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Merge branch 'rs/code-cleaning'
[git/debian.git] / date.c
blob782de95d90c6ac1a02ddfa0df81ca93ecdf910c4
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(unsigned long 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 return time + minutes * 60;
50 }
51
52 /*
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"
56 */
57 static struct tm *time_to_tm(unsigned long time, int tz)
58 {
59 time_t t = gm_time_t(time, tz);
60 return gmtime(&t);
61 }
62
63 /*
64 * What value of "tz" was in effect back then at "time" in the
65 * local timezone?
66 */
67 static int local_tzoffset(unsigned long time)
68 {
69 time_t t, t_local;
70 struct tm tm;
71 int offset, eastwest;
72
73 t = time;
74 localtime_r(&t, &tm);
75 t_local = tm_to_time_t(&tm);
76
77 if (t_local < t) {
78 eastwest = -1;
79 offset = t - t_local;
80 } else {
81 eastwest = 1;
82 offset = t_local - t;
83 }
84 offset /= 60; /* in minutes */
85 offset = (offset % 60) + ((offset / 60) * 100);
86 return offset * eastwest;
87 }
88
89 void show_date_relative(unsigned long time, int tz,
90 const struct timeval *now,
91 struct strbuf *timebuf)
92 {
93 unsigned long diff;
94 if (now->tv_sec < time) {
95 strbuf_addstr(timebuf, _("in the future"));
96 return;
97 }
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;
103 }
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;
110 }
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;
117 }
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;
124 }
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;
131 }
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;
138 }
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;
156 }
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);
161 }
162
163 const char *show_date(unsigned long time, int tz, enum date_mode mode)
164 {
165 struct tm *tm;
166 static struct strbuf timebuf = STRBUF_INIT;
167
168 if (mode == DATE_RAW) {
169 strbuf_reset(&timebuf);
170 strbuf_addf(&timebuf, "%lu %+05d", time, tz);
171 return timebuf.buf;
172 }
173
174 if (mode == DATE_RELATIVE) {
175 struct timeval now;
176
177 strbuf_reset(&timebuf);
178 gettimeofday(&now, NULL);
179 show_date_relative(time, tz, &now, &timebuf);
180 return timebuf.buf;
181 }
182
183 if (mode == DATE_LOCAL)
184 tz = local_tzoffset(time);
185
186 tm = time_to_tm(time, tz);
187 if (!tm) {
188 tm = time_to_tm(0, 0);
189 tz = 0;
190 }
191
192 strbuf_reset(&timebuf);
193 if (mode == DATE_SHORT)
194 strbuf_addf(&timebuf, "%04d-%02d-%02d", tm->tm_year + 1900,
195 tm->tm_mon + 1, tm->tm_mday);
196 else if (mode == DATE_ISO8601)
197 strbuf_addf(&timebuf, "%04d-%02d-%02d %02d:%02d:%02d %+05d",
198 tm->tm_year + 1900,
199 tm->tm_mon + 1,
200 tm->tm_mday,
201 tm->tm_hour, tm->tm_min, tm->tm_sec,
202 tz);
203 else if (mode == DATE_RFC2822)
204 strbuf_addf(&timebuf, "%.3s, %d %.3s %d %02d:%02d:%02d %+05d",
205 weekday_names[tm->tm_wday], tm->tm_mday,
206 month_names[tm->tm_mon], tm->tm_year + 1900,
207 tm->tm_hour, tm->tm_min, tm->tm_sec, tz);
208 else
209 strbuf_addf(&timebuf, "%.3s %.3s %d %02d:%02d:%02d %d%c%+05d",
210 weekday_names[tm->tm_wday],
211 month_names[tm->tm_mon],
212 tm->tm_mday,
213 tm->tm_hour, tm->tm_min, tm->tm_sec,
214 tm->tm_year + 1900,
215 (mode == DATE_LOCAL) ? 0 : ' ',
216 tz);
217 return timebuf.buf;
218 }
219
220 /*
221 * Check these. And note how it doesn't do the summer-time conversion.
222 *
223 * In my world, it's always summer, and things are probably a bit off
224 * in other ways too.
