lib/sh/strftime.c

   1 /* strftime - formatted time and date to a string */
   2 /*
   3  * Modified slightly by Chet Ramey for inclusion in Bash
   4  */
   5 /*
   6  * strftime.c
   7  *
   8  * Public-domain implementation of ISO C library routine.
   9  *
  10  * If you can't do prototypes, get GCC.
  11  *
  12  * The C99 standard now specifies just about all of the formats
  13  * that were additional in the earlier versions of this file.
  14  *
  15  * For extensions from SunOS, add SUNOS_EXT.
  16  * For extensions from HP/UX, add HPUX_EXT.
  17  * For VMS dates, add VMS_EXT.
  18  * For complete POSIX semantics, add POSIX_SEMANTICS.
  19  *
  20  * The code for %c, %x, and %X follows the C99 specification for
  21  * the "C" locale.
  22  *
  23  * This version ignores LOCALE information.
  24  * It also doesn't worry about multi-byte characters.
  25  * So there.
  26  *
  27  * This file is also shipped with GAWK (GNU Awk), gawk specific bits of
  28  * code are included if GAWK is defined.
  29  *
  30  * Arnold Robbins
  31  * January, February, March, 1991
  32  * Updated March, April 1992
  33  * Updated April, 1993
  34  * Updated February, 1994
  35  * Updated May, 1994
  36  * Updated January, 1995
  37  * Updated September, 1995
  38  * Updated January, 1996
  39  * Updated July, 1997
  40  * Updated October, 1999
  41  * Updated September, 2000
  42  *
  43  * Fixes from ado@elsie.nci.nih.gov,
  44  * February 1991, May 1992
  45  * Fixes from Tor Lillqvist tml@tik.vtt.fi,
  46  * May 1993
  47  * Further fixes from ado@elsie.nci.nih.gov,
  48  * February 1994
  49  * %z code from chip@chinacat.unicom.com,
  50  * Applied September 1995
  51  * %V code fixed (again) and %G, %g added,
  52  * January 1996
  53  * %v code fixed, better configuration,
  54  * July 1997
  55  * Moved to C99 specification.
  56  * September 2000
  57  */
  58 #include <config.h>
  59
  60 #ifndef GAWK
  61 #include <stdio.h>
  62 #include <ctype.h>
  63 #include <time.h>
  64 #endif
  65 #if defined(TM_IN_SYS_TIME)
  66 #include <sys/types.h>
  67 #include <sys/time.h>
  68 #endif
  69
  70 #include <stdlib.h>
  71 #include <string.h>
  72
  73 /* defaults: season to taste */
  74 #define SUNOS_EXT       1       /* stuff in SunOS strftime routine */
  75 #define VMS_EXT         1       /* include %v for VMS date format */
  76 #define HPUX_EXT        1       /* non-conflicting stuff in HP-UX date */
  77 #ifndef GAWK
  78 #define POSIX_SEMANTICS 1       /* call tzset() if TZ changes */
  79 #endif
  80
  81 #undef strchr   /* avoid AIX weirdness */
  82
  83 #if defined (SHELL)
  84 extern char *get_string_value (const char *);
  85 #endif
  86
  87 extern void tzset(void);
  88 static int weeknumber(const struct tm *timeptr, int firstweekday);
  89 static int iso8601wknum(const struct tm *timeptr);
  90
  91 #ifndef inline
  92 #ifdef __GNUC__
  93 #define inline  __inline__
  94 #else
  95 #define inline  /**/
  96 #endif
  97 #endif
  98
  99 #define range(low, item, hi)    max(low, min(item, hi))
 100
 101 #if !defined(OS2) && !defined(MSDOS) && defined(HAVE_TZNAME)
 102 extern char *tzname[2];
 103 extern int daylight;
 104 #if defined(SOLARIS) || defined(mips) || defined (M_UNIX)
 105 extern long int timezone, altzone;
 106 #else
 107 #  if defined (HPUX)
 108 extern long int timezone;
 109 #  else
 110 extern int timezone, altzone;
 111 #  endif /* !HPUX */
 112 #endif /* !SOLARIS && !mips && !M_UNIX */
 113 #endif
 114
 115 #undef min      /* just in case */
 116
 117 /* min --- return minimum of two numbers */
 118
 119 static inline int
 120 min(int a, int b)
 121 {
 122         return (a < b ? a : b);
 123 }
 124
 125 #undef max      /* also, just in case */
 126
 127 /* max --- return maximum of two numbers */
 128
 129 static inline int
 130 max(int a, int b)
