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Merge branch 'nd/help-commands-verbose-by-default'
[git.git] / date.c
blob49f943e25b5dc4f288963077f5eabaf24f651aab
1 /*
2 * GIT - The information manager from hell
3 *
4 * Copyright (C) Linus Torvalds, 2005
5 */
6
7 #include "cache.h"
8
9 /*
10 * This is like mktime, but without normalization of tm_wday and tm_yday.
11 */
12 static time_t tm_to_time_t(const struct tm *tm)
13 {
14 static const int mdays[] = {
15 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334
16 };
17 int year = tm->tm_year - 70;
18 int month = tm->tm_mon;
19 int day = tm->tm_mday;
20
21 if (year < 0 || year > 129) /* algo only works for 1970-2099 */
22 return -1;
23 if (month < 0 || month > 11) /* array bounds */
24 return -1;
25 if (month < 2 || (year + 2) % 4)
26 day--;
27 if (tm->tm_hour < 0 || tm->tm_min < 0 || tm->tm_sec < 0)
28 return -1;
29 return (year * 365 + (year + 1) / 4 + mdays[month] + day) * 24*60*60UL +
30 tm->tm_hour * 60*60 + tm->tm_min * 60 + tm->tm_sec;
31 }
32
33 static const char *month_names[] = {
34 "January", "February", "March", "April", "May", "June",
35 "July", "August", "September", "October", "November", "December"
36 };
37
38 static const char *weekday_names[] = {
39 "Sundays", "Mondays", "Tuesdays", "Wednesdays", "Thursdays", "Fridays", "Saturdays"
40 };
41
42 static time_t gm_time_t(timestamp_t time, int tz)
43 {
44 int minutes;
45
46 minutes = tz < 0 ? -tz : tz;
47 minutes = (minutes / 100)*60 + (minutes % 100);
48 minutes = tz < 0 ? -minutes : minutes;
49
50 if (minutes > 0) {
51 if (unsigned_add_overflows(time, minutes * 60))
52 die("Timestamp+tz too large: %"PRItime" +%04d",
53 time, tz);
54 } else if (time < -minutes * 60)
55 die("Timestamp before Unix epoch: %"PRItime" %04d", time, tz);
56 time += minutes * 60;
57 if (date_overflows(time))
58 die("Timestamp too large for this system: %"PRItime, time);
59 return (time_t)time;
60 }
61
62 /*
63 * The "tz" thing is passed in as this strange "decimal parse of tz"
64 * thing, which means that tz -0100 is passed in as the integer -100,
65 * even though it means "sixty minutes off"
66 */
67 static struct tm *time_to_tm(timestamp_t time, int tz)
68 {
69 time_t t = gm_time_t(time, tz);
70 return gmtime(&t);
71 }
72
73 static struct tm *time_to_tm_local(timestamp_t time)
74 {
75 time_t t = time;
76 return localtime(&t);
77 }
78
79 /*
80 * What value of "tz" was in effect back then at "time" in the
81 * local timezone?
82 */
83 static int local_tzoffset(timestamp_t time)
84 {
85 time_t t, t_local;
86 struct tm tm;
87 int offset, eastwest;
88
89 if (date_overflows(time))
90 die("Timestamp too large for this system: %"PRItime, time);
91
92 t = (time_t)time;
93 localtime_r(&t, &tm);
94 t_local = tm_to_time_t(&tm);
95
96 if (t_local == -1)
97 return 0; /* error; just use +0000 */
98 if (t_local < t) {
99 eastwest = -1;
100 offset = t - t_local;
101 } else {
102 eastwest = 1;
103 offset = t_local - t;
104 }
105 offset /= 60; /* in minutes */
106 offset = (offset % 60) + ((offset / 60) * 100);
107 return offset * eastwest;
108 }
109
110 void show_date_relative(timestamp_t time, int tz,
111 const struct timeval *now,
112 struct strbuf *timebuf)
113 {
114 timestamp_t diff;
115 if (now->tv_sec < time) {
116 strbuf_addstr(timebuf, _("in the future"));
117 return;
118 }
119 diff = now->tv_sec - time;
120 if (diff < 90) {
121 strbuf_addf(timebuf,
122 Q_("%"PRItime" second ago", "%"PRItime" seconds ago", diff), diff);
123 return;
124 }
125 /* Turn it into minutes */
126 diff = (diff + 30) / 60;
127 if (diff < 90) {
128 strbuf_addf(timebuf,
129 Q_("%"PRItime" minute ago", "%"PRItime" minutes ago", diff), diff);
130 return;
131 }
132 /* Turn it into hours */
133 diff = (diff + 30) / 60;
134 if (diff < 36) {
135 strbuf_addf(timebuf,
136 Q_("%"PRItime" hour ago", "%"PRItime" hours ago", diff), diff);
137 return;
138 }
139 /* We deal with number of days from here on */
140 diff = (diff + 12) / 24;
141 if (diff < 14) {