225 */
226 static const struct {
227 const char *name;
228 int offset;
229 int dst;
230 } timezone_names[] = {
231 { "IDLW", -12, 0, }, /* International Date Line West */
232 { "NT", -11, 0, }, /* Nome */
233 { "CAT", -10, 0, }, /* Central Alaska */
234 { "HST", -10, 0, }, /* Hawaii Standard */
235 { "HDT", -10, 1, }, /* Hawaii Daylight */
236 { "YST", -9, 0, }, /* Yukon Standard */
237 { "YDT", -9, 1, }, /* Yukon Daylight */
238 { "PST", -8, 0, }, /* Pacific Standard */
239 { "PDT", -8, 1, }, /* Pacific Daylight */
240 { "MST", -7, 0, }, /* Mountain Standard */
241 { "MDT", -7, 1, }, /* Mountain Daylight */
242 { "CST", -6, 0, }, /* Central Standard */
243 { "CDT", -6, 1, }, /* Central Daylight */
244 { "EST", -5, 0, }, /* Eastern Standard */
245 { "EDT", -5, 1, }, /* Eastern Daylight */
246 { "AST", -3, 0, }, /* Atlantic Standard */
247 { "ADT", -3, 1, }, /* Atlantic Daylight */
248 { "WAT", -1, 0, }, /* West Africa */
249
250 { "GMT", 0, 0, }, /* Greenwich Mean */
251 { "UTC", 0, 0, }, /* Universal (Coordinated) */
252 { "Z", 0, 0, }, /* Zulu, alias for UTC */
253
254 { "WET", 0, 0, }, /* Western European */
255 { "BST", 0, 1, }, /* British Summer */
256 { "CET", +1, 0, }, /* Central European */
257 { "MET", +1, 0, }, /* Middle European */
258 { "MEWT", +1, 0, }, /* Middle European Winter */
259 { "MEST", +1, 1, }, /* Middle European Summer */
260 { "CEST", +1, 1, }, /* Central European Summer */
261 { "MESZ", +1, 1, }, /* Middle European Summer */
262 { "FWT", +1, 0, }, /* French Winter */
263 { "FST", +1, 1, }, /* French Summer */
264 { "EET", +2, 0, }, /* Eastern Europe, USSR Zone 1 */
265 { "EEST", +2, 1, }, /* Eastern European Daylight */
266 { "WAST", +7, 0, }, /* West Australian Standard */
267 { "WADT", +7, 1, }, /* West Australian Daylight */
268 { "CCT", +8, 0, }, /* China Coast, USSR Zone 7 */
269 { "JST", +9, 0, }, /* Japan Standard, USSR Zone 8 */
270 { "EAST", +10, 0, }, /* Eastern Australian Standard */
271 { "EADT", +10, 1, }, /* Eastern Australian Daylight */
272 { "GST", +10, 0, }, /* Guam Standard, USSR Zone 9 */
273 { "NZT", +12, 0, }, /* New Zealand */
274 { "NZST", +12, 0, }, /* New Zealand Standard */
275 { "NZDT", +12, 1, }, /* New Zealand Daylight */
276 { "IDLE", +12, 0, }, /* International Date Line East */
277 };
278
279 static int match_string(const char *date, const char *str)
280 {
281 int i = 0;
282
283 for (i = 0; *date; date++, str++, i++) {
284 if (*date == *str)
285 continue;
286 if (toupper(*date) == toupper(*str))
287 continue;
288 if (!isalnum(*date))
289 break;
290 return 0;
291 }
292 return i;
293 }
294
295 static int skip_alpha(const char *date)
296 {
297 int i = 0;
298 do {
299 i++;
300 } while (isalpha(date[i]));
301 return i;
302 }
303
304 /*
305 * Parse month, weekday, or timezone name
306 */
307 static int match_alpha(const char *date, struct tm *tm, int *offset)
308 {
309 int i;
310
311 for (i = 0; i < 12; i++) {
312 int match = match_string(date, month_names[i]);
313 if (match >= 3) {
314 tm->tm_mon = i;
315 return match;
316 }
317 }
318
319 for (i = 0; i < 7; i++) {
320 int match = match_string(date, weekday_names[i]);
321 if (match >= 3) {
322 tm->tm_wday = i;
323 return match;
324 }
325 }
326
327 for (i = 0; i < ARRAY_SIZE(timezone_names); i++) {
328 int match = match_string(date, timezone_names[i].name);
