Merge branch 'jk/filter-branch-no-index'
[git/debian.git] / date.c
blob7c9f76998ac7a00fb5f8781dd8e460f899edbfac
1 /*
2 * GIT - The information manager from hell
4 * Copyright (C) Linus Torvalds, 2005
5 */
7 #include "cache.h"
9 /*
10 * This is like mktime, but without normalization of tm_wday and tm_yday.
12 static time_t tm_to_time_t(const struct tm *tm)
14 static const int mdays[] = {
15 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334
17 int year = tm->tm_year - 70;
18 int month = tm->tm_mon;
19 int day = tm->tm_mday;
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;
33 static const char *month_names[] = {
34 "January", "February", "March", "April", "May", "June",
35 "July", "August", "September", "October", "November", "December"
38 static const char *weekday_names[] = {
39 "Sundays", "Mondays", "Tuesdays", "Wednesdays", "Thursdays", "Fridays", "Saturdays"
42 static time_t gm_time_t(unsigned long time, int tz)
44 int minutes;
46 minutes = tz < 0 ? -tz : tz;
47 minutes = (minutes / 100)*60 + (minutes % 100);
48 minutes = tz < 0 ? -minutes : minutes;
49 return time + minutes * 60;
53 * The "tz" thing is passed in as this strange "decimal parse of tz"
54 * thing, which means that tz -0100 is passed in as the integer -100,
55 * even though it means "sixty minutes off"
57 static struct tm *time_to_tm(unsigned long time, int tz)
59 time_t t = gm_time_t(time, tz);
60 return gmtime(&t);
64 * What value of "tz" was in effect back then at "time" in the
65 * local timezone?
67 static int local_tzoffset(unsigned long time)
69 time_t t, t_local;
70 struct tm tm;
71 int offset, eastwest;
73 t = time;
74 localtime_r(&t, &tm);
75 t_local = tm_to_time_t(&tm);
77 if (t_local < t) {
78 eastwest = -1;
79 offset = t - t_local;
80 } else {
81 eastwest = 1;
82 offset = t_local - t;
84 offset /= 60; /* in minutes */
85 offset = (offset % 60) + ((offset / 60) * 100);
86 return offset * eastwest;
89 void show_date_relative(unsigned long time, int tz,
90 const struct timeval *now,
91 struct strbuf *timebuf)
93 unsigned long diff;
94 if (now->tv_sec < time) {
95 strbuf_addstr(timebuf, _("in the future"));
96 return;
98 diff = now->tv_sec - time;
99 if (diff < 90) {
100 strbuf_addf(timebuf,
101 Q_("%lu second ago", "%lu seconds ago", diff), diff);
102 return;
104 /* Turn it into minutes */
105 diff = (diff + 30) / 60;
106 if (diff < 90) {
107 strbuf_addf(timebuf,
108 Q_("%lu minute ago", "%lu minutes ago", diff), diff);
109 return;
111 /* Turn it into hours */
112 diff = (diff + 30) / 60;
113 if (diff < 36) {
114 strbuf_addf(timebuf,
115 Q_("%lu hour ago", "%lu hours ago", diff), diff);
116 return;
118 /* We deal with number of days from here on */
119 diff = (diff + 12) / 24;
120 if (diff < 14) {
121 strbuf_addf(timebuf,
122 Q_("%lu day ago", "%lu days ago", diff), diff);
123 return;
125 /* Say weeks for the past 10 weeks or so */
126 if (diff < 70) {
127 strbuf_addf(timebuf,
128 Q_("%lu week ago", "%lu weeks ago", (diff + 3) / 7),
129 (diff + 3) / 7);
130 return;
132 /* Say months for the past 12 months or so */
133 if (diff < 365) {
134 strbuf_addf(timebuf,
135 Q_("%lu month ago", "%lu months ago", (diff + 15) / 30),
136 (diff + 15) / 30);