 131 {
 132         return (a > b ? a : b);
 133 }
 134
 135 /* strftime --- produce formatted time */
 136
 137 size_t
 138 strftime(char *s, size_t maxsize, const char *format, const struct tm *timeptr)
 139 {
 140         char *endp = s + maxsize;
 141         char *start = s;
 142         auto char tbuf[100];
 143         long off;
 144         int i, w, y;
 145         static short first = 1;
 146 #ifdef POSIX_SEMANTICS
 147         static char *savetz = NULL;
 148         static int savetzlen = 0;
 149         char *tz;
 150 #endif /* POSIX_SEMANTICS */
 151 #ifndef HAVE_TM_ZONE
 152 #ifndef HAVE_TM_NAME
 153 #ifndef HAVE_TZNAME
 154         extern char *timezone();
 155         struct timeval tv;
 156         struct timezone zone;
 157 #endif /* HAVE_TZNAME */
 158 #endif /* HAVE_TM_NAME */
 159 #endif /* HAVE_TM_ZONE */
 160
 161         /* various tables, useful in North America */
 162         static const char *days_a[] = {
 163                 "Sun", "Mon", "Tue", "Wed",
 164                 "Thu", "Fri", "Sat",
 165         };
 166         static const char *days_l[] = {
 167                 "Sunday", "Monday", "Tuesday", "Wednesday",
 168                 "Thursday", "Friday", "Saturday",
 169         };
 170         static const char *months_a[] = {
 171                 "Jan", "Feb", "Mar", "Apr", "May", "Jun",
 172                 "Jul", "Aug", "Sep", "Oct", "Nov", "Dec",
 173         };
 174         static const char *months_l[] = {
 175                 "January", "February", "March", "April",
 176                 "May", "June", "July", "August", "September",
 177                 "October", "November", "December",
 178         };
 179         static const char *ampm[] = { "AM", "PM", };
 180
 181         if (s == NULL || format == NULL || timeptr == NULL || maxsize == 0)
 182                 return 0;
 183
 184         /* quick check if we even need to bother */
 185         if (strchr(format, '%') == NULL && strlen(format) + 1 >= maxsize)
 186                 return 0;
 187
 188 #ifndef POSIX_SEMANTICS
 189         if (first) {
 190                 tzset();
 191                 first = 0;
 192         }
 193 #else   /* POSIX_SEMANTICS */
 194 #if defined (SHELL)
 195         tz = get_string_value ("TZ");
 196 #else
 197         tz = getenv("TZ");
 198 #endif
 199         if (first) {
 200                 if (tz != NULL) {
 201                         int tzlen = strlen(tz);
 202
 203                         savetz = (char *) malloc(tzlen + 1);
 204                         if (savetz != NULL) {
 205                                 savetzlen = tzlen + 1;
 206                                 strcpy(savetz, tz);
 207                         }
 208                 }
 209                 tzset();
 210                 first = 0;
 211         }
 212         /* if we have a saved TZ, and it is different, recapture and reset */
 213         if (tz && savetz && (tz[0] != savetz[0] || strcmp(tz, savetz) != 0)) {
 214                 i = strlen(tz) + 1;
 215                 if (i > savetzlen) {
 216                         savetz = (char *) realloc(savetz, i);
 217                         if (savetz) {
 218                                 savetzlen = i;
 219                                 strcpy(savetz, tz);
 220                         }
 221                 } else
 222                         strcpy(savetz, tz);
 223                 tzset();
 224         }
 225 #endif  /* POSIX_SEMANTICS */
 226
 227         for (; *format && s < endp - 1; format++) {
 228                 tbuf[0] = '\0';
 229                 if (*format != '%') {
 230                         *s++ = *format;
 231                         continue;
 232                 }
 233         again:
 234                 switch (*++format) {
 235                 case '\0':
 236                         *s++ = '%';