329 if (match >= 3 || match == strlen(timezone_names[i].name)) {
330 int off = timezone_names[i].offset;
331
332 /* This is bogus, but we like summer */
333 off += timezone_names[i].dst;
334
335 /* Only use the tz name offset if we don't have anything better */
336 if (*offset == -1)
337 *offset = 60*off;
338
339 return match;
340 }
341 }
342
343 if (match_string(date, "PM") == 2) {
344 tm->tm_hour = (tm->tm_hour % 12) + 12;
345 return 2;
346 }
347
348 if (match_string(date, "AM") == 2) {
349 tm->tm_hour = (tm->tm_hour % 12) + 0;
350 return 2;
351 }
352
353 /* BAD CRAP */
354 return skip_alpha(date);
355 }
356
357 static int is_date(int year, int month, int day, struct tm *now_tm, time_t now, struct tm *tm)
358 {
359 if (month > 0 && month < 13 && day > 0 && day < 32) {
360 struct tm check = *tm;
361 struct tm *r = (now_tm ? &check : tm);
362 time_t specified;
363
364 r->tm_mon = month - 1;
365 r->tm_mday = day;
366 if (year == -1) {
367 if (!now_tm)
368 return 1;
369 r->tm_year = now_tm->tm_year;
370 }
371 else if (year >= 1970 && year < 2100)
372 r->tm_year = year - 1900;
373 else if (year > 70 && year < 100)
374 r->tm_year = year;
375 else if (year < 38)
376 r->tm_year = year + 100;
377 else
378 return 0;
379 if (!now_tm)
380 return 1;
381
382 specified = tm_to_time_t(r);
383
384 /* Be it commit time or author time, it does not make
385 * sense to specify timestamp way into the future. Make
386 * sure it is not later than ten days from now...
387 */
388 if ((specified != -1) && (now + 10*24*3600 < specified))
389 return 0;
390 tm->tm_mon = r->tm_mon;
391 tm->tm_mday = r->tm_mday;
392 if (year != -1)
393 tm->tm_year = r->tm_year;
394 return 1;
395 }
396 return 0;
397 }
398
399 static int match_multi_number(unsigned long num, char c, const char *date, char *end, struct tm *tm)
400 {
401 time_t now;
402 struct tm now_tm;
403 struct tm *refuse_future;
404 long num2, num3;
405
406 num2 = strtol(end+1, &end, 10);
407 num3 = -1;
408 if (*end == c && isdigit(end[1]))
409 num3 = strtol(end+1, &end, 10);
410
411 /* Time? Date? */
412 switch (c) {
413 case ':':
414 if (num3 < 0)
415 num3 = 0;
416 if (num < 25 && num2 >= 0 && num2 < 60 && num3 >= 0 && num3 <= 60) {
417 tm->tm_hour = num;
418 tm->tm_min = num2;
419 tm->tm_sec = num3;
420 break;
421 }
422 return 0;
423
424 case '-':
425 case '/':
426 case '.':
427 now = time(NULL);
428 refuse_future = NULL;
429 if (gmtime_r(&now, &now_tm))
430 refuse_future = &now_tm;
431
432 if (num > 70) {
433 /* yyyy-mm-dd? */
434 if (is_date(num, num2, num3, refuse_future, now, tm))
435 break;
436 /* yyyy-dd-mm? */
437 if (is_date(num, num3, num2, refuse_future, now, tm))
438 break;
439 }
440 /* Our eastern European friends say dd.mm.yy[yy]
441 * is the norm there, so giving precedence to
442 * mm/dd/yy[yy] form only when separator is not '.'
443 */
444 if (c != '.' &&
445 is_date(num3, num, num2, refuse_future, now, tm))
446 break;
447 /* European dd.mm.yy[yy] or funny US dd/mm/yy[yy] */
448 if (is_date(num3, num2, num, refuse_future, now, tm))
449 break;
450 /* Funny European mm.dd.yy */
451 if (c == '.' &&
452 is_date(num3, num, num2, refuse_future, now, tm))
453 break;
454 return 0;
455 }
456 return end - date;
457 }
458
459 /*
460 * Have we filled in any part of the time/date yet?
