summaryrefslogtreecommitdiff
path: root/ext/date/date_strftime.c
blob: 06ca9b0aff7c5d3db44ea29b26ca9afc5f94d8eb (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
/* -*- c-file-style: "linux" -*- */

/*
 * strftime.c
 *
 * Public-domain implementation of ANSI C library routine.
 *
 * It's written in old-style C for maximal portability.
 * However, since I'm used to prototypes, I've included them too.
 *
 * If you want stuff in the System V ascftime routine, add the SYSV_EXT define.
 * For extensions from SunOS, add SUNOS_EXT.
 * For stuff needed to implement the P1003.2 date command, add POSIX2_DATE.
 * For VMS dates, add VMS_EXT.
 * For a an RFC822 time format, add MAILHEADER_EXT.
 * For ISO week years, add ISO_DATE_EXT.
 * For complete POSIX semantics, add POSIX_SEMANTICS.
 *
 * The code for %c, %x, and %X now follows the 1003.2 specification for
 * the POSIX locale.
 * This version ignores LOCALE information.
 * It also doesn't worry about multi-byte characters.
 * So there.
 *
 * This file is also shipped with GAWK (GNU Awk), gawk specific bits of
 * code are included if GAWK is defined.
 *
 * Arnold Robbins
 * January, February, March, 1991
 * Updated March, April 1992
 * Updated April, 1993
 * Updated February, 1994
 * Updated May, 1994
 * Updated January, 1995
 * Updated September, 1995
 * Updated January, 1996
 *
 * Fixes from ado@elsie.nci.nih.gov
 * February 1991, May 1992
 * Fixes from Tor Lillqvist tml@tik.vtt.fi
 * May, 1993
 * Further fixes from ado@elsie.nci.nih.gov
 * February 1994
 * %z code from chip@chinacat.unicom.com
 * Applied September 1995
 * %V code fixed (again) and %G, %g added,
 * January 1996
 */

#include "ruby/ruby.h"
#include "timev.h"

#ifndef GAWK
#include <stdio.h>
#include <ctype.h>
#include <string.h>
#include <time.h>
#include <sys/types.h>
#include <errno.h>
#endif
#if defined(TM_IN_SYS_TIME) || !defined(GAWK)
#include <sys/types.h>
#if HAVE_SYS_TIME_H
#include <sys/time.h>
#endif
#endif
#include <math.h>

/* defaults: season to taste */
#define SYSV_EXT	1	/* stuff in System V ascftime routine */
#define SUNOS_EXT	1	/* stuff in SunOS strftime routine */
#define POSIX2_DATE	1	/* stuff in Posix 1003.2 date command */
#define VMS_EXT		1	/* include %v for VMS date format */
#define MAILHEADER_EXT	1	/* add %z for HHMM format */
#define ISO_DATE_EXT	1	/* %G and %g for year of ISO week */

#if defined(ISO_DATE_EXT)
#if ! defined(POSIX2_DATE)
#define POSIX2_DATE	1
#endif
#endif

#if defined(POSIX2_DATE)
#if ! defined(SYSV_EXT)
#define SYSV_EXT	1
#endif
#if ! defined(SUNOS_EXT)
#define SUNOS_EXT	1
#endif
#endif

#if defined(POSIX2_DATE)
#define adddecl(stuff)	stuff
#else
#define adddecl(stuff)
#endif

#undef strchr	/* avoid AIX weirdness */

#if !defined __STDC__ && !defined _WIN32
#define const	/**/
static int weeknumber();
adddecl(static int iso8601wknum();)
static int weeknumber_v();
adddecl(static int iso8601wknum_v();)
#else
static int weeknumber(const struct tm *timeptr, int firstweekday);
adddecl(static int iso8601wknum(const struct tm *timeptr);)
static int weeknumber_v(const struct vtm *vtm, int firstweekday);
adddecl(static int iso8601wknum_v(const struct vtm *vtm);)
#endif

#ifdef STDC_HEADERS
#include <stdlib.h>
#include <string.h>
#else
extern void *malloc();
extern void *realloc();
extern char *getenv();
extern char *strchr();
#endif

#define range(low, item, hi)	max((low), min((item), (hi)))

#undef min	/* just in case */

/* min --- return minimum of two numbers */

#ifndef __STDC__
static inline int
min(a, b)
int a, b;
#else
static inline int
min(int a, int b)
#endif
{
	return (a < b ? a : b);
}

#undef max	/* also, just in case */

/* max --- return maximum of two numbers */

#ifndef __STDC__
static inline int
max(a, b)
int a, b;
#else
static inline int
max(int a, int b)
#endif
{
	return (a > b ? a : b);
}

#ifdef NO_STRING_LITERAL_CONCATENATION
#error No string literal concatenation
#endif

