1 /*
2 * strftime.c
3 *
4 * Public-domain implementation of ANSI C library routine.
5 *
6 * It's written in old-style C for maximal portability.
7 * However, since I'm used to prototypes, I've included them too.
8 *
9 * If you want stuff in the System V ascftime routine, add the SYSV_EXT define.
10 * For extensions from SunOS, add SUNOS_EXT.
11 * For stuff needed to implement the P1003.2 date command, add POSIX2_DATE.
12 * For VMS dates, add VMS_EXT.
13 * For a an RFC822 time format, add MAILHEADER_EXT.
14 * For ISO week years, add ISO_DATE_EXT.
15 * For complete POSIX semantics, add POSIX_SEMANTICS.
16 *
17 * The code for %c, %x, and %X now follows the 1003.2 specification for
18 * the POSIX locale.
19 * This version ignores LOCALE information.
20 * It also doesn't worry about multi-byte characters.
21 * So there.
22 *
23 * This file is also shipped with GAWK (GNU Awk), gawk specific bits of
24 * code are included if GAWK is defined.
25 *
26 * Arnold Robbins
27 * January, February, March, 1991
28 * Updated March, April 1992
29 * Updated April, 1993
30 * Updated February, 1994
31 * Updated May, 1994
32 * Updated January, 1995
33 * Updated September, 1995
34 * Updated January, 1996
35 *
36 * Fixes from ado@elsie.nci.nih.gov
37 * February 1991, May 1992
38 * Fixes from Tor Lillqvist tml@tik.vtt.fi
39 * May, 1993
40 * Further fixes from ado@elsie.nci.nih.gov
41 * February 1994
42 * %z code from chip@chinacat.unicom.com
43 * Applied September 1995
44 * %V code fixed (again) and %G, %g added,
45 * January 1996
46 */
47
48 #include "config.h"
49
50 #ifndef GAWK
51 #include <stdio.h>
52 #include <ctype.h>
53 #include <string.h>
54 #include <time.h>
55 #endif
56 #if defined(TM_IN_SYS_TIME) || ! defined(GAWK)
57 #include <sys/types.h>
58 #include <sys/time.h>
59 #endif
60
61 /* defaults: season to taste */
62 #define SYSV_EXT 1 /* stuff in System V ascftime routine */
63 #define SUNOS_EXT 1 /* stuff in SunOS strftime routine */
64 #define POSIX2_DATE 1 /* stuff in Posix 1003.2 date command */
65 #define VMS_EXT 1 /* include %v for VMS date format */
66 #define MAILHEADER_EXT 1 /* add %z for HHMM format */
67 #define ISO_DATE_EXT 1 /* %G and %g for year of ISO week */
68 #ifndef GAWK
69 #define POSIX_SEMANTICS 1 /* call tzset() if TZ changes */
70 #endif
71
72 #if defined(ISO_DATE_EXT)
73 #if ! defined(POSIX2_DATE)
74 #define POSIX2_DATE 1
75 #endif
76 #endif
77
78 #if defined(POSIX2_DATE)
79 #if ! defined(SYSV_EXT)
80 #define SYSV_EXT 1
81 #endif
82 #if ! defined(SUNOS_EXT)
83 #define SUNOS_EXT 1
84 #endif
85 #endif
86
87 #if defined(POSIX2_DATE)
88 #define adddecl(stuff) stuff
89 #else
90 #define adddecl(stuff)
91 #endif
92
93 #undef strchr /* avoid AIX weirdness */
94
95 #ifndef __STDC__
96 #define const /**/
97 extern void tzset();
98 static int weeknumber();
99 adddecl(static int iso8601wknum();)
100 #else
101 extern void tzset(void);
102 static int weeknumber(const struct tm *timeptr, int firstweekday);
103 adddecl(static int iso8601wknum(const struct tm *timeptr);)
104 #endif
105
106 #ifdef STDC_HEADERS
107 #include <stdlib.h>
108 #include <string.h>
109 #else
110 extern void *malloc();
111 extern void *realloc();
112 extern char *getenv();
113 extern char *strchr();
114 #endif
115
116 #define range(low, item, hi) max(low, min(item, hi))
117
118 #if !defined(OS2) && !defined(MSDOS) && defined(HAVE_TZNAME)
119 extern char *tzname[2];
120 extern int daylight;