 237                         goto out;
 238
 239                 case '%':
 240                         *s++ = '%';
 241                         continue;
 242
 243                 case 'a':       /* abbreviated weekday name */
 244                         if (timeptr->tm_wday < 0 || timeptr->tm_wday > 6)
 245                                 strcpy(tbuf, "?");
 246                         else
 247                                 strcpy(tbuf, days_a[timeptr->tm_wday]);
 248                         break;
 249
 250                 case 'A':       /* full weekday name */
 251                         if (timeptr->tm_wday < 0 || timeptr->tm_wday > 6)
 252                                 strcpy(tbuf, "?");
 253                         else
 254                                 strcpy(tbuf, days_l[timeptr->tm_wday]);
 255                         break;
 256
 257                 case 'b':       /* abbreviated month name */
 258                 short_month:
 259                         if (timeptr->tm_mon < 0 || timeptr->tm_mon > 11)
 260                                 strcpy(tbuf, "?");
 261                         else
 262                                 strcpy(tbuf, months_a[timeptr->tm_mon]);
 263                         break;
 264
 265                 case 'B':       /* full month name */
 266                         if (timeptr->tm_mon < 0 || timeptr->tm_mon > 11)
 267                                 strcpy(tbuf, "?");
 268                         else
 269                                 strcpy(tbuf, months_l[timeptr->tm_mon]);
 270                         break;
 271
 272                 case 'c':       /* appropriate date and time representation */
 273                         /*
 274                          * This used to be:
 275                          *
 276                          * strftime(tbuf, sizeof tbuf, "%a %b %e %H:%M:%S %Y", timeptr);
 277                          *
 278                          * Now, per the ISO 1999 C standard, it this:
 279                          */
 280                         strftime(tbuf, sizeof tbuf, "%A %B %d %T %Y", timeptr);
 281                         break;
 282
 283                 case 'C':
 284                 century:
 285                         sprintf(tbuf, "%02d", (timeptr->tm_year + 1900) / 100);
 286                         break;
 287
 288                 case 'd':       /* day of the month, 01 - 31 */
 289                         i = range(1, timeptr->tm_mday, 31);
 290                         sprintf(tbuf, "%02d", i);
 291                         break;
 292
 293                 case 'D':       /* date as %m/%d/%y */
 294                         strftime(tbuf, sizeof tbuf, "%m/%d/%y", timeptr);
 295                         break;
 296
 297                 case 'e':       /* day of month, blank padded */
 298                         sprintf(tbuf, "%2d", range(1, timeptr->tm_mday, 31));
 299                         break;
 300
 301                 case 'E':
 302                         /* POSIX (now C99) locale extensions, ignored for now */
 303                         goto again;
 304
 305                 case 'F':       /* ISO 8601 date representation */
 306                         strftime(tbuf, sizeof tbuf, "%Y-%m-%d", timeptr);
 307                         break;
 308
 309                 case 'g':
 310                 case 'G':
 311                         /*
 312                          * Year of ISO week.
 313                          *
 314                          * If it's December but the ISO week number is one,
 315                          * that week is in next year.
 316                          * If it's January but the ISO week number is 52 or
 317                          * 53, that week is in last year.
 318                          * Otherwise, it's this year.
