usr.sbin/zic/zdump.c

   1 /*
   2  * @(#)zdump.c  8.8
   3  * $FreeBSD: src/usr.sbin/zic/zdump.c,v 1.7 1999/08/28 01:21:19 peter Exp $
   4  * $DragonFly: src/usr.sbin/zic/zdump.c,v 1.5 2008/10/19 20:15:58 swildner Exp $
   5  */
   6 /*
   7 ** This code has been made independent of the rest of the time
   8 ** conversion package to increase confidence in the verification it provides.
   9 ** You can use this code to help in verifying other implementations.
  10 */
  11
  12 #include <ctype.h>      /* for isalpha et al. */
  13 #include <err.h>
  14 #include <float.h>      /* for FLT_MAX and DBL_MAX */
  15 #include <stdio.h>      /* for stdout, stderr */
  16 #include <stdlib.h>     /* for exit, malloc, atoi */
  17 #include <string.h>     /* for strcpy */
  18 #include <sys/types.h>  /* for time_t */
  19 #include <time.h>       /* for struct tm */
  20 #include <unistd.h>
  21
  22 #ifndef ZDUMP_LO_YEAR
  23 #define ZDUMP_LO_YEAR   (-500)
  24 #endif /* !defined ZDUMP_LO_YEAR */
  25
  26 #ifndef ZDUMP_HI_YEAR
  27 #define ZDUMP_HI_YEAR   2500
  28 #endif /* !defined ZDUMP_HI_YEAR */
  29
  30 #ifndef MAX_STRING_LENGTH
  31 #define MAX_STRING_LENGTH       1024
  32 #endif /* !defined MAX_STRING_LENGTH */
  33
  34 #ifndef TRUE
  35 #define TRUE            1
  36 #endif /* !defined TRUE */
  37
  38 #ifndef FALSE
  39 #define FALSE           0
  40 #endif /* !defined FALSE */
  41
  42 #ifndef EXIT_SUCCESS
  43 #define EXIT_SUCCESS    0
  44 #endif /* !defined EXIT_SUCCESS */
  45
  46 #ifndef EXIT_FAILURE
  47 #define EXIT_FAILURE    1
  48 #endif /* !defined EXIT_FAILURE */
  49
  50 #ifndef SECSPERMIN
  51 #define SECSPERMIN      60
  52 #endif /* !defined SECSPERMIN */
  53
  54 #ifndef MINSPERHOUR
  55 #define MINSPERHOUR     60
  56 #endif /* !defined MINSPERHOUR */
  57
  58 #ifndef SECSPERHOUR
  59 #define SECSPERHOUR     (SECSPERMIN * MINSPERHOUR)
  60 #endif /* !defined SECSPERHOUR */
  61
  62 #ifndef HOURSPERDAY
  63 #define HOURSPERDAY     24
  64 #endif /* !defined HOURSPERDAY */
  65
  66 #ifndef EPOCH_YEAR
  67 #define EPOCH_YEAR      1970
  68 #endif /* !defined EPOCH_YEAR */
  69
  70 #ifndef TM_YEAR_BASE
  71 #define TM_YEAR_BASE    1900
  72 #endif /* !defined TM_YEAR_BASE */
  73
  74 #ifndef DAYSPERNYEAR
  75 #define DAYSPERNYEAR    365
  76 #endif /* !defined DAYSPERNYEAR */
  77
  78 #ifndef isleap
  79 #define isleap(y) (((y) % 4) == 0 && (((y) % 100) != 0 || ((y) % 400) == 0))
  80 #endif /* !defined isleap */
  81
  82 #ifndef isleap_sum
  83 /*
  84 ** See tzfile.h for details on isleap_sum.