121 #ifdef SOLARIS
122 extern long timezone, altzone;
123 #else
124 extern int timezone, altzone;
125 #endif
126 #endif
127
128 #undef min /* just in case */
129
130 /* min --- return minimum of two numbers */
131
132 #ifndef __STDC__
133 static inline int
134 min(a, b)
135 int a, b;
136 #else
137 static inline int
138 min(int a, int b)
139 #endif
140 {
141 return (a < b ? a : b);
142 }
143
144 #undef max /* also, just in case */
145
146 /* max --- return maximum of two numbers */
147
148 #ifndef __STDC__
149 static inline int
150 max(a, b)
151 int a, b;
152 #else
153 static inline int
154 max(int a, int b)
155 #endif
156 {
157 return (a > b ? a : b);
158 }
159
160 /* strftime --- produce formatted time */
161
162 #ifndef __STDC__
163 size_t
164 strftime(s, maxsize, format, timeptr)
165 char *s;
166 size_t maxsize;
167 const char *format;
168 const struct tm *timeptr;
169 #else
170 size_t
171 strftime(char *s, size_t maxsize, const char *format, const struct tm *timeptr)
172 #endif
173 {
174 char *endp = s + maxsize;
175 char *start = s;
176 auto char tbuf[100];
177 long off;
178 int i, w;
179 long y;
180 static short first = 1;
181 #ifdef POSIX_SEMANTICS
182 static char *savetz = NULL;
183 static int savetzlen = 0;
184 char *tz;
185 #endif /* POSIX_SEMANTICS */
186 #ifndef HAVE_TM_ZONE
187 #ifndef HAVE_TM_NAME
188 #ifndef HAVE_TZNAME
189 extern char *timezone();
190 struct timeval tv;
191 struct timezone zone;
192 #endif /* HAVE_TZNAME */
193 #endif /* HAVE_TM_NAME */
194 #endif /* HAVE_TM_ZONE */
195
196 /* various tables, useful in North America */
197 static const char *days_a[] = {
198 "Sun", "Mon", "Tue", "Wed",
199 "Thu", "Fri", "Sat",
200 };
201 static const char *days_l[] = {
202 "Sunday", "Monday", "Tuesday", "Wednesday",
203 "Thursday", "Friday", "Saturday",
204 };
205 static const char *months_a[] = {
206 "Jan", "Feb", "Mar", "Apr", "May", "Jun",
207 "Jul", "Aug", "Sep", "Oct", "Nov", "Dec",
208 };
209 static const char *months_l[] = {
210 "January", "February", "March", "April",
211 "May", "June", "July", "August", "September",
212 "October", "November", "December",
213 };
214 static const char *ampm[] = { "AM", "PM", };
215
216 if (s == NULL || format == NULL || timeptr == NULL || maxsize == 0)
217 return 0;
218
219 /* quick check if we even need to bother */
220 if (strchr(format, '%') == NULL && strlen(format) + 1 >= maxsize)
221 return 0;
222
223 #ifndef POSIX_SEMANTICS
224 if (first) {
225 tzset();
226 first = 0;
227 }
228 #else /* POSIX_SEMANTICS */
229 tz = getenv("TZ");
230 if (first) {
231 if (tz != NULL) {
232 int tzlen = strlen(tz);
233
234 savetz = (char *) malloc(tzlen + 1);
235 if (savetz != NULL) {
236 savetzlen = tzlen + 1;
237 strcpy(savetz, tz);
238 }
239 }
240 tzset();
241 first = 0;
242 }
243 /* if we have a saved TZ, and it is different, recapture and reset */
244 if (tz && savetz && (tz[0] != savetz[0] || strcmp(tz, savetz) != 0)) {
245 i = strlen(tz) + 1;
246 if (i > savetzlen) {
247 savetz = (char *) realloc(savetz, i);
248 if (savetz) {
249 savetzlen = i;
250 strcpy(savetz, tz);
251 }
252 } else
253 strcpy(savetz, tz);
254 tzset();
255 }
256 #endif /* POSIX_SEMANTICS */
257
258 for (; *format && s < endp - 1; format++) {
259 tbuf[0] = '\0';
260 if (*format != '%') {
261 *s++ = *format;
262 continue;
263 }
264 again:
265 switch (*++format) {
266 case '\0':
267 *s++ = '%';
268 goto out;
269
270 case '%':