 319                          */
 320                         w = iso8601wknum(timeptr);
 321                         if (timeptr->tm_mon == 11 && w == 1)
 322                                 y = 1900 + timeptr->tm_year + 1;
 323                         else if (timeptr->tm_mon == 0 && w >= 52)
 324                                 y = 1900 + timeptr->tm_year - 1;
 325                         else
 326                                 y = 1900 + timeptr->tm_year;
 327
 328                         if (*format == 'G')
 329                                 sprintf(tbuf, "%d", y);
 330                         else
 331                                 sprintf(tbuf, "%02d", y % 100);
 332                         break;
 333
 334                 case 'h':       /* abbreviated month name */
 335                         goto short_month;
 336
 337                 case 'H':       /* hour, 24-hour clock, 00 - 23 */
 338                         i = range(0, timeptr->tm_hour, 23);
 339                         sprintf(tbuf, "%02d", i);
 340                         break;
 341
 342                 case 'I':       /* hour, 12-hour clock, 01 - 12 */
 343                         i = range(0, timeptr->tm_hour, 23);
 344                         if (i == 0)
 345                                 i = 12;
 346                         else if (i > 12)
 347                                 i -= 12;
 348                         sprintf(tbuf, "%02d", i);
 349                         break;
 350
 351                 case 'j':       /* day of the year, 001 - 366 */
 352                         sprintf(tbuf, "%03d", timeptr->tm_yday + 1);
 353                         break;
 354
 355                 case 'm':       /* month, 01 - 12 */
 356                         i = range(0, timeptr->tm_mon, 11);
 357                         sprintf(tbuf, "%02d", i + 1);
 358                         break;
 359
 360                 case 'M':       /* minute, 00 - 59 */
 361                         i = range(0, timeptr->tm_min, 59);
 362                         sprintf(tbuf, "%02d", i);
 363                         break;
 364
 365                 case 'n':       /* same as \n */
 366                         tbuf[0] = '\n';
 367                         tbuf[1] = '\0';
 368                         break;
 369
 370                 case 'O':
 371                         /* POSIX (now C99) locale extensions, ignored for now */
 372                         goto again;
 373
 374                 case 'p':       /* am or pm based on 12-hour clock */
 375                         i = range(0, timeptr->tm_hour, 23);
 376                         if (i < 12)
 377                                 strcpy(tbuf, ampm[0]);
 378                         else
 379                                 strcpy(tbuf, ampm[1]);
 380                         break;
 381
 382                 case 'r':       /* time as %I:%M:%S %p */
 383                         strftime(tbuf, sizeof tbuf, "%I:%M:%S %p", timeptr);
 384                         break;
 385
 386                 case 'R':       /* time as %H:%M */
 387                         strftime(tbuf, sizeof tbuf, "%H:%M", timeptr);
 388                         break;
 389
 390 #if defined(HAVE_MKTIME) || defined(GAWK)
 391                 case 's':       /* time as seconds since the Epoch */
 392                 {
 393                         struct tm non_const_timeptr;
 394
 395                         non_const_timeptr = *timeptr;
 396                         sprintf(tbuf, "%ld", mktime(& non_const_timeptr));
 397                         break;
 398                 }
 399 #endif /* defined(HAVE_MKTIME) || defined(GAWK) */
 400
 401                 case 'S':       /* second, 00 - 60 */
 402                         i = range(0, timeptr->tm_sec, 60);
 403                         sprintf(tbuf, "%02d", i);
 404                         break;
 405
 406                 case 't':       /* same as \t */
 407                         tbuf[0] = '\t';
 408                         tbuf[1] = '\0';
 409                         break;
 410
 411                 case 'T':       /* time as %H:%M:%S */
 412                 the_time:
 413                         strftime(tbuf, sizeof tbuf, "%H:%M:%S", timeptr);
 414                         break;
 415
 416                 case 'u':
 417                 /* ISO 8601: Weekday as a decimal number [1 (Monday) - 7] */
 418                         sprintf(tbuf, "%d", timeptr->tm_wday == 0 ? 7 :
 419                                         timeptr->tm_wday);
 420                         break;
 421
 422                 case 'U':       /* week of year, Sunday is first day of week */
 423                         sprintf(tbuf, "%02d", weeknumber(timeptr, 0));
 424                         break;
 425
 426                 case 'V':       /* week of year according ISO 8601 */
 427                         sprintf(tbuf, "%02d", iso8601wknum(timeptr));
 428                         break;
 429
 430                 case 'w':       /* weekday, Sunday == 0, 0 - 6 */
 431                         i = range(0, timeptr->tm_wday, 6);
 432                         sprintf(tbuf, "%d", i);
 433                         break;
 434
 435                 case 'W':       /* week of year, Monday is first day of week */
 436                         sprintf(tbuf, "%02d", weeknumber(timeptr, 1));
 437                         break;
 438
 439                 case 'x':       /* appropriate date representation */
 440                         strftime(tbuf, sizeof tbuf, "%A %B %d %Y", timeptr);
 441                         break;
 442
 443                 case 'X':       /* appropriate time representation */
 444                         goto the_time;
 445                         break;
 446
 447                 case 'y':       /* year without a century, 00 - 99 */
 448                 year:
 449                         i = timeptr->tm_year % 100;
 450                         sprintf(tbuf, "%02d", i);
 451                         break;
 452
 453                 case 'Y':       /* year with century */
 454                 fullyear:
 455                         sprintf(tbuf, "%d", 1900 + timeptr->tm_year);
 456                         break;
 457
 458                 /*
 459                  * From: Chip Rosenthal <chip@chinacat.unicom.com>
 460                  * Date: Sun, 19 Mar 1995 00:33:29 -0600 (CST)
 461                  *
 462                  * Warning: the %z [code] is implemented by inspecting the
 463                  * timezone name conditional compile settings, and
 464                  * inferring a method to get timezone offsets. I've tried
 465                  * this code on a couple of machines, but I don't doubt
 466                  * there is some system out there that won't like it.