142 strbuf_addf(timebuf,
143 Q_("%"PRItime" day ago", "%"PRItime" days ago", diff), diff);
144 return;
145 }
146 /* Say weeks for the past 10 weeks or so */
147 if (diff < 70) {
148 strbuf_addf(timebuf,
149 Q_("%"PRItime" week ago", "%"PRItime" weeks ago", (diff + 3) / 7),
150 (diff + 3) / 7);
151 return;
152 }
153 /* Say months for the past 12 months or so */
154 if (diff < 365) {
155 strbuf_addf(timebuf,
156 Q_("%"PRItime" month ago", "%"PRItime" months ago", (diff + 15) / 30),
157 (diff + 15) / 30);
158 return;
159 }
160 /* Give years and months for 5 years or so */
161 if (diff < 1825) {
162 timestamp_t totalmonths = (diff * 12 * 2 + 365) / (365 * 2);
163 timestamp_t years = totalmonths / 12;
164 timestamp_t months = totalmonths % 12;
165 if (months) {
166 struct strbuf sb = STRBUF_INIT;
167 strbuf_addf(&sb, Q_("%"PRItime" year", "%"PRItime" years", years), years);
168 strbuf_addf(timebuf,
169 /* TRANSLATORS: "%s" is "<n> years" */
170 Q_("%s, %"PRItime" month ago", "%s, %"PRItime" months ago", months),
171 sb.buf, months);
172 strbuf_release(&sb);
173 } else
174 strbuf_addf(timebuf,
175 Q_("%"PRItime" year ago", "%"PRItime" years ago", years), years);
176 return;
177 }
178 /* Otherwise, just years. Centuries is probably overkill. */
179 strbuf_addf(timebuf,
180 Q_("%"PRItime" year ago", "%"PRItime" years ago", (diff + 183) / 365),
181 (diff + 183) / 365);
182 }
183
184 struct date_mode *date_mode_from_type(enum date_mode_type type)
185 {
186 static struct date_mode mode;
187 if (type == DATE_STRFTIME)
188 BUG("cannot create anonymous strftime date_mode struct");
189 mode.type = type;
190 mode.local = 0;
191 return &mode;
192 }
193
194 const char *show_date(timestamp_t time, int tz, const struct date_mode *mode)
195 {
196 struct tm *tm;
197 static struct strbuf timebuf = STRBUF_INIT;
198
199 if (mode->type == DATE_UNIX) {
200 strbuf_reset(&timebuf);
201 strbuf_addf(&timebuf, "%"PRItime, time);
202 return timebuf.buf;
203 }
204
205 if (mode->local)
206 tz = local_tzoffset(time);
207
208 if (mode->type == DATE_RAW) {
209 strbuf_reset(&timebuf);
210 strbuf_addf(&timebuf, "%"PRItime" %+05d", time, tz);
211 return timebuf.buf;
212 }
213
214 if (mode->type == DATE_RELATIVE) {
215 struct timeval now;
216
217 strbuf_reset(&timebuf);
218 gettimeofday(&now, NULL);
219 show_date_relative(time, tz, &now, &timebuf);
220 return timebuf.buf;
221 }
222
223 if (mode->local)
224 tm = time_to_tm_local(time);
225 else
226 tm = time_to_tm(time, tz);
227 if (!tm) {
228 tm = time_to_tm(0, 0);
229 tz = 0;
230 }
231
232 strbuf_reset(&timebuf);
233 if (mode->type == DATE_SHORT)
234 strbuf_addf(&timebuf, "%04d-%02d-%02d", tm->tm_year + 1900,
235 tm->tm_mon + 1, tm->tm_mday);
236 else if (mode->type == DATE_ISO8601)
237 strbuf_addf(&timebuf, "%04d-%02d-%02d %02d:%02d:%02d %+05d",
238 tm->tm_year + 1900,
239 tm->tm_mon + 1,
240 tm->tm_mday,
241 tm->tm_hour, tm->tm_min, tm->tm_sec,
242 tz);
243 else if (mode->type == DATE_ISO8601_STRICT) {
244 char sign = (tz >= 0) ? '+' : '-';
245 tz = abs(tz);
246 strbuf_addf(&timebuf, "%04d-%02d-%02dT%02d:%02d:%02d%c%02d:%02d",
247 tm->tm_year + 1900,
248 tm->tm_mon + 1,
249 tm->tm_mday,
250 tm->tm_hour, tm->tm_min, tm->tm_sec,
251 sign, tz / 100, tz % 100);
252 } else if (mode->type == DATE_RFC2822)
253 strbuf_addf(&timebuf, "%.3s, %d %.3s %d %02d:%02d:%02d %+05d",
254 weekday_names[tm->tm_wday], tm->tm_mday,
255 month_names[tm->tm_mon], tm->tm_year + 1900,
256 tm->tm_hour, tm->tm_min, tm->tm_sec, tz);
257 else if (mode->type == DATE_STRFTIME)
258 strbuf_addftime(&timebuf, mode->strftime_fmt, tm, tz,
259 !mode->local);
260 else
261 strbuf_addf(&timebuf, "%.3s %.3s %d %02d:%02d:%02d %d%c%+05d",
262 weekday_names[tm->tm_wday],
263 month_names[tm->tm_mon],
264 tm->tm_mday,
265 tm->tm_hour, tm->tm_min, tm->tm_sec,
266 tm->tm_year + 1900,
267 mode->local ? 0 : ' ',
268 tz);
269 return timebuf.buf;
270 }
271
272 /*
273 * Check these. And note how it doesn't do the summer-time conversion.