271 *s++ = '%';
272 continue;
273
274 case 'a': /* abbreviated weekday name */
275 if (timeptr->tm_wday < 0 || timeptr->tm_wday > 6)
276 strcpy(tbuf, "?");
277 else
278 strcpy(tbuf, days_a[timeptr->tm_wday]);
279 break;
280
281 case 'A': /* full weekday name */
282 if (timeptr->tm_wday < 0 || timeptr->tm_wday > 6)
283 strcpy(tbuf, "?");
284 else
285 strcpy(tbuf, days_l[timeptr->tm_wday]);
286 break;
287
288 #ifdef SYSV_EXT
289 case 'h': /* abbreviated month name */
290 #endif
291 case 'b': /* abbreviated month name */
292 if (timeptr->tm_mon < 0 || timeptr->tm_mon > 11)
293 strcpy(tbuf, "?");
294 else
295 strcpy(tbuf, months_a[timeptr->tm_mon]);
296 break;
297
298 case 'B': /* full month name */
299 if (timeptr->tm_mon < 0 || timeptr->tm_mon > 11)
300 strcpy(tbuf, "?");
301 else
302 strcpy(tbuf, months_l[timeptr->tm_mon]);
303 break;
304
305 case 'c': /* appropriate date and time representation */
306 strftime(tbuf, sizeof tbuf, "%a %b %e %H:%M:%S %Y", timeptr);
307 break;
308
309 case 'd': /* day of the month, 01 - 31 */
310 i = range(1, timeptr->tm_mday, 31);
311 sprintf(tbuf, "%02d", i);
312 break;
313
314 case 'H': /* hour, 24-hour clock, 00 - 23 */
315 i = range(0, timeptr->tm_hour, 23);
316 sprintf(tbuf, "%02d", i);
317 break;
318
319 case 'I': /* hour, 12-hour clock, 01 - 12 */
320 i = range(0, timeptr->tm_hour, 23);
321 if (i == 0)
322 i = 12;
323 else if (i > 12)
324 i -= 12;
325 sprintf(tbuf, "%02d", i);
326 break;
327
328 case 'j': /* day of the year, 001 - 366 */
329 sprintf(tbuf, "%03d", timeptr->tm_yday + 1);
330 break;
331
332 case 'm': /* month, 01 - 12 */
333 i = range(0, timeptr->tm_mon, 11);
334 sprintf(tbuf, "%02d", i + 1);
335 break;
336
337 case 'M': /* minute, 00 - 59 */
338 i = range(0, timeptr->tm_min, 59);
339 sprintf(tbuf, "%02d", i);
340 break;
341
342 case 'p': /* am or pm based on 12-hour clock */
343 i = range(0, timeptr->tm_hour, 23);
344 if (i < 12)
345 strcpy(tbuf, ampm[0]);
346 else
347 strcpy(tbuf, ampm[1]);
348 break;
349
350 case 'S': /* second, 00 - 60 */
351 i = range(0, timeptr->tm_sec, 60);
352 sprintf(tbuf, "%02d", i);
353 break;
354
355 case 'U': /* week of year, Sunday is first day of week */
356 sprintf(tbuf, "%02d", weeknumber(timeptr, 0));
357 break;
358
359 case 'w': /* weekday, Sunday == 0, 0 - 6 */
360 i = range(0, timeptr->tm_wday, 6);
361 sprintf(tbuf, "%d", i);
362 break;
363
364 case 'W': /* week of year, Monday is first day of week */
365 sprintf(tbuf, "%02d", weeknumber(timeptr, 1));
366 break;
367
368 case 'x': /* appropriate date representation */
369 strftime(tbuf, sizeof tbuf, "%m/%d/%y", timeptr);
370 break;
371
372 case 'X': /* appropriate time representation */
373 strftime(tbuf, sizeof tbuf, "%H:%M:%S", timeptr);
374 break;
375
376 case 'y': /* year without a century, 00 - 99 */
377 i = timeptr->tm_year % 100;
378 sprintf(tbuf, "%02d", i);
379 break;
380
381 case 'Y': /* year with century */
382 sprintf(tbuf, "%ld", 1900L + timeptr->tm_year);
383 break;
384
385 #ifdef MAILHEADER_EXT
386 /*
387 * From: Chip Rosenthal <chip@chinacat.unicom.com>
388 * Date: Sun, 19 Mar 1995 00:33:29 -0600 (CST)
389 *
390 * Warning: the %z [code] is implemented by inspecting the
391 * timezone name conditional compile settings, and
392 * inferring a method to get timezone offsets. I've tried
393 * this code on a couple of machines, but I don't doubt
394 * there is some system out there that won't like it.