461 * We just do a binary 'and' to see if the sign bit
462 * is set in all the values.
463 */
464 static inline int nodate(struct tm *tm)
465 {
466 return (tm->tm_year &
467 tm->tm_mon &
468 tm->tm_mday &
469 tm->tm_hour &
470 tm->tm_min &
471 tm->tm_sec) < 0;
472 }
473
474 /*
475 * We've seen a digit. Time? Year? Date?
476 */
477 static int match_digit(const char *date, struct tm *tm, int *offset, int *tm_gmt)
478 {
479 int n;
480 char *end;
481 unsigned long num;
482
483 num = strtoul(date, &end, 10);
484
485 /*
486 * Seconds since 1970? We trigger on that for any numbers with
487 * more than 8 digits. This is because we don't want to rule out
488 * numbers like 20070606 as a YYYYMMDD date.
489 */
490 if (num >= 100000000 && nodate(tm)) {
491 time_t time = num;
492 if (gmtime_r(&time, tm)) {
493 *tm_gmt = 1;
494 return end - date;
495 }
496 }
497
498 /*
499 * Check for special formats: num[-.:/]num[same]num
500 */
501 switch (*end) {
502 case ':':
503 case '.':
504 case '/':
505 case '-':
506 if (isdigit(end[1])) {
507 int match = match_multi_number(num, *end, date, end, tm);
508 if (match)
509 return match;
510 }
511 }
512
513 /*
514 * None of the special formats? Try to guess what
515 * the number meant. We use the number of digits
516 * to make a more educated guess..
517 */
518 n = 0;
519 do {
520 n++;
521 } while (isdigit(date[n]));
522
523 /* Four-digit year or a timezone? */
524 if (n == 4) {
525 if (num <= 1400 && *offset == -1) {
526 unsigned int minutes = num % 100;
527 unsigned int hours = num / 100;
528 *offset = hours*60 + minutes;
529 } else if (num > 1900 && num < 2100)
530 tm->tm_year = num - 1900;
531 return n;
532 }
533
534 /*
535 * Ignore lots of numerals. We took care of 4-digit years above.
536 * Days or months must be one or two digits.
537 */
538 if (n > 2)
539 return n;
540
541 /*
542 * NOTE! We will give precedence to day-of-month over month or
543 * year numbers in the 1-12 range. So 05 is always "mday 5",
544 * unless we already have a mday..
545 *
546 * IOW, 01 Apr 05 parses as "April 1st, 2005".
547 */
548 if (num > 0 && num < 32 && tm->tm_mday < 0) {
549 tm->tm_mday = num;
550 return n;
551 }
552
553 /* Two-digit year? */
554 if (n == 2 && tm->tm_year < 0) {
555 if (num < 10 && tm->tm_mday >= 0) {
556 tm->tm_year = num + 100;
557 return n;
558 }
559 if (num >= 70) {
560 tm->tm_year = num;
561 return n;
562 }
563 }
564
565 if (num > 0 && num < 13 && tm->tm_mon < 0)
566 tm->tm_mon = num-1;
567
568 return n;
569 }
570
571 static int match_tz(const char *date, int *offp)
572 {
573 char *end;
574 int hour = strtoul(date + 1, &end, 10);
575 int n = end - (date + 1);
576 int min = 0;
577
578 if (n == 4) {
579 /* hhmm */
580 min = hour % 100;
581 hour = hour / 100;
582 } else if (n != 2) {
583 min = 99; /* random crap */
584 } else if (*end == ':') {
585 /* hh:mm? */
586 min = strtoul(end + 1, &end, 10);
587 if (end - (date + 1) != 5)
588 min = 99; /* random crap */
589 } /* otherwise we parsed "hh" */
590
591 /*
592 * Don't accept any random crap. Even though some places have
593 * offset larger than 12 hours (e.g. Pacific/Kiritimati is at
594 * UTC+14), there is something wrong if hour part is much
595 * larger than that. We might also want to check that the
596 * minutes are divisible by 15 or something too. (Offset of
597 * Kathmandu, Nepal is UTC+5:45)
598 */
599 if (min < 60 && hour < 24) {
600 int offset = hour * 60 + min;
601 if (*date == '-')
602 offset = -offset;
603 *offp = offset;
604 }
605 return end - date;
606 }
607
608 static int date_string(unsigned long date, int offset, char *buf, int len)
609 {
610 int sign = '+';
611
612 if (offset < 0) {
613 offset = -offset;
614 sign = '-';
615 }
616 return snprintf(buf, len, "%lu %c%02d%02d", date, sign, offset / 60, offset % 60);
617 }
618
619 /*
620 * Parse a string like "0 +0000" as ancient timestamp near epoch, but
621 * only when it appears not as part of any other string.