137 return;
139 /* Give years and months for 5 years or so */
140 if (diff < 1825) {
141 unsigned long totalmonths = (diff * 12 * 2 + 365) / (365 * 2);
142 unsigned long years = totalmonths / 12;
143 unsigned long months = totalmonths % 12;
144 if (months) {
145 struct strbuf sb = STRBUF_INIT;
146 strbuf_addf(&sb, Q_("%lu year", "%lu years", years), years);
147 strbuf_addf(timebuf,
148 /* TRANSLATORS: "%s" is "<n> years" */
149 Q_("%s, %lu month ago", "%s, %lu months ago", months),
150 sb.buf, months);
151 strbuf_release(&sb);
152 } else
153 strbuf_addf(timebuf,
154 Q_("%lu year ago", "%lu years ago", years), years);
155 return;
157 /* Otherwise, just years. Centuries is probably overkill. */
158 strbuf_addf(timebuf,
159 Q_("%lu year ago", "%lu years ago", (diff + 183) / 365),
160 (diff + 183) / 365);
163 struct date_mode *date_mode_from_type(enum date_mode_type type)
165 static struct date_mode mode;
166 if (type == DATE_STRFTIME)
167 die("BUG: cannot create anonymous strftime date_mode struct");
168 mode.type = type;
169 mode.local = 0;
170 return &mode;
173 const char *show_date(unsigned long time, int tz, const struct date_mode *mode)
175 struct tm *tm;
176 static struct strbuf timebuf = STRBUF_INIT;
178 if (mode->local)
179 tz = local_tzoffset(time);
181 if (mode->type == DATE_RAW) {
182 strbuf_reset(&timebuf);
183 strbuf_addf(&timebuf, "%lu %+05d", time, tz);
184 return timebuf.buf;
187 if (mode->type == DATE_RELATIVE) {
188 struct timeval now;
190 strbuf_reset(&timebuf);
191 gettimeofday(&now, NULL);
192 show_date_relative(time, tz, &now, &timebuf);
193 return timebuf.buf;
196 tm = time_to_tm(time, tz);
197 if (!tm) {
198 tm = time_to_tm(0, 0);
199 tz = 0;
202 strbuf_reset(&timebuf);
203 if (mode->type == DATE_SHORT)
204 strbuf_addf(&timebuf, "%04d-%02d-%02d", tm->tm_year + 1900,
205 tm->tm_mon + 1, tm->tm_mday);
206 else if (mode->type == DATE_ISO8601)
207 strbuf_addf(&timebuf, "%04d-%02d-%02d %02d:%02d:%02d %+05d",
208 tm->tm_year + 1900,
209 tm->tm_mon + 1,
210 tm->tm_mday,
211 tm->tm_hour, tm->tm_min, tm->tm_sec,
212 tz);
213 else if (mode->type == DATE_ISO8601_STRICT) {
214 char sign = (tz >= 0) ? '+' : '-';
215 tz = abs(tz);
216 strbuf_addf(&timebuf, "%04d-%02d-%02dT%02d:%02d:%02d%c%02d:%02d",
217 tm->tm_year + 1900,
218 tm->tm_mon + 1,
219 tm->tm_mday,
220 tm->tm_hour, tm->tm_min, tm->tm_sec,
221 sign, tz / 100, tz % 100);
222 } else if (mode->type == DATE_RFC2822)
223 strbuf_addf(&timebuf, "%.3s, %d %.3s %d %02d:%02d:%02d %+05d",
224 weekday_names[tm->tm_wday], tm->tm_mday,
225 month_names[tm->tm_mon], tm->tm_year + 1900,
226 tm->tm_hour, tm->tm_min, tm->tm_sec, tz);
227 else if (mode->type == DATE_STRFTIME)
228 strbuf_addftime(&timebuf, mode->strftime_fmt, tm);
229 else
230 strbuf_addf(&timebuf, "%.3s %.3s %d %02d:%02d:%02d %d%c%+05d",
231 weekday_names[tm->tm_wday],
232 month_names[tm->tm_mon],
233 tm->tm_mday,
234 tm->tm_hour, tm->tm_min, tm->tm_sec,
235 tm->tm_year + 1900,
236 mode->local ? 0 : ' ',
237 tz);
238 return timebuf.buf;
242 * Check these. And note how it doesn't do the summer-time conversion.
244 * In my world, it's always summer, and things are probably a bit off
245 * in other ways too.