395 * Maybe the easiest thing to do would be to bracket this
396 * with an #ifdef that can turn it off. The %z feature
397 * would be an admittedly obscure one that most folks can
398 * live without, but it would be a great help to those of
399 * us that muck around with various message processors.
400 */
401 case 'z': /* time zone offset east of GMT e.g. -0600 */
402 #ifdef HAVE_TM_NAME
403 /*
404 * Systems with tm_name probably have tm_tzadj as
405 * secs west of GMT. Convert to mins east of GMT.
406 */
407 off = -timeptr->tm_tzadj / 60;
408 #else /* !HAVE_TM_NAME */
409 #ifdef HAVE_TM_ZONE
410 /*
411 * Systems with tm_zone probably have tm_gmtoff as
412 * secs east of GMT. Convert to mins east of GMT.
413 */
414 off = timeptr->tm_gmtoff / 60;
415 #else /* !HAVE_TM_ZONE */
416 #if HAVE_TZNAME
417 /*
418 * Systems with tzname[] probably have timezone as
419 * secs west of GMT. Convert to mins east of GMT.
420 */
421 off = -(daylight ? timezone : altzone) / 60;
422 #else /* !HAVE_TZNAME */
423 gettimeofday(&tv, &zone);
424 off = -zone.tz_minuteswest;
425 #endif /* !HAVE_TZNAME */
426 #endif /* !HAVE_TM_ZONE */
427 #endif /* !HAVE_TM_NAME */
428 if (off < 0) {
429 tbuf[0] = '-';
430 off = -off;
431 } else {
432 tbuf[0] = '+';
433 }
434 sprintf(tbuf+1, "%02d%02d", off/60, off%60);
435 break;
436 #endif /* MAILHEADER_EXT */
437
438 case 'Z': /* time zone name or abbrevation */
439 #ifdef HAVE_TZNAME
440 i = (daylight && timeptr->tm_isdst > 0); /* 0 or 1 */
441 strcpy(tbuf, tzname[i]);
442 #else
443 #ifdef HAVE_TM_ZONE
444 strcpy(tbuf, timeptr->tm_zone);
445 #else
446 #ifdef HAVE_TM_NAME
447 strcpy(tbuf, timeptr->tm_name);
448 #else
449 gettimeofday(& tv, & zone);
450 #ifdef __CYGWIN__
451 strcpy(tbuf, timezone());
452 #else
453 strcpy(tbuf, timezone(zone.tz_minuteswest,
454 timeptr->tm_isdst > 0));
455 #endif
456 #endif /* HAVE_TM_NAME */
457 #endif /* HAVE_TM_ZONE */
458 #endif /* HAVE_TZNAME */
459 break;
460
461 #ifdef SYSV_EXT
462 case 'n': /* same as \n */
463 tbuf[0] = '\n';
464 tbuf[1] = '\0';
465 break;
466
467 case 't': /* same as \t */
468 tbuf[0] = '\t';
469 tbuf[1] = '\0';
470 break;
471
472 case 'D': /* date as %m/%d/%y */
473 strftime(tbuf, sizeof tbuf, "%m/%d/%y", timeptr);
474 break;
475
476 case 'e': /* day of month, blank padded */
477 sprintf(tbuf, "%2d", range(1, timeptr->tm_mday, 31));
478 break;
479
480 case 'r': /* time as %I:%M:%S %p */
481 strftime(tbuf, sizeof tbuf, "%I:%M:%S %p", timeptr);
482 break;
483
484 case 'R': /* time as %H:%M */
485 strftime(tbuf, sizeof tbuf, "%H:%M", timeptr);
486 break;
487
488 case 'T': /* time as %H:%M:%S */
489 strftime(tbuf, sizeof tbuf, "%H:%M:%S", timeptr);
490 break;
491 #endif
492
493 #ifdef SUNOS_EXT
494 case 'k': /* hour, 24-hour clock, blank pad */
495 sprintf(tbuf, "%2d", range(0, timeptr->tm_hour, 23));
496 break;
497
498 case 'l': /* hour, 12-hour clock, 1 - 12, blank pad */
499 i = range(0, timeptr->tm_hour, 23);
500 if (i == 0)
501 i = 12;
502 else if (i > 12)
503 i -= 12;
504 sprintf(tbuf, "%2d", i);
505 break;
506 #endif
507
508
509 #ifdef VMS_EXT
510 case 'v': /* date as dd-bbb-YYYY */
