zdump.c revision 7c478bd95313f5f23a4c958a745db2134aa03244
1/*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License, Version 1.0 only
6 * (the "License").  You may not use this file except in compliance
7 * with the License.
8 *
9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10 * or http://www.opensolaris.org/os/licensing.
11 * See the License for the specific language governing permissions
12 * and limitations under the License.
13 *
14 * When distributing Covered Code, include this CDDL HEADER in each
15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16 * If applicable, add the following below this CDDL HEADER, with the
17 * fields enclosed by brackets "[]" replaced with your own identifying
18 * information: Portions Copyright [yyyy] [name of copyright owner]
19 *
20 * CDDL HEADER END
21 */
22/*
23 * Copyright 1986-2002 Sun Microsystems, Inc.  All rights reserved.
24 * Use is subject to license terms.
25 */
26
27/*
28 * zdump 7.24
29 * Taken from elsie.nci.nih.gov to replace the existing Solaris zdump,
30 * which was based on an earlier version of the elsie code.
31 *
32 * For zdump 7.24, the following changes were made to the elsie code:
33 *   locale/textdomain/messages to match existing Solaris style.
34 *   Solaris verbose mode is documented to display the current time first.
35 *   cstyle cleaned code.
36 *   removed old locale/textdomain code.
37 */
38#pragma ident	"%Z%%M%	%I%	%E% SMI"
39
40/* static char	elsieid[] = "@(#)zdump.c	7.28"; */
41
42/*
43 * This code has been made independent of the rest of the time
44 * conversion package to increase confidence in the verification it provides.
45 * You can use this code to help in verifying other implementations.
46 */
47
48#include "stdio.h"	/* for stdout, stderr, perror */
49#include "string.h"	/* for strcpy */
50#include "sys/types.h"	/* for time_t */
51#include "time.h"	/* for struct tm */
52#include "stdlib.h"	/* for exit, malloc, atoi */
53#include "locale.h"	/* for setlocale, textdomain */
54#include "libintl.h"
55#include "tzfile.h"	/* for defines */
56
57#ifndef MAX_STRING_LENGTH
58#define	MAX_STRING_LENGTH	1024
59#endif /* !defined MAX_STRING_LENGTH */
60
61#ifndef TRUE
62#define	TRUE		1
63#endif /* !defined TRUE */
64
65#ifndef FALSE
66#define	FALSE		0
67#endif /* !defined FALSE */
68
69#ifndef INITIALIZE
70#ifdef lint
71#define	INITIALIZE(x)	((x) = 0)
72#endif /* defined lint */
73#ifndef lint
74#define	INITIALIZE(x)
75#endif /* !defined lint */
76#endif /* !defined INITIALIZE */
77
78extern char **	environ;
79
80static char *	abbr(struct tm *);
81static long	delta(struct tm *, struct tm *);
82static time_t	hunt(char *, time_t, time_t);
83static size_t	longest;
84static char *	progname;
85static void	show(char *, time_t, int);
86static void	usage(char *);
87
88int
89main(argc, argv)
90int	argc;
91char *	argv[];
92{
93	register int		i;
94	register int		c;
95	register int		vflag;
96	register char *		cutoff;
97	register int		cutyear;
98	register long		cuttime;
99	char **			fakeenv;
100	time_t			now;
101	time_t			t;
102	time_t			newt;
103	time_t			hibit;
104	struct tm		tm;
105	struct tm		newtm;
106
107	INITIALIZE(cuttime);
108
109	(void) setlocale(LC_ALL, "");
110#if !defined(TEXT_DOMAIN)		/* Should be defined by cc -D */
111#define	TEXT_DOMAIN	"SYS_TEST"	/* Use this only if it weren't */
112#endif
113	(void) textdomain(TEXT_DOMAIN);
114
115	progname = argv[0];
116	vflag = 0;
117	cutoff = NULL;
118	while ((c = getopt(argc, argv, "c:v")) == 'c' || c == 'v')
119		if (c == 'v')
120			vflag = 1;
121		else	cutoff = optarg;
122	if (c != EOF ||
123		(optind == argc - 1 && strcmp(argv[optind], "=") == 0)) {
124			usage(argv[0]);
125			/* NOTREACHED */
126	}
127	if (cutoff != NULL) {
128		int	y;
129
130		cutyear = atoi(cutoff);
131		cuttime = 0;
132		for (y = EPOCH_YEAR; y < cutyear; ++y)
133			cuttime += DAYSPERNYEAR + isleap(y);
134		cuttime *= SECSPERHOUR * HOURSPERDAY;
135	}
136	(void) time(&now);
137	longest = 0;
138	for (i = optind; i < argc; ++i)
139		if (strlen(argv[i]) > longest)
140			longest = strlen(argv[i]);
141	for (hibit = 1; (hibit << 1) != 0; hibit <<= 1)
142		continue;
143	{
144		register int	from;
145		register int	to;
146
147		for (i = 0;  environ[i] != NULL;  ++i)
148			continue;
149		fakeenv = (char **) malloc((size_t) ((i + 2) *
150			sizeof (*fakeenv)));
151		if (fakeenv == NULL ||
152			(fakeenv[0] = (char *) malloc(longest + 4)) == NULL) {
153					(void) perror(progname);
154					(void) exit(EXIT_FAILURE);
155		}
156		to = 0;
157		(void) strcpy(fakeenv[to++], "TZ=");
158		for (from = 0; environ[from] != NULL; ++from)
159			if (strncmp(environ[from], "TZ=", 3) != 0)
160				fakeenv[to++] = environ[from];
161		fakeenv[to] = NULL;
162		environ = fakeenv;
163	}
164	for (i = optind; i < argc; ++i) {
165		static char	buf[MAX_STRING_LENGTH];
166
167		(void) strcpy(&fakeenv[0][3], argv[i]);
168		if (!vflag) {
169			show(argv[i], now, FALSE);
170			continue;
171		}
172
173#if defined(sun)
174		/*
175		 * We show the current time first, probably because we froze
176		 * the behavior of zdump some time ago and then it got
177		 * changed.