622 */
623 static int match_object_header_date(const char *date, unsigned long *timestamp, int *offset)
624 {
625 char *end;
626 unsigned long stamp;
627 int ofs;
628
629 if (*date < '0' || '9' < *date)
630 return -1;
631 stamp = strtoul(date, &end, 10);
632 if (*end != ' ' || stamp == ULONG_MAX || (end[1] != '+' && end[1] != '-'))
633 return -1;
634 date = end + 2;
635 ofs = strtol(date, &end, 10);
636 if ((*end != '\0' && (*end != '\n')) || end != date + 4)
637 return -1;
638 ofs = (ofs / 100) * 60 + (ofs % 100);
639 if (date[-1] == '-')
640 ofs = -ofs;
641 *timestamp = stamp;
642 *offset = ofs;
643 return 0;
644 }
645
646 /* Gr. strptime is crap for this; it doesn't have a way to require RFC2822
647 (i.e. English) day/month names, and it doesn't work correctly with %z. */
648 int parse_date_basic(const char *date, unsigned long *timestamp, int *offset)
649 {
650 struct tm tm;
651 int tm_gmt;
652 unsigned long dummy_timestamp;
653 int dummy_offset;
654
655 if (!timestamp)
656 timestamp = &dummy_timestamp;
657 if (!offset)
658 offset = &dummy_offset;
659
660 memset(&tm, 0, sizeof(tm));
661 tm.tm_year = -1;
662 tm.tm_mon = -1;
663 tm.tm_mday = -1;
664 tm.tm_isdst = -1;
665 tm.tm_hour = -1;
666 tm.tm_min = -1;
667 tm.tm_sec = -1;
668 *offset = -1;
669 tm_gmt = 0;
670
671 if (*date == '@' &&
672 !match_object_header_date(date + 1, timestamp, offset))
673 return 0; /* success */
674 for (;;) {
675 int match = 0;
676 unsigned char c = *date;
677
678 /* Stop at end of string or newline */
679 if (!c || c == '\n')
680 break;
681
682 if (isalpha(c))
683 match = match_alpha(date, &tm, offset);
684 else if (isdigit(c))
685 match = match_digit(date, &tm, offset, &tm_gmt);
686 else if ((c == '-' || c == '+') && isdigit(date[1]))
687 match = match_tz(date, offset);
688
689 if (!match) {
690 /* BAD CRAP */
691 match = 1;
692 }
693
694 date += match;
695 }
696
697 /* mktime uses local timezone */
698 *timestamp = tm_to_time_t(&tm);
699 if (*offset == -1) {
700 time_t temp_time = mktime(&tm);
701 if ((time_t)*timestamp > temp_time) {
702 *offset = ((time_t)*timestamp - temp_time) / 60;
703 } else {
704 *offset = -(int)((temp_time - (time_t)*timestamp) / 60);
705 }
706 }
707
708 if (*timestamp == -1)
709 return -1;
710
711 if (!tm_gmt)
712 *timestamp -= *offset * 60;
713 return 0; /* success */
714 }
715
716 int parse_expiry_date(const char *date, unsigned long *timestamp)
717 {
718 int errors = 0;
719
720 if (!strcmp(date, "never") || !strcmp(date, "false"))
721 *timestamp = 0;
722 else if (!strcmp(date, "all") || !strcmp(date, "now"))
723 /*
724 * We take over "now" here, which usually translates
725 * to the current timestamp. This is because the user
726 * really means to expire everything she has done in
727 * the past, and by definition reflogs are the record
728 * of the past, and there is nothing from the future
729 * to be kept.