511 sprintf(tbuf, "%2d-%3.3s-%4ld",
512 range(1, timeptr->tm_mday, 31),
513 months_a[range(0, timeptr->tm_mon, 11)],
514 timeptr->tm_year + 1900L);
515 for (i = 3; i < 6; i++)
516 if (islower(tbuf[i]))
517 tbuf[i] = toupper(tbuf[i]);
518 break;
519 #endif
520
521
522 #ifdef POSIX2_DATE
523 case 'C':
524 sprintf(tbuf, "%02ld", (timeptr->tm_year + 1900L) / 100);
525 break;
526
527
528 case 'E':
529 case 'O':
530 /* POSIX locale extensions, ignored for now */
531 goto again;
532
533 case 'V': /* week of year according ISO 8601 */
534 sprintf(tbuf, "%02d", iso8601wknum(timeptr));
535 break;
536
537 case 'u':
538 /* ISO 8601: Weekday as a decimal number [1 (Monday) - 7] */
539 sprintf(tbuf, "%d", timeptr->tm_wday == 0 ? 7 :
540 timeptr->tm_wday);
541 break;
542 #endif /* POSIX2_DATE */
543
544 #ifdef ISO_DATE_EXT
545 case 'G':
546 case 'g':
547 /*
548 * Year of ISO week.
549 *
550 * If it's December but the ISO week number is one,
551 * that week is in next year.
552 * If it's January but the ISO week number is 52 or
553 * 53, that week is in last year.
554 * Otherwise, it's this year.
555 */
556 w = iso8601wknum(timeptr);
557 if (timeptr->tm_mon == 11 && w == 1)
558 y = 1900L + timeptr->tm_year + 1;
559 else if (timeptr->tm_mon == 0 && w >= 52)
560 y = 1900L + timeptr->tm_year - 1;
561 else
562 y = 1900L + timeptr->tm_year;
563
564 if (*format == 'G')
565 sprintf(tbuf, "%ld", y);
566 else
567 sprintf(tbuf, "%02ld", y % 100);
568 break;
569 #endif /* ISO_DATE_EXT */
570 default:
571 tbuf[0] = '%';
572 tbuf[1] = *format;
573 tbuf[2] = '\0';
574 break;
575 }
576 i = strlen(tbuf);
577 if (i) {
578 if (s + i < endp - 1) {
579 strcpy(s, tbuf);
580 s += i;
581 } else
582 return 0;
583 }
584 }
585 out:
586 if (s < endp && *format == '\0') {
587 *s = '\0';
588 return (s - start);
589 } else
590 return 0;
591 }
592
593 /* isleap --- is a year a leap year? */
594
595 #ifndef __STDC__
596 static int
597 isleap(year)
598 long year;
599 #else
600 static int
601 isleap(long year)
602 #endif
603 {
604 return ((year % 4 == 0 && year % 100 != 0) || year % 400 == 0);
605 }
606
607
608 #ifdef POSIX2_DATE
609 /* iso8601wknum --- compute week number according to ISO 8601 */
610
611 #ifndef __STDC__
612 static int
613 iso8601wknum(timeptr)
614 const struct tm *timeptr;
615 #else
616 static int
617 iso8601wknum(const struct tm *timeptr)
618 #endif
619 {
620 /*
621 * From 1003.2:
622 * If the week (Monday to Sunday) containing January 1
623 * has four or more days in the new year, then it is week 1;
624 * otherwise it is the highest numbered week of the previous
625 * year (52 or 53), and the next week is week 1.
626 *
627 * ADR: This means if Jan 1 was Monday through Thursday,
628 * it was week 1, otherwise week 52 or 53.
629 *
630 * XPG4 erroneously included POSIX.2 rationale text in the
631 * main body of the standard. Thus it requires week 53.
632 */
633
634 int weeknum, jan1day, diff;
635
636 /* get week number, Monday as first day of the week */
637 weeknum = weeknumber(timeptr, 1);
638
639 /*
640 * With thanks and tip of the hatlo to tml@tik.vtt.fi
641 *
642 * What day of the week does January 1 fall on?
