Merge git://git.kernel.org/pub/scm/gitk/gitk
[git/git.git] / date.c
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 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 return (year * 365 + (year + 1) / 4 + mdays[month] + day) * 24*60*60UL +
28 tm->tm_hour * 60*60 + tm->tm_min * 60 + tm->tm_sec;
29 }
30
31 static const char *month_names[] = {
32 "January", "February", "March", "April", "May", "June",
33 "July", "August", "September", "October", "November", "December"
34 };
35
36 static const char *weekday_names[] = {
37 "Sundays", "Mondays", "Tuesdays", "Wednesdays", "Thursdays", "Fridays", "Saturdays"
38 };
39
40 static time_t gm_time_t(unsigned long time, int tz)
41 {
42 int minutes;
43
44 minutes = tz < 0 ? -tz : tz;
45 minutes = (minutes / 100)*60 + (minutes % 100);
46 minutes = tz < 0 ? -minutes : minutes;
47 return time + minutes * 60;
48 }
49
50 /*
51 * The "tz" thing is passed in as this strange "decimal parse of tz"
52 * thing, which means that tz -0100 is passed in as the integer -100,
53 * even though it means "sixty minutes off"
54 */
55 static struct tm *time_to_tm(unsigned long time, int tz)
56 {
57 time_t t = gm_time_t(time, tz);
58 return gmtime(&t);
59 }
60
61 /*
62 * What value of "tz" was in effect back then at "time" in the
63 * local timezone?
64 */
65 static int local_tzoffset(unsigned long time)
66 {
67 time_t t, t_local;
68 struct tm tm;
69 int offset, eastwest;
70
71 t = time;
72 localtime_r(&t, &tm);
73 t_local = tm_to_time_t(&tm);
74
75 if (t_local < t) {
76 eastwest = -1;
77 offset = t - t_local;
78 } else {
79 eastwest = 1;
80 offset = t_local - t;
81 }
82 offset /= 60; /* in minutes */
83 offset = (offset % 60) + ((offset / 60) * 100);
84 return offset * eastwest;
85 }
86
87 const char *show_date(unsigned long time, int tz, enum date_mode mode)
88 {
89 struct tm *tm;
90 static char timebuf[200];
91
92 if (mode == DATE_RAW) {
93 snprintf(timebuf, sizeof(timebuf), "%lu %+05d", time, tz);
94 return timebuf;
95 }
96
97 if (mode == DATE_RELATIVE) {
98 unsigned long diff;
99 struct timeval now;
100 gettimeofday(&now, NULL);
101 if (now.tv_sec < time)
102 return "in the future";
103 diff = now.tv_sec - time;
104 if (diff < 90) {
105 snprintf(timebuf, sizeof(timebuf), "%lu seconds ago", diff);
106 return timebuf;
107 }
108 /* Turn it into minutes */
109 diff = (diff + 30) / 60;
110 if (diff < 90) {
111 snprintf(timebuf, sizeof(timebuf), "%lu minutes ago", diff);
112 return timebuf;
113 }
114 /* Turn it into hours */
115 diff = (diff + 30) / 60;
116 if (diff < 36) {
117 snprintf(timebuf, sizeof(timebuf), "%lu hours ago", diff);
118 return timebuf;
119 }
120 /* We deal with number of days from here on */
121 diff = (diff + 12) / 24;
122 if (diff < 14) {
123 snprintf(timebuf, sizeof(timebuf), "%lu days ago", diff);
124 return timebuf;
125 }
126 /* Say weeks for the past 10 weeks or so */
127 if (diff < 70) {
128 snprintf(timebuf, sizeof(timebuf), "%lu weeks ago", (diff + 3) / 7);
129 return timebuf;
130 }
131 /* Say months for the past 12 months or so */
132 if (diff < 360) {
133 snprintf(timebuf, sizeof(timebuf), "%lu months ago", (diff + 15) / 30);
134 return timebuf;
135 }
136 /* Give years and months for 5 years or so */
137 if (diff < 1825) {