247 static const struct {
248 const char *name;
249 int offset;
250 int dst;
251 } timezone_names[] = {
252 { "IDLW", -12, 0, }, /* International Date Line West */
253 { "NT", -11, 0, }, /* Nome */
254 { "CAT", -10, 0, }, /* Central Alaska */
255 { "HST", -10, 0, }, /* Hawaii Standard */
256 { "HDT", -10, 1, }, /* Hawaii Daylight */
257 { "YST", -9, 0, }, /* Yukon Standard */
258 { "YDT", -9, 1, }, /* Yukon Daylight */
259 { "PST", -8, 0, }, /* Pacific Standard */
260 { "PDT", -8, 1, }, /* Pacific Daylight */
261 { "MST", -7, 0, }, /* Mountain Standard */
262 { "MDT", -7, 1, }, /* Mountain Daylight */
263 { "CST", -6, 0, }, /* Central Standard */
264 { "CDT", -6, 1, }, /* Central Daylight */
265 { "EST", -5, 0, }, /* Eastern Standard */
266 { "EDT", -5, 1, }, /* Eastern Daylight */
267 { "AST", -3, 0, }, /* Atlantic Standard */
268 { "ADT", -3, 1, }, /* Atlantic Daylight */
269 { "WAT", -1, 0, }, /* West Africa */
271 { "GMT", 0, 0, }, /* Greenwich Mean */
272 { "UTC", 0, 0, }, /* Universal (Coordinated) */
273 { "Z", 0, 0, }, /* Zulu, alias for UTC */
275 { "WET", 0, 0, }, /* Western European */
276 { "BST", 0, 1, }, /* British Summer */
277 { "CET", +1, 0, }, /* Central European */
278 { "MET", +1, 0, }, /* Middle European */
279 { "MEWT", +1, 0, }, /* Middle European Winter */
280 { "MEST", +1, 1, }, /* Middle European Summer */
281 { "CEST", +1, 1, }, /* Central European Summer */
282 { "MESZ", +1, 1, }, /* Middle European Summer */
283 { "FWT", +1, 0, }, /* French Winter */
284 { "FST", +1, 1, }, /* French Summer */
285 { "EET", +2, 0, }, /* Eastern Europe, USSR Zone 1 */
286 { "EEST", +2, 1, }, /* Eastern European Daylight */
287 { "WAST", +7, 0, }, /* West Australian Standard */
288 { "WADT", +7, 1, }, /* West Australian Daylight */
289 { "CCT", +8, 0, }, /* China Coast, USSR Zone 7 */
290 { "JST", +9, 0, }, /* Japan Standard, USSR Zone 8 */
291 { "EAST", +10, 0, }, /* Eastern Australian Standard */
292 { "EADT", +10, 1, }, /* Eastern Australian Daylight */
293 { "GST", +10, 0, }, /* Guam Standard, USSR Zone 9 */
294 { "NZT", +12, 0, }, /* New Zealand */
295 { "NZST", +12, 0, }, /* New Zealand Standard */
296 { "NZDT", +12, 1, }, /* New Zealand Daylight */
297 { "IDLE", +12, 0, }, /* International Date Line East */
300 static int match_string(const char *date, const char *str)
302 int i = 0;
304 for (i = 0; *date; date++, str++, i++) {
305 if (*date == *str)
306 continue;
307 if (toupper(*date) == toupper(*str))
308 continue;
309 if (!isalnum(*date))
310 break;
311 return 0;
313 return i;
316 static int skip_alpha(const char *date)
318 int i = 0;
319 do {
320 i++;
321 } while (isalpha(date[i]));
322 return i;
326 * Parse month, weekday, or timezone name
328 static int match_alpha(const char *date, struct tm *tm, int *offset)
330 int i;
332 for (i = 0; i < 12; i++) {
333 int match = match_string(date, month_names[i]);
334 if (match >= 3) {
335 tm->tm_mon = i;
336 return match;
340 for (i = 0; i < 7; i++) {
341 int match = match_string(date, weekday_names[i]);
342 if (match >= 3) {
343 tm->tm_wday = i;
344 return match;
348 for (i = 0; i < ARRAY_SIZE(timezone_names); i++) {
349 int match = match_string(date, timezone_names[i].name);
350 if (match >= 3 || match == strlen(timezone_names[i].name)) {
351 int off = timezone_names[i].offset;
353 /* This is bogus, but we like summer */
354 off += timezone_names[i].dst;
356 /* Only use the tz name offset if we don't have anything better */
357 if (*offset == -1)
358 *offset = 60*off;
360 return match;
364 if (match_string(date, "PM") == 2) {
365 tm->tm_hour = (tm->tm_hour % 12) + 12;
366 return 2;
369 if (match_string(date, "AM") == 2) {
370 tm->tm_hour = (tm->tm_hour % 12) + 0;
371 return 2;
374 /* BAD CRAP */
375 return skip_alpha(date);
378 static int is_date(int year, int month, int day, struct tm *now_tm, time_t now, struct tm *tm)
380 if (month > 0 && month < 13 && day > 0 && day < 32) {
381 struct tm check = *tm;
382 struct tm *r = (now_tm ? &check : tm);
383 time_t specified;
385 r->tm_mon = month - 1;
386 r->tm_mday = day;
387 if (year == -1) {
388 if (!now_tm)
389 return 1;
390 r->tm_year = now_tm->tm_year;
392 else if (year >= 1970 && year < 2100)
393 r->tm_year = year - 1900;
394 else if (year > 70 && year < 100)
395 r->tm_year = year;
396 else if (year < 38)
397 r->tm_year = year + 100;
398 else
399 return 0;
400 if (!now_tm)
401 return 1;
403 specified = tm_to_time_t(r);
405 /* Be it commit time or author time, it does not make
406 * sense to specify timestamp way into the future. Make
407 * sure it is not later than ten days from now...