730 */
731 *timestamp = ULONG_MAX;
732 else
733 *timestamp = approxidate_careful(date, &errors);
734
735 return errors;
736 }
737
738 int parse_date(const char *date, char *result, int maxlen)
739 {
740 unsigned long timestamp;
741 int offset;
742 if (parse_date_basic(date, &timestamp, &offset))
743 return -1;
744 return date_string(timestamp, offset, result, maxlen);
745 }
746
747 enum date_mode parse_date_format(const char *format)
748 {
749 if (!strcmp(format, "relative"))
750 return DATE_RELATIVE;
751 else if (!strcmp(format, "iso8601") ||
752 !strcmp(format, "iso"))
753 return DATE_ISO8601;
754 else if (!strcmp(format, "rfc2822") ||
755 !strcmp(format, "rfc"))
756 return DATE_RFC2822;
757 else if (!strcmp(format, "short"))
758 return DATE_SHORT;
759 else if (!strcmp(format, "local"))
760 return DATE_LOCAL;
761 else if (!strcmp(format, "default"))
762 return DATE_NORMAL;
763 else if (!strcmp(format, "raw"))
764 return DATE_RAW;
765 else
766 die("unknown date format %s", format);
767 }
768
769 void datestamp(char *buf, int bufsize)
770 {
771 time_t now;
772 int offset;
773
774 time(&now);
775
776 offset = tm_to_time_t(localtime(&now)) - now;
777 offset /= 60;
778
779 date_string(now, offset, buf, bufsize);
780 }
781
782 /*
783 * Relative time update (eg "2 days ago"). If we haven't set the time
784 * yet, we need to set it from current time.
785 */
786 static unsigned long update_tm(struct tm *tm, struct tm *now, unsigned long sec)
787 {
788 time_t n;
789
790 if (tm->tm_mday < 0)
791 tm->tm_mday = now->tm_mday;
792 if (tm->tm_mon < 0)
793 tm->tm_mon = now->tm_mon;
794 if (tm->tm_year < 0) {
795 tm->tm_year = now->tm_year;
796 if (tm->tm_mon > now->tm_mon)
797 tm->tm_year--;
798 }
799
800 n = mktime(tm) - sec;
801 localtime_r(&n, tm);
802 return n;
803 }
804
805 static void date_now(struct tm *tm, struct tm *now, int *num)
806 {
807 update_tm(tm, now, 0);
808 }
809
810 static void date_yesterday(struct tm *tm, struct tm *now, int *num)
811 {
812 update_tm(tm, now, 24*60*60);
813 }
814
815 static void date_time(struct tm *tm, struct tm *now, int hour)
816 {
817 if (tm->tm_hour < hour)
818 date_yesterday(tm, now, NULL);
819 tm->tm_hour = hour;
820 tm->tm_min = 0;
821 tm->tm_sec = 0;
822 }
823
824 static void date_midnight(struct tm *tm, struct tm *now, int *num)
825 {
826 date_time(tm, now, 0);
827 }
828
829 static void date_noon(struct tm *tm, struct tm *now, int *num)
830 {
831 date_time(tm, now, 12);
832 }
833
834 static void date_tea(struct tm *tm, struct tm *now, int *num)
835 {
836 date_time(tm, now, 17);
837 }
838
839 static void date_pm(struct tm *tm, struct tm *now, int *num)
840 {
841 int hour, n = *num;
842 *num = 0;
843
844 hour = tm->tm_hour;
845 if (n) {
846 hour = n;
847 tm->tm_min = 0;
848 tm->tm_sec = 0;
849 }
850 tm->tm_hour = (hour % 12) + 12;
851 }
852
853 static void date_am(struct tm *tm, struct tm *now, int *num)
854 {
855 int hour, n = *num;
856 *num = 0;
857
858 hour = tm->tm_hour;
859 if (n) {
860 hour = n;
861 tm->tm_min = 0;
862 tm->tm_sec = 0;
863 }
864 tm->tm_hour = (hour % 12);
865 }
866
867 static void date_never(struct tm *tm, struct tm *now, int *num)
868 {
869 time_t n = 0;
870 localtime_r(&n, tm);
871 }
872
873 static const struct special {
874 const char *name;
875 void (*fn)(struct tm *, struct tm *, int *);
876 } special[] = {
877 { "yesterday", date_yