timezone/zdump.c

   1 static char     elsieid[] = "@(#)zdump.c        7.74";
   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 #include "float.h"      /* for FLT_MAX and DBL_MAX */
  15 #include "ctype.h"      /* for isalpha et al. */
  16 #ifndef isascii
  17 #define isascii(x) 1
  18 #endif
  19
  20 #ifndef ZDUMP_LO_YEAR
  21 #define ZDUMP_LO_YEAR   (-500)
  22 #endif /* !defined ZDUMP_LO_YEAR */
  23
  24 #ifndef ZDUMP_HI_YEAR
  25 #define ZDUMP_HI_YEAR   2500
  26 #endif /* !defined ZDUMP_HI_YEAR */
  27
  28 #ifndef MAX_STRING_LENGTH
  29 #define MAX_STRING_LENGTH       1024
  30 #endif /* !defined MAX_STRING_LENGTH */
  31
  32 #ifndef TRUE
  33 #define TRUE            1
  34 #endif /* !defined TRUE */
  35
  36 #ifndef FALSE
  37 #define FALSE           0
  38 #endif /* !defined FALSE */
  39
  40 #ifndef EXIT_SUCCESS
  41 #define EXIT_SUCCESS    0
  42 #endif /* !defined EXIT_SUCCESS */
  43
  44 #ifndef EXIT_FAILURE
  45 #define EXIT_FAILURE    1
  46 #endif /* !defined EXIT_FAILURE */
  47
  48 #ifndef SECSPERMIN
  49 #define SECSPERMIN      60
  50 #endif /* !defined SECSPERMIN */
  51
  52 #ifndef MINSPERHOUR
  53 #define MINSPERHOUR     60
  54 #endif /* !defined MINSPERHOUR */
  55
  56 #ifndef SECSPERHOUR
  57 #define SECSPERHOUR     (SECSPERMIN * MINSPERHOUR)
  58 #endif /* !defined SECSPERHOUR */
  59
  60 #ifndef HOURSPERDAY
  61 #define HOURSPERDAY     24
  62 #endif /* !defined HOURSPERDAY */
  63
  64 #ifndef EPOCH_YEAR
  65 #define EPOCH_YEAR      1970
  66 #endif /* !defined EPOCH_YEAR */
  67
  68 #ifndef TM_YEAR_BASE
  69 #define TM_YEAR_BASE    1900
  70 #endif /* !defined TM_YEAR_BASE */
  71
  72 #ifndef DAYSPERNYEAR
  73 #define DAYSPERNYEAR    365
  74 #endif /* !defined DAYSPERNYEAR */
  75
  76 #ifndef isleap
  77 #define isleap(y) (((y) % 4) == 0 && (((y) % 100) != 0 || ((y) % 400) == 0))
  78 #endif /* !defined isleap */
  79
  80 #ifndef isleap_sum
  81 /*
  82 ** See tzfile.h for details on isleap_sum.
  83 */
  84 #define isleap_sum(a, b)        isleap((a) % 400 + (b) % 400)
  85 #endif /* !defined isleap_sum */
  86
  87 #define SECSPERDAY      ((long) SECSPERHOUR * HOURSPERDAY)
  88 #define SECSPERNYEAR    (SECSPERDAY * DAYSPERNYEAR)
  89 #define SECSPERLYEAR    (SECSPERNYEAR + SECSPERDAY)
  90
  91 #if HAVE_GETTEXT
  92 #include "locale.h"     /* for setlocale */
  93 #include "libintl.h"
  94 #endif /* HAVE_GETTEXT */
  95
  96 #ifndef GNUC_or_lint
  97 #ifdef lint
  98 #define GNUC_or_lint
  99 #else /* !defined lint */
 100 #ifdef __GNUC__
 101 #define GNUC_or_lint
 102 #endif /* defined __GNUC__ */
 103 #endif /* !defined lint */
 104 #endif /* !defined GNUC_or_lint */
 105
 106 #ifndef INITIALIZE
 107 #ifdef GNUC_or_lint
 108 #define INITIALIZE(x)   ((x) = 0)
 109 #else /* !defined GNUC_or_lint */
 110 #define INITIALIZE(x)
 111 #endif /* !defined GNUC_or_lint */
 112 #endif /* !defined INITIALIZE */
 113
 114 /*
 115 ** For the benefit of GNU folk...