274 *
275 * In my world, it's always summer, and things are probably a bit off
276 * in other ways too.
277 */
278 static const struct {
279 const char *name;
280 int offset;
281 int dst;
282 } timezone_names[] = {
283 { "IDLW", -12, 0, }, /* International Date Line West */
284 { "NT", -11, 0, }, /* Nome */
285 { "CAT", -10, 0, }, /* Central Alaska */
286 { "HST", -10, 0, }, /* Hawaii Standard */
287 { "HDT", -10, 1, }, /* Hawaii Daylight */
288 { "YST", -9, 0, }, /* Yukon Standard */
289 { "YDT", -9, 1, }, /* Yukon Daylight */
290 { "PST", -8, 0, }, /* Pacific Standard */
291 { "PDT", -8, 1, }, /* Pacific Daylight */
292 { "MST", -7, 0, }, /* Mountain Standard */
293 { "MDT", -7, 1, }, /* Mountain Daylight */
294 { "CST", -6, 0, }, /* Central Standard */
295 { "CDT", -6, 1, }, /* Central Daylight */
296 { "EST", -5, 0, }, /* Eastern Standard */
297 { "EDT", -5, 1, }, /* Eastern Daylight */
298 { "AST", -3, 0, }, /* Atlantic Standard */
299 { "ADT", -3, 1, }, /* Atlantic Daylight */
300 { "WAT", -1, 0, }, /* West Africa */
301
302 { "GMT", 0, 0, }, /* Greenwich Mean */
303 { "UTC", 0, 0, }, /* Universal (Coordinated) */
304 { "Z", 0, 0, }, /* Zulu, alias for UTC */
305
306 { "WET", 0, 0, }, /* Western European */
307 { "BST", 0, 1, }, /* British Summer */
308 { "CET", +1, 0, }, /* Central European */
309 { "MET", +1, 0, }, /* Middle European */
310 { "MEWT", +1, 0, }, /* Middle European Winter */
311 { "MEST", +1, 1, }, /* Middle European Summer */
312 { "CEST", +1, 1, }, /* Central European Summer */
313 { "MESZ", +1, 1, }, /* Middle European Summer */
314 { "FWT", +1, 0, }, /* French Winter */
315 { "FST", +1, 1, }, /* French Summer */
316 { "EET", +2, 0, }, /* Eastern Europe, USSR Zone 1 */
317 { "EEST", +2, 1, }, /* Eastern European Daylight */
318 { "WAST", +7, 0, }, /* West Australian Standard */
319 { "WADT", +7, 1, }, /* West Australian Daylight */
320 { "CCT", +8, 0, }, /* China Coast, USSR Zone 7 */
321 { "JST", +9, 0, }, /* Japan Standard, USSR Zone 8 */
322 { "EAST", +10, 0, }, /* Eastern Australian Standard */
323 { "EADT", +10, 1, }, /* Eastern Australian Daylight */
324 { "GST", +10, 0, }, /* Guam Standard, USSR Zone 9 */
325 { "NZT", +12, 0, }, /* New Zealand */
326 { "NZST", +12, 0, }, /* New Zealand Standard */
327 { "NZDT", +12, 1, }, /* New Zealand Daylight */
328 { "IDLE", +12, 0, }, /* International Date Line East */
329 };
330
331 static int match_string(const char *date, const char *str)
332 {
333 int i = 0;
334
335 for (i = 0; *date; date++, str++, i++) {
336 if (*date == *str)
337 continue;
338 if (toupper(*date) == toupper(*str))
339 continue;
340 if (!isalnum(*date))
341 break;
342 return 0;
343 }
344 return i;
345 }
346
347 static int skip_alpha(const char *date)
348 {
349 int i = 0;
350 do {
351 i++;
352 } while (isalpha(date[i]));
353 return i;
354 }
355
356 /*
357 * Parse month, weekday, or timezone name
358 */
359 static int match_alpha(const char *date, struct tm *tm, int *offset)
360 {
361 int i;
362
363 for (i = 0; i < 12; i++) {
364 int match = match_string(date, month_names[i]);
365 if (match >= 3) {
366 tm->tm_mon = i;
367 return match;
368 }
369 }
370
371 for (i = 0; i < 7; i++) {
372 int match = match_string(date, weekday_names[i]);
373 if (match >= 3) {
374 tm->tm_wday = i;
375 return match;
376 }
377 }
378
379 for (i = 0; i < ARRAY_SIZE(timezone_names); i++) {
380 int match = match_string(date, timezone_names[i].name);
381 if (match >= 3 || match == strlen(timezone_names[i].name)) {
382 int off = timezone_names[i].offset;
383
384 /* This is bogus, but we like summer */
385 off += timezone_names[i].dst;
386
387 /* Only use the tz name offset if we don't have anything better */
388 if (*offset == -1)