409 if ((specified != -1) && (now + 10*24*3600 < specified))
410 return 0;
411 tm->tm_mon = r->tm_mon;
412 tm->tm_mday = r->tm_mday;
413 if (year != -1)
414 tm->tm_year = r->tm_year;
415 return 1;
417 return 0;
420 static int match_multi_number(unsigned long num, char c, const char *date,
421 char *end, struct tm *tm, time_t now)
423 struct tm now_tm;
424 struct tm *refuse_future;
425 long num2, num3;
427 num2 = strtol(end+1, &end, 10);
428 num3 = -1;
429 if (*end == c && isdigit(end[1]))
430 num3 = strtol(end+1, &end, 10);
432 /* Time? Date? */
433 switch (c) {
434 case ':':
435 if (num3 < 0)
436 num3 = 0;
437 if (num < 25 && num2 >= 0 && num2 < 60 && num3 >= 0 && num3 <= 60) {
438 tm->tm_hour = num;
439 tm->tm_min = num2;
440 tm->tm_sec = num3;
441 break;
443 return 0;
445 case '-':
446 case '/':
447 case '.':
448 if (!now)
449 now = time(NULL);
450 refuse_future = NULL;
451 if (gmtime_r(&now, &now_tm))
452 refuse_future = &now_tm;
454 if (num > 70) {
455 /* yyyy-mm-dd? */
456 if (is_date(num, num2, num3, NULL, now, tm))
457 break;
458 /* yyyy-dd-mm? */
459 if (is_date(num, num3, num2, NULL, now, tm))
460 break;
462 /* Our eastern European friends say dd.mm.yy[yy]
463 * is the norm there, so giving precedence to
464 * mm/dd/yy[yy] form only when separator is not '.'
466 if (c != '.' &&
467 is_date(num3, num, num2, refuse_future, now, tm))
468 break;
469 /* European dd.mm.yy[yy] or funny US dd/mm/yy[yy] */
470 if (is_date(num3, num2, num, refuse_future, now, tm))
471 break;
472 /* Funny European mm.dd.yy */
473 if (c == '.' &&
474 is_date(num3, num, num2, refuse_future, now, tm))
475 break;
476 return 0;
478 return end - date;
482 * Have we filled in any part of the time/date yet?
483 * We just do a binary 'and' to see if the sign bit
484 * is set in all the values.
486 static inline int nodate(struct tm *tm)
488 return (tm->tm_year &
489 tm->tm_mon &
490 tm->tm_mday &
491 tm->tm_hour &
492 tm->tm_min &
493 tm->tm_sec) < 0;
497 * We've seen a digit. Time? Year? Date?
499 static int match_digit(const char *date, struct tm *tm, int *offset, int *tm_gmt)
501 int n;
502 char *end;
503 unsigned long num;
505 num = strtoul(date, &end, 10);
508 * Seconds since 1970? We trigger on that for any numbers with
509 * more than 8 digits. This is because we don't want to rule out
510 * numbers like 20070606 as a YYYYMMDD date.
512 if (num >= 100000000 && nodate(tm)) {
513 time_t time = num;
514 if (gmtime_r(&time, tm)) {
515 *tm_gmt = 1;
516 return end - date;
521 * Check for special formats: num[-.:/]num[same]num
523 switch (*end) {
524 case ':':
525 case '.':
526 case '/':
527 case '-':
528 if (isdigit(end[1])) {
529 int match = match_multi_number(num, *end, date, end, tm, 0);
530 if (match)
531 return match;
536 * None of the special formats? Try to guess what
537 * the number meant. We use the number of digits
538 * to make a more educated guess..
540 n = 0;
541 do {
542 n++;
543 } while (isdigit(date[n]));
545 /* Four-digit year or a timezone? */
546 if (n == 4) {
547 if (num <= 1400 && *offset == -1) {
548 unsigned int minutes = num % 100;
549 unsigned int hours = num / 100;
550 *offset = hours*60 + minutes;
551 } else if (num > 1900 && num < 2100)
552 tm->tm_year = num - 1900;
553 return n;
557 * Ignore lots of numerals. We took care of 4-digit years above.
558 * Days or months must be one or two digits.
560 if (n > 2)
561 return n;
564 * NOTE! We will give precedence to day-of-month over month or
565 * year numbers in the 1-12 range. So 05 is always "mday 5",
566 * unless we already have a mday..
568 * IOW, 01 Apr 05 parses as "April 1st, 2005".
570 if (num > 0 && num < 32 && tm->tm_mday < 0) {
571 tm->tm_mday = num;
572 return n;
575 /* Two-digit year? */
576 if (n == 2 && tm->tm_year < 0) {
577 if (num < 10 && tm->tm_mday >= 0) {
578 tm->tm_year = num + 100;
579 return n;
581 if (num >= 70) {
582 tm->tm_year = num;
583 return n;
587 if (num > 0 && num < 13 && tm->tm_mon < 0)
588 tm->tm_mon = num-1;
590 return n;
593 static int match_tz(const char *date, int *offp)
595 char *end;
596 int hour = strtoul(date + 1, &end, 10);
597 int n = end - (date + 1);
598 int min = 0;
600 if (n == 4) {
601 /* hhmm */
602 min = hour % 100;
603 hour = hour / 100;
604 } else if (n != 2) {
605 min = 99; /* random crap */
606 } else if (*end == ':') {
607 /* hh:mm? */
608 min = strtoul(end + 1, &end, 10);
609 if (end - (date + 1) != 5)
610 min = 99; /* random crap */
611 } /* otherwise we parsed "hh" */
614 * Don't accept any random crap. Even though some places have
615 * offset larger than 12 hours (e.g. Pacific/Kiritimati is at
616 * UTC+14), there is something wrong if hour part is much
617 * larger than that. We might also want to check that the
618 * minutes are divisible by 15 or something too. (Offset of
619 * Kathmandu, Nepal is UTC+5:45)
621 if (min < 60 && hour < 24) {
622 int offset = hour * 60 + min;
623 if (*date == '-')
624 offset = -offset;
625 *offp = offset;
627 return end - date;
630 static void date_string(unsigned long date, int offset, struct strbuf *buf)
632 int sign = '+';
634 if (offset < 0) {
635 offset = -offset;
636 sign = '-';
638 strbuf_addf(buf, "%lu %c%02d%02d", date, sign, offset / 60, offset % 60);
642 * Parse a string like "0 +0000" as ancient timestamp near epoch, but
643 * only when it appears not as part of any other string.
645 static int match_object_header_date(const char *date, unsigned long *timestamp, int *offset)
647 char *end;
648 unsigned long stamp;
649 int ofs;
651 if (*date < '0' || '9' < *date)
652 return -1;
653 stamp = strtoul(date, &end, 10);
654 if (*end != ' ' || stamp == ULONG_MAX || (end[1] != '+' && end[1] != '-'))
655 return -1;
656 date = end + 2;
657 ofs = strtol(date, &end, 10);
658 if ((*end != '\0' && (*end != '\n')) || end != date + 4)
659 return -1;
660 ofs = (ofs / 100) * 60 + (ofs % 100);
661 if (date[-1] == '-')
662 ofs = -ofs;
663 *timestamp = stamp;
664 *offset = ofs;
665 return 0;
668 /* Gr. strptime is crap for this; it doesn't have a way to require RFC2822
669 (i.e. English) day/month names, and it doesn't work correctly with %z. */
670 int parse_date_basic(const char *date, unsigned long *timestamp, int *offset)
672 struct tm tm;
673 int tm_gmt;
674 unsigned long dummy_timestamp;
675 int dummy_offset;
677 if (!timestamp)
678 timestamp = &dummy_timestamp;
679 if (!offset)
680 offset = &dummy_offset;
682 memset(&tm, 0, sizeof(tm));
683 tm.tm_year = -1;
684 tm.tm_mon = -1;
685 tm.tm_mday = -1;
686 tm.tm_isdst = -1;
687 tm.tm_hour = -1;
688 tm.tm_min = -1;
689 tm.tm_sec = -1;
690 *offset = -1;
691 tm_gmt = 0;
693 if (*date == '@' &&
694 !match_object_header_date(date + 1, timestamp, offset))
695 return 0; /* success */
696 for (;;) {
697 int match = 0;
698 unsigned char c = *date;
700 /* Stop at end of string or newline */
701 if (!c || c == '\n')
702 break;
704 if (isalpha(c))
705 match = match_alpha(date, &tm, offset);
706 else if (isdigit(c))
707 match = match_digit(date, &tm, offset, &tm_gmt);
708 else if ((c == '-' || c == '+') && isdigit(date[1]))
709 match = match_tz(date, offset);
711 if (!match) {
712 /* BAD CRAP */
713 match = 1;
716 date += match;
719 /* do not use mktime(), which uses local timezone, here */
720 *timestamp = tm_to_time_t(&tm);
721 if (*timestamp == -1)
722 return -1;
724 if (*offset == -1) {
725 time_t temp_time;
727 /* gmtime_r() in match_digit() may have clobbered it */
728 tm.tm_isdst = -1;
729 temp_time = mktime(&tm);
730 if ((time_t)*timestamp > temp_time) {
731 *offset = ((time_t)*timestamp - temp_time) / 60;
732 } else {
733 *offset = -(int)((temp_time - (time_t)*timestamp) / 60);
737 if (!tm_gmt)
738 *timestamp -= *offset * 60;
739 return 0; /* success */
742 int parse_expiry_date(const char *date, unsigned long *timestamp)
744 int errors = 0;
746 if (!strcmp(date, "never") || !strcmp(date, "false"))
747 *timestamp = 0;
748 else if (!strcmp(date, "all") || !strcmp(date, "now"))
750 * We take over "now" here, which usually translates
751 * to the current timestamp. This is because the user
752 * really means to expire everything she has done in
753 * the past, and by definition reflogs are the record
754 * of the past, and there is nothing from the future
755 * to be kept.
757 *timestamp = ULONG_MAX;
758 else
759 *timestamp = approxidate_careful(date, &errors);
761 return errors;
764 int parse_date(const char *date, struct strbuf *result)
766 unsigned long timestamp;
767 int offset;
768 if (parse_date_basic(date, &timestamp, &offset))
769 return -1;
770 date_string(timestamp, offset, result);
771 return 0;
774 static enum date_mode_type parse_date_type(const char *format, const char **end)
776 if (skip_prefix(format, "relative", end))
777 return DATE_RELATIVE;
778 if (skip_prefix(format, "iso8601-strict", end) ||
779 skip_prefix(format, "iso-strict", end))
780 return DATE_ISO8601_STRICT;
781 if (skip_prefix(format, "iso8601", end) ||
782 skip_prefix(format, "iso", end))
783 return DATE_ISO8601;
784 if (skip_prefix(format, "rfc2822", end) ||
785 skip_prefix(format, "rfc", end))
786 return DATE_RFC2822;
787 if (skip_prefix(format, "short", end))
788 return DATE_SHORT;
789 if (skip_prefix(format, "default", end))
790 return DATE_NORMAL;
791 if (skip_prefix(format, "raw", end))
792 return DATE_RAW;
793 if (skip_prefix(format, "format", end))
794 return DATE_STRFTIME;
796 die("unknown date format %s", format);
799 void parse_date_format(const char *format, struct date_mode *mode)
801 const char *p;
803 /* historical alias */
804 if (!strcmp(format, "local"))
805 format = "default-local";
807 mode->type = parse_date_type(format, &p);
808 mode->local = 0;
810 if (skip_prefix(p, "-local", &p))
811 mode->local = 1;
813 if (mode->type == DATE_STRFTIME) {
814 if (!skip_prefix(p, ":", &p))
815 die("date format missing colon separator: %s", format);
816 mode->strftime_fmt = xstrdup(p);
817 } else if (*p)
818 die("unknown date format %s", format);
821 void datestamp(struct strbuf *out)
823 time_t now;
824 int offset;
826 time(&now);
828 offset = tm_to_time_t(localtime(&now)) - now;
829 offset /= 60;
831 date_string(now, offset, out);
835 * Relative time update (eg "2 days ago"). If we haven't set the time
836 * yet, we need to set it from current time.
838 static unsigned long update_tm(struct tm *tm, struct tm *now, unsigned long sec)
840 time_t n;
842 if (tm->tm_mday < 0)
843 tm->tm_mday = now->tm_mday;
844 if (tm->tm_mon < 0)
845 tm->tm_mon = now->tm_mon;
846 if (tm->tm_year < 0) {
847 tm->tm_year = now->tm_year;
848 if (tm->tm_mon > now->tm_mon)
849 tm->tm_year--;
852 n = mktime(tm) - sec;
853 localtime_r(&n, tm);
854 return n;
857 static void date_now(struct tm *tm, struct tm *now, int *num)
859 update_tm(tm, now, 0);
862 static void date_yesterday(struct tm *tm, struct tm *now, int *num)
864 update_tm(tm, now, 24*60*60);
867 static void date_time(struct tm *tm, struct tm *now, int hour)
869 if (tm->tm_hour < hour)
870 date_yesterday(tm, now, NULL);
871 tm->tm_hour = hour;
872 tm->tm_min = 0;
873 tm->tm_sec = 0;
876 static void date_midnight(struct tm *tm, struct tm *now, int *num)
878 date_time(tm, now, 0);
881 static void date_noon(struct tm *tm, struct tm *now, int *num)
883 date_time(tm, now, 12);
886 static void date_tea(struct tm *tm, struct tm *now, int *num)
888 date_time(tm, now, 17);
891 static void date_pm(struct tm *tm, struct tm *now, int *num)
893 int hour, n = *num;
894 *num = 0;
896 hour = tm->tm_hour;
897 if (n) {
898 hour = n;
899 tm->tm_min = 0;
900 tm->tm_sec = 0;
902 tm->tm_hour = (hour % 12) + 12;
905 static void date_am(struct tm *tm, struct tm *now, int *num)
907 int hour, n = *num;
908 *num = 0;
910 hour = tm->tm_hour;
911 if (n) {
912 hour = n;
913 tm->tm_min = 0;
914 tm->tm_sec = 0;
916 tm->tm_hour = (hour % 12);
919 static void date_never(struct tm *tm, struct tm *now, int *num)
921 time_t n = 0;
922 localtime_r(&n, tm);
925 static const struct special {
926 const char *name;
927 void (*fn)(struct tm *, struct tm *, int *);
928 } special[] = {
929 { "yesterday", date_yesterday },
930 { "noon", date_noon },
931 { "midnight", date_midnight },
932 { "tea", date_tea },
933 { "PM", date_pm },
934 { "AM", date_am },
935 { "never", date_never },
936 { "now", date_now },
937 { NULL }
940 static const char *number_name[] = {
941 "zero", "one", "two", "three", "four",
942 "five", "six", "seven", "eight", "nine", "ten",
945 static const struct typelen {
946 const char *type;
947 int length;
948 } typelen[] = {
949 { "seconds", 1 },
950 { "minutes", 60 },
951 { "hours", 60*60 },
952 { "days", 24*60*60 },
953 { "weeks", 7*24*60*60 },
954 { NULL }
957 static const char *approxidate_alpha(const char *date, struct tm *tm, struct tm *now, int *num, int *touched)
959 const struct typelen *tl;
960 const struct special *s;
961 const char *end = date;
962 int i;
964 while (isalpha(*++end))
967 for (i = 0; i < 12; i++) {
968 int match = match_string(date, month_names[i]);
969 if (match >= 3) {
970 tm->tm_mon = i;
971 *touched = 1;
972 return end;
976 for (s = special; s->name; s++) {
977 int len = strlen(s->name);
978 if (match_string(date, s->name) == len) {
979 s->fn(tm, now, num);
980 *touched = 1;
981 return end;
985 if (!*num) {
986 for (i = 1; i < 11; i++) {
987 int len = strlen(number_name[i]);
988 if (match_string(date, number_name[i]) == len) {
989 *num = i;
990 *touched = 1;
991 return end;
994 if (match_string(date, "last") == 4) {
995 *num = 1;
996 *touched = 1;
998 return end;
1001 tl = typelen;
1002 while (tl->type) {
1003 int len = strlen(tl->type);
1004 if (match_string(date, tl->type) >= len-1) {
1005 update_tm(tm, now, tl->length * *num);
1006 *num = 0;
1007 *touched = 1;
1008 return end;
1010 tl++;
1013 for (i = 0; i < 7; i++) {
1014 int match = match_string(date, weekday_names[i]);
1015 if (match >= 3) {
1016 int diff, n = *num -1;
1017 *num = 0;
1019 diff = tm->tm_wday - i;
1020 if (diff <= 0)
1021 n++;