 467                  * Maybe the easiest thing to do would be to bracket this
 468                  * with an #ifdef that can turn it off. The %z feature
 469                  * would be an admittedly obscure one that most folks can
 470                  * live without, but it would be a great help to those of
 471                  * us that muck around with various message processors.
 472                  */
 473                 case 'z':       /* time zone offset east of GMT e.g. -0600 */
 474                         if (timeptr->tm_isdst < 0)
 475                                 break;
 476 #ifdef HAVE_TM_NAME
 477                         /*
 478                          * Systems with tm_name probably have tm_tzadj as
 479                          * secs west of GMT.  Convert to mins east of GMT.
 480                          */
 481                         off = -timeptr->tm_tzadj / 60;
 482 #else /* !HAVE_TM_NAME */
 483 #ifdef HAVE_TM_ZONE
 484                         /*
 485                          * Systems with tm_zone probably have tm_gmtoff as
 486                          * secs east of GMT.  Convert to mins east of GMT.
 487                          */
 488                         off = timeptr->tm_gmtoff / 60;
 489 #else /* !HAVE_TM_ZONE */
 490 #if HAVE_TZNAME
 491                         /*
 492                          * Systems with tzname[] probably have timezone as
 493                          * secs west of GMT.  Convert to mins east of GMT.
 494                          */
 495 #  ifdef HPUX
 496                         off = -timezone / 60;
 497 #  else
 498                         off = -(daylight ? altzone : timezone) / 60;
 499 #  endif /* !HPUX */
 500 #else /* !HAVE_TZNAME */
 501                         gettimeofday(& tv, & zone);
 502                         off = -zone.tz_minuteswest;
 503 #endif /* !HAVE_TZNAME */
 504 #endif /* !HAVE_TM_ZONE */
 505 #endif /* !HAVE_TM_NAME */
 506                         if (off < 0) {
 507                                 tbuf[0] = '-';
 508                                 off = -off;
 509                         } else {
 510                                 tbuf[0] = '+';
 511                         }
 512                         sprintf(tbuf+1, "%02d%02d", off/60, off%60);
 513                         break;
 514
 515                 case 'Z':       /* time zone name or abbrevation */
 516 #ifdef HAVE_TZNAME
 517                         i = (daylight && timeptr->tm_isdst > 0); /* 0 or 1 */
 518                         strcpy(tbuf, tzname[i]);
 519 #else
 520 #ifdef HAVE_TM_ZONE
 521                         strcpy(tbuf, timeptr->tm_zone);
 522 #else
 523 #ifdef HAVE_TM_NAME
 524                         strcpy(tbuf, timeptr->tm_name);
 525 #else
 526                         gettimeofday(& tv, & zone);
 527                         strcpy(tbuf, timezone(zone.tz_minuteswest,
 528                                                 timeptr->tm_isdst > 0));
 529 #endif /* HAVE_TM_NAME */
 530 #endif /* HAVE_TM_ZONE */
 531 #endif /* HAVE_TZNAME */
 532                         break;
 533
 534 #ifdef SUNOS_EXT
 535                 case 'k':       /* hour, 24-hour clock, blank pad */
 536                         sprintf(tbuf, "%2d", range(0, timeptr->tm_hour, 23));
 537                         break;
 538
 539                 case 'l':       /* hour, 12-hour clock, 1 - 12, blank pad */
 540                         i = range(0, timeptr->tm_hour, 23);
 541                         if (i == 0)
 542                                 i = 12;
 543                         else if (i > 12)
 544                                 i -= 12;
 545                         sprintf(tbuf, "%2d", i);
 546                         break;
 547 #endif
 548
 549 #ifdef HPUX_EXT
 550                 case 'N':       /* Emperor/Era name */
 551                         /* this is essentially the same as the century */
 552                         goto century;   /* %C */
 553