389 *offset = 60*off;
390
391 return match;
392 }
393 }
394
395 if (match_string(date, "PM") == 2) {
396 tm->tm_hour = (tm->tm_hour % 12) + 12;
397 return 2;
398 }
399
400 if (match_string(date, "AM") == 2) {
401 tm->tm_hour = (tm->tm_hour % 12) + 0;
402 return 2;
403 }
404
405 /* BAD CRAP */
406 return skip_alpha(date);
407 }
408
409 static int is_date(int year, int month, int day, struct tm *now_tm, time_t now, struct tm *tm)
410 {
411 if (month > 0 && month < 13 && day > 0 && day < 32) {
412 struct tm check = *tm;
413 struct tm *r = (now_tm ? &check : tm);
414 time_t specified;
415
416 r->tm_mon = month - 1;
417 r->tm_mday = day;
418 if (year == -1) {
419 if (!now_tm)
420 return 1;
421 r->tm_year = now_tm->tm_year;
422 }
423 else if (year >= 1970 && year < 2100)
424 r->tm_year = year - 1900;
425 else if (year > 70 && year < 100)
426 r->tm_year = year;
427 else if (year < 38)
428 r->tm_year = year + 100;
429 else
430 return 0;
431 if (!now_tm)
432 return 1;
433
434 specified = tm_to_time_t(r);
435
436 /* Be it commit time or author time, it does not make
437 * sense to specify timestamp way into the future. Make
438 * sure it is not later than ten days from now...
439 */
440 if ((specified != -1) && (now + 10*24*3600 < specified))
441 return 0;
442 tm->tm_mon = r->tm_mon;
443 tm->tm_mday = r->tm_mday;
444 if (year != -1)
445 tm->tm_year = r->tm_year;
446 return 1;
447 }
448 return 0;
449 }
450
451 static int match_multi_number(timestamp_t num, char c, const char *date,
452 char *end, struct tm *tm, time_t now)
453 {
454 struct tm now_tm;
455 struct tm *refuse_future;
456 long num2, num3;
457
458 num2 = strtol(end+1, &end, 10);
459 num3 = -1;
460 if (*end == c && isdigit(end[1]))
461 num3 = strtol(end+1, &end, 10);
462
463 /* Time? Date? */
464 switch (c) {
465 case ':':
466 if (num3 < 0)
467 num3 = 0;
468 if (num < 25 && num2 >= 0 && num2 < 60 && num3 >= 0 && num3 <= 60) {
469 tm->tm_hour = num;
470 tm->tm_min = num2;
471 tm->tm_sec = num3;
472 break;
473 }
474 return 0;
475
476 case '-':
477 case '/':
478 case '.':
479 if (!now)
480 now = time(NULL);
481 refuse_future = NULL;
482 if (gmtime_r(&now, &now_tm))
483 refuse_future = &now_tm;
484
485 if (num > 70) {
486 /* yyyy-mm-dd? */
487 if (is_date(num, num2, num3, NULL, now, tm))
488 break;
489 /* yyyy-dd-mm? */
490 if (is_date(num, num3, num2, NULL, now, tm))
491 break;
492 }
493 /* Our eastern European friends say dd.mm.yy[yy]
494 * is the norm there, so giving precedence to
495 * mm/dd/yy[yy] form only when separator is not '.'
496 */
497 if (c != '.' &&
498 is_date(num3, num, num2, refuse_future, now, tm))
499 break;
500 /* European dd.mm.yy[yy] or funny US dd/mm/yy[yy] */
501 if (is_date(num3, num2, num, refuse_future, now, tm))
502 break;
503 /* Funny European mm.dd.yy */
504 if (c == '.' &&
505 is_date(num3, num, num2, refuse_future, now, tm))
506 break;
507 return 0;
508 }
509 return end - date;
510 }
511
512 /*
513 * Have we filled in any part of the time/date yet?
514 * We just do a binary 'and' to see if the sign bit
515 * is set in all the values.
516 */
517 static inline int nodate(struct tm *tm)
518 {
519 return (tm->tm_year &
520 tm->tm_mon &
521 tm->tm_mday &
522 tm->tm_hour &
523 tm->tm_min &
524 tm->tm_sec) < 0;
525 }
526
527 /*
528 * We've seen a digit. Time? Year? Date?
529 */
530 static int match_digit(const char *date, struct tm *tm, int *offset, int *tm_gmt)
531 {
532 int n;
533 char *end;
534 timestamp_t num;
535
536 num = parse_timestamp(date, &end, 10);
537
538 /*
539 * Seconds since 1970? We trigger on that for any numbers with
540 * more than 8 digits. This is because we don't want to rule out
541 * numbers like 20070606 as a YYYYMMDD date.
