zdump.c revision 1.1.1.7
1 static char elsieid[] = "@(#)zdump.c 7.31"; 2 3 /* 4 ** This code has been made independent of the rest of the time 5 ** conversion package to increase confidence in the verification it provides. 6 ** You can use this code to help in verifying other implementations. 7 */ 8 9 #include "stdio.h" /* for stdout, stderr, perror */ 10 #include "string.h" /* for strcpy */ 11 #include "sys/types.h" /* for time_t */ 12 #include "time.h" /* for struct tm */ 13 #include "stdlib.h" /* for exit, malloc, atoi */ 14 15 #ifndef MAX_STRING_LENGTH 16 #define MAX_STRING_LENGTH 1024 17 #endif /* !defined MAX_STRING_LENGTH */ 18 19 #ifndef TRUE 20 #define TRUE 1 21 #endif /* !defined TRUE */ 22 23 #ifndef FALSE 24 #define FALSE 0 25 #endif /* !defined FALSE */ 26 27 #ifndef EXIT_SUCCESS 28 #define EXIT_SUCCESS 0 29 #endif /* !defined EXIT_SUCCESS */ 30 31 #ifndef EXIT_FAILURE 32 #define EXIT_FAILURE 1 33 #endif /* !defined EXIT_FAILURE */ 34 35 #ifndef SECSPERMIN 36 #define SECSPERMIN 60 37 #endif /* !defined SECSPERMIN */ 38 39 #ifndef MINSPERHOUR 40 #define MINSPERHOUR 60 41 #endif /* !defined MINSPERHOUR */ 42 43 #ifndef SECSPERHOUR 44 #define SECSPERHOUR (SECSPERMIN * MINSPERHOUR) 45 #endif /* !defined SECSPERHOUR */ 46 47 #ifndef HOURSPERDAY 48 #define HOURSPERDAY 24 49 #endif /* !defined HOURSPERDAY */ 50 51 #ifndef EPOCH_YEAR 52 #define EPOCH_YEAR 1970 53 #endif /* !defined EPOCH_YEAR */ 54 55 #ifndef TM_YEAR_BASE 56 #define TM_YEAR_BASE 1900 57 #endif /* !defined TM_YEAR_BASE */ 58 59 #ifndef DAYSPERNYEAR 60 #define DAYSPERNYEAR 365 61 #endif /* !defined DAYSPERNYEAR */ 62 63 #ifndef isleap 64 #define isleap(y) ((((y) % 4) == 0 && ((y) % 100) != 0) || ((y) % 400) == 0) 65 #endif /* !defined isleap */ 66 67 #if HAVE_GETTEXT - 0 68 #include "locale.h" /* for setlocale */ 69 #include "libintl.h" 70 #endif /* HAVE_GETTEXT - 0 */ 71 72 #ifndef GNUC_or_lint 73 #ifdef lint 74 #define GNUC_or_lint 75 #endif /* defined lint */ 76 #ifndef lint 77 #ifdef __GNUC__ 78 #define GNUC_or_lint 79 #endif /* defined __GNUC__ */ 80 #endif /* !defined lint */ 81 #endif /* !defined GNUC_or_lint */ 82 83 #ifndef INITIALIZE 84 #ifdef GNUC_or_lint 85 #define INITIALIZE(x) ((x) = 0) 86 #endif /* defined GNUC_or_lint */ 87 #ifndef GNUC_or_lint 88 #define INITIALIZE(x) 89 #endif /* !defined GNUC_or_lint */ 90 #endif /* !defined INITIALIZE */ 91 92 /* 93 ** For the benefit of GNU folk... 94 ** `_(MSGID)' uses the current locale's message library string for MSGID. 95 ** The default is to use gettext if available, and use MSGID otherwise. 96 */ 97 98 #ifndef _ 99 #if HAVE_GETTEXT - 0 100 #define _(msgid) gettext(msgid) 101 #else /* !(HAVE_GETTEXT - 0) */ 102 #define _(msgid) msgid 103 #endif /* !