643 * We know that
644 * (timeptr->tm_yday - jan1.tm_yday) MOD 7 ==
645 * (timeptr->tm_wday - jan1.tm_wday) MOD 7
646 * and that
647 * jan1.tm_yday == 0
648 * and that
649 * timeptr->tm_wday MOD 7 == timeptr->tm_wday
650 * from which it follows that. . .
651 */
652 jan1day = timeptr->tm_wday - (timeptr->tm_yday % 7);
653 if (jan1day < 0)
654 jan1day += 7;
655
656 /*
657 * If Jan 1 was a Monday through Thursday, it was in
658 * week 1. Otherwise it was last year's highest week, which is
659 * this year's week 0.
660 *
661 * What does that mean?
662 * If Jan 1 was Monday, the week number is exactly right, it can
663 * never be 0.
664 * If it was Tuesday through Thursday, the weeknumber is one
665 * less than it should be, so we add one.
666 * Otherwise, Friday, Saturday or Sunday, the week number is
667 * OK, but if it is 0, it needs to be 52 or 53.
668 */
669 switch (jan1day) {
670 case 1: /* Monday */
671 break;
672 case 2: /* Tuesday */
673 case 3: /* Wednesday */
674 case 4: /* Thursday */
675 weeknum++;
676 break;
677 case 5: /* Friday */
678 case 6: /* Saturday */
679 case 0: /* Sunday */
680 if (weeknum == 0) {
681 #ifdef USE_BROKEN_XPG4
682 /* XPG4 (as of March 1994) says 53 unconditionally */
683 weeknum = 53;
684 #else
685 /* get week number of last week of last year */
686 struct tm dec31ly; /* 12/31 last year */
687 dec31ly = *timeptr;
688 dec31ly.tm_year--;
689 dec31ly.tm_mon = 11;
690 dec31ly.tm_mday = 31;
691 dec31ly.tm_wday = (jan1day == 0) ? 6 : jan1day - 1;
692 dec31ly.tm_yday = 364 + isleap(dec31ly.tm_year + 1900L);
693 weeknum = iso8601wknum(& dec31ly);
694 #endif
695 }
696 break;
697 }
698
699 if (timeptr->tm_mon == 11) {
700 /*
701 * The last week of the year
702 * can be in week 1 of next year.
703 * Sigh.
704 *
705 * This can only happen if
706 * M T W
707 * 29 30 31
708 * 30 31
709 * 31
710 */
711 int wday, mday;
712
713 wday = timeptr->tm_wday;
714 mday = timeptr->tm_mday;
715 if ( (wday == 1 && (mday >= 29 && mday <= 31))
716 || (wday == 2 && (mday == 30 || mday == 31))
717 || (wday == 3 && mday == 31))
718 weeknum = 1;
719 }
720
721 return weeknum;
722 }
723 #endif
724
725 /* weeknumber --- figure how many weeks into the year */
726
727 /* With thanks and tip of the hatlo to ado@elsie.nci.nih.gov */
728
729 #ifndef __STDC__
730 static int
731 weeknumber(timeptr, firstweekday)
732 const struct tm *timeptr;
733 int firstweekday;
734 #else
735 static int
736 weeknumber(const struct tm *timeptr, int firstweekday)
737 #endif
738 {
739 int wday = timeptr->tm_wday;
740 int ret;
741
742 if (firstweekday == 1) {
743 if (wday == 0) /* sunday */
744 wday = 6;
745 else
746 wday--;
747 }
748 ret = ((timeptr->tm_yday + 7 - wday) / 7);
749 if (ret < 0)
750 ret = 0;
751 return ret;
752 }
753
754 #if 0
755 /* ADR --- I'm loathe to mess with ado's code ... */
756
757 Date: Wed, 24 Apr 91 20:54:08 MDT
758 From: Michal Jaegermann <audfax!emory!vm.ucs.UAlberta.CA!NTOMCZAK>
759 To: arnold@audiofax.com
760
761 Hi Arnold,
762 in a process of fixing of strftime() in libraries on Atari ST I grabbed
763 some pieces of code from your own strftime. When doing that it came
764 to mind that your weeknumber() function compiles a little bit nicer
765 in the following form:
766 /*
767 * firstweekday is 0 if starting in Sunday, non-zero if in Monday
768 */
769 {
770 return (timeptr->tm_yday - timeptr->tm_wday +
771 (firstweekday ? (timeptr->tm_wday ? 8 : 1) : 7)) / 7;
772 }
773 How nicer it depends on a compiler, of course, but always a tiny bit.
774
775 Cheers,
776 Michal
777 ntomczak@vm.ucs.ualberta.ca
778 #endif
779
780 #ifdef TEST_STRFTIME
781
782 /*
783 * NAME:
784 * tst
785 *
786 * SYNOPSIS:
787 * tst
788 *
789 * DESCRIPTION:
790 * "tst" is a test driver for the function "strftime".
