoff;
137	register int		cutyear;
138	register long		cuttime;
139	char **			fakeenv;
140	time_t			now;
141	time_t			t;
142	time_t			newt;
143	time_t			hibit;
144	struct tm		tm;
145	struct tm		newtm;
146
147	INITIALIZE(cuttime);
148#if HAVE_GETTEXT - 0
149	(void) setlocale(LC_MESSAGES, "");
150#ifdef TZ_DOMAINDIR
151	(void) bindtextdomain(TZ_DOMAIN, TZ_DOMAINDIR);
152#endif /* defined(TEXTDOMAINDIR) */
153	(void) textdomain(TZ_DOMAIN);
154#endif /* HAVE_GETTEXT - 0 */
155	progname = argv[0];
156	vflag = 0;
157	cutoff = NULL;
158	while ((c = getopt(argc, argv, "c:v")) == 'c' || c == 'v')
159		if (c == 'v')
160			vflag = 1;
161		else	cutoff = optarg;
162	if (c != EOF ||
163		(optind == argc - 1 && strcmp(argv[optind], "=") == 0)) {
164			(void) fprintf(stderr,
165_("%s: usage is %s [ -v ] [ -c cutoff ] zonename ...\n"),
166				argv[0], argv[0]);
167			(void) exit(EXIT_FAILURE);
168	}
169	if (cutoff != NULL) {
170		int	y;
171
172		cutyear = atoi(cutoff);
173		cuttime = 0;
174		for (y = EPOCH_YEAR; y < cutyear; ++y)
175			cuttime += DAYSPERNYEAR + isleap(y);
176		cuttime *= SECSPERHOUR * HOURSPERDAY;
177	}
178	(void) time(&now);
179	longest = 0;
180	for (i = optind; i < argc; ++i)
181		if (strlen(argv[i]) > longest)
182			longest = strlen(argv[i]);
183	for (hibit = 1; (hibit << 1) != 0; hibit <<= 1)
184		continue;
185	{
186		register int	from;
187		register int	to;
188
189		for (i = 0;  environ[i] != NULL;  ++i)
190			continue;
191		fakeenv = (char **) malloc((size_t) ((i + 2) *
192			sizeof *fakeenv));
193		if (fakeenv == NULL ||
194			(fakeenv[0] = (char *) malloc((size_t) (longest +
195				4))) == NULL) {
196					(void) perror(progname);
197					(void) exit(EXIT_FAILURE);
198		}
199		to = 0;
200		(void) strcpy(fakeenv[to++], "TZ=");
201		for (from = 0; environ[from] != NULL; ++from)
202			if (strncmp(environ[from], "TZ=", 3) != 0)
203				fakeenv[to++] = environ[from];
204		fakeenv[to] = NULL;
205		environ = fakeenv;
206	}
207	for (i = optind; i < argc; ++i) {
208		static char	buf[MAX_STRING_LENGTH];
209
210		(void) strcpy(&fakeenv[0][3], argv[i]);
211		if (!vflag) {
212			show(argv[i], now, FALSE);
213			continue;
214		}
215		/*
216		** Get lowest value of t.
217		*/
218		t = hibit;
219		if (t > 0)		/* time_t is unsigned */
220			t = 0;
221		show(argv[i], t, TRUE);
222		t += SECSPERHOUR * HOURSPERDAY;
223		show(argv[i], t, TRUE);
224		tm = *localtime(&t);
225		(void) strncpy(buf, abbr(&tm), (sizeof buf) - 1);
226		for ( ; ; ) {
227			if (cutoff != NULL && t >= cuttime)
228				break;
229			newt = t + SECSPERHOUR * 12;
230			if (cutoff != NULL && newt >= cuttime)
231				break;
232			if (newt <= t)
233				break;
234			newtm = *localtime(&newt);
235			if (delta(&newtm, &tm) != (newt - t) ||
236				newtm.tm_isdst != tm.tm_isdst ||
237				strcmp(abbr(&newtm), buf) != 0) {
238					newt = hunt(argv[i], t, newt);
239					newtm = *localtime(&newt);
240					(void) strncpy(buf, abbr(&newtm),
241						(sizeof buf) - 1);
242			}
243			t = newt;
244			tm = newtm;
245		}
246		/*
247		** Get highest value of t.