178		 */
179		show(argv[i], now, TRUE);
180#endif
181
182		/*
183		 * Get lowest value of t.
184		 */
185		t = hibit;
186		if (t > 0)		/* time_t is unsigned */
187			t = 0;
188		show(argv[i], t, TRUE);
189		t += SECSPERHOUR * HOURSPERDAY;
190		show(argv[i], t, TRUE);
191		tm = *localtime(&t);
192		(void) strncpy(buf, abbr(&tm), (sizeof (buf)) - 1);
193		for (;;) {
194			if (cutoff != NULL && t >= cuttime)
195				break;
196			newt = t + SECSPERHOUR * 12;
197			if (cutoff != NULL && newt >= cuttime)
198				break;
199			if (newt <= t)
200				break;
201			newtm = *localtime(&newt);
202			if (delta(&newtm, &tm) != (newt - t) ||
203				newtm.tm_isdst != tm.tm_isdst ||
204				strcmp(abbr(&newtm), buf) != 0) {
205					newt = hunt(argv[i], t, newt);
206					newtm = *localtime(&newt);
207					(void) strncpy(buf, abbr(&newtm),
208						(sizeof (buf)) - 1);
209			}
210			t = newt;
211			tm = newtm;
212		}
213		/*
214		 * Get highest value of t.
215		 */
216		t = ~((time_t) 0);
217		if (t < 0)		/* time_t is signed */
218			t &= ~hibit;
219#if defined(sun)
220		show(argv[i], t, TRUE);
221		t -= SECSPERHOUR * HOURSPERDAY;
222		show(argv[i], t, TRUE);
223#else /* !defined(sun) */
224		t -= SECSPERHOUR * HOURSPERDAY;
225		show(argv[i], t, TRUE);
226		t += SECSPERHOUR * HOURSPERDAY;
227		show(argv[i], t, TRUE);
228#endif /* !defined(sun) */
229	}
230	if (fflush(stdout) || ferror(stdout)) {
231		(void) fprintf(stderr, gettext(
232		    "%s: Error writing standard output "), argv[0]);
233		(void) perror(gettext("standard output"));
234		usage(argv[0]);
235	}
236	return (EXIT_SUCCESS);
237}
238
239static time_t
240hunt(name, lot, hit)
241char *	name;
242time_t	lot;
243time_t	hit;
244{
245	time_t		t;
246	struct tm	lotm;
247	struct tm	tm;
248	static char	loab[MAX_STRING_LENGTH];
249
250	lotm = *localtime(&lot);
251	(void) strncpy(loab, abbr(&lotm), (sizeof (loab)) - 1);
252	while ((hit - lot) >= 2) {
253		t = lot / 2 + hit / 2;
254		if (t <= lot)
255			++t;
256		else if (t >= hit)
257			--t;
258		tm = *localtime(&t);
259		if (delta(&tm, &lotm) == (t - lot) &&
260			tm.tm_isdst == lotm.tm_isdst &&
261			strcmp(abbr(&tm), loab) == 0) {
262				lot = t;
263				lotm = tm;
264		} else	hit = t;
265	}
266	show(name, lot, TRUE);
267	show(name, hit, TRUE);
268	return (hit);
269}
270
271/*
272 * Thanks to Paul Eggert (eggert@twinsun.com) for logic used in delta.
273 */
274
275static long
276delta(newp, oldp)
277struct tm *	newp;
278struct tm *	oldp;
279{
280	long	result;
281	int	tmy;
282
283	if (newp->tm_year < oldp->tm_year)
284		return (-delta(oldp, newp));
285	result = 0;
286	for (tmy = oldp->tm_year; tmy < newp->tm_year; ++tmy)
287		result += DAYSPERNYEAR + isleap(tmy + TM_YEAR_BASE);
288	result += newp->tm_yday - oldp->tm_yday;
289	result *= HOURSPERDAY;
290	result += newp->tm_hour - oldp->tm_hour;
291	result *= MINSPERHOUR;
292	result += newp->tm_min - oldp->tm_min;
293	result *= SECSPERMIN;
294	result += newp->tm_sec - oldp->tm_sec;
295	return (result);
296}
297
298static void
299show(zone, t, v)
300char *	zone;
301time_t	t;
302int	v;
303{
304	struct tm *	tmp;
305
306	(void) printf("%-*s  ", (int)longest, zone);
307	if (v)
308		(void) printf("%.24s UTC = ", asctime(gmtime(&t)));
309	tmp = localtime(&t);
310	(void) printf("%.24s", asctime(tmp));
311	if (*abbr(tmp) != '\0')
312		(void) printf(" %s", abbr(tmp));
313	if (v) {
314		(void) printf(" isdst=%d", tmp->tm_isdst);
315	}
316	(void) printf("\n");
317}
318
319static char *
320abbr(tmp)
321struct tm *	tmp;
322{
323	register char *	result;
324	static char	nada;
325
326	if (tmp->tm_isdst != 0 && tmp->tm_isdst != 1)
327		return (&nada);
328	result = tzname[tmp->tm_isdst];
329	return ((result == NULL) ? &nada : result);
330}
331
332static void
333usage(char *progname)
334{
335	(void) fprintf(stderr, gettext(
336	    "%s: [ -v ] [ -c cutoffyear ] [ zonename ... ]\n"), progname);
337	(void) exit(EXIT_FAILURE);
338	/* NOTREACHED */
339}
340