 116 ** `_(MSGID)' uses the current locale's message library string for MSGID.
 117 ** The default is to use gettext if available, and use MSGID otherwise.
 118 */
 119
 120 #ifndef _
 121 #if HAVE_GETTEXT
 122 #define _(msgid) gettext(msgid)
 123 #else /* !HAVE_GETTEXT */
 124 #define _(msgid) msgid
 125 #endif /* !HAVE_GETTEXT */
 126 #endif /* !defined _ */
 127
 128 #ifndef TZ_DOMAIN
 129 #define TZ_DOMAIN "tz"
 130 #endif /* !defined TZ_DOMAIN */
 131
 132 #ifndef P
 133 #ifdef __STDC__
 134 #define P(x)    x
 135 #else /* !defined __STDC__ */
 136 #define P(x)    ()
 137 #endif /* !defined __STDC__ */
 138 #endif /* !defined P */
 139
 140 extern char **  environ;
 141 extern int      getopt P((int argc, char * const argv[],
 142                         const char * options));
 143 extern char *   optarg;
 144 extern int      optind;
 145 extern char *   tzname[2];
 146
 147 static time_t   absolute_min_time;
 148 static time_t   absolute_max_time;
 149 static size_t   longest;
 150 static char *   progname;
 151 static int      warned;
 152
 153 static char *   abbr P((struct tm * tmp));
 154 static void     abbrok P((const char * abbrp, const char * zone));
 155 static long     delta P((struct tm * newp, struct tm * oldp));
 156 static void     dumptime P((const struct tm * tmp));
 157 static time_t   hunt P((char * name, time_t lot, time_t hit));
 158 static void     setabsolutes P((void));
 159 static void     show P((char * zone, time_t t, int v));
 160 static const char *     tformat P((void));
 161 static time_t   yeartot P((long y));
 162
 163 #ifndef TYPECHECK
 164 #define my_localtime    localtime
 165 #else /* !defined TYPECHECK */
 166 static struct tm *
 167 my_localtime(tp)
 168 time_t *        tp;
 169 {
 170         register struct tm *    tmp;
 171
 172         tmp = localtime(tp);
 173         if (tp != NULL && tmp != NULL) {
 174                 struct tm       tm;
 175                 register time_t t;
 176
 177                 tm = *tmp;
 178                 t = mktime(&tm);
 179                 if (t - *tp >= 1 || *tp - t >= 1) {
 180                         (void) fflush(stdout);
 181                         (void) fprintf(stderr, "\n%s: ", progname);
 182                         (void) fprintf(stderr, tformat(), *tp);
 183                         (void) fprintf(stderr, " ->");
 184                         (void) fprintf(stderr, " year=%d", tmp->tm_year);
 185                         (void) fprintf(stderr, " mon=%d", tmp->tm_mon);
 186                         (void) fprintf(stderr, " mday=%d", tmp->tm_mday);
 187                         (void) fprintf(stderr, " hour=%d", tmp->tm_hour);
 188                         (void) fprintf(stderr, " min=%d", tmp->tm_min);
 189                         (void) fprintf(stderr, " sec=%d", tmp->tm_sec);
 190                         (void) fprintf(stderr, " isdst=%d", tmp->tm_isdst);
 191                         (void) fprintf(stderr, " -> ");
 192                         (void) fprintf(stderr, tformat(), t);
 193                         (void) fprintf(stderr, "\n");
 194                 }
 195         }
 196         return tmp;
 197 }
 198 #endif /* !defined TYPECHECK */
 199
 200 static void
 201 abbrok(abbrp, zone)
 202 const char * const      abbrp;
 203 const char * const      zone;
 204 {
 205         register const char *   cp;
 206         register char *         wp;
 207
 208         if (warned)
 209                 return;
 210         cp = abbrp;
 211         wp = NULL;
 212         while (isascii((unsigned char) *cp) && isalpha((unsigned char) *cp))
 213                 ++cp;
 214         if (cp - abbrp == 0)
 215                 wp = _("lacks alphabetic at start");
 216         else if (cp - abbrp < 3)
 217                 wp = _("has fewer than 3 alphabetics");
 218         else if (cp - abbrp > 6)
 219                 wp = _("has more than 6 alphabetics");
 220         if (wp == NULL && (*cp == '+' || *cp == '-')) {
 221                 ++cp;
 222                 if (isascii((unsigned char) *cp) &&
 223                         isdigit((unsigned char) *cp))
 224                                 if (*cp++ == '1' && *cp >= '0' && *cp <= '4')
 225                                         ++cp;
 226                 if (*cp != '\0')
 227                         wp = _("differs from POSIX standard");
 228         }
 229         if (wp == NULL)
 230                 return;
 231         (void) fflush(stdout);