 554                 case 'o':       /* Emperor/Era year */
 555                         goto year;      /* %y */
 556 #endif /* HPUX_EXT */
 557
 558
 559 #ifdef VMS_EXT
 560                 case 'v':       /* date as dd-bbb-YYYY */
 561                         sprintf(tbuf, "%2d-%3.3s-%4d",
 562                                 range(1, timeptr->tm_mday, 31),
 563                                 months_a[range(0, timeptr->tm_mon, 11)],
 564                                 timeptr->tm_year + 1900);
 565                         for (i = 3; i < 6; i++)
 566                                 if (islower(tbuf[i]))
 567                                         tbuf[i] = toupper(tbuf[i]);
 568                         break;
 569 #endif
 570
 571                 default:
 572                         tbuf[0] = '%';
 573                         tbuf[1] = *format;
 574                         tbuf[2] = '\0';
 575                         break;
 576                 }
 577                 i = strlen(tbuf);
 578                 if (i) {
 579                         if (s + i < endp - 1) {
 580                                 strcpy(s, tbuf);
 581                                 s += i;
 582                         } else
 583                                 return 0;
 584                 }
 585         }
 586 out:
 587         if (s < endp && *format == '\0') {
 588                 *s = '\0';
 589                 return (s - start);
 590         } else
 591                 return 0;
 592 }
 593
 594 /* isleap --- is a year a leap year? */
 595
 596 static int
 597 isleap(int year)
 598 {
 599         return ((year % 4 == 0 && year % 100 != 0) || year % 400 == 0);
 600 }
 601
 602
 603 /* iso8601wknum --- compute week number according to ISO 8601 */
 604
 605 static int
 606 iso8601wknum(const struct tm *timeptr)
 607 {
 608         /*
 609          * From 1003.2:
 610          *      If the week (Monday to Sunday) containing January 1
 611          *      has four or more days in the new year, then it is week 1;
 612          *      otherwise it is the highest numbered week of the previous
 613          *      year (52 or 53), and the next week is week 1.
 614          *
 615          * ADR: This means if Jan 1 was Monday through Thursday,
 616          *      it was week 1, otherwise week 52 or 53.
 617          *
 618          * XPG4 erroneously included POSIX.2 rationale text in the
 619          * main body of the standard. Thus it requires week 53.
 620          */
 621
 622         int weeknum, jan1day, diff;
 623
 624         /* get week number, Monday as first day of the week */
 625         weeknum = weeknumber(timeptr, 1);
 626
 627         /*
 628          * With thanks and tip of the hatlo to tml@tik.vtt.fi
 629          *
 630          * What day of the week does January 1 fall on?
 631          * We know that
 632          *      (timeptr->tm_yday - jan1.tm_yday) MOD 7 ==
 633          *              (timeptr->tm_wday - jan1.tm_wday) MOD 7
 634          * and that
 635          *      jan1.tm_yday == 0
 636          * and that
 637          *      timeptr->tm_wday MOD 7 == timeptr->tm_wday
 638          * from which it follows that. . .
 639          */
 640         jan1day = timeptr->tm_wday - (timeptr->tm_yday % 7);
 641         if (jan1day < 0)
 642                 jan1day += 7;
 643
 644         /*
 645          * If Jan 1 was a Monday through Thursday, it was in
 646          * week 1.  Otherwise it was last year's highest week, which is
 647          * this year's week 0.
 648          *
 649          * What does that mean?
 650          * If Jan 1 was Monday, the week number is exactly right, it can
 651          *      never be 0.
 652          * If it was Tuesday through Thursday, the weeknumber is one
 653          *      less than it should be, so we add one.
 654          * Otherwise, Friday, Saturday or Sunday, the week number is
 655          * OK, but if it is 0, it needs to be 52 or 53.