(HAVE_GETTEXT - 0) */ 104 #endif /* !defined _ */ 105 106 #ifndef TZ_DOMAIN 107 #define TZ_DOMAIN "tz" 108 #endif /* !defined TZ_DOMAIN */ 109 110 #ifndef P 111 #ifdef __STDC__ 112 #define P(x) x 113 #endif /* defined __STDC__ */ 114 #ifndef __STDC__ 115 #define P(x) () 116 #endif /* !defined __STDC__ */ 117 #endif /* !defined P */ 118 119 extern char ** environ; 120 extern int getopt P((int argc, char * const argv[], 121 const char * options)); 122 extern char * optarg; 123 extern int optind; 124 extern char * tzname[2]; 125 126 static char * abbr P((struct tm * tmp)); 127 static long delta P((struct tm * newp, struct tm * oldp)); 128 static time_t hunt P((char * name, time_t lot, time_t hit)); 129 static size_t longest; 130 static char * progname; 131 static void show P((char * zone, time_t t, int v)); 132 133 int 134 main(argc, argv) 135 int argc; 136 char * argv[]; 137 { 138 register int i; 139 register int c; 140 register int vflag; 141 register char * cutoff; 142 register int cutyear; 143 register long cuttime; 144 char ** fakeenv; 145 time_t now; 146 time_t t; 147 time_t newt; 148 time_t hibit; 149 struct tm tm; 150 struct tm newtm; 151 152 INITIALIZE(cuttime); 153 #if HAVE_GETTEXT - 0 154 (void) setlocale(LC_MESSAGES, ""); 155 #ifdef TZ_DOMAINDIR 156 (void) bindtextdomain(TZ_DOMAIN, TZ_DOMAINDIR); 157 #endif /* defined(TEXTDOMAINDIR) */ 158 (void) textdomain(TZ_DOMAIN); 159 #endif /* HAVE_GETTEXT - 0 */ 160 progname = argv[0]; 161 for (i = 1; i < argc; ++i) 162 if (strcmp(argv[i], "--version") == 0) { 163 (void) printf("%s\n", elsieid); 164 (void) exit(EXIT_SUCCESS); 165 } 166 vflag = 0; 167 cutoff = NULL; 168 while ((c = getopt(argc, argv, "c:v")) == 'c' || c == 'v') 169 if (c == 'v') 170 vflag = 1; 171 else cutoff = optarg; 172 if ((c != EOF && c != -1) || 173 (optind == argc - 1 && strcmp(argv[optind], "=") == 0)) { 174 (void) fprintf(stderr, 175 _("%s: usage is %s [ --version ] [ -v ] [ -c cutoff ] zonename ...\n"), 176 argv[0], argv[0]); 177 (void) exit(EXIT_FAILURE); 178 } 179 if (cutoff != NULL) { 180 int y; 181 182 cutyear = atoi(cutoff); 183 cuttime = 0; 184 for (y = EPOCH_YEAR; y < cutyear; ++y) 185 cuttime += DAYSPERNYEAR + isleap(y); 186 cuttime *= SECSPERHOUR * HOURSPERDAY; 187 } 188 (void) time(&now); 189 longest = 0; 190 for (i = optind; i < argc; ++i) 191 if (strlen(argv[i]) > longest) 192 longest = strlen(argv[i]); 193 for (hibit = 1; (hibit << 1) != 0; hibit <<= 1) 194 continue; 195 { 196 register int from; 197 register int to; 198 199 for (i = 0; environ[i] != NULL; ++i) 200 continue; 201 fakeenv = (char **) malloc((size_t) ((i + 2) * 202 sizeof *fakeenv)); 203 if (fakeenv == NULL || 204 (fakeenv[0] = (char *) malloc(longest + 4)) == NULL) { 205 (void) perror(progname); 206 (void) exit(EXIT_FAILURE); 207 } 208 to = 0; 209 (void) strcpy(fakeenv[to++], "TZ="); 210 for (from = 0; environ[from] != NULL; ++from) 211 if (strncmp(environ[from], "TZ=", 3) != 0) 212 fakeenv[to++] = environ[from]; 213 fakeenv[to] = NULL; 214 environ = fakeenv; 215 } 216 for (i = optind; i < argc; ++i) { 217 static char buf[MAX_STRING_LENGTH]; 218 219 (void) strcpy(&fakeenv[0][3], argv[i]); 220 if (!vflag) { 221 show(argv[i], now, FALSE); 222 continue; 223 } 224 /* 225 ** Get lowest value of t. 226 */ 227 t = hibit; 228 if (t > 0) /* time_t is unsigned */ 229 t = 0; 230 show(argv[i], t, TRUE); 231 t += SECSPERHOUR * HOURSPERDAY; 232 show(argv[i], t, TRUE); 233 tm = *localtime(&t); 234 (void) strncpy(buf, abbr(&tm), (sizeof buf) - 1); 235 for ( ; ; ) { 236 if (cutoff != NULL && t >= cuttime) 237 break; 238 newt = t + SECSPERHOUR * 12; 239 if (cutoff != NULL && newt >= cuttime) 240 break; 241 if (newt <= t) 242 break; 243 newtm = *localtime(&newt); 244 if (delta(&newtm, &tm) != (newt - t) || 245 newtm.tm_isdst != tm.tm_isdst || 246 strcmp(abbr(&newtm), buf) != 0) { 247 newt = hunt(argv[i], t, newt); 248 newtm = *localtime(&newt); 249 (void) strncpy(buf, abbr(&newtm), 250 (sizeof buf) - 1); 251 } 252 t = newt; 253 tm = newtm; 254 } 255 /* 256 ** Get highest value of t. 257 */ 258 t = ~((time_t) 0); 259 if (t < 0) /* time_t is signed */ 260 t &= ~hibit; 261 t -= SECSPERHOUR * HOURSPERDAY; 262 show(argv[i], t, TRUE); 263 t += SECSPERHOUR * HOURSPERDAY; 264 show(argv[i], t, TRUE); 265 } 266 if (fflush(stdout) || ferror(stdout)) { 267 (void) fprintf(stderr, "%s: ", argv[0]); 268 (void) perror(_("Error writing standard output")); 269 (void) exit(EXIT_FAILURE); 270 } 271 exit(EXIT_SUCCESS); 272 273 /* gcc -Wall pacifier */ 274 for ( ; ; ) 275 continue; 276 } 277 278 static time_t 279 hunt(name, lot, hit) 280 char * name; 281 time_t lot; 282 time_t hit; 283 { 284 time_t t; 285 struct tm lotm; 286 struct tm tm; 287 static char loab[MAX_STRING_LENGTH]; 288 289 lotm = *localtime(&lot); 290 (void) strncpy(loab, abbr(&lotm), (sizeof loab) - 1); 291 while ((hit - lot) >= 2) { 292 t = lot / 2 + hit / 2; 293 if (t <= lot) 294 ++t; 295 else if (t >= hit) 296 --t; 297 tm = *localtime(&t); 298 if (delta(&tm, &lotm) == (t - lot) && 299 tm.tm_isdst == lotm.tm_isdst && 300 strcmp(abbr(&tm), loab) == 0) { 301 lot = t; 302 lotm = tm; 303 } else hit = t; 304 } 305 show(name, lot, TRUE); 306 show(name, hit, TRUE); 307 return hit; 308 } 309 310 /* 311 ** Thanks to Paul Eggert (eggert (at) twinsun.com) for logic used in delta. 312 */ 313 314 static long 315 delta(newp, oldp) 316 struct tm * newp; 317 struct tm * oldp; 318 { 319 long result; 320 int tmy; 321 322 if (newp->tm_year < oldp->tm_year) 323 return -delta(oldp, newp); 324 result = 0; 325 for (tmy = oldp->tm_year; tmy < newp->tm_year; ++tmy) 326 result += DAYSPERNYEAR + isleap(tmy + TM_YEAR_BASE); 327 result += newp->tm_yday - oldp->tm_yday; 328 result *= HOURSPERDAY; 329 result += newp->tm_hour - oldp->tm_hour; 330 result *= MINSPERHOUR; 331 result += newp->tm_min - oldp->tm_min; 332 result *= SECSPERMIN; 333 result += newp->tm_sec - oldp->tm_sec; 334 return result; 335 } 336 337 static void 338 show(zone, t, v) 339 char * zone; 340 time_t t; 341 int v; 342 { 343 struct tm * tmp; 344 345 (void) printf("%-*s ", (int) longest, zone); 346 if (v) 347 (void) printf("%.24s UTC = ", asctime(gmtime(&t))); 348 tmp = localtime(&t); 349 (void) printf("%.24s", asctime(tmp)); 350 if (*abbr(tmp) != '\0') 351 (void) printf(" %s", abbr(tmp)); 352 if (v) { 353 (void) printf(" isdst=%d", tmp->tm_isdst); 354 #ifdef TM_GMTOFF 355 (void) printf(" gmtoff=%ld", tmp->TM_GMTOFF); 356 #endif /* defined TM_GMTOFF */ 357 } 358 (void) printf("\n"); 359 } 360 361 static char * 362 abbr(tmp) 363 struct tm * tmp; 364 { 365 register char * result; 366 static char nada; 367 368 if (tmp->tm_isdst != 0 && tmp->tm_isdst != 1) 369 return &nada; 370 result = tzname[tmp->tm_isdst]; 371 return (result == NULL) ? &nada : result; 372 } 373
Indexes created Sat Sep 20 22:09:52 GMT 2025