 232         (void) fprintf(stderr,
 233                 _("%s: warning: zone \"%s\" abbreviation \"%s\" %s\n"),
 234                 progname, zone, abbrp, wp);
 235         warned = TRUE;
 236 }
 237
 238 int
 239 main(argc, argv)
 240 int     argc;
 241 char *  argv[];
 242 {
 243         register int            i;
 244         register int            c;
 245         register int            vflag;
 246         register char *         cutarg;
 247         register long           cutloyear = ZDUMP_LO_YEAR;
 248         register long           cuthiyear = ZDUMP_HI_YEAR;
 249         register time_t         cutlotime;
 250         register time_t         cuthitime;
 251         register char **        fakeenv;
 252         time_t                  now;
 253         time_t                  t;
 254         time_t                  newt;
 255         struct tm               tm;
 256         struct tm               newtm;
 257         register struct tm *    tmp;
 258         register struct tm *    newtmp;
 259
 260         INITIALIZE(cutlotime);
 261         INITIALIZE(cuthitime);
 262 #if HAVE_GETTEXT
 263         (void) setlocale(LC_ALL, "");
 264 #ifdef TZ_DOMAINDIR
 265         (void) bindtextdomain(TZ_DOMAIN, TZ_DOMAINDIR);
 266 #endif /* defined TEXTDOMAINDIR */
 267         (void) textdomain(TZ_DOMAIN);
 268 #endif /* HAVE_GETTEXT */
 269         progname = argv[0];
 270         for (i = 1; i < argc; ++i)
 271                 if (strcmp(argv[i], "--version") == 0) {
 272                         (void) printf("%s\n", elsieid);
 273                         exit(EXIT_SUCCESS);
 274                 }
 275         vflag = 0;
 276         cutarg = NULL;
 277         while ((c = getopt(argc, argv, "c:v")) == 'c' || c == 'v')
 278                 if (c == 'v')
 279                         vflag = 1;
 280                 else    cutarg = optarg;
 281         if ((c != EOF && c != -1) ||
 282                 (optind == argc - 1 && strcmp(argv[optind], "=") == 0)) {
 283                         (void) fprintf(stderr,
 284 _("%s: usage is %s [ --version ] [ -v ] [ -c [loyear,]hiyear ] zonename ...\n"),
 285                                 progname, progname);
 286                         exit(EXIT_FAILURE);
 287         }
 288         if (vflag) {
 289                 if (cutarg != NULL) {
 290                         long    lo;
 291                         long    hi;
 292                         char    dummy;
 293
 294                         if (sscanf(cutarg, "%ld%c", &hi, &dummy) == 1) {
 295                                 cuthiyear = hi;
 296                         } else if (sscanf(cutarg, "%ld,%ld%c",
 297                                 &lo, &hi, &dummy) == 2) {
 298                                         cutloyear = lo;
 299                                         cuthiyear = hi;
 300                         } else {
 301 (void) fprintf(stderr, _("%s: wild -c argument %s\n"),
 302                                         progname, cutarg);
 303                                 exit(EXIT_FAILURE);
 304                         }
 305                 }
 306                 setabsolutes();
 307                 cutlotime = yeartot(cutloyear);
 308                 cuthitime = yeartot(cuthiyear);
 309         }
 310         (void) time(&now);
 311         longest = 0;
 312         for (i = optind; i < argc; ++i)
 313                 if (strlen(argv[i]) > longest)
 314                         longest = strlen(argv[i]);
 315         {
 316                 register int    from;
 317                 register int    to;
 318
 319                 for (i = 0; environ[i] != NULL; ++i)
 320                         continue;
 321                 fakeenv = (char **) malloc((size_t) ((i + 2) *
 322                         sizeof *fakeenv));
 323                 if (fakeenv == NULL ||
 324                         (fakeenv[0] = (char *) malloc(longest + 4)) == NULL) {
 325                                         (void) perror(progname);
 326                                         exit(EXIT_FAILURE);
 327                 }
 328                 to = 0;
 329                 (void) strcpy(fakeenv[to++], "TZ=");
 330                 for (from = 0; environ[from] != NULL; ++from)
 331                         if (strncmp(environ[from], "TZ=", 3) != 0)
 332                                 fakeenv[to++] = environ[from];
 333                 fakeenv[to] = NULL;