#define add(x,y) (rb_funcall((x), '+', 1, (y)))
#define sub(x,y) (rb_funcall((x), '-', 1, (y)))
#define mul(x,y) (rb_funcall((x), '*', 1, (y)))
#define quo(x,y) (rb_funcall((x), rb_intern("quo"), 1, (y)))
#define div(x,y) (rb_funcall((x), rb_intern("div"), 1, (y)))
#define mod(x,y) (rb_funcall((x), '%', 1, (y)))

/* strftime --- produce formatted time */

static size_t
date_strftime_wo_timespec(char *s, size_t maxsize, const char *format,
			  const struct vtm *vtm, VALUE timev)
{
	char *endp = s + maxsize;
	char *start = s;
	const char *sp, *tp;
	auto char tbuf[100];
	long off;
	ptrdiff_t i;
	int w;
	long y;
	int precision, flags, colons;
	char padding;
	enum {LEFT, CHCASE, LOWER, UPPER, LOCALE_O, LOCALE_E};
#define BIT_OF(n) (1U<<(n))

	/* various tables, useful in North America */
	static const char days_l[][10] = {
		"Sunday", "Monday", "Tuesday", "Wednesday",
		"Thursday", "Friday", "Saturday",
	};
	static const char months_l[][10] = {
		"January", "February", "March", "April",
		"May", "June", "July", "August", "September",
		"October", "November", "December",
	};
	static const char ampm[][3] = { "AM", "PM", };

	if (s == NULL || format == NULL || vtm == NULL || maxsize == 0)
		return 0;

	/* quick check if we even need to bother */
	if (strchr(format, '%') == NULL && strlen(format) + 1 >= maxsize) {
	err:
		errno = ERANGE;
		return 0;
	}

	for (; *format && s < endp - 1; format++) {
#define FLAG_FOUND() do { \
			if (precision > 0 || flags & (BIT_OF(LOCALE_E)|BIT_OF(LOCALE_O))) \
				goto unknown; \
		} while (0)
#define NEEDS(n) do if (s + (n) >= endp - 1) goto err; while (0)
#define FILL_PADDING(i) do { \
	if (!(flags & BIT_OF(LEFT)) && precision > (i)) { \
		NEEDS(precision); \
		memset(s, padding ? padding : ' ', precision - (i)); \
		s += precision - (i); \
	} \
	else { \
		NEEDS(i); \
	} \
} while (0);
#define FMT(def_pad, def_prec, fmt, val) \
		do { \
			int l; \
			if (precision <= 0) precision = (def_prec); \
			if (flags & BIT_OF(LEFT)) precision = 1; \
			l = snprintf(s, endp - s, \
				     ((padding == '0' || (!padding && (def_pad) == '0')) ? "%0*"fmt : "%*"fmt), \
				     precision, (val)); \
			if (l < 0) goto err; \
			s += l; \
		} while (0)
#define STRFTIME(fmt) \
		do { \
			i = date_strftime_wo_timespec(s, endp - s, (fmt), vtm, timev); \
			if (!i) return 0; \
			if (precision > i) {\
				if (start + maxsize < s + precision) { \
					errno = ERANGE; \
					return 0; \
				} \
				memmove(s + precision - i, s, i);\
				memset(s, padding ? padding : ' ', precision - i); \
				s += precision;	\
	                }\
			else s += i; \
		} while (0)
#define FMTV(def_pad, def_prec, fmt, val) \
                do { \
                        VALUE tmp = (val); \
                        if (FIXNUM_P(tmp)) { \
                                FMT((def_pad), (def_prec), "l"fmt, FIX2LONG(tmp)); \
                        } \
                        else { \
                                VALUE args[2], result; \
                                size_t l; \
                                if (precision <= 0) precision = (def_prec); \
                                if (flags & BIT_OF(LEFT)) precision = 1; \
                                args[0] = INT2FIX(precision); \
                                args[1] = (val); \
                                if (padding == '0' || (!padding && (def_pad) == '0')) \
                                        result = rb_str_format(2, args, rb_str_new2("%0*"fmt)); \
                                else \
                                        result = rb_str_format(2, args, rb_str_new2("%*"fmt)); \
                                l = strlcpy(s, StringValueCStr(result), endp-s); \
                                if ((size_t)(endp-s) <= l) \
                                        goto err; \
                                s += l; \
                        } \
                } while (0)
#define SKIP_MODIFIER_E \
		if (flags & BIT_OF(LOCALE_E)) {	\
			format--; \
			goto unknown; \
		}
#define SKIP_MODIFIER_O \
		if (flags & BIT_OF(LOCALE_O)) { \
			format--; \
			goto unknown; \
		}
#define SKIP_MODIFIER_EO \
		{ SKIP_MODIFIER_E; SKIP_MODIFIER_O }