542 */
543 if (num >= 100000000 && nodate(tm)) {
544 time_t time = num;
545 if (gmtime_r(&time, tm)) {
546 *tm_gmt = 1;
547 return end - date;
548 }
549 }
550
551 /*
552 * Check for special formats: num[-.:/]num[same]num
553 */
554 switch (*end) {
555 case ':':
556 case '.':
557 case '/':
558 case '-':
559 if (isdigit(end[1])) {
560 int match = match_multi_number(num, *end, date, end, tm, 0);
561 if (match)
562 return match;
563 }
564 }
565
566 /*
567 * None of the special formats? Try to guess what
568 * the number meant. We use the number of digits
569 * to make a more educated guess..
570 */
571 n = 0;
572 do {
573 n++;
574 } while (isdigit(date[n]));
575
576 /* Four-digit year or a timezone? */
577 if (n == 4) {
578 if (num <= 1400 && *offset == -1) {
579 unsigned int minutes = num % 100;
580 unsigned int hours = num / 100;
581 *offset = hours*60 + minutes;
582 } else if (num > 1900 && num < 2100)
583 tm->tm_year = num - 1900;
584 return n;
585 }
586
587 /*
588 * Ignore lots of numerals. We took care of 4-digit years above.
589 * Days or months must be one or two digits.
590 */
591 if (n > 2)
592 return n;
593
594 /*
595 * NOTE! We will give precedence to day-of-month over month or
596 * year numbers in the 1-12 range. So 05 is always "mday 5",
597 * unless we already have a mday..
598 *
599 * IOW, 01 Apr 05 parses as "April 1st, 2005".
600 */
601 if (num > 0 && num < 32 && tm->tm_mday < 0) {
602 tm->tm_mday = num;
603 return n;
604 }
605
606 /* Two-digit year? */
607 if (n == 2 && tm->tm_year < 0) {
608 if (num < 10 && tm->tm_mday >= 0) {
609 tm->tm_year = num + 100;
610 return n;
611 }
612 if (num >= 70) {
613 tm->tm_year = num;
614 return n;
615 }
616 }
617
618 if (num > 0 && num < 13 && tm->tm_mon < 0)
619 tm->tm_mon = num-1;
620
621 return n;
622 }
623
624 static int match_tz(const char *date, int *offp)
625 {
626 char *end;
627 int hour = strtoul(date + 1, &end, 10);
628 int n = end - (date + 1);
629 int min = 0;
630
631 if (n == 4) {
632 /* hhmm */
633 min = hour % 100;
634 hour = hour / 100;
635 } else if (n != 2) {
636 min = 99; /* random crap */
637 } else if (*end == ':') {
638 /* hh:mm? */
639 min = strtoul(end + 1, &end, 10);
640 if (end - (date + 1) != 5)
641 min = 99; /* random crap */
642 } /* otherwise we parsed "hh" */
643
644 /*
645 * Don't accept any random crap. Even though some places have
646 * offset larger than 12 hours (e.g. Pacific/Kiritimati is at
647 * UTC+14), there is something wrong if hour part is much
648 * larger than that. We might also want to check that the
649 * minutes are divisible by 15 or something too. (Offset of
650 * Kathmandu, Nepal is UTC+5:45)
651 */
652 if (min < 60 && hour < 24) {
653 int offset = hour * 60 + min;
654 if (*date == '-')
655 offset = -offset;
656 *offp = offset;
657 }
658 return end - date;
659 }
660
661 static void date_string(timestamp_t date, int offset, struct strbuf *buf)
662 {
663 int sign = '+';
664
665 if (offset < 0) {
666 offset = -offset;
667 sign = '-';
668 }
669 strbuf_addf(buf, "%"PRItime" %c%02d%02d", date, sign, offset / 60, offset % 60);
670 }
671
672 /*
673 * Parse a string like "0 +0000" as ancient timestamp near epoch, but
674 * only when it appears not as part of any other string.