 334                 environ = fakeenv;
 335         }
 336         for (i = optind; i < argc; ++i) {
 337                 static char     buf[MAX_STRING_LENGTH];
 338
 339                 (void) strcpy(&fakeenv[0][3], argv[i]);
 340                 if (!vflag) {
 341                         show(argv[i], now, FALSE);
 342                         continue;
 343                 }
 344                 warned = FALSE;
 345                 t = absolute_min_time;
 346                 show(argv[i], t, TRUE);
 347                 t += SECSPERHOUR * HOURSPERDAY;
 348                 show(argv[i], t, TRUE);
 349                 if (t < cutlotime)
 350                         t = cutlotime;
 351                 tmp = my_localtime(&t);
 352                 if (tmp != NULL) {
 353                         tm = *tmp;
 354                         (void) strncpy(buf, abbr(&tm), (sizeof buf) - 1);
 355                 }
 356                 for ( ; ; ) {
 357                         if (t >= cuthitime)
 358                                 break;
 359                         newt = t + SECSPERHOUR * 12;
 360                         if (newt >= cuthitime)
 361                                 break;
 362                         if (newt <= t)
 363                                 break;
 364                         newtmp = localtime(&newt);
 365                         if (newtmp != NULL)
 366                                 newtm = *newtmp;
 367                         if ((tmp == NULL || newtmp == NULL) ? (tmp != newtmp) :
 368                                 (delta(&newtm, &tm) != (newt - t) ||
 369                                 newtm.tm_isdst != tm.tm_isdst ||
 370                                 strcmp(abbr(&newtm), buf) != 0)) {
 371                                         newt = hunt(argv[i], t, newt);
 372                                         newtmp = localtime(&newt);
 373                                         if (newtmp != NULL) {
 374                                                 newtm = *newtmp;
 375                                                 (void) strncpy(buf,
 376                                                         abbr(&newtm),
 377                                                         (sizeof buf) - 1);
 378                                         }
 379                         }
 380                         t = newt;
 381                         tm = newtm;
 382                         tmp = newtmp;
 383                 }
 384                 t = absolute_max_time;
 385                 t -= SECSPERHOUR * HOURSPERDAY;
 386                 show(argv[i], t, TRUE);
 387                 t += SECSPERHOUR * HOURSPERDAY;
 388                 show(argv[i], t, TRUE);
 389         }
 390         if (fflush(stdout) || ferror(stdout)) {
 391                 (void) fprintf(stderr, "%s: ", progname);
 392                 (void) perror(_("Error writing to standard output"));
 393                 exit(EXIT_FAILURE);
 394         }
 395         exit(EXIT_SUCCESS);
 396         /* If exit fails to exit... */
 397         return EXIT_FAILURE;
 398 }
 399
 400 static void
 401 setabsolutes()
 402 {
 403         if (0.5 == (time_t) 0.5) {
 404                 /*
 405                 ** time_t is floating.
 406                 */
 407                 if (sizeof (time_t) == sizeof (float)) {
 408                         absolute_min_time = (time_t) -FLT_MAX;
 409                         absolute_max_time = (time_t) FLT_MAX;
 410                 } else if (sizeof (time_t) == sizeof (double)) {
 411                         absolute_min_time = (time_t) -DBL_MAX;
 412                         absolute_max_time = (time_t) DBL_MAX;
 413                 } else {
 414                         (void) fprintf(stderr,
 415 _("%s: use of -v on system with floating time_t other than float or double\n"),
 416                                 progname);
 417                         exit(EXIT_FAILURE);
 418                 }
 419         } else if (0 > (time_t) -1) {
 420                 /*
 421                 ** time_t is signed.
 422                 */
 423                 register time_t hibit;
 424
 425                 for (hibit = 1; (hibit * 2) != 0; hibit *= 2)
 426                         continue;
 427                 absolute_min_time = hibit;
 428                 absolute_max_time = -(hibit + 1);
 429         } else {
 430                 /*
 431                 ** time_t is unsigned.
