xref: /illumos-gate/usr/src/cmd/zdump/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 
78 extern char **	environ;
79 
80 static char *	abbr(struct tm *);
81 static long	delta(struct tm *, struct tm *);
82 static time_t	hunt(char *, time_t, time_t);
83 static size_t	longest;
84 static char *	progname;
85 static void	show(char *, time_t, int);
86 static void	usage(char *);
87 
88 int
89 main(argc, argv)
90 int	argc;
91 char *	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 
239 static time_t
240 hunt(name, lot, hit)
241 char *	name;
242 time_t	lot;
243 time_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 
275 static long
276 delta(newp, oldp)
277 struct tm *	newp;
278 struct 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 
298 static void
299 show(zone, t, v)
300 char *	zone;
301 time_t	t;
302 int	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 
319 static char *
320 abbr(tmp)
321 struct 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 
332 static void
333 usage(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