  85 */
  86 #define isleap_sum(a, b)        isleap((a) % 400 + (b) % 400)
  87 #endif /* !defined isleap_sum */
  88
  89 #define SECSPERDAY      ((long) SECSPERHOUR * HOURSPERDAY)
  90 #define SECSPERNYEAR    (SECSPERDAY * DAYSPERNYEAR)
  91 #define SECSPERLYEAR    (SECSPERNYEAR + SECSPERDAY)
  92
  93 #ifndef GNUC_or_lint
  94 #ifdef lint
  95 #define GNUC_or_lint
  96 #else /* !defined lint */
  97 #ifdef __GNUC__
  98 #define GNUC_or_lint
  99 #endif /* defined __GNUC__ */
 100 #endif /* !defined lint */
 101 #endif /* !defined GNUC_or_lint */
 102
 103 #ifndef INITIALIZE
 104 #ifdef GNUC_or_lint
 105 #define INITIALIZE(x)   ((x) = 0)
 106 #else /* !defined GNUC_or_lint */
 107 #define INITIALIZE(x)
 108 #endif /* !defined GNUC_or_lint */
 109 #endif /* !defined INITIALIZE */
 110
 111 /*
 112 ** For the benefit of GNU folk...
 113 ** `_(MSGID)' uses the current locale's message library string for MSGID.
 114 ** The default is to use gettext if available, and use MSGID otherwise.
 115 */
 116
 117 #ifndef _
 118 #define _(msgid) msgid
 119 #endif /* !defined _ */
 120
 121 #ifndef TZ_DOMAIN
 122 #define TZ_DOMAIN "tz"
 123 #endif /* !defined TZ_DOMAIN */
 124
 125 extern char **  environ;
 126 extern char *   tzname[2];
 127
 128 static time_t    absolute_min_time;
 129 static time_t    absolute_max_time;
 130 static size_t    longest;
 131 static int       warned;
 132
 133 static char     *abbr(struct tm *tmp);
 134 static void      abbrok(const char *abbrp, const char *zone);
 135 static long      delta(struct tm *newp, struct tm *oldp);
 136 static void      dumptime(const struct tm *tmp);
 137 static time_t    hunt(char *name, time_t lot, time_t hit);
 138 static void      setabsolutes(void);
 139 static void      show(char *zone, time_t t, int v);
 140 static const char *tformat(void);
 141 static time_t    yeartot(long y);
 142 static void      usage(void);
 143
 144 #ifndef TYPECHECK
 145 #define my_localtime    localtime
 146 #else /* !defined TYPECHECK */
 147 static struct tm *
 148 my_localtime(time_t *tp)
 149 {
 150         struct tm *     tmp;
 151
 152         tmp = localtime(tp);
 153         if (tp != NULL && tmp != NULL) {
 154                 struct tm       tm;
 155                 time_t          t;
 156
 157                 tm = *tmp;
 158                 t = mktime(&tm);
 159                 if (t - *tp >= 1 || *tp - t >= 1) {
 160                         fflush(stdout);
 161                         fprintf(stderr, "\n%s: ", progname);
 162                         fprintf(stderr, tformat(), *tp);
 163                         fprintf(stderr, " ->");
 164                         fprintf(stderr, " year=%d", tmp->tm_year);
 165                         fprintf(stderr, " mon=%d", tmp->tm_mon);
 166                         fprintf(stderr, " mday=%d", tmp->tm_mday);
 167                         fprintf(stderr, " hour=%d", tmp->tm_hour);
 168                         fprintf(stderr, " min=%d", tmp->tm_min);
 169                         fprintf(stderr, " sec=%d", tmp->tm_sec);
 170                         fprintf(stderr, " isdst=%d", tmp->tm_isdst);
 171                         fprintf(stderr, " -> ");
 172                         fprintf(stderr, tformat(), t);
 173                         fprintf(stderr, "\n");
 174                 }
 175         }
 176         return tmp;
 177 }
 178 #endif /* !defined TYPECHECK */
 179
 180 static void
 181 abbrok(const char * const abbrp, const char * const zone)
 182 {
 183         const char *cp;
 184         char *wp;
 185
 186         if (warned)
 187                 return;
 188         cp = abbrp;
 189         wp = NULL;
 190         while (isascii((unsigned char) *cp) && isalpha((unsigned char) *cp))
 191                 ++cp;
 192         if (cp - abbrp == 0)
 193                 wp = _("lacks alphabetic at start");
 194         else if (cp - abbrp < 3)
 195                 wp = _("has fewer than 3 alphabetics");
 196         else if (cp - abbrp > 6)
 197                 wp = _("has more than 6 alphabetics");