138 unsigned long years = (diff + 183) / 365;
139 unsigned long months = (diff % 365 + 15) / 30;
140 int n;
141 n = snprintf(timebuf, sizeof(timebuf), "%lu year%s",
142 years, (years > 1 ? "s" : ""));
143 if (months)
144 snprintf(timebuf + n, sizeof(timebuf) - n,
145 ", %lu month%s ago",
146 months, (months > 1 ? "s" : ""));
147 else
148 snprintf(timebuf + n, sizeof(timebuf) - n,
149 " ago");
150 return timebuf;
151 }
152 /* Otherwise, just years. Centuries is probably overkill. */
153 snprintf(timebuf, sizeof(timebuf), "%lu years ago", (diff + 183) / 365);
154 return timebuf;
155 }
156
157 if (mode == DATE_LOCAL)
158 tz = local_tzoffset(time);
159
160 tm = time_to_tm(time, tz);
161 if (!tm)
162 return NULL;
163 if (mode == DATE_SHORT)
164 sprintf(timebuf, "%04d-%02d-%02d", tm->tm_year + 1900,
165 tm->tm_mon + 1, tm->tm_mday);
166 else if (mode == DATE_ISO8601)
167 sprintf(timebuf, "%04d-%02d-%02d %02d:%02d:%02d %+05d",
168 tm->tm_year + 1900,
169 tm->tm_mon + 1,
170 tm->tm_mday,
171 tm->tm_hour, tm->tm_min, tm->tm_sec,
172 tz);
173 else if (mode == DATE_RFC2822)
174 sprintf(timebuf, "%.3s, %d %.3s %d %02d:%02d:%02d %+05d",
175 weekday_names[tm->tm_wday], tm->tm_mday,
176 month_names[tm->tm_mon], tm->tm_year + 1900,
177 tm->tm_hour, tm->tm_min, tm->tm_sec, tz);
178 else
179 sprintf(timebuf, "%.3s %.3s %d %02d:%02d:%02d %d%c%+05d",
180 weekday_names[tm->tm_wday],
181 month_names[tm->tm_mon],
182 tm->tm_mday,
183 tm->tm_hour, tm->tm_min, tm->tm_sec,
184 tm->tm_year + 1900,
185 (mode == DATE_LOCAL) ? 0 : ' ',
186 tz);
187 return timebuf;
188 }
189
190 /*
191 * Check these. And note how it doesn't do the summer-time conversion.
192 *
193 * In my world, it's always summer, and things are probably a bit off
194 * in other ways too.
195 */
196 static const struct {
197 const char *name;
198 int offset;
199 int dst;
200 } timezone_names[] = {
201 { "IDLW", -12, 0, }, /* International Date Line West */
202 { "NT", -11, 0, }, /* Nome */
203 { "CAT", -10, 0, }, /* Central Alaska */
204 { "HST", -10, 0, }, /* Hawaii Standard */
205 { "HDT", -10, 1, }, /* Hawaii Daylight */
206 { "YST", -9, 0, }, /* Yukon Standard */
207 { "YDT", -9, 1, }, /* Yukon Daylight */
208 { "PST", -8, 0, }, /* Pacific Standard */
209 { "PDT", -8, 1, }, /* Pacific Daylight */
210 { "MST", -7, 0, }, /* Mountain Standard */
211 { "MDT", -7, 1, }, /* Mountain Daylight */
212 { "CST", -6, 0, }, /* Central Standard */
213 { "CDT", -6, 1, }, /* Central Daylight */
214 { "EST", -5, 0, }, /* Eastern Standard */
215 { "EDT", -5, 1, }, /* Eastern Daylight */
216 { "AST", -3, 0, }, /* Atlantic Standard */
217 { "ADT", -3, 1, }, /* Atlantic Daylight */
218 { "WAT", -1, 0, }, /* West Africa */
219
220 { "GMT", 0, 0, }, /* Greenwich Mean */
221 { "UTC", 0, 0, }, /* Universal (Coordinated) */
222
223 { "WET", 0, 0, }, /* Western European */
224 { "BST", 0, 1, }, /* British Summer */
225 { "CET", +1, 0, }, /* Central European */
226 { "MET", +1, 0, }, /* Middle European */
227 { "MEWT", +1, 0, }, /* Middle European Winter */
228 { "MEST", +1, 1, }, /* Middle European Summer */
229 { "CEST", +1, 1, }, /* Central European Summer */
230 { "MESZ", +1, 1, }, /* Middle European Summer */
231 { "FWT", +1, 0, }, /* French Winter */