		if (*format != '%') {
			*s++ = *format;
			continue;
		}
		tp = tbuf;
		sp = format;
		precision = -1;
		flags = 0;
		padding = 0;
                colons = 0;
	again:
		switch (*++format) {
		case '\0':
			format--;
			goto unknown;

		case '%':
			SKIP_MODIFIER_EO;
			FILL_PADDING(1);
			*s++ = '%';
			continue;

		case 'a':	/* abbreviated weekday name */
			SKIP_MODIFIER_EO;
			if (flags & BIT_OF(CHCASE)) {
				flags &= ~(BIT_OF(LOWER)|BIT_OF(CHCASE));
				flags |= BIT_OF(UPPER);
			}
			if (vtm->wday < 0 || vtm->wday > 6)
				i = 1, tp = "?";
			else
				i = 3, tp = days_l[vtm->wday];
			break;

		case 'A':	/* full weekday name */
			SKIP_MODIFIER_EO;
			if (flags & BIT_OF(CHCASE)) {
				flags &= ~(BIT_OF(LOWER)|BIT_OF(CHCASE));
				flags |= BIT_OF(UPPER);
			}
			if (vtm->wday < 0 || vtm->wday > 6)
				i = 1, tp = "?";
			else
				i = strlen(tp = days_l[vtm->wday]);
			break;

#ifdef SYSV_EXT
		case 'h':	/* abbreviated month name */
#endif
		case 'b':	/* abbreviated month name */
			SKIP_MODIFIER_EO;
			if (flags & BIT_OF(CHCASE)) {
				flags &= ~(BIT_OF(LOWER)|BIT_OF(CHCASE));
				flags |= BIT_OF(UPPER);
			}
			if (vtm->mon < 1 || vtm->mon > 12)
				i = 1, tp = "?";
			else
				i = 3, tp = months_l[vtm->mon-1];
			break;

		case 'B':	/* full month name */
			SKIP_MODIFIER_EO;
			if (flags & BIT_OF(CHCASE)) {
				flags &= ~(BIT_OF(LOWER)|BIT_OF(CHCASE));
				flags |= BIT_OF(UPPER);
			}
			if (vtm->mon < 1 || vtm->mon > 12)
				i = 1, tp = "?";
			else
				i = strlen(tp = months_l[vtm->mon-1]);
			break;

		case 'c':	/* appropriate date and time representation */
			SKIP_MODIFIER_O;
			STRFTIME("%a %b %e %H:%M:%S %Y");
			continue;

		case 'd':	/* day of the month, 01 - 31 */
			SKIP_MODIFIER_E;
			i = range(1, vtm->mday, 31);
			FMT('0', 2, "d", (int)i);
			continue;

		case 'H':	/* hour, 24-hour clock, 00 - 23 */
			SKIP_MODIFIER_E;
			i = range(0, vtm->hour, 23);
			FMT('0', 2, "d", (int)i);
			continue;

		case 'I':	/* hour, 12-hour clock, 01 - 12 */
			SKIP_MODIFIER_E;
			i = range(0, vtm->hour, 23);
			if (i == 0)
				i = 12;
			else if (i > 12)
				i -= 12;
			FMT('0', 2, "d", (int)i);
			continue;

		case 'j':	/* day of the year, 001 - 366 */
			SKIP_MODIFIER_EO;
			FMT('0', 3, "d", vtm->yday);
			continue;

		case 'm':	/* month, 01 - 12 */
			SKIP_MODIFIER_E;
			i = range(1, vtm->mon, 12);
			FMT('0', 2, "d", (int)i);
			continue;

		case 'M':	/* minute, 00 - 59 */
			SKIP_MODIFIER_E;
			i = range(0, vtm->min, 59);
			FMT('0', 2, "d", (int)i);
			continue;

		case 'p':	/* AM or PM based on 12-hour clock */
		case 'P':	/* am or pm based on 12-hour clock */
			SKIP_MODIFIER_EO;
			if ((*format == 'p' && (flags & BIT_OF(CHCASE))) ||
			    (*format == 'P' && !(flags & (BIT_OF(CHCASE)|BIT_OF(UPPER))))) {
				flags &= ~(BIT_OF(UPPER)|BIT_OF(CHCASE));
				flags |= BIT_OF(LOWER);
			}
			i = range(0, vtm->hour, 23);
			if (i < 12)
				tp = ampm[0];
			else
				tp = ampm[1];
			i = 2;
			break;

		case 's':
			SKIP_MODIFIER_EO;
			{
                                VALUE sec = div(timev, INT2FIX(1));
                                FMTV('0', 1, "d", sec);
                        }
                        continue;