 656          */
 657         switch (jan1day) {
 658         case 1:         /* Monday */
 659                 break;
 660         case 2:         /* Tuesday */
 661         case 3:         /* Wednesday */
 662         case 4:         /* Thursday */
 663                 weeknum++;
 664                 break;
 665         case 5:         /* Friday */
 666         case 6:         /* Saturday */
 667         case 0:         /* Sunday */
 668                 if (weeknum == 0) {
 669 #ifdef USE_BROKEN_XPG4
 670                         /* XPG4 (as of March 1994) says 53 unconditionally */
 671                         weeknum = 53;
 672 #else
 673                         /* get week number of last week of last year */
 674                         struct tm dec31ly;      /* 12/31 last year */
 675                         dec31ly = *timeptr;
 676                         dec31ly.tm_year--;
 677                         dec31ly.tm_mon = 11;
 678                         dec31ly.tm_mday = 31;
 679                         dec31ly.tm_wday = (jan1day == 0) ? 6 : jan1day - 1;
 680                         dec31ly.tm_yday = 364 + isleap(dec31ly.tm_year + 1900);
 681                         weeknum = iso8601wknum(& dec31ly);
 682 #endif
 683                 }
 684                 break;
 685         }
 686
 687         if (timeptr->tm_mon == 11) {
 688                 /*
 689                  * The last week of the year
 690                  * can be in week 1 of next year.
 691                  * Sigh.
 692                  *
 693                  * This can only happen if
 694                  *      M   T  W
 695                  *      29  30 31
 696                  *      30  31
 697                  *      31
 698                  */
 699                 int wday, mday;
 700
 701                 wday = timeptr->tm_wday;
 702                 mday = timeptr->tm_mday;
 703                 if (   (wday == 1 && (mday >= 29 && mday <= 31))
 704                     || (wday == 2 && (mday == 30 || mday == 31))
 705                     || (wday == 3 &&  mday == 31))
 706                         weeknum = 1;
 707         }
 708
 709         return weeknum;
 710 }
 711
 712 /* weeknumber --- figure how many weeks into the year */
 713
 714 /* With thanks and tip of the hatlo to ado@elsie.nci.nih.gov */
 715
 716 static int
 717 weeknumber(const struct tm *timeptr, int firstweekday)
 718 {
 719         int wday = timeptr->tm_wday;
 720         int ret;
 721
 722         if (firstweekday == 1) {
 723                 if (wday == 0)  /* sunday */
 724                         wday = 6;
 725                 else
 726                         wday--;
 727         }
 728         ret = ((timeptr->tm_yday + 7 - wday) / 7);
 729         if (ret < 0)
 730                 ret = 0;
 731         return ret;
 732 }
 733
 734 #if 0
 735 /* ADR --- I'm loathe to mess with ado's code ... */
 736
 737 Date:         Wed, 24 Apr 91 20:54:08 MDT
 738 From: Michal Jaegermann <audfax!emory!vm.ucs.UAlberta.CA!NTOMCZAK>
 739 To: arnold@audiofax.com
 740
 741 Hi Arnold,
 742 in a process of fixing of strftime() in libraries on Atari ST I grabbed
 743 some pieces of code from your own strftime.  When doing that it came
 744 to mind that your weeknumber() function compiles a little bit nicer
 745 in the following form:
 746 /*
 747  * firstweekday is 0 if starting in Sunday, non-zero if in Monday
 748  */
 749 {
 750     return (timeptr->tm_yday - timeptr->tm_wday +
 751             (firstweekday ? (timeptr->tm_wday ? 8 : 1) : 7)) / 7;
 752 }
 753 How nicer it depends on a compiler, of course, but always a tiny bit.
 754
 755    Cheers,
 756    Michal
 757    ntomczak@vm.ucs.ualberta.ca
 758 #endif
 759
 760 #ifdef  TEST_STRFTIME
 761
 762 /*
 763  * NAME:
 764  *      tst
 765  *
 766  * SYNOPSIS:
 767  *      tst
 768  *
 769  * DESCRIPTION:
 770  *      "tst" is a test driver for the function "strftime".
 771  *
 772  * OPTIONS:
 773  *      None.
 774  *
 775  * AUTHOR:
 776  *      Karl Vogel
 777  *      Control Data Systems, Inc.
 778  *      vogelke@c-17igp.wpafb.af.mil
 779  *
 780  * BUGS:
 781  *      None noticed yet.