232 { "FST", +1, 1, }, /* French Summer */
233 { "EET", +2, 0, }, /* Eastern Europe, USSR Zone 1 */
234 { "EEST", +2, 1, }, /* Eastern European Daylight */
235 { "WAST", +7, 0, }, /* West Australian Standard */
236 { "WADT", +7, 1, }, /* West Australian Daylight */
237 { "CCT", +8, 0, }, /* China Coast, USSR Zone 7 */
238 { "JST", +9, 0, }, /* Japan Standard, USSR Zone 8 */
239 { "EAST", +10, 0, }, /* Eastern Australian Standard */
240 { "EADT", +10, 1, }, /* Eastern Australian Daylight */
241 { "GST", +10, 0, }, /* Guam Standard, USSR Zone 9 */
242 { "NZT", +12, 0, }, /* New Zealand */
243 { "NZST", +12, 0, }, /* New Zealand Standard */
244 { "NZDT", +12, 1, }, /* New Zealand Daylight */
245 { "IDLE", +12, 0, }, /* International Date Line East */
246 };
247
248 static int match_string(const char *date, const char *str)
249 {
250 int i = 0;
251
252 for (i = 0; *date; date++, str++, i++) {
253 if (*date == *str)
254 continue;
255 if (toupper(*date) == toupper(*str))
256 continue;
257 if (!isalnum(*date))
258 break;
259 return 0;
260 }
261 return i;
262 }
263
264 static int skip_alpha(const char *date)
265 {
266 int i = 0;
267 do {
268 i++;
269 } while (isalpha(date[i]));
270 return i;
271 }
272
273 /*
274 * Parse month, weekday, or timezone name
275 */
276 static int match_alpha(const char *date, struct tm *tm, int *offset)
277 {
278 int i;
279
280 for (i = 0; i < 12; i++) {
281 int match = match_string(date, month_names[i]);
282 if (match >= 3) {
283 tm->tm_mon = i;
284 return match;
285 }
286 }
287
288 for (i = 0; i < 7; i++) {
289 int match = match_string(date, weekday_names[i]);
290 if (match >= 3) {
291 tm->tm_wday = i;
292 return match;
293 }
294 }
295
296 for (i = 0; i < ARRAY_SIZE(timezone_names); i++) {
297 int match = match_string(date, timezone_names[i].name);
298 if (match >= 3) {
299 int off = timezone_names[i].offset;
300
301 /* This is bogus, but we like summer */
302 off += timezone_names[i].dst;
303
304 /* Only use the tz name offset if we don't have anything better */
305 if (*offset == -1)
306 *offset = 60*off;
307
308 return match;
309 }
310 }
311
312 if (match_string(date, "PM") == 2) {
313 tm->tm_hour = (tm->tm_hour % 12) + 12;
314 return 2;
315 }
316
317 if (match_string(date, "AM") == 2) {
318 tm->tm_hour = (tm->tm_hour % 12) + 0;
319 return 2;
320 }
321
322 /* BAD CRAP */
323 return skip_alpha(date);
324 }
325
326 static int is_date(int year, int month, int day, struct tm *now_tm, time_t now, struct tm *tm)
327 {
328 if (month > 0 && month < 13 && day > 0 && day < 32) {
329 struct tm check = *tm;
330 struct tm *r = (now_tm ? &check : tm);
331 time_t specified;
332
333 r->tm_mon = month - 1;
334 r->tm_mday = day;
335 if (year == -1) {
336 if (!now_tm)
337 return 1;
338 r->tm_year = now_tm->tm_year;
339 }
340 else if (year >= 1970 && year < 2100)
341 r->tm_year = year - 1900;
342 else if (year > 70 && year < 100)
343 r->tm_year = year;
344 else if (year < 38)
345 r->tm_year = year + 100;
346 else
347 return 0;
348 if (!now_tm)
349 return 1;
350
351 specified = tm_to_time_t(r);
352
353 /* Be it commit time or author time, it does not make
354 * sense to specify timestamp way into the future. Make
355 * sure it is not later than ten days from now...
