zdump.c revision 1.8
1 /* $NetBSD: zdump.c,v 1.8 1998/01/22 07:07:00 jtc Exp $ */ 2 3 #include <sys/cdefs.h> 4 #ifndef lint 5 #ifndef NOID 6 #if 0 7 static char elsieid[] = "@(#)zdump.c 7.27"; 8 #else 9 __RCSID("$NetBSD: zdump.c,v 1.8 1998/01/22 07:07:00 jtc Exp $"); 10 #endif 11 #endif /* !defined NOID */ 12 #endif /* !defined lint */ 13 14 /* 15 ** This code has been made independent of the rest of the time 16 ** conversion package to increase confidence in the verification it provides. 17 ** You can use this code to help in verifying other implementations. 18 */ 19 20 #include "stdio.h" /* for stdout, stderr, perror */ 21 #include "string.h" /* for strcpy */ 22 #include "sys/types.h" /* for time_t */ 23 #include "time.h" /* for struct tm */ 24 #include "stdlib.h" /* for exit, malloc, atoi */ 25 26 #ifndef MAX_STRING_LENGTH 27 #define MAX_STRING_LENGTH 1024 28 #endif /* !defined MAX_STRING_LENGTH */ 29 30 #ifndef TRUE 31 #define TRUE 1 32 #endif /* !defined TRUE */ 33 34 #ifndef FALSE 35 #define FALSE 0 36 #endif /* !defined FALSE */ 37 38 #ifndef EXIT_SUCCESS 39 #define EXIT_SUCCESS 0 40 #endif /* !defined EXIT_SUCCESS */ 41 42 #ifndef EXIT_FAILURE 43 #define EXIT_FAILURE 1 44 #endif /* !defined EXIT_FAILURE */ 45 46 #ifndef SECSPERMIN 47 #define SECSPERMIN 60 48 #endif /* !defined SECSPERMIN */ 49 50 #ifndef MINSPERHOUR 51 #define MINSPERHOUR 60 52 #endif /* !defined MINSPERHOUR */ 53 54 #ifndef SECSPERHOUR 55 #define SECSPERHOUR (SECSPERMIN * MINSPERHOUR) 56 #endif /* !defined SECSPERHOUR */ 57 58 #ifndef HOURSPERDAY 59 #define HOURSPERDAY 24 60 #endif /* !defined HOURSPERDAY */ 61 62 #ifndef EPOCH_YEAR 63 #define EPOCH_YEAR 1970 64 #endif /* !defined EPOCH_YEAR */ 65 66 #ifndef TM_YEAR_BASE 67 #define TM_YEAR_BASE 1900 68 #endif /* !defined TM_YEAR_BASE */ 69 70 #ifndef DAYSPERNYEAR 71 #define DAYSPERNYEAR 365 72 #endif /* !defined DAYSPERNYEAR */ 73 74 #ifndef isleap 75 #define isleap(y) ((((y) % 4) == 0 && ((y) % 100) != 0) || ((y) % 400) == 0) 76 #endif /* !defined isleap */ 77 78 #if HAVE_GETTEXT - 0 79 #include "locale.h" /* for setlocale */ 80 #include "libintl.h" 81 #endif /* HAVE_GETTEXT - 0 */ 82 83 #ifndef GNUC_or_lint 84 #ifdef lint 85 #define GNUC_or_lint 86 #endif /* defined lint */ 87 #ifndef lint 88 #ifdef __GNUC__ 89 #define GNUC_or_lint 90 #endif /* defined __GNUC__ */ 91 #endif /* !defined lint */ 92 #endif /* !defined GNUC_or_lint */ 93 94 #ifndef INITIALIZE 95 #ifdef GNUC_or_lint 96 #define INITIALIZE(x) ((x) = 0) 97 #endif /* defined GNUC_or_lint */ 98 #ifndef GNUC_or_lint 99 #define INITIALIZE(x) 100 #endif /* !defined GNUC_or_lint */ 101 #endif /* !defined INITIALIZE */ 102 103 /* 104 ** For the benefit of GNU folk... 105 ** `_(MSGID)' uses the current locale's message library string for MSGID. 106 ** The default is to use gettext if available, and use MSGID otherwise. 107 */ 108 109 #ifndef _ 110 #if HAVE_GETTEXT - 0 111 #define _(msgid) gettext(msgid) 112 #else /* !(HAVE_GETTEXT - 0) */ 113 #define _(msgid) msgid 114 #endif /* !(HAVE_GETTEXT - 0) */ 115 #endif /* !defined _ */ 116 117 #ifndef TZ_DOMAIN 118 #define TZ_DOMAIN "tz" 119 #endif /* !defined TZ_DOMAIN */ 120 121 #ifndef P 122 #ifdef __STDC__ 123 #define P(x) x 124 #endif /* defined __STDC__ */ 125 #ifndef __STDC__ 126 #define P(x) () 127 #endif /* !defined __STDC__ */ 128 #endif /* !defined P */ 129 130 extern char ** environ; 131 extern int getopt P((int argc, char * const argv[], 132 const char * options)); 133 extern char * optarg; 134 extern int optind; 135 extern char * tzname[2]; 136 137 static char * abbr P((struct tm * tmp)); 138 static long delta P((struct tm * newp, struct tm * oldp)); 139 static time_t hunt P((char * name, time_t lot, time_t hit)); 140 int main P((int, char **)); 141 static size_t longest; 142 static char * progname; 143 static void show P((char * zone, time_t t, int v)); 144 145 int 146 main(argc, argv) 147 int argc; 148 char * argv[]; 149 { 150 register int i; 151 register int c; 152 register int vflag; 153 register char * cutoff; 154 register int cutyear; 155 register long cuttime; 156 char ** fakeenv; 157 time_t now; 158 time_t t; 159 time_t newt; 160 time_t hibit; 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 progname = argv[0]; 173 vflag = 0; 174 cutoff = NULL; 175 while ((c = getopt(argc, argv, "c:v")) == 'c' || c == 'v') 176 if (c == 'v') 177 vflag = 1; 178 else cutoff = optarg; 179 if ((c != EOF && c != -1) || 180 (optind == argc - 1 && strcmp(argv[optind], "=") == 0)) { 181 (void) fprintf(stderr, 182 _("%s: usage is %s [ -v ] [ -c cutoff ] zonename ...\n"), 183 argv[0], argv[0]); 184 (void) exit(EXIT_FAILURE); 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 for (hibit = 1; (hibit << 1) != 0; hibit <<= 1) 201 continue; 202 { 203 register int from; 204 register int to; 205 206 for (i = 0; environ[i] != NULL; ++i) 207 continue; 208 fakeenv = (char **) malloc((size_t) ((i + 2) * 209 sizeof *fakeenv)); 210 if (fakeenv == NULL || 211 (fakeenv[0] = (char *) malloc(longest + 4)) == NULL) { 212 (void) perror(progname); 213 (void) exit(EXIT_FAILURE); 214 } 215 to = 0; 216 (void)strcpy(fakeenv[to++], "TZ="); /* XXX strcpy is safe */ 217 for (from = 0; environ[from] != NULL; ++from) 218 if (strncmp(environ[from], "TZ=", 3) != 0) 219 fakeenv[to++] = environ[from]; 220 fakeenv[to] = NULL; 221 environ = fakeenv; 222 } 223 for (i = optind; i < argc; ++i) { 224 static char buf[MAX_STRING_LENGTH]; 225 226 (void) strcpy(&fakeenv[0][3], argv[i]); /* XXX strcpy is safe */ 227 if (!vflag) { 228 show(argv[i], now, FALSE); 229 continue; 230 } 231 /* 232 ** Get lowest value of t. 233 */ 234 t = hibit; 235 if (t > 0) /* time_t is unsigned */ 236 t = 0; 237 show(argv[i], t, TRUE); 238 t += SECSPERHOUR * HOURSPERDAY; 239 show(argv[i], t, TRUE); 240 tm = *localtime(&t); 241 (void) strncpy(buf, abbr(&tm), (sizeof buf) - 1); 242 for ( ; ; ) { 243 if (cutoff != NULL && t >= cuttime) 244 break; 245 newt = t + SECSPERHOUR * 12; 246 if (cutoff != NULL && newt >= cuttime) 247 break; 248 if (newt <= t) 249 break; 250 newtm = *localtime(&newt); 251 if (delta(&newtm, &tm) != (newt - t) || 252 