		case 'Q':
			SKIP_MODIFIER_EO;
			{
				VALUE sec = div(timev,
						rb_rational_new2(INT2FIX(1),
								 INT2FIX(1000)));
				FMTV('0', 1, "d", sec);
			}
                        continue;

		case 'S':	/* second, 00 - 60 */
			SKIP_MODIFIER_E;
			i = range(0, vtm->sec, 60);
			FMT('0', 2, "d", (int)i);
			continue;

		case 'U':	/* week of year, Sunday is first day of week */
			SKIP_MODIFIER_E;
			FMT('0', 2, "d", weeknumber_v(vtm, 0));
			continue;

		case 'w':	/* weekday, Sunday == 0, 0 - 6 */
			SKIP_MODIFIER_E;
			i = range(0, vtm->wday, 6);
			FMT('0', 1, "d", (int)i);
			continue;

		case 'W':	/* week of year, Monday is first day of week */
			SKIP_MODIFIER_E;
			FMT('0', 2, "d", weeknumber_v(vtm, 1));
			continue;

		case 'x':	/* appropriate date representation */
			SKIP_MODIFIER_O;
			STRFTIME("%m/%d/%y");
			continue;

		case 'X':	/* appropriate time representation */
			SKIP_MODIFIER_O;
			STRFTIME("%H:%M:%S");
			continue;

		case 'y':	/* year without a century, 00 - 99 */
			i = NUM2INT(mod(vtm->year, INT2FIX(100)));
			FMT('0', 2, "d", (int)i);
			continue;

		case 'Y':	/* year with century */
			SKIP_MODIFIER_O;
                        if (FIXNUM_P(vtm->year)) {
                            long y = FIX2LONG(vtm->year);
                            FMT('0', 0 <= y ? 4 : 5, "ld", y);
                        }
                        else {
                            FMTV('0', 4, "d", vtm->year);
                        }
			continue;

#ifdef MAILHEADER_EXT
		case 'z':	/* time zone offset east of GMT e.g. -0600 */
			SKIP_MODIFIER_EO;
			{
				int aoff, hl, hw;

				off = NUM2LONG(rb_funcall(vtm->utc_offset, rb_intern("round"), 0));

				aoff = off;
				if (aoff < 0)
					aoff = -off;

				if ((aoff / 3600) < 10)
					hl = 1;
				else
					hl = 2;
				hw = 2;
				if (flags & BIT_OF(LEFT) && hl == 1)
					hw = 1;

				switch (colons) {
				case 0: /* %z -> +hhmm */
					precision = precision <= (3 + hw) ? hw : precision-3;
					NEEDS(precision + 3);
					break;

				case 1: /* %:z -> +hh:mm */
					precision = precision <= (4 + hw) ? hw : precision-4;
					NEEDS(precision + 4);
					break;

				case 2: /* %::z -> +hh:mm:ss */
					precision = precision <= (7 + hw) ? hw : precision-7;
					NEEDS(precision + 7);
					break;

				case 3: /* %:::z -> +hh[:mm[:ss]] */
				{
					if (aoff % 3600 == 0) {
						precision = precision <= (1 + hw) ? hw : precision-1;
						NEEDS(precision + 3);
					}
					else if (aoff % 60 == 0) {
						precision = precision <= (4 + hw) ? hw : precision-4;
						NEEDS(precision + 4);
					}
					else {
						precision = precision <= (7 + hw) ? hw : precision-7;
						NEEDS(precision + 7);
					}
				}
				break;

				default:
					format--;
					goto unknown;
				}
				if (padding == ' ' && precision > hl) {
					i = snprintf(s, endp - s, "%*s", precision - hl, "");
					precision = hl;
					if (i < 0) goto err;
					s += i;
				}
				if (off < 0) {
					off = -off;
					*s++ = '-';
				} else {
					*s++ = '+';
				}
				i = snprintf(s, endp - s, "%.*ld", precision, off / 3600);
				if (i < 0) goto err;
				s += i;
				off = off % 3600;
				if (colons == 3 && off == 0)
					continue;
				if (1 <= colons)
					*s++ = ':';
				i = snprintf(s, endp - s, "%02d", (int)(off / 60));
				if (i < 0) goto err;
				s += i;
				off = off % 60;
				if (colons == 3 && off == 0)
					continue;
				if (2 <= colons) {
					*s++ = ':';
					i = snprintf(s, endp - s, "%02d", (int)off);
					if (i < 0) goto err;
					s += i;
				}
			}
			continue;
#endif /* MAILHEADER_EXT */

		case 'Z':	/* time zone name or abbreviation */
			SKIP_MODIFIER_EO;
			if (flags & BIT_OF(CHCASE)) {
				flags &= ~(BIT_OF(UPPER)|BIT_OF(CHCASE));
				flags |= BIT_OF(LOWER);
			}
                        if (vtm->zone == NULL)
                            tp = "";
                        else
                            tp = vtm->zone;
			i = strlen(tp);
			break;

#ifdef SYSV_EXT
		case 'n':	/* same as \n */
			SKIP_MODIFIER_EO;
			FILL_PADDING(1);
			*s++ = '\n';
			continue;

		case 't':	/* same as \t */
			SKIP_MODIFIER_EO;
			FILL_PADDING(1);
			*s++ = '\t';
			continue;

		case 'D':	/* date as %m/%d/%y */
			SKIP_MODIFIER_EO;
			STRFTIME("%m/%d/%y");
			continue;

		case 'e':	/* day of month, blank padded */
			SKIP_MODIFIER_E;
			FMT(' ', 2, "d", range(1, vtm->mday, 31));
			continue;

		case 'r':	/* time as %I:%M:%S %p */
			SKIP_MODIFIER_EO;
			STRFTIME("%I:%M:%S %p");
			continue;

		case 'R':	/* time as %H:%M */
			SKIP_MODIFIER_EO;
			STRFTIME("%H:%M");
			continue;

		case 'T':	/* time as %H:%M:%S */
			SKIP_MODIFIER_EO;
			STRFTIME("%H:%M:%S");
			continue;
#endif

#ifdef SUNOS_EXT
		case 'k':	/* hour, 24-hour clock, blank pad */
			SKIP_MODIFIER_EO;
			i = range(0, vtm->hour, 23);
			FMT(' ', 2, "d", (int)i);
			continue;

		case 'l':	/* hour, 12-hour clock, 1 - 12, blank pad */
			SKIP_MODIFIER_EO;
			i = range(0, vtm->hour, 23);
			if (i == 0)
				i = 12;
			else if (i > 12)
				i -= 12;
			FMT(' ', 2, "d", (int)i);
			continue;
#endif


#ifdef VMS_EXT
		case 'v':	/* date as dd-bbb-YYYY */
			SKIP_MODIFIER_EO;
			STRFTIME("%e-%^b-%4Y");
			continue;
#endif


#ifdef POSIX2_DATE
		case 'C':
			SKIP_MODIFIER_O;
                        FMTV('0', 2, "d", div(vtm->year, INT2FIX(100)));
			continue;

		case 'E':
			/* POSIX locale extensions, ignored for now */
			flags |= BIT_OF(LOCALE_E);
			goto again;
		case 'O':
			/* POSIX locale extensions, ignored for now */
			flags |= BIT_OF(LOCALE_O);
			goto again;

		case 'V':	/* week of year according ISO 8601 */
			SKIP_MODIFIER_E;
			FMT('0', 2, "d", iso8601wknum_v(vtm));
			continue;

		case 'u':
		/* ISO 8601: Weekday as a decimal number [1 (Monday) - 7] */
			SKIP_MODIFIER_E;
			FMT('0', 1, "d", vtm->wday == 0 ? 7 : vtm->wday);
			continue;
#endif	/* POSIX2_DATE */

#ifdef ISO_DATE_EXT
		case 'G':
		case 'g':
			/*
			 * Year of ISO week.
			 *
			 * If it's December but the ISO week number is one,
			 * that week is in next year.
			 * If it's January but the ISO week number is 52 or
			 * 53, that week is in last year.
			 * Otherwise, it's this year.
			 */
			SKIP_MODIFIER_EO;
                        {
                                VALUE yv = vtm->year;
                                w = iso8601wknum_v(vtm);
                                if (vtm->mon == 12 && w == 1)
                                        yv = add(yv, INT2FIX(1));
                                else if (vtm->mon == 1 && w >= 52)
                                        yv = sub(yv, INT2FIX(1));

                                if (*format == 'G') {
                                        if (FIXNUM_P(yv)) {
                                                long y = FIX2LONG(yv);
                                                FMT('0', 0 <= y ? 4 : 5, "ld", y);
                                        }
                                        else {
                                                FMTV('0', 4, "d", yv);
                                        }
                                }
                                else {
                                        yv = mod(yv, INT2FIX(100));
                                        y = FIX2LONG(yv);
                                        FMT('0', 2, "ld", y);
                                }
                                continue;
                        }

#endif /* ISO_DATE_EXT */


		case 'L':
			SKIP_MODIFIER_EO;
			w = 3;
			goto subsec;

		case 'N':
			SKIP_MODIFIER_EO;
			/*
			 * fractional second digits. default is 9 digits
			 * (nanosecond).
			 *
			 * %3N  millisecond (3 digits)
			 * %6N  microsecond (6 digits)
			 * %9N  nanosecond (9 digits)
			 */
			w = 9;
		subsec:
                        if (precision <= 0) {
                            precision = w;
                        }
                        NEEDS(precision);

			{
                                VALUE subsec = mod(timev, INT2FIX(1));
                                int ww;
                                long n;

                                ww = precision;
                                while (9 <= ww) {
                                        subsec = mul(subsec, INT2FIX(1000000000));
                                        ww -= 9;
                                }
                                n = 1;
                                for (; 0 < ww; ww--)
                                        n *= 10;
                                if (n != 1)
                                        subsec = mul(subsec, INT2FIX(n));
                                subsec = div(subsec, INT2FIX(1));

                                if (FIXNUM_P(subsec)) {
                                        int l;
                                        l = snprintf(s, endp - s, "%0*ld", precision, FIX2LONG(subsec));
                                        s += precision;
                                }
                                else {
                                        VALUE args[2], result;
                                        size_t l;
                                        args[0] = INT2FIX(precision);
                                        args[1] = subsec;
                                        result = rb_str_format(2, args, rb_str_new2("%0*d"));
                                        l = strlcpy(s, StringValueCStr(result), endp-s);
                                        s += precision;
                                }
			}
			continue;

		case 'F':	/*  Equivalent to %Y-%m-%d */
			SKIP_MODIFIER_EO;
			STRFTIME("%Y-%m-%d");
			continue;
		case '+':
			SKIP_MODIFIER_EO;
			STRFTIME("%a %b %e %H:%M:%S %Z %Y");
			continue;

		case '-':
			FLAG_FOUND();
			flags |= BIT_OF(LEFT);
			padding = precision = 0;
			goto again;

		case '^':
			FLAG_FOUND();
			flags |= BIT_OF(UPPER);
			goto again;

		case '#':
			FLAG_FOUND();
			flags |= BIT_OF(CHCASE);
			goto again;

		case '_':
			FLAG_FOUND();
			padding = ' ';
			goto again;

		case ':':
                        colons++;
			goto again;

		case '0':
			padding = '0';
		case '1':  case '2': case '3': case '4':
		case '5': case '6':  case '7': case '8': case '9':
			{
				char *e;
				precision = (int)strtoul(format, &e, 10);
				format = e - 1;
				goto again;
			}

		default:
		unknown:
			i = format - sp + 1;
			tp = sp;
			precision = -1;
			flags = 0;
			padding = 0;
                        colons = 0;
			break;
		}
		if (i) {
			FILL_PADDING(i);
			memcpy(s, tp, i);
			switch (flags & (BIT_OF(UPPER)|BIT_OF(LOWER))) {
			case BIT_OF(UPPER):
				do {
					if (ISLOWER(*s)) *s = TOUPPER(*s);
				} while (s++, --i);
				break;
			case BIT_OF(LOWER):
				do {
					if (ISUPPER(*s)) *s = TOLOWER(*s);
				} while (s++, --i);
				break;
			default:
				s += i;
				break;
			}
		}
	}
	if (s >= endp) {
		goto err;
	}
	if (*format == '\0') {
		*s = '\0';
		return (s - start);
	} else
		return 0;
}

size_t
date_strftime(char *s, size_t maxsize, const char *format, const struct vtm *vtm, VALUE timev)
{
	return date_strftime_wo_timespec(s, maxsize, format, vtm, timev);
}

/* isleap --- is a year a leap year? */

#ifndef __STDC__
static int
isleap(year)
long year;
#else
static int
isleap(long year)
#endif
{
	return ((year % 4 == 0 && year % 100 != 0) || year % 400 == 0);
}


static void
vtm2tm_noyear(const struct vtm *vtm, struct tm *result)
{
    struct tm tm;

    /* for isleap() in iso8601wknum.  +100 is -1900 (mod 400). */
    tm.tm_year = FIX2INT(mod(vtm->year, INT2FIX(400))) + 100;

    tm.tm_mon = vtm->mon-1;
    tm.tm_mday = vtm->mday;
    tm.tm_hour = vtm->hour;
    tm.tm_min = vtm->min;
    tm.tm_sec = vtm->sec;
    tm.tm_wday = vtm->wday;
    tm.tm_yday = vtm->yday-1;
    tm.tm_isdst = vtm->isdst;
#if defined(HAVE_STRUCT_TM_TM_GMTOFF)
    tm.tm_gmtoff = NUM2LONG(vtm->utc_offset);
#endif
#if defined(HAVE_TM_ZONE)
    tm.tm_zone = (char *)vtm->zone;
#endif
    *result = tm;
}

#ifdef POSIX2_DATE
/* iso8601wknum --- compute week number according to ISO 8601 */