675 */
676 static int match_object_header_date(const char *date, timestamp_t *timestamp, int *offset)
677 {
678 char *end;
679 timestamp_t stamp;
680 int ofs;
681
682 if (*date < '0' || '9' < *date)
683 return -1;
684 stamp = parse_timestamp(date, &end, 10);
685 if (*end != ' ' || stamp == TIME_MAX || (end[1] != '+' && end[1] != '-'))
686 return -1;
687 date = end + 2;
688 ofs = strtol(date, &end, 10);
689 if ((*end != '\0' && (*end != '\n')) || end != date + 4)
690 return -1;
691 ofs = (ofs / 100) * 60 + (ofs % 100);
692 if (date[-1] == '-')
693 ofs = -ofs;
694 *timestamp = stamp;
695 *offset = ofs;
696 return 0;
697 }
698
699 /* Gr. strptime is crap for this; it doesn't have a way to require RFC2822
700 (i.e. English) day/month names, and it doesn't work correctly with %z. */
701 int parse_date_basic(const char *date, timestamp_t *timestamp, int *offset)
702 {
703 struct tm tm;
704 int tm_gmt;
705 timestamp_t dummy_timestamp;
706 int dummy_offset;
707
708 if (!timestamp)
709 timestamp = &dummy_timestamp;
710 if (!offset)
711 offset = &dummy_offset;
712
713 memset(&tm, 0, sizeof(tm));
714 tm.tm_year = -1;
715 tm.tm_mon = -1;
716 tm.tm_mday = -1;
717 tm.tm_isdst = -1;
718 tm.tm_hour = -1;
719 tm.tm_min = -1;
720 tm.tm_sec = -1;
721 *offset = -1;
722 tm_gmt = 0;
723
724 if (*date == '@' &&
725 !match_object_header_date(date + 1, timestamp, offset))
726 return 0; /* success */
727 for (;;) {
728 int match = 0;
729 unsigned char c = *date;
730
731 /* Stop at end of string or newline */
732 if (!c || c == '\n')
733 break;
734
735 if (isalpha(c))
736 match = match_alpha(date, &tm, offset);
737 else if (isdigit(c))
738 match = match_digit(date, &tm, offset, &tm_gmt);
739 else if ((c == '-' || c == '+') && isdigit(date[1]))
740 match = match_tz(date, offset);
741
742 if (!match) {
743 /* BAD CRAP */
744 match = 1;
745 }
746
747 date += match;
748 }
749
750 /* do not use mktime(), which uses local timezone, here */
751 *timestamp = tm_to_time_t(&tm);
752 if (*timestamp == -1)
753 return -1;
754
755 if (*offset == -1) {
756 time_t temp_time;
757
758 /* gmtime_r() in match_digit() may have clobbered it */
759 tm.tm_isdst = -1;
760 temp_time = mktime(&tm);
761 if ((time_t)*timestamp > temp_time) {
762 *offset = ((time_t)*timestamp - temp_time) / 60;
763 } else {
764 *offset = -(int)((temp_time - (time_t)*timestamp) / 60);
765 }
766 }
767
768 if (!tm_gmt)
769 *timestamp -= *offset * 60;
770 return 0; /* success */
771 }
772
773 int parse_expiry_date(const char *date, timestamp_t *timestamp)
774 {
775 int errors = 0;
776
777 if (!strcmp(date, "never") || !strcmp(date, "false"))
778 *timestamp = 0;
779 else if (!strcmp(date, "all") || !strcmp(date, "now"))
780 /*
781 * We take over "now" here, which usually translates
782 * to the current timestamp. This is because the user
783 * really means to expire everything she has done in
784 * the past, and by definition reflogs are the record
785 * of the past, and there is nothing from the future
786 * to be kept.
787 */
788 *timestamp = TIME_MAX;
789 else
790 *timestamp = approxidate_careful(date, &errors);
791
792 return errors;
793 }
794
795 int parse_date(const char *date, struct strbuf *result)
796 {
797 timestamp_t timestamp;
798 int offset;
799 if (parse_date_basic(date, &timestamp, &offset))
800 return -1;
801 date_string(timestamp, offset, result);
802 return 0;
803 }
804
805 static enum date_mode_type parse_date_type(const char *format, const char **end)
806 {
807 if (skip_prefix(format, "relative", end))
808 return DATE_RELATIVE;
809 if (skip_prefix(format, "iso8601-strict", end) ||
810 skip_prefix(format, "iso-strict", end))
811 return DATE_ISO8601_STRICT;
812 if (skip_prefix(format, "iso8601", end) ||
813 skip_prefix(format, "iso", end))
814 return DATE_ISO8601;
815 if (skip_prefix(format, "rfc2822", end) ||
816 skip_prefix(format, "rfc", end))
817 return DATE_RFC2822;
818 if (skip_prefix(format, "short", end))
819 return DATE_SHORT;
820 if (skip_prefix(format, "default", end))
821 return DATE_NORMAL;
822 if (skip_prefix(format, "raw", end))
823 return DATE_RAW;
824 if (skip_prefix(format, "unix", end))
825 return DATE_UNIX;
826 if (skip_prefix(format, "format", end))
827 return DATE_STRFTIME;
828
829 die("unknown date format %s", format);
830 }
831
832 void parse_date_format(const char *format, struct date_mode *mode)
833 {
834 const char *p;
835
836 /* historical alias */
837 if (!strcmp(format, "local"))
838 format = "default-local";
839
840 mode->type = parse_date_type(format, &p);
841 mode->local = 0;
842
843 if (skip_prefix(p, "-local", &p))
844 mode->local = 1;
845
846 if (mode->type == DATE_STRFTIME) {
847 if (!skip_prefix(p, ":", &p))
848 die("date format missing colon separator: %s", format);
849 mode->strftime_fmt = xstrdup(p);
850 } else if (*p)
851 die("unknown date format %s", format);
852 }
853
854 void datestamp(struct strbuf *out)
855 {
856 time_t now;
857 int offset;
858
859 time(&now);
860
861 offset = tm_to_time_t(localtime(&now)) - now;
862 offset /= 60;
863
864 date_string(now, offset, out);
865 }
866
867 /*
868 * Relative time update (eg "2 days ago"). If we haven't set the time
869 * yet, we need to set it from current time.