 198         if (wp == NULL && (*cp == '+' || *cp == '-')) {
 199                 ++cp;
 200                 if (isascii((unsigned char) *cp) &&
 201                         isdigit((unsigned char) *cp))
 202                                 if (*cp++ == '1' && *cp >= '0' && *cp <= '4')
 203                                         ++cp;
 204                 if (*cp != '\0')
 205                         wp = _("differs from POSIX standard");
 206         }
 207         if (wp == NULL)
 208                 return;
 209         fflush(stdout);
 210         warnx(_("warning: zone \"%s\" abbreviation \"%s\" %s\n"),
 211                 zone, abbrp, wp);
 212         warned = TRUE;
 213 }
 214
 215 int
 216 main(int argc, char *argv[])
 217 {
 218         int i;
 219         int c;
 220         int vflag;
 221         char *cutarg;
 222         long cutloyear = ZDUMP_LO_YEAR;
 223         long cuthiyear = ZDUMP_HI_YEAR;
 224         time_t cutlotime;
 225         time_t cuthitime;
 226         char **fakeenv;
 227         time_t now;
 228         time_t t;
 229         time_t newt;
 230         struct tm tm;
 231         struct tm newtm;
 232         struct tm *tmp;
 233         struct tm *newtmp;
 234
 235         INITIALIZE(cutlotime);
 236         INITIALIZE(cuthitime);
 237         vflag = 0;
 238         cutarg = NULL;
 239         while ((c = getopt(argc, argv, "c:v")) == 'c' || c == 'v')
 240                 if (c == 'v')
 241                         vflag = 1;
 242                 else    cutarg = optarg;
 243         if ((c != EOF && c != -1) ||
 244                 (optind == argc - 1 && strcmp(argv[optind], "=") == 0)) {
 245                         usage();
 246         }
 247         if (vflag) {
 248                 if (cutarg != NULL) {
 249                         long    lo;
 250                         long    hi;
 251                         char    dummy;
 252
 253                         if (sscanf(cutarg, "%ld%c", &hi, &dummy) == 1) {
 254                                 cuthiyear = hi;
 255                         } else if (sscanf(cutarg, "%ld,%ld%c",
 256                                 &lo, &hi, &dummy) == 2) {
 257                                         cutloyear = lo;
 258                                         cuthiyear = hi;
 259                         } else {
 260                                 errx(EXIT_FAILURE,
 261                                         _("wild -c argument %s\n"),
 262                                         cutarg);
 263                         }
 264                 }
 265                 setabsolutes();
 266                 cutlotime = yeartot(cutloyear);
 267                 cuthitime = yeartot(cuthiyear);
 268         }
 269         time(&now);
 270         longest = 0;
 271         for (i = optind; i < argc; ++i)
 272                 if (strlen(argv[i]) > longest)
 273                         longest = strlen(argv[i]);
 274         {
 275                 int from;
 276                 int to;
 277
 278                 for (i = 0; environ[i] != NULL;  ++i)
 279                         continue;
 280                 fakeenv = (char **) malloc((size_t) ((i + 2) *
 281                         sizeof *fakeenv));
 282                 if (fakeenv == NULL ||
 283                         (fakeenv[0] = (char *) malloc((size_t) (longest +
 284                                 4))) == NULL)
 285                                         errx(EXIT_FAILURE,
 286                                              _("malloc() failed"));
 287                 to = 0;
 288                 strcpy(fakeenv[to++], "TZ=");
 289                 for (from = 0; environ[from] != NULL; ++from)
 290                         if (strncmp(environ[from], "TZ=", 3) != 0)
 291                                 fakeenv[to++] = environ[from];
 292                 fakeenv[to] = NULL;
 293                 environ = fakeenv;
 294         }
 295         for (i = optind; i < argc; ++i) {
 296                 static char     buf[MAX_STRING_LENGTH];
 297
 298                 strcpy(&fakeenv[0][3], argv[i]);