356 */
357 if (now + 10*24*3600 < specified)
358 return 0;
359 tm->tm_mon = r->tm_mon;
360 tm->tm_mday = r->tm_mday;
361 if (year != -1)
362 tm->tm_year = r->tm_year;
363 return 1;
364 }
365 return 0;
366 }
367
368 static int match_multi_number(unsigned long num, char c, const char *date, char *end, struct tm *tm)
369 {
370 time_t now;
371 struct tm now_tm;
372 struct tm *refuse_future;
373 long num2, num3;
374
375 num2 = strtol(end+1, &end, 10);
376 num3 = -1;
377 if (*end == c && isdigit(end[1]))
378 num3 = strtol(end+1, &end, 10);
379
380 /* Time? Date? */
381 switch (c) {
382 case ':':
383 if (num3 < 0)
384 num3 = 0;
385 if (num < 25 && num2 >= 0 && num2 < 60 && num3 >= 0 && num3 <= 60) {
386 tm->tm_hour = num;
387 tm->tm_min = num2;
388 tm->tm_sec = num3;
389 break;
390 }
391 return 0;
392
393 case '-':
394 case '/':
395 case '.':
396 now = time(NULL);
397 refuse_future = NULL;
398 if (gmtime_r(&now, &now_tm))
399 refuse_future = &now_tm;
400
401 if (num > 70) {
402 /* yyyy-mm-dd? */
403 if (is_date(num, num2, num3, refuse_future, now, tm))
404 break;
405 /* yyyy-dd-mm? */
406 if (is_date(num, num3, num2, refuse_future, now, tm))
407 break;
408 }
409 /* Our eastern European friends say dd.mm.yy[yy]
410 * is the norm there, so giving precedence to
411 * mm/dd/yy[yy] form only when separator is not '.'
412 */
413 if (c != '.' &&
414 is_date(num3, num, num2, refuse_future, now, tm))
415 break;
416 /* European dd.mm.yy[yy] or funny US dd/mm/yy[yy] */
417 if (is_date(num3, num2, num, refuse_future, now, tm))
418 break;
419 /* Funny European mm.dd.yy */
420 if (c == '.' &&
421 is_date(num3, num, num2, refuse_future, now, tm))
422 break;
423 return 0;
424 }
425 return end - date;
426 }
427
428 /* Have we filled in any part of the time/date yet? */
429 static inline int nodate(struct tm *tm)
430 {
431 return tm->tm_year < 0 &&
432 tm->tm_mon < 0 &&
433 tm->tm_mday < 0 &&
434 !(tm->tm_hour | tm->tm_min | tm->tm_sec);
435 }
436
437 /*
438 * We've seen a digit. Time? Year? Date?
439 */
440 static int match_digit(const char *date, struct tm *tm, int *offset, int *tm_gmt)
441 {
442 int n;
443 char *end;
444 unsigned long num;
445
446 num = strtoul(date, &end, 10);
447
448 /*
449 * Seconds since 1970? We trigger on that for any numbers with
450 * more than 8 digits. This is because we don't want to rule out
451 * numbers like 20070606 as a YYYYMMDD date.