870 */
871 static time_t update_tm(struct tm *tm, struct tm *now, time_t sec)
872 {
873 time_t n;
874
875 if (tm->tm_mday < 0)
876 tm->tm_mday = now->tm_mday;
877 if (tm->tm_mon < 0)
878 tm->tm_mon = now->tm_mon;
879 if (tm->tm_year < 0) {
880 tm->tm_year = now->tm_year;
881 if (tm->tm_mon > now->tm_mon)
882 tm->tm_year--;
883 }
884
885 n = mktime(tm) - sec;
886 localtime_r(&n, tm);
887 return n;
888 }
889
890 static void date_now(struct tm *tm, struct tm *now, int *num)
891 {
892 update_tm(tm, now, 0);
893 }
894
895 static void date_yesterday(struct tm *tm, struct tm *now, int *num)
896 {
897 update_tm(tm, now, 24*60*60);
898 }
899
900 static void date_time(struct tm *tm, struct tm *now, int hour)
901 {
902 if (tm->tm_hour < hour)
903 date_yesterday(tm, now, NULL);
904 tm->tm_hour = hour;
905 tm->tm_min = 0;
906 tm->tm_sec = 0;
907 }
908
909 static void date_midnight(struct tm *tm, struct tm *now, int *num)
910 {
911 date_time(tm, now, 0);
912 }
913
914 static void date_noon(struct tm *tm, struct tm *now, int *num)
915 {
916 date_time(tm, now, 12);
917 }
918
919 static void date_tea(struct tm *tm, struct tm *now, int *num)
920 {
921 date_time(tm, now, 17);
922 }
923
924 static void date_pm(struct tm *tm, struct tm *now, int *num)
925 {
926 int hour, n = *num;
927 *num = 0;
928
929 hour = tm->tm_hour;
930 if (n) {
931 hour = n;
932 tm->tm_min = 0;
933 tm->tm_sec = 0;
934 }
935 tm->tm_hour = (hour % 12) + 12;
936 }
937
938 static void date_am(struct tm *tm, struct tm *now, int *num)
939 {
940 int hour, n = *num;
941 *num = 0;
942
943 hour = tm->tm_hour;
944 if (n) {
945 hour = n;
946 tm->tm_min = 0;
947 tm->tm_sec = 0;
948 }
949 tm->tm_hour = (hour % 12);
950 }
951
952 static void date_never(struct tm *tm, struct tm *now, int *num)
953 {
954 time_t n = 0;
955 localtime_r(&n, tm);
956 }
957
958 static const struct special {
959 const char *name;
960 void (*fn)(struct tm *, struct tm *, int *);
961 } special[] = {
962 { "yesterday", date_yesterday },
963 { "noon", date_noon },
964 { "midnight", date_midnight },
965 { "tea", date_tea },
966 { "PM", date_pm },
967 { "AM", date_am },
968 { "never", date_never },
969 { "now", date_now },
970 { NULL }
971 };
972
973 static const char *number_name[] = {
974 "zero", "one", "two", "three", "four",
975 "five", "six", "seven", "eight", "nine", "ten",
976 };
977
978 static const struct typelen {
979 const char *type;
980 int length;
981 } typelen[] = {
982 { "seconds", 1 },
983 { "minutes", 60 },
984 { "hours", 60*60 },
985 { "days", 24*60*60 },
986 { "weeks", 7*24*60*60 },
987 { NULL }
988 };
989
990 static const char *approxidate_alpha(const char *date, struct tm *tm, struct tm *now, int *num, int *touched)
991 {
992 const struct typelen *tl;
993 const struct special *s;
994 const char *end = date;
995 int i;
996
997 while (isalpha(*++end))
998 ;
999
1000 for (i = 0; i < 12; i++) {
1001 int match = match_string(date, month_names[i]);
1002 if (match >= 3) {
1003 tm->tm_mon = i;
1004 *touched = 1;
1005 return end;
1006 }
1007 }
1008
1009 for (s = special; s->name; s++) {
1010 int len = strlen(s->name);
1011 if (match_string(date, s->name) == len) {
1012 s->fn(tm, now, num);
1013 *touched = 1;
1014 return end;
1015 }
1016 }
1017
1018 if (!*num) {
1019 for (i = 1; i < 11; i++) {
1020 int len = strlen(number_name[i]);
1021 if (match_string(date, number_name[i]) == len) {
1022 *num = i;
1023 *touched = 1;
1024 return end;
1025 }
1026 }
1027 if (match_string(date, "last") == 4) {
1028 *num = 1;
1029 *touched = 1;
1030 }
1031 return end;
1032 }
1033
1034 tl = typelen;
1035 while (tl->type) {
1036 int len = strlen(tl->type);
1037 if (match_string(date, tl->type) >= len-1) {
1038 update_tm(tm, now, tl->length * *num);
1039 *num = 0;
1040 *touched = 1;
1041 return end;
1042 }
1043 tl++;
1044 }
1045
1046 for (i = 0; i < 7; i++) {
1047 int match = match_string(date, weekday_names[i]);
1048 if (match >= 3) {
1049 int diff, n = *num -1;
1050 *num = 0;
1051
1052 diff = tm->tm_wday - i;
1053 if (diff <= 0)
1054 n++;
1055 diff += 7*n;
1056