248		*/
249		t = ~((time_t) 0);
250		if (t < 0)		/* time_t is signed */
251			t &= ~hibit;
252		t -= SECSPERHOUR * HOURSPERDAY;
253		show(argv[i], t, TRUE);
254		t += SECSPERHOUR * HOURSPERDAY;
255		show(argv[i], t, TRUE);
256	}
257	if (fflush(stdout) || ferror(stdout)) {
258		(void) fprintf(stderr, _("%s: Error writing standard output "),
259			argv[0]);
260		(void) perror(_("standard output"));
261		(void) exit(EXIT_FAILURE);
262	}
263	exit(EXIT_SUCCESS);
264
265	/* gcc -Wall pacifier */
266	for ( ; ; )
267		continue;
268}
269
270static time_t
271hunt(name, lot, hit)
272char *	name;
273time_t	lot;
274time_t	hit;
275{
276	time_t		t;
277	struct tm	lotm;
278	struct tm	tm;
279	static char	loab[MAX_STRING_LENGTH];
280
281	lotm = *localtime(&lot);
282	(void) strncpy(loab, abbr(&lotm), (sizeof loab) - 1);
283	while ((hit - lot) >= 2) {
284		t = lot / 2 + hit / 2;
285		if (t <= lot)
286			++t;
287		else if (t >= hit)
288			--t;
289		tm = *localtime(&t);
290		if (delta(&tm, &lotm) == (t - lot) &&
291			tm.tm_isdst == lotm.tm_isdst &&
292			strcmp(abbr(&tm), loab) == 0) {
293				lot = t;
294				lotm = tm;
295		} else	hit = t;
296	}
297	show(name, lot, TRUE);
298	show(name, hit, TRUE);
299	return hit;
300}
301
302/*
303** Thanks to Paul Eggert (eggert@twinsun.com) for logic used in delta.
304*/
305
306static long
307delta(newp, oldp)
308struct tm *	newp;
309struct tm *	oldp;
310{
311	long	result;
312	int	tmy;
313
314	if (newp->tm_year < oldp->tm_year)
315		return -delta(oldp, newp);
316	result = 0;
317	for (tmy = oldp->tm_year; tmy < newp->tm_year; ++tmy)
318		result += DAYSPERNYEAR + isleap(tmy + TM_YEAR_BASE);
319	result += newp->tm_yday - oldp->tm_yday;
320	result *= HOURSPERDAY;
321	result += newp->tm_hour - oldp->tm_hour;
322	result *= MINSPERHOUR;
323	result += newp->tm_min - oldp->tm_min;
324	result *= SECSPERMIN;
325	result += newp->tm_sec - oldp->tm_sec;
326	return result;
327}
328
329extern struct tm *	localtime();
330
331static void
332show(zone, t, v)
333char *	zone;
334time_t	t;
335int	v;
336{
337	struct tm *	tmp;
338
339	(void) printf("%-*s  ", longest, zone);
340	if (v)
341		(void) printf("%.24s GMT = ", asctime(gmtime(&t)));
342	tmp = localtime(&t);
343	(void) printf("%.24s", asctime(tmp));
344	if (*abbr(tmp) != '\0')
345		(void) printf(" %s", abbr(tmp));
346	if (v) {
347		(void) printf(" isdst=%d", tmp->tm_isdst);
348#ifdef TM_GMTOFF
349		(void) printf(" gmtoff=%ld", tmp->TM_GMTOFF);
350#endif /* defined TM_GMTOFF */
351	}
352	(void) printf("\n");
353}
354
355static char *
356abbr(tmp)
357struct tm *	tmp;
358{
359	register char *	result;
360	static char	nada;
361
362	if (tmp->tm_isdst != 0 && tmp->tm_isdst != 1)
363		return &nada;
364	result = tzname[tmp->tm_isdst];
365	return (result == NULL) ? &nada : result;
366}
367