452 */
453 if (num >= 100000000 && nodate(tm)) {
454 time_t time = num;
455 if (gmtime_r(&time, tm)) {
456 *tm_gmt = 1;
457 return end - date;
458 }
459 }
460
461 /*
462 * Check for special formats: num[-.:/]num[same]num
463 */
464 switch (*end) {
465 case ':':
466 case '.':
467 case '/':
468 case '-':
469 if (isdigit(end[1])) {
470 int match = match_multi_number(num, *end, date, end, tm);
471 if (match)
472 return match;
473 }
474 }
475
476 /*
477 * None of the special formats? Try to guess what
478 * the number meant. We use the number of digits
479 * to make a more educated guess..
480 */
481 n = 0;
482 do {
483 n++;
484 } while (isdigit(date[n]));
485
486 /* Four-digit year or a timezone? */
487 if (n == 4) {
488 if (num <= 1400 && *offset == -1) {
489 unsigned int minutes = num % 100;
490 unsigned int hours = num / 100;
491 *offset = hours*60 + minutes;
492 } else if (num > 1900 && num < 2100)
493 tm->tm_year = num - 1900;
494 return n;
495 }
496
497 /*
498 * Ignore lots of numerals. We took care of 4-digit years above.
499 * Days or months must be one or two digits.
500 */
501 if (n > 2)
502 return n;
503
504 /*
505 * NOTE! We will give precedence to day-of-month over month or
506 * year numbers in the 1-12 range. So 05 is always "mday 5",
507 * unless we already have a mday..
508 *
509 * IOW, 01 Apr 05 parses as "April 1st, 2005".
510 */
511 if (num > 0 && num < 32 && tm->tm_mday < 0) {
512 tm->tm_mday = num;
513 return n;
514 }
515
516 /* Two-digit year? */
517 if (n == 2 && tm->tm_year < 0) {
518 if (num < 10 && tm->tm_mday >= 0) {
519 tm->tm_year = num + 100;
520 return n;
521 }
522 if (num >= 70) {
523 tm->tm_year = num;
524 return n;
525 }
526 }
527
528 if (num > 0 && num < 32) {
529 tm->tm_mday = num;
530 } else if (num > 0 && num < 13) {
531 tm->tm_mon = num-1;
532 }
533
534 return n;
535 }
536
537 static int match_tz(const char *date, int *offp)
538 {
539 char *end;
540 int offset = strtoul(date+1, &end, 10);
541 int min, hour;
542 int n = end - date - 1;
543
544 min = offset % 100;
545 hour = offset / 100;
546
547 /*
548 * Don't accept any random crap.. At least 3 digits, and
549 * a valid minute. We might want to check that the minutes
550 * are divisible by 30 or something too.
551 */
552 if (min < 60 && n > 2) {
553 offset = hour*60+min;
554 if (*date == '-')
555 offset = -offset;
556
557 *offp = offset;
558 }
559 return end - date;
560 }
561
562 static int date_string(unsigned long date, int offset, char *buf, int len)
563 {
564 int sign = '+';
565
566 if (offset < 0) {
567 offset = -offset;
568 sign = '-';
569 }
570 return snprintf(buf, len, "%lu %c%02d%02d", date, sign, offset / 60, offset % 60);
571 }
572
573 /* Gr. strptime is crap for this; it doesn't have a way to require RFC2822
574 (i.e. English) day/month names, and it doesn't work correctly with %z. */
575 int parse_date(const char *date, char *result, int maxlen)
576 {
577 struct tm tm;
578 int offset, tm_gmt;
579 time_t then;
580
581 memset(&tm, 0, sizeof(tm));
582 tm.tm_year = -1;
583 tm.tm_mon = -1;
584 tm.tm_mday = -1;
585 tm.tm_isdst = -1;
586 offset = -1;
587 tm_gmt = 0;
588
589 for (;;) {
590 int match = 0;
591 unsigned char c = *date;
592
593 /* Stop at end of string or newline */