791 *
792 * OPTIONS:
793 * None.
794 *
795 * AUTHOR:
796 * Karl Vogel
797 * Control Data Systems, Inc.
798 * vogelke@c-17igp.wpafb.af.mil
799 *
800 * BUGS:
801 * None noticed yet.
802 *
803 * COMPILE:
804 * cc -o tst -DTEST_STRFTIME strftime.c
805 */
806
807 /* ADR: I reformatted this to my liking, and deleted some unneeded code. */
808
809 #ifndef NULL
810 #include <stdio.h>
811 #endif
812 #include <sys/time.h>
813 #include <string.h>
814
815 #define MAXTIME 132
816
817 /*
818 * Array of time formats.
819 */
820
821 static char *array[] =
822 {
823 "(%%A) full weekday name, var length (Sunday..Saturday) %A",
824 "(%%B) full month name, var length (January..December) %B",
825 "(%%C) Century %C",
826 "(%%D) date (%%m/%%d/%%y) %D",
827 "(%%E) Locale extensions (ignored) %E",
828 "(%%H) hour (24-hour clock, 00..23) %H",
829 "(%%I) hour (12-hour clock, 01..12) %I",
830 "(%%M) minute (00..59) %M",
831 "(%%O) Locale extensions (ignored) %O",
832 "(%%R) time, 24-hour (%%H:%%M) %R",
833 "(%%S) second (00..60) %S",
834 "(%%T) time, 24-hour (%%H:%%M:%%S) %T",
835 "(%%U) week of year, Sunday as first day of week (00..53) %U",
836 "(%%V) week of year according to ISO 8601 %V",
837 "(%%W) week of year, Monday as first day of week (00..53) %W",
838 "(%%X) appropriate locale time representation (%H:%M:%S) %X",
839 "(%%Y) year with century (1970...) %Y",
840 "(%%Z) timezone (EDT), or blank if timezone not determinable %Z",
841 "(%%a) locale's abbreviated weekday name (Sun..Sat) %a",
842 "(%%b) locale's abbreviated month name (Jan..Dec) %b",
843 "(%%c) full date (Sat Nov 4 12:02:33 1989)%n%t%t%t %c",
844 "(%%d) day of the month (01..31) %d",
845 "(%%e) day of the month, blank-padded ( 1..31) %e",
846 "(%%h) should be same as (%%b) %h",
847 "(%%j) day of the year (001..366) %j",
848 "(%%k) hour, 24-hour clock, blank pad ( 0..23) %k",
849 "(%%l) hour, 12-hour clock, blank pad ( 0..12) %l",
850 "(%%m) month (01..12) %m",
851 "(%%p) locale's AM or PM based on 12-hour clock %p",
852 "(%%r) time, 12-hour (same as %%I:%%M:%%S %%p) %r",
853 "(%%u) ISO 8601: Weekday as decimal number [1 (Monday) - 7] %u",
854 "(%%v) VMS date (dd-bbb-YYYY) %v",
855 "(%%w) day of week (0..6, Sunday == 0) %w",
856 "(%%x) appropriate locale date representation %x",
857 "(%%y) last two digits of year (00..99) %y",
858 "(%%z) timezone offset east of GMT as HHMM (e.g. -0500) %z",
859 (char *) NULL
860 };
861
862 /* main routine. */
863
864 int
865 main(argc, argv)
866 int argc;
867 char **argv;
868 {
869 long time();
870
871 char *next;
872 char string[MAXTIME];
873
874 int k;
875 int length;
876
877 struct tm *tm;
878
879 long clock;
880
881 /* Call the function. */
882
883 clock = time((long *) 0);
884 tm = localtime(&clock);
885
886 for (k = 0; next = array[k]; k++) {
887 length = strftime(string, MAXTIME, next, tm);
888 printf("%s\n", string);
889 }
890
891 exit(0);
892 }
893 #endif /* TEST_STRFTIME */