 432                 */
 433                 absolute_min_time = 0;
 434                 absolute_max_time = absolute_min_time - 1;
 435         }
 436 }
 437
 438 static time_t
 439 yeartot(y)
 440 const long      y;
 441 {
 442         register long   myy;
 443         register long   seconds;
 444         register time_t t;
 445
 446         myy = EPOCH_YEAR;
 447         t = 0;
 448         while (myy != y) {
 449                 if (myy < y) {
 450                         seconds = isleap(myy) ? SECSPERLYEAR : SECSPERNYEAR;
 451                         ++myy;
 452                         if (t > absolute_max_time - seconds) {
 453                                 t = absolute_max_time;
 454                                 break;
 455                         }
 456                         t += seconds;
 457                 } else {
 458                         --myy;
 459                         seconds = isleap(myy) ? SECSPERLYEAR : SECSPERNYEAR;
 460                         if (t < absolute_min_time + seconds) {
 461                                 t = absolute_min_time;
 462                                 break;
 463                         }
 464                         t -= seconds;
 465                 }
 466         }
 467         return t;
 468 }
 469
 470 static time_t
 471 hunt(name, lot, hit)
 472 char *  name;
 473 time_t  lot;
 474 time_t  hit;
 475 {
 476         time_t                  t;
 477         long                    diff;
 478         struct tm               lotm;
 479         register struct tm *    lotmp;
 480         struct tm               tm;
 481         register struct tm *    tmp;
 482         char                    loab[MAX_STRING_LENGTH];
 483
 484         lotmp = my_localtime(&lot);
 485         if (lotmp != NULL) {
 486                 lotm = *lotmp;
 487                 (void) strncpy(loab, abbr(&lotm), (sizeof loab) - 1);
 488         }
 489         for ( ; ; ) {
 490                 diff = (long) (hit - lot);
 491                 if (diff < 2)
 492                         break;
 493                 t = lot;
 494                 t += diff / 2;
 495                 if (t <= lot)
 496                         ++t;
 497                 else if (t >= hit)
 498                         --t;
 499                 tmp = my_localtime(&t);
 500                 if (tmp != NULL)
 501                         tm = *tmp;
 502                 if ((lotmp == NULL || tmp == NULL) ? (lotmp == tmp) :
 503                         (delta(&tm, &lotm) == (t - lot) &&
 504                         tm.tm_isdst == lotm.tm_isdst &&
 505                         strcmp(abbr(&tm), loab) == 0)) {
 506                                 lot = t;
 507                                 lotm = tm;
 508                                 lotmp = tmp;
 509                 } else  hit = t;
 510         }
 511         show(name, lot, TRUE);
 512         show(name, hit, TRUE);
 513         return hit;
 514 }
 515
 516 /*
 517 ** Thanks to Paul Eggert for logic used in delta.
 518 */
 519
 520 static long
 521 delta(newp, oldp)
 522 struct tm *     newp;
 523 struct tm *     oldp;
 524 {
 525         register long   result;
 526         register int    tmy;
 527
 528         if (newp->tm_year < oldp->tm_year)
 529                 return -delta(oldp, newp);
 530         result = 0;
 531         for (tmy = oldp->tm_year; tmy < newp->tm_year; ++tmy)
 532                 result += DAYSPERNYEAR + isleap_sum(tmy, TM_YEAR_BASE);
 533         result += newp->tm_yday - oldp->tm_yday;
 534         result *= HOURSPERDAY;
 535         result += newp->tm_hour - oldp->tm_hour;
 536         result *= MINSPERHOUR;
 537         result += newp->tm_min - oldp->tm_min;
 538         result *= SECSPERMIN;
 539         result += newp->tm_sec - oldp->tm_sec;
 540         return result;
 541 }
 542
 543 static void
 544 show(zone, t, v)
 545 char *  zone;
 546 time_t  t;
 547 int     v;
 548 {
 549         register struct tm *    tmp;
 550
 551         (void) printf("%-*s  ", (int) longest, zone);
 552         if (v) {
 553                 tmp = gmtime(&t);
 554                 if (tmp == NULL) {
 555                         (void) printf(tformat(), t);
 556                 } else {
 557                         dumptime(tmp);
 558                         (void) printf(" UTC");
 559                 }
 560                 (void) printf(" = ");
 561         }
 562         tmp = my_localtime(&t);
 563         dumptime(tmp);
 564         if (tmp != NULL) {
 565                 if (*abbr(tmp) != '\0')
 566                         (void) printf(" %s", abbr(tmp));
 567                 if (v) {
 568                         (void) printf(" isdst=%d", tmp->tm_isdst);
 569 #ifdef TM_GMTOFF
 570                         (void) printf(" gmtoff=%ld", tmp->TM_GMTOFF);
 571 #endif /* defined TM_GMTOFF */
 572                 }
 573         }
 574         (void) printf("\n");
 575         if (tmp != NULL && *abbr(tmp) != '\0')
 576                 abbrok(abbr(tmp), zone);
 577 }
 578
 579 static char *
 580 abbr(tmp)
 581 struct tm *     tmp;
 582 {
 583         register char * result;
 584         static char     nada;
 585
 586         if (tmp->tm_isdst != 0 && tmp->tm_isdst != 1)
 587                 return &nada;
 588         result = tzname[tmp->tm_isdst];
 589         return (result == NULL) ? &nada : result;
 590 }
 591
 592 /*
 593 ** The code below can fail on certain theoretical systems;
 594 ** it works on all known real-world systems as of 2004-12-30.