 299                 if (!vflag) {
 300                         show(argv[i], now, FALSE);
 301                         continue;
 302                 }
 303                 warned = FALSE;
 304                 t = absolute_min_time;
 305                 show(argv[i], t, TRUE);
 306                 t += SECSPERHOUR * HOURSPERDAY;
 307                 show(argv[i], t, TRUE);
 308                 if (t < cutlotime)
 309                         t = cutlotime;
 310                 tmp = my_localtime(&t);
 311                 if (tmp != NULL) {
 312                         tm = *tmp;
 313                         strncpy(buf, abbr(&tm), (sizeof buf) - 1);
 314                 }
 315                 for ( ; ; ) {
 316                         if (t >= cuthitime || t >= cuthitime - SECSPERHOUR * 12)
 317                                 break;
 318                         newt = t + SECSPERHOUR * 12;
 319                         newtmp = localtime(&newt);
 320                         if (newtmp != NULL)
 321                                 newtm = *newtmp;
 322                         if ((tmp == NULL || newtmp == NULL) ? (tmp != newtmp) :
 323                                 (delta(&newtm, &tm) != (newt - t) ||
 324                                 newtm.tm_isdst != tm.tm_isdst ||
 325                                 strcmp(abbr(&newtm), buf) != 0)) {
 326                                         newt = hunt(argv[i], t, newt);
 327                                         newtmp = localtime(&newt);
 328                                         if (newtmp != NULL) {
 329                                                 newtm = *newtmp;
 330                                                 strncpy(buf,
 331                                                         abbr(&newtm),
 332                                                         (sizeof buf) - 1);
 333                                         }
 334                         }
 335                         t = newt;
 336                         tm = newtm;
 337                         tmp = newtmp;
 338                 }
 339                 t = absolute_max_time;
 340                 t -= SECSPERHOUR * HOURSPERDAY;
 341                 show(argv[i], t, TRUE);
 342                 t += SECSPERHOUR * HOURSPERDAY;
 343                 show(argv[i], t, TRUE);
 344         }
 345         if (fflush(stdout) || ferror(stdout))
 346                 errx(EXIT_FAILURE, _("error writing standard output"));
 347         exit(EXIT_SUCCESS);
 348         /* If exit fails to exit... */
 349         return EXIT_FAILURE;
 350 }
 351
 352 static void
 353 setabsolutes(void)
 354 {
 355         if (0.5 == (time_t) 0.5) {
 356                 /*
 357                 ** time_t is floating.
 358                 */
 359                 if (sizeof (time_t) == sizeof (float)) {
 360                         absolute_min_time = (time_t) -FLT_MAX;
 361                         absolute_max_time = (time_t) FLT_MAX;
 362                 } else if (sizeof (time_t) == sizeof (double)) {
 363                         absolute_min_time = (time_t) -DBL_MAX;
 364                         absolute_max_time = (time_t) DBL_MAX;
 365                 } else {
 366                         errx(EXIT_FAILURE,
 367 _("use of -v on system with floating time_t other than float or double\n"));
 368                 }
 369         } else if (0 > (time_t) -1) {
 370                 /*
 371                 ** time_t is signed.  Assume overflow wraps around.
 372                 */
 373                 time_t t = 0;
 374                 time_t t1 = 1;
 375
 376                 while (t < t1) {
 377                         t = t1;
 378                         t1 = 2 * t1 + 1;
 379                 }
 380
 381                 absolute_max_time = t;
 382                 t = -t;
 383                 absolute_min_time = t - 1;
 384                 if (t < absolute_min_time)
 385                         absolute_min_time = t;
 386         } else {
 387                 /*
 388                 ** time_t is unsigned.
 389                 */
 390                 absolute_min_time = 0;
 391                 absolute_max_time = absolute_min_time - 1;
 392         }
 393 }
 394
 395 static void
 396 usage(void)
 397 {
 398         fprintf(stderr, _("usage: zdump [-v] [-c [loyear,]hiyear] zonename ...\n"));
 399         exit(EXIT_FAILURE);
 400 }
 401
 402 static time_t
 403 yeartot(const long y)
 404 {
 405         long    myy;
 406         long    seconds;
 407         time_t  t;
 408
 409         myy = EPOCH_YEAR;
 410         t = 0;
 411         while (myy != y) {
 412                 if (myy < y) {
 413                         seconds = isleap(myy) ? SECSPERLYEAR : SECSPERNYEAR;
 414                         ++myy;
 415                         if (t > absolute_max_time - seconds) {
 416                                 t = absolute_max_time;
 417                                 break;
 418                         }
 419                         t += seconds;
 420                 } else {
 421                         --myy;
 422                         seconds = isleap(myy) ? SECSPERLYEAR : SECSPERNYEAR;
 423                         if (t < absolute_min_time + seconds) {
 424                                 t = absolute_min_time;
 425                                 break;
 426                         }
 427                         t -= seconds;
 428                 }
 429         }
 430         return t;
 431 }
 432
 433 static time_t
 434 hunt(char *name, time_t lot, time_t hit)
 435 {
 436         time_t          t;
 437         long            diff;
 438         struct tm       lotm;
 439         struct tm *     lotmp;
 440         struct tm       tm;
 441         struct tm *     tmp;
 442         char                    loab[MAX_STRING_LENGTH];
 443
 444         lotmp = my_localtime(&lot);
 445         if (lotmp != NULL) {
 446                 lotm = *lotmp;
 447                 strncpy(loab, abbr(&lotm), (sizeof loab) - 1);
 448         }
 449         for ( ; ; ) {
 450                 diff = (long) (hit - lot);
 451                 if (diff < 2)
 452                         break;
 453                 t = lot;
 454                 t += diff / 2;
 455                 if (t <= lot)
 456                         ++t;
 457                 else if (t >= hit)
 458                         --t;
 459                 tmp = my_localtime(&t);
 460                 if (tmp != NULL)
 461                         tm = *tmp;
 462                 if ((lotmp == NULL || tmp == NULL) ? (lotmp == tmp) :
 463                         (delta(&tm, &lotm) == (t - lot) &&
 464                         tm.tm_isdst == lotm.tm_isdst &&
 465                         strcmp(abbr(&tm), loab) == 0)) {
 466                                 lot = t;
 467                                 lotm = tm;
 468                                 lotmp = tmp;
 469                 } else  hit = t;
 470         }
 471         show(name, lot, TRUE);
 472         show(name, hit, TRUE);
 473         return hit;
 474 }
 475
 476 /*
 477 ** Thanks to Paul Eggert for logic used in delta.
 478 */
 479
 480 static long
 481 delta(struct tm *newp, struct tm *oldp)
 482 {
 483         long    result;
 484         int     tmy;
 485
 486         if (newp->tm_year < oldp->tm_year)
 487                 return -delta(oldp, newp);
 488         result = 0;
 489         for (tmy = oldp->tm_year; tmy < newp->tm_year; ++tmy)
 490                 result += DAYSPERNYEAR + isleap_sum(tmy, TM_YEAR_BASE);
 491         result += newp->tm_yday - oldp->tm_yday;
 492         result *= HOURSPERDAY;
 493         result += newp->tm_hour - oldp->tm_hour;
 494         result *= MINSPERHOUR;
 495         result += newp->tm_min - oldp->tm_min;
 496         result *= SECSPERMIN;
 497         result += newp->tm_sec - oldp->tm_sec;
 498         return result;
 499 }
 500
 501 static void
 502 show(char *zone, time_t t, int v)
 503 {
 504         struct tm *     tmp;
 505
 506         printf("%-*s  ", (int) longest, zone);
 507         if (v) {
 508                 tmp = gmtime(&t);
 509                 if (tmp == NULL) {
 510                         printf(tformat(), t);
 511                 } else {
 512                         dumptime(tmp);
 513                         printf(" UTC");
 514                 }
 515                 printf(" = ");
 516         }
 517         tmp = my_localtime(&t);
 518         dumptime(tmp);
 519         if (tmp != NULL) {
 520                 if (*abbr(tmp) != '\0')
 521                         printf(" %s", abbr(tmp));
 522                 if (v) {
 523                         printf(" isdst=%d", tmp->tm_isdst);
 524 #ifdef TM_GMTOFF
 525                         printf(" gmtoff=%ld", tmp->TM_GMTOFF);
 526 #endif /* defined TM_GMTOFF */
 527                 }
 528         }
 529         printf("\n");
 530         if (tmp != NULL && *abbr(tmp) != '\0')
 531                 abbrok(abbr(tmp), zone);
 532 }
 533
 534 static char *
 535 abbr(struct tm *tmp)
 536 {
 537         char * result;
 538         static char nada;
 539
 540         if (tmp->tm_isdst != 0 && tmp->tm_isdst != 1)
 541                 return &nada;
 542         result = tzname[tmp->tm_isdst];
 543         return (result == NULL) ? &nada : result;
 544 }
 545
 546 /*
 547 ** The code below can fail on certain theoretical systems;
 548 ** it works on all known real-world systems as of 2004-12-30.
 549 */
 550
 551 static const char *
 552 tformat(void)
 553 {
 554         if (0.5 == (time_t) 0.5) {      /* floating */
 555                 if (sizeof (time_t) > sizeof (double))
 556                         return "%Lg";
 557                 return "%g";
 558         }
 559         if (0 > (time_t) -1) {          /* signed */
 560                 if (sizeof (time_t) > sizeof (long))
 561                         return "%lld";
 562                 if (sizeof (time_t) > sizeof (int))
 563                         return "%ld";
 564                 return "%d";
 565         }
 566         if (sizeof (time_t) > sizeof (unsigned long))
 567                 return "%llu";
 568         if (sizeof (time_t) > sizeof (unsigned int))
 569                 return "%lu";
 570         return "%u";
 571 }
 572
 573 static void
 574 dumptime(const struct tm *timeptr)
 575 {
 576         static const char       wday_name[][3] = {
 577                 "Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"
 578         };
 579         static const char       mon_name[][3] = {
 580                 "Jan", "Feb", "Mar", "Apr", "May", "Jun",
 581                 "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"
 582         };
 583         const char *    wn;
 584         const char *    mn;
 585         int             lead;
 586         int             trail;
 587
 588         if (timeptr == NULL) {
 589                 printf("NULL");
 590                 return;
 591         }
 592         /*
 593         ** The packaged versions of localtime and gmtime never put out-of-range
 594         ** values in tm_wday or tm_mon, but since this code might be compiled
 595         ** with other (perhaps experimental) versions, paranoia is in order.
 596         */
 597         if (timeptr->tm_wday < 0 || timeptr->tm_wday >=
 598                 (int) (sizeof wday_name / sizeof wday_name[0]))
 599                         wn = "???";
 600         else            wn = wday_name[timeptr->tm_wday];
 601         if (timeptr->tm_mon < 0 || timeptr->tm_mon >=
 602                 (int) (sizeof mon_name / sizeof mon_name[0]))
 603                         mn = "???";
 604         else            mn = mon_name[timeptr->tm_mon];
 605         printf("%.3s %.3s%3d %.2d:%.2d:%.2d ",
 606                 wn, mn,
 607                 timeptr->tm_mday, timeptr->tm_hour,
 608                 timeptr->tm_min, timeptr->tm_sec);
 609 #define DIVISOR 10
 610         trail = timeptr->tm_year % DIVISOR + TM_YEAR_BASE % DIVISOR;
 611         lead = timeptr->tm_year / DIVISOR + TM_YEAR_BASE / DIVISOR +
 612                 trail / DIVISOR;
 613         trail %= DIVISOR;
 614         if (trail < 0 && lead > 0) {
 615                 trail += DIVISOR;
 616                 --lead;
 617         } else if (lead < 0 && trail > 0) {
 618                 trail -= DIVISOR;
 619                 ++lead;
 620         }
 621         if (lead == 0)
 622                 printf("%d", trail);
 623         else    printf("%d%d", lead, ((trail < 0) ? -trail : trail));
 624 }