594 if (!c || c == '\n')
595 break;
596
597 if (isalpha(c))
598 match = match_alpha(date, &tm, &offset);
599 else if (isdigit(c))
600 match = match_digit(date, &tm, &offset, &tm_gmt);
601 else if ((c == '-' || c == '+') && isdigit(date[1]))
602 match = match_tz(date, &offset);
603
604 if (!match) {
605 /* BAD CRAP */
606 match = 1;
607 }
608
609 date += match;
610 }
611
612 /* mktime uses local timezone */
613 then = tm_to_time_t(&tm);
614 if (offset == -1)
615 offset = (then - mktime(&tm)) / 60;
616
617 if (then == -1)
618 return -1;
619
620 if (!tm_gmt)
621 then -= offset * 60;
622 return date_string(then, offset, result, maxlen);
623 }
624
625 enum date_mode parse_date_format(const char *format)
626 {
627 if (!strcmp(format, "relative"))
628 return DATE_RELATIVE;
629 else if (!strcmp(format, "iso8601") ||
630 !strcmp(format, "iso"))
631 return DATE_ISO8601;
632 else if (!strcmp(format, "rfc2822") ||
633 !strcmp(format, "rfc"))
634 return DATE_RFC2822;
635 else if (!strcmp(format, "short"))
636 return DATE_SHORT;
637 else if (!strcmp(format, "local"))
638 return DATE_LOCAL;
639 else if (!strcmp(format, "default"))
640 return DATE_NORMAL;
641 else if (!strcmp(format, "raw"))
642 return DATE_RAW;
643 else
644 die("unknown date format %s", format);
645 }
646
647 void datestamp(char *buf, int bufsize)
648 {
649 time_t now;
650 int offset;
651
652 time(&now);
653
654 offset = tm_to_time_t(localtime(&now)) - now;
655 offset /= 60;
656
657 date_string(now, offset, buf, bufsize);
658 }
659
660 static void update_tm(struct tm *tm, unsigned long sec)
661 {
662 time_t n = mktime(tm) - sec;
663 localtime_r(&n, tm);
664 }
665
666 static void date_yesterday(struct tm *tm, int *num)
667 {
668 update_tm(tm, 24*60*60);
669 }
670
671 static void date_time(struct tm *tm, int hour)
672 {
673 if (tm->tm_hour < hour)
674 date_yesterday(tm, NULL);
675 tm->tm_hour = hour;
676 tm->tm_min = 0;
677 tm->tm_sec = 0;
678 }
679
680 static void date_midnight(struct tm *tm, int *num)
681 {
682 date_time(tm, 0);
683 }
684
685 static void date_noon(struct tm *tm, int *num)
686 {
687 date_time(tm, 12);
688 }
689
690 static void date_tea(struct tm *tm, int *num)
691 {
692 date_time(tm, 17);
693 }
694
695 static void date_pm(struct tm *tm, int *num)
696 {
697 int hour, n = *num;
698 *num = 0;
699
700 hour = tm->tm_hour;
701 if (n) {
702 hour = n;
703 tm->tm_min = 0;
704 tm->tm_sec = 0;
705 }
706 tm->tm_hour = (hour % 12) + 12;
707 }
708
709 static void date_am(struct tm *tm, int *num)
710 {
711 int hour, n = *num;
712 *num = 0;
713
714 hour = tm->tm_hour;
715 if (n) {
716 hour = n;
717 tm->tm_min = 0;
718 tm->tm_sec = 0;
719 }
720 tm->tm_hour = (hour % 12);
721 }
722
723 static void date_never(struct tm *tm, int *num)
724 {
725 time_t n = 0;
726 localtime_r(&n, tm);
727 }
728
729 static const struct special {
730 const char *name;
731 void (*fn)(struct tm *, int *);
732 } special[] = {
733 { "yesterday", date_yesterday },
734 { "noon", date_noon },
735 { "midnight", date_midnight },
736 { "tea", date_tea },
737 { "PM", date_pm },
738 { "AM", date_am },
739 { "never", date_never },
740 { NULL }
741 };
742
743 static const char *number_name[] = {
744 "zero", "one", "two", "three", "four",
745 "five", "six", "seven", "eight", "nine", "ten",
746 };
747
748 static const struct typelen {
749 const char *type;
750 int length;
751 } typelen[] = {
752 { "seconds", 1 },
753 { "minutes", 60 },
754 { "hours", 60*60 },
755 { "days", 24*60*60 },
756 { "weeks", 7*24*60*60 },
757 { NULL }
758 };
759
760 static const char *approxidate_alpha(const char *date, struct tm *tm, int *num)
761 {
762 const struct typelen *tl;
763 const struct special *s;
764 const char *end = date;
765 int i;
766
767 while (isalpha(*++end));
768 ;
769
770 for (i = 0; i < 12; i++) {
771 int match = match_string(date, month_names[i]);
772 if (match >= 3) {
773 tm->tm_mon = i;
774 return end;
775 }
776 }
777
778 for (s = special; s->name; s++) {
779 int len = strlen(s->name);
780 if (match_string(date, s->name) == len) {
781 s->fn(tm, num);
782 return end;
783 }
784 }
785
786 if (!*num) {
787 for (i = 1; i < 11; i++) {
788 int len = strlen(number_name[i]);
789 if (match_string(date, number_name[i]) == len) {
790 *num = i;
791 return end;
792 }
793 }
794 if (match_string(date, "last") == 4)
795 *num = 1;
796 return end;
797 }
798
799 tl = typelen;
800 while (tl->type) {
801 int len = strlen(tl->type);
802 if (match_string(date, tl->type) >= len-1) {
803 update_tm(tm, tl->length * *num);
804 *num = 0;
805 return end;
806 }
807 tl++;
808 }
809
810 for (i = 0; i < 7; i++) {
811 int match = match_string(date, weekday_names[i]);
812 if (match >= 3) {
813 int diff, n = *num -1;
814 *num = 0;
815
816 diff = tm->tm_wday - i;
817 if (diff <= 0)
818 n++;
819 diff += 7*n;
820
821 update_tm(tm, diff * 24 * 60 * 60);
822 return end;
823 }
824 }
825
826 if (match_string(date, "months") >= 5) {
827 int n = tm->tm_mon - *num;
828 *num = 0;
829 while (n < 0) {
830 n += 12;
831 tm->tm_year--;
832 }
833 tm->tm_mon = n;
834 return end;
835 }
836
837 if (match_string(date, "years") >= 4) {
838 tm->tm_year -= *num;
839 *num = 0;
840 return end;
841 }
842
843 return end;
844 }
845
846 static const char *approxidate_digit(const char *date, struct tm *tm, int *num)
847 {
848 char *end;
849 unsigned long number = strtoul(date, &end, 10);
850
851 switch (*end) {
852 case ':':
853 case '.':
854 case '/':
855 case '-':
856 if (isdigit(end[1])) {
857 int match = match_multi_number(number, *end, date, end, tm);
858 if (match)
859 return date + match;
860 }
861 }
862
863 /* Accept zero-padding only for small numbers ("Dec 02", never "Dec 0002") */
864 if (date[0] != '0' || end - date <= 2)
865 *num = number;
866 return end;
867 }
868
869 unsigned long approxidate(const char *date)
870 {
871 int number = 0;
872 struct tm tm, now;
873 struct timeval tv;
874 char buffer[50];
875
876 if (parse_date(date, buffer, sizeof(buffer)) > 0)
877 return strtoul(buffer, NULL, 10);
878
879 gettimeofday(&tv, NULL);
880 localtime_r(&tv.tv_sec, &tm);
881 now = tm;
882 for (;;) {
883 unsigned char c = *date;
884 if (!c)
885 break;
886 date++;
887 if (isdigit(c)) {
888 date = approxidate_digit(date-1, &tm, &number);
889 continue;
890 }
891 if (isalpha(c))
892 date = approxidate_alpha(date-1, &tm, &number);
893 }
894 if (number > 0 && number < 32)
895 tm.tm_mday = number;
896 if (tm.tm_mon > now.tm_mon && tm.tm_year == now.tm_year)
897 tm.tm_year--;
898 return mktime(&tm);
899 }