 595 */
 596
 597 static const char *
 598 tformat()
 599 {
 600         if (0.5 == (time_t) 0.5) {      /* floating */
 601                 if (sizeof (time_t) > sizeof (double))
 602                         return "%Lg";
 603                 return "%g";
 604         }
 605         if (0 > (time_t) -1) {          /* signed */
 606                 if (sizeof (time_t) > sizeof (long))
 607                         return "%lld";
 608                 if (sizeof (time_t) > sizeof (int))
 609                         return "%ld";
 610                 return "%d";
 611         }
 612         if (sizeof (time_t) > sizeof (unsigned long))
 613                 return "%llu";
 614         if (sizeof (time_t) > sizeof (unsigned int))
 615                 return "%lu";
 616         return "%u";
 617 }
 618
 619 static void
 620 dumptime(timeptr)
 621 register const struct tm *      timeptr;
 622 {
 623         static const char       wday_name[][3] = {
 624                 "Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"
 625         };
 626         static const char       mon_name[][3] = {
 627                 "Jan", "Feb", "Mar", "Apr", "May", "Jun",
 628                 "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"
 629         };
 630         register const char *   wn;
 631         register const char *   mn;
 632         register int            lead;
 633         register int            trail;
 634
 635         if (timeptr == NULL) {
 636                 (void) printf("NULL");
 637                 return;
 638         }
 639         /*
 640         ** The packaged versions of localtime and gmtime never put out-of-range
 641         ** values in tm_wday or tm_mon, but since this code might be compiled
 642         ** with other (perhaps experimental) versions, paranoia is in order.
 643         */
 644         if (timeptr->tm_wday < 0 || timeptr->tm_wday >=
 645                 (int) (sizeof wday_name / sizeof wday_name[0]))
 646                         wn = "???";
 647         else            wn = wday_name[timeptr->tm_wday];
 648         if (timeptr->tm_mon < 0 || timeptr->tm_mon >=
 649                 (int) (sizeof mon_name / sizeof mon_name[0]))
 650                         mn = "???";
 651         else            mn = mon_name[timeptr->tm_mon];
 652         (void) printf("%.3s %.3s%3d %.2d:%.2d:%.2d ",
 653                 wn, mn,
 654                 timeptr->tm_mday, timeptr->tm_hour,
 655                 timeptr->tm_min, timeptr->tm_sec);
 656 #define DIVISOR 10
 657         trail = timeptr->tm_year % DIVISOR + TM_YEAR_BASE % DIVISOR;
 658         lead = timeptr->tm_year / DIVISOR + TM_YEAR_BASE / DIVISOR +
 659                 trail / DIVISOR;
 660         trail %= DIVISOR;
 661         if (trail < 0 && lead > 0) {
 662                 trail += DIVISOR;
 663                 --lead;
 664         } else if (lead < 0 && trail > 0) {
 665                 trail -= DIVISOR;
 666                 ++lead;
 667         }
 668         if (lead == 0)
 669                 (void) printf("%d", trail);
 670         else    (void) printf("%d%d", lead, ((trail < 0) ? -trail : trail));
 671 }