newtm.tm_isdst != tm.tm_isdst || 253 strcmp(abbr(&newtm), buf) != 0) { 254 newt = hunt(argv[i], t, newt); 255 newtm = *localtime(&newt); 256 (void) strncpy(buf, abbr(&newtm), 257 (sizeof buf) - 1); 258 } 259 t = newt; 260 tm = newtm; 261 } 262 /* 263 ** Get highest value of t. 264 */ 265 t = ~((time_t) 0); 266 if (t < 0) /* time_t is signed */ 267 t &= ~hibit; 268 t -= SECSPERHOUR * HOURSPERDAY; 269 show(argv[i], t, TRUE); 270 t += SECSPERHOUR * HOURSPERDAY; 271 show(argv[i], t, TRUE); 272 } 273 if (fflush(stdout) || ferror(stdout)) { 274 (void) fprintf(stderr, _("%s: Error writing standard output "), 275 argv[0]); 276 (void) perror(_("standard output")); 277 (void) exit(EXIT_FAILURE); 278 } 279 exit(EXIT_SUCCESS); 280 281 /* gcc -Wall pacifier */ 282 for ( ; ; ) 283 continue; 284 } 285 286 static time_t 287 hunt(name, lot, hit) 288 char * name; 289 time_t lot; 290 time_t hit; 291 { 292 time_t t; 293 struct tm lotm; 294 struct tm tm; 295 static char loab[MAX_STRING_LENGTH]; 296 297 lotm = *localtime(&lot); 298 (void) strncpy(loab, abbr(&lotm), (sizeof loab) - 1); 299 while ((hit - lot) >= 2) { 300 t = lot / 2 + hit / 2; 301 if (t <= lot) 302 ++t; 303 else if (t >= hit) 304 --t; 305 tm = *localtime(&t); 306 if (delta(&tm, &lotm) == (t - lot) && 307 tm.tm_isdst == lotm.tm_isdst && 308 strcmp(abbr(&tm), loab) == 0) { 309 lot = t; 310 lotm = tm; 311 } else hit = t; 312 } 313 show(name, lot, TRUE); 314 show(name, hit, TRUE); 315 return hit; 316 } 317 318 /* 319 ** Thanks to Paul Eggert (eggert (at) twinsun.com) for logic used in delta. 320 */ 321 322 static long 323 delta(newp, oldp) 324 struct tm * newp; 325 struct tm * oldp; 326 { 327 long result; 328 int tmy; 329 330 if (newp->tm_year < oldp->tm_year) 331 return -delta(oldp, newp); 332 result = 0; 333 for (tmy = oldp->tm_year; tmy < newp->tm_year; ++tmy) 334 result += DAYSPERNYEAR + isleap(tmy + TM_YEAR_BASE); 335 result += newp->tm_yday - oldp->tm_yday; 336 result *= HOURSPERDAY; 337 result += newp->tm_hour - oldp->tm_hour; 338 result *= MINSPERHOUR; 339 result += newp->tm_min - oldp->tm_min; 340 result *= SECSPERMIN; 341 result += newp->tm_sec - oldp->tm_sec; 342 return result; 343 } 344 345 static void 346 show(zone, t, v) 347 char * zone; 348 time_t t; 349 int v; 350 { 351 struct tm * tmp; 352 353 (void) printf("%-*s ", (int) longest, zone); 354 if (v) 355 (void) printf("%.24s UTC = ", asctime(gmtime(&t))); 356 tmp = localtime(&t); 357 (void) printf("%.24s", asctime(tmp)); 358 if (*abbr(tmp) != '\0') 359 (void) printf(" %s", abbr(tmp)); 360 if (v) { 361 (void) printf(" isdst=%d", tmp->tm_isdst); 362 #ifdef TM_GMTOFF 363 (void) printf(" gmtoff=%ld", tmp->TM_GMTOFF); 364 #endif /* defined TM_GMTOFF */ 365 } 366 (void) printf("\n"); 367 } 368 369 static char * 370 abbr(tmp) 371 struct tm * tmp; 372 { 373 register char * result; 374 static char nada; 375 376 if (tmp->tm_isdst != 0 && tmp->tm_isdst != 1) 377 return &nada; 378 result = tzname[tmp->tm_isdst]; 379 return (result == NULL) ? &nada : result; 380 } 381
Indexes created Sat Sep 20 22:09:52 GMT 2025