 782  *
 783  * COMPILE:
 784  *      cc -o tst -DTEST_STRFTIME strftime.c
 785  */
 786
 787 /* ADR: I reformatted this to my liking, and deleted some unneeded code. */
 788
 789 #ifndef NULL
 790 #include        <stdio.h>
 791 #endif
 792 #include        <sys/time.h>
 793 #include        <string.h>
 794
 795 #define         MAXTIME         132
 796
 797 /*
 798  * Array of time formats.
 799  */
 800
 801 static char *array[] =
 802 {
 803         "(%%A)      full weekday name, var length (Sunday..Saturday)  %A",
 804         "(%%B)       full month name, var length (January..December)  %B",
 805         "(%%C)                                               Century  %C",
 806         "(%%D)                                       date (%%m/%%d/%%y)  %D",
 807         "(%%E)                           Locale extensions (ignored)  %E",
 808         "(%%F)       full month name, var length (January..December)  %F",
 809         "(%%H)                          hour (24-hour clock, 00..23)  %H",
 810         "(%%I)                          hour (12-hour clock, 01..12)  %I",
 811         "(%%M)                                       minute (00..59)  %M",
 812         "(%%N)                                      Emporer/Era Name  %N",
 813         "(%%O)                           Locale extensions (ignored)  %O",
 814         "(%%R)                                 time, 24-hour (%%H:%%M)  %R",
 815         "(%%S)                                       second (00..60)  %S",
 816         "(%%T)                              time, 24-hour (%%H:%%M:%%S)  %T",
 817         "(%%U)    week of year, Sunday as first day of week (00..53)  %U",
 818         "(%%V)                    week of year according to ISO 8601  %V",
 819         "(%%W)    week of year, Monday as first day of week (00..53)  %W",
 820         "(%%X)     appropriate locale time representation (%H:%M:%S)  %X",
 821         "(%%Y)                           year with century (1970...)  %Y",
 822         "(%%Z) timezone (EDT), or blank if timezone not determinable  %Z",
 823         "(%%a)          locale's abbreviated weekday name (Sun..Sat)  %a",
 824         "(%%b)            locale's abbreviated month name (Jan..Dec)  %b",
 825         "(%%c)           full date (Sat Nov  4 12:02:33 1989)%n%t%t%t  %c",
 826         "(%%d)                             day of the month (01..31)  %d",
 827         "(%%e)               day of the month, blank-padded ( 1..31)  %e",
 828         "(%%h)                                should be same as (%%b)  %h",
 829         "(%%j)                            day of the year (001..366)  %j",
 830         "(%%k)               hour, 24-hour clock, blank pad ( 0..23)  %k",
 831         "(%%l)               hour, 12-hour clock, blank pad ( 0..12)  %l",
 832         "(%%m)                                        month (01..12)  %m",
 833         "(%%o)                                      Emporer/Era Year  %o",
 834         "(%%p)              locale's AM or PM based on 12-hour clock  %p",
 835         "(%%r)                   time, 12-hour (same as %%I:%%M:%%S %%p)  %r",
 836         "(%%u) ISO 8601: Weekday as decimal number [1 (Monday) - 7]   %u",
 837         "(%%v)                                VMS date (dd-bbb-YYYY)  %v",
 838         "(%%w)                       day of week (0..6, Sunday == 0)  %w",
 839         "(%%x)                appropriate locale date representation  %x",
 840         "(%%y)                      last two digits of year (00..99)  %y",
 841         "(%%z)      timezone offset east of GMT as HHMM (e.g. -0500)  %z",
 842         (char *) NULL
 843 };
 844
 845 /* main routine. */
 846
 847 int
 848 main(argc, argv)
 849 int argc;
 850 char **argv;
 851 {
 852         long time();
 853
 854         char *next;
 855         char string[MAXTIME];
 856
 857         int k;
 858         int length;
 859
 860         struct tm *tm;
 861
 862         long clock;
 863
 864         /* Call the function. */
 865
 866         clock = time((long *) 0);
 867         tm = localtime(&clock);
 868
 869         for (k = 0; next = array[k]; k++) {
 870                 length = strftime(string, MAXTIME, next, tm);
 871                 printf("%s\n", string);
 872         }
 873
 874         exit(0);
 875 }
 876 #endif  /* TEST_STRFTIME */