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