#ifndef __STDC__
static int
iso8601wknum(timeptr)
const struct tm *timeptr;
#else
static int
iso8601wknum(const struct tm *timeptr)
#endif
{
	/*
	 * From 1003.2:
	 *	If the week (Monday to Sunday) containing January 1
	 *	has four or more days in the new year, then it is week 1;
	 *	otherwise it is the highest numbered week of the previous
	 *	year (52 or 53), and the next week is week 1.
	 *
	 * ADR: This means if Jan 1 was Monday through Thursday,
	 *	it was week 1, otherwise week 52 or 53.
	 *
	 * XPG4 erroneously included POSIX.2 rationale text in the
	 * main body of the standard. Thus it requires week 53.
	 */

	int weeknum, jan1day;

	/* get week number, Monday as first day of the week */
	weeknum = weeknumber(timeptr, 1);

	/*
	 * With thanks and tip of the hatlo to tml@tik.vtt.fi
	 *
	 * What day of the week does January 1 fall on?
	 * We know that
	 *	(timeptr->tm_yday - jan1.tm_yday) MOD 7 ==
	 *		(timeptr->tm_wday - jan1.tm_wday) MOD 7
	 * and that
	 * 	jan1.tm_yday == 0
	 * and that
	 * 	timeptr->tm_wday MOD 7 == timeptr->tm_wday
	 * from which it follows that. . .
	 */
	jan1day = timeptr->tm_wday - (timeptr->tm_yday % 7);
	if (jan1day < 0)
		jan1day += 7;

	/*
	 * If Jan 1 was a Monday through Thursday, it was in
	 * week 1.  Otherwise it was last year's highest week, which is
	 * this year's week 0.
	 *
	 * What does that mean?
	 * If Jan 1 was Monday, the week number is exactly right, it can
	 *	never be 0.
	 * If it was Tuesday through Thursday, the weeknumber is one
	 *	less than it should be, so we add one.
	 * Otherwise, Friday, Saturday or Sunday, the week number is
	 * OK, but if it is 0, it needs to be 52 or 53.
	 */
	switch (jan1day) {
	case 1:		/* Monday */
		break;
	case 2:		/* Tuesday */
	case 3:		/* Wednesday */
	case 4:		/* Thursday */
		weeknum++;
		break;
	case 5:		/* Friday */
	case 6:		/* Saturday */
	case 0:		/* Sunday */
		if (weeknum == 0) {
#ifdef USE_BROKEN_XPG4
			/* XPG4 (as of March 1994) says 53 unconditionally */
			weeknum = 53;
#else
			/* get week number of last week of last year */
			struct tm dec31ly;	/* 12/31 last year */
			dec31ly = *timeptr;
			dec31ly.tm_year--;
			dec31ly.tm_mon = 11;
			dec31ly.tm_mday = 31;
			dec31ly.tm_wday = (jan1day == 0) ? 6 : jan1day - 1;
			dec31ly.tm_yday = 364 + isleap(dec31ly.tm_year + 1900L);
			weeknum = iso8601wknum(& dec31ly);
#endif
		}
		break;
	}

	if (timeptr->tm_mon == 11) {
		/*
		 * The last week of the year
		 * can be in week 1 of next year.
		 * Sigh.
		 *
		 * This can only happen if
		 *	M   T  W
		 *	29  30 31
		 *	30  31
		 *	31
		 */
		int wday, mday;

		wday = timeptr->tm_wday;
		mday = timeptr->tm_mday;
		if (   (wday == 1 && (mday >= 29 && mday <= 31))
		    || (wday == 2 && (mday == 30 || mday == 31))
		    || (wday == 3 &&  mday == 31))
			weeknum = 1;
	}

	return weeknum;
}

static int
iso8601wknum_v(const struct vtm *vtm)
{
        struct tm tm;
        vtm2tm_noyear(vtm, &tm);
        return iso8601wknum(&tm);
}

#endif

/* weeknumber --- figure how many weeks into the year */

/* With thanks and tip of the hatlo to ado@elsie.nci.nih.gov */

#ifndef __STDC__
static int
weeknumber(timeptr, firstweekday)
const struct tm *timeptr;
int firstweekday;
#else
static int
weeknumber(const struct tm *timeptr, int firstweekday)
#endif
{
	int wday = timeptr->tm_wday;
	int ret;

	if (firstweekday == 1) {
		if (wday == 0)	/* sunday */
			wday = 6;
		else
			wday--;
	}
	ret = ((timeptr->tm_yday + 7 - wday) / 7);
	if (ret < 0)
		ret = 0;
	return ret;
}

static int
weeknumber_v(const struct vtm *vtm, int firstweekday)
{
        struct tm tm;
        vtm2tm_noyear(vtm, &tm);
        return weeknumber(&tm, firstweekday);
}

#if 0
/* ADR --- I'm loathe to mess with ado's code ... */

Date:         Wed, 24 Apr 91 20:54:08 MDT
From: Michal Jaegermann <audfax!emory!vm.ucs.UAlberta.CA!NTOMCZAK>
To: arnold@audiofax.com

Hi Arnold,
in a process of fixing of strftime() in libraries on Atari ST I grabbed
some pieces of code from your own strftime.  When doing that it came
to mind that your weeknumber() function compiles a little bit nicer
in the following form:
/*
 * firstweekday is 0 if starting in Sunday, non-zero if in Monday
 */
{
    return (timeptr->tm_yday - timeptr->tm_wday +
	    (firstweekday ? (timeptr->tm_wday ? 8 : 1) : 7)) / 7;
}
How nicer it depends on a compiler, of course, but always a tiny bit.