1022 diff += 7*n;
1024 update_tm(tm, now, diff * 24 * 60 * 60);
1025 *touched = 1;
1026 return end;
1030 if (match_string(date, "months") >= 5) {
1031 int n;
1032 update_tm(tm, now, 0); /* fill in date fields if needed */
1033 n = tm->tm_mon - *num;
1034 *num = 0;
1035 while (n < 0) {
1036 n += 12;
1037 tm->tm_year--;
1039 tm->tm_mon = n;
1040 *touched = 1;
1041 return end;
1044 if (match_string(date, "years") >= 4) {
1045 update_tm(tm, now, 0); /* fill in date fields if needed */
1046 tm->tm_year -= *num;
1047 *num = 0;
1048 *touched = 1;
1049 return end;
1052 return end;
1055 static const char *approxidate_digit(const char *date, struct tm *tm, int *num,
1056 time_t now)
1058 char *end;
1059 unsigned long number = strtoul(date, &end, 10);
1061 switch (*end) {
1062 case ':':
1063 case '.':
1064 case '/':
1065 case '-':
1066 if (isdigit(end[1])) {
1067 int match = match_multi_number(number, *end, date, end,
1068 tm, now);
1069 if (match)
1070 return date + match;
1074 /* Accept zero-padding only for small numbers ("Dec 02", never "Dec 0002") */
1075 if (date[0] != '0' || end - date <= 2)
1076 *num = number;
1077 return end;
1081 * Do we have a pending number at the end, or when
1082 * we see a new one? Let's assume it's a month day,
1083 * as in "Dec 6, 1992"
1085 static void pending_number(struct tm *tm, int *num)
1087 int number = *num;
1089 if (number) {
1090 *num = 0;
1091 if (tm->tm_mday < 0 && number < 32)
1092 tm->tm_mday = number;
1093 else if (tm->tm_mon < 0 && number < 13)
1094 tm->tm_mon = number-1;
1095 else if (tm->tm_year < 0) {
1096 if (number > 1969 && number < 2100)
1097 tm->tm_year = number - 1900;
1098 else if (number > 69 && number < 100)
1099 tm->tm_year = number;
1100 else if (number < 38)
1101 tm->tm_year = 100 + number;
1102 /* We screw up for number = 00 ? */
1107 static unsigned long approxidate_str(const char *date,
1108 const struct timeval *tv,
1109 int *error_ret)
1111 int number = 0;
1112 int touched = 0;
1113 struct tm tm, now;
1114 time_t time_sec;
1116 time_sec = tv->tv_sec;
1117 localtime_r(&time_sec, &tm);
1118 now = tm;
1120 tm.tm_year = -1;
1121 tm.tm_mon = -1;
1122 tm.tm_mday = -1;
1124 for (;;) {
1125 unsigned char c = *date;
1126 if (!c)
1127 break;
1128 date++;
1129 if (isdigit(c)) {
1130 pending_number(&tm, &number);
1131 date = approxidate_digit(date-1, &tm, &number, time_sec);
1132 touched = 1;
1133 continue;
1135 if (isalpha(c))
1136 date = approxidate_alpha(date-1, &tm, &now, &number, &touched);
1138 pending_number(&tm, &number);
1139 if (!touched)
1140 *error_ret = 1;
1141 return update_tm(&tm, &now, 0);
1144 unsigned long approxidate_relative(const char *date, const struct timeval *tv)
1146 unsigned long timestamp;
1147 int offset;
1148 int errors = 0;
1150 if (!parse_date_basic(date, &timestamp, &offset))
1151 return timestamp;
1152 return approxidate_str(date, tv, &errors);
1155 unsigned long approxidate_careful(const char *date, int *error_ret)
1157 struct timeval tv;
1158 unsigned long timestamp;
1159 int offset;
1160 int dummy = 0;
1161 if (!error_ret)
1162 error_ret = &dummy;
1164 if (!parse_date_basic(date, &timestamp, &offset)) {
1165 *error_ret = 0;
1166 return timestamp;
1169 gettimeofday(&tv, NULL);
1170 return approxidate_str(date, &tv, error_ret);
1173 int date_overflows(unsigned long t)
1175 time_t sys;
1177 /* If we overflowed our unsigned long, that's bad... */
1178 if (t == ULONG_MAX)
1179 return 1;
1182 * ...but we also are going to feed the result to system
1183 * functions that expect time_t, which is often "signed long".
1184 * Make sure that we fit into time_t, as well.
1186 sys = t;
1187 return t != sys || (t < 1) != (sys < 1);