1057 update_tm(tm, now, diff * 24 * 60 * 60);
1058 *touched = 1;
1059 return end;
1060 }
1061 }
1062
1063 if (match_string(date, "months") >= 5) {
1064 int n;
1065 update_tm(tm, now, 0); /* fill in date fields if needed */
1066 n = tm->tm_mon - *num;
1067 *num = 0;
1068 while (n < 0) {
1069 n += 12;
1070 tm->tm_year--;
1071 }
1072 tm->tm_mon = n;
1073 *touched = 1;
1074 return end;
1075 }
1076
1077 if (match_string(date, "years") >= 4) {
1078 update_tm(tm, now, 0); /* fill in date fields if needed */
1079 tm->tm_year -= *num;
1080 *num = 0;
1081 *touched = 1;
1082 return end;
1083 }
1084
1085 return end;
1086 }
1087
1088 static const char *approxidate_digit(const char *date, struct tm *tm, int *num,
1089 time_t now)
1090 {
1091 char *end;
1092 timestamp_t number = parse_timestamp(date, &end, 10);
1093
1094 switch (*end) {
1095 case ':':
1096 case '.':
1097 case '/':
1098 case '-':
1099 if (isdigit(end[1])) {
1100 int match = match_multi_number(number, *end, date, end,
1101 tm, now);
1102 if (match)
1103 return date + match;
1104 }
1105 }
1106
1107 /* Accept zero-padding only for small numbers ("Dec 02", never "Dec 0002") */
1108 if (date[0] != '0' || end - date <= 2)
1109 *num = number;
1110 return end;
1111 }
1112
1113 /*
1114 * Do we have a pending number at the end, or when
1115 * we see a new one? Let's assume it's a month day,
1116 * as in "Dec 6, 1992"
1117 */
1118 static void pending_number(struct tm *tm, int *num)
1119 {
1120 int number = *num;
1121
1122 if (number) {
1123 *num = 0;
1124 if (tm->tm_mday < 0 && number < 32)
1125 tm->tm_mday = number;
1126 else if (tm->tm_mon < 0 && number < 13)
1127 tm->tm_mon = number-1;
1128 else if (tm->tm_year < 0) {
1129 if (number > 1969 && number < 2100)
1130 tm->tm_year = number - 1900;
1131 else if (number > 69 && number < 100)
1132 tm->tm_year = number;
1133 else if (number < 38)
1134 tm->tm_year = 100 + number;
1135 /* We screw up for number = 00 ? */
1136 }
1137 }
1138 }
1139
1140 static timestamp_t approxidate_str(const char *date,
1141 const struct timeval *tv,
1142 int *error_ret)
1143 {
1144 int number = 0;
1145 int touched = 0;
1146 struct tm tm, now;
1147 time_t time_sec;
1148
1149 time_sec = tv->tv_sec;
1150 localtime_r(&time_sec, &tm);
1151 now = tm;
1152
1153 tm.tm_year = -1;
1154 tm.tm_mon = -1;
1155 tm.tm_mday = -1;
1156
1157 for (;;) {
1158 unsigned char c = *date;
1159 if (!c)
1160 break;
1161 date++;
1162 if (isdigit(c)) {
1163 pending_number(&tm, &number);
1164 date = approxidate_digit(date-1, &tm, &number, time_sec);
1165 touched = 1;
1166 continue;
1167 }
1168 if (isalpha(c))
1169 date = approxidate_alpha(date-1, &tm, &now, &number, &touched);
1170 }
1171 pending_number(&tm, &number);
1172 if (!touched)
1173 *error_ret = 1;
1174 return (timestamp_t)update_tm(&tm, &now, 0);
1175 }
1176
1177 timestamp_t approxidate_relative(const char *date, const struct timeval *tv)
1178 {
1179 timestamp_t timestamp;
1180 int offset;
1181 int errors = 0;
1182
1183 if (!parse_date_basic(date, &timestamp, &offset))
1184 return timestamp;
1185 return approxidate_str(date, tv, &errors);
1186 }
1187
1188 timestamp_t approxidate_careful(const char *date, int *error_ret)
1189 {
1190 struct timeval tv;
1191 timestamp_t timestamp;
1192 int offset;
1193 int dummy = 0;
1194 if (!error_ret)
1195 error_ret = &dummy;
1196
1197 if (!parse_date_basic(date, &timestamp, &offset)) {
1198 *error_ret = 0;
1199 return timestamp;
1200 }
1201
1202 gettimeofday(&tv, NULL);
1203 return approxidate_str(date, &tv, error_ret);
1204 }
1205
1206 int date_overflows(timestamp_t t)
1207 {
1208 time_t sys;
1209
1210 /* If we overflowed our timestamp data type, that's bad... */
1211 if ((uintmax_t)t >= TIME_MAX)
1212 return 1;
1213
1214 /*
1215 * ...but we also are going to feed the result to system
1216 * functions that expect time_t, which is often "signed long".
1217 * Make sure that we fit into time_t, as well.
1218 */
1219 sys = t;
1220 return t != sys || (t < 1) != (sys < 1);
1221 }
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