   Cheers,
   Michal
   ntomczak@vm.ucs.ualberta.ca
#endif

#ifdef	TEST_STRFTIME

/*
 * NAME:
 *	tst
 *
 * SYNOPSIS:
 *	tst
 *
 * DESCRIPTION:
 *	"tst" is a test driver for the function "strftime".
 *
 * OPTIONS:
 *	None.
 *
 * AUTHOR:
 *	Karl Vogel
 *	Control Data Systems, Inc.
 *	vogelke@c-17igp.wpafb.af.mil
 *
 * BUGS:
 *	None noticed yet.
 *
 * COMPILE:
 *	cc -o tst -DTEST_STRFTIME strftime.c
 */

/* ADR: I reformatted this to my liking, and deleted some unneeded code. */

#ifndef NULL
#include	<stdio.h>
#endif
#include	<sys/time.h>
#include	<string.h>

#define		MAXTIME		132

/*
 * Array of time formats.
 */

static char *array[] =
{
	"(%%A)      full weekday name, var length (Sunday..Saturday)  %A",
	"(%%B)       full month name, var length (January..December)  %B",
	"(%%C)                                               Century  %C",
	"(%%D)                                       date (%%m/%%d/%%y)  %D",
	"(%%E)                           Locale extensions (ignored)  %E",
	"(%%H)                          hour (24-hour clock, 00..23)  %H",
	"(%%I)                          hour (12-hour clock, 01..12)  %I",
	"(%%M)                                       minute (00..59)  %M",
	"(%%O)                           Locale extensions (ignored)  %O",
	"(%%R)                                 time, 24-hour (%%H:%%M)  %R",
	"(%%S)                                       second (00..60)  %S",
	"(%%T)                              time, 24-hour (%%H:%%M:%%S)  %T",
	"(%%U)    week of year, Sunday as first day of week (00..53)  %U",
	"(%%V)                    week of year according to ISO 8601  %V",
	"(%%W)    week of year, Monday as first day of week (00..53)  %W",
	"(%%X)     appropriate locale time representation (%H:%M:%S)  %X",
	"(%%Y)                           year with century (1970...)  %Y",
	"(%%Z) timezone (EDT), or blank if timezone not determinable  %Z",
	"(%%a)          locale's abbreviated weekday name (Sun..Sat)  %a",
	"(%%b)            locale's abbreviated month name (Jan..Dec)  %b",
	"(%%c)           full date (Sat Nov  4 12:02:33 1989)%n%t%t%t  %c",
	"(%%d)                             day of the month (01..31)  %d",
	"(%%e)               day of the month, blank-padded ( 1..31)  %e",
	"(%%h)                                should be same as (%%b)  %h",
	"(%%j)                            day of the year (001..366)  %j",
	"(%%k)               hour, 24-hour clock, blank pad ( 0..23)  %k",
	"(%%l)               hour, 12-hour clock, blank pad ( 1..12)  %l",
	"(%%m)                                        month (01..12)  %m",
	"(%%p)              locale's AM or PM based on 12-hour clock  %p",
	"(%%r)                   time, 12-hour (same as %%I:%%M:%%S %%p)  %r",
	"(%%u) ISO 8601: Weekday as decimal number [1 (Monday) - 7]   %u",
	"(%%v)                                VMS date (dd-bbb-YYYY)  %v",
	"(%%w)                       day of week (0..6, Sunday == 0)  %w",
	"(%%x)                appropriate locale date representation  %x",
	"(%%y)                      last two digits of year (00..99)  %y",
	"(%%z)      timezone offset east of GMT as HHMM (e.g. -0500)  %z",
	(char *) NULL
};

/* main routine. */

int
main(argc, argv)
int argc;
char **argv;
{
	long time();

	char *next;
	char string[MAXTIME];

	int k;
	int length;

	struct tm *tm;

	long clock;

	/* Call the function. */

	clock = time((long *) 0);
	tm = localtime(&clock);

	for (k = 0; next = array[k]; k++) {
		length = strftime(string, MAXTIME, next, tm);
		printf("%s\n", string);
	}

	exit(0);
}
#endif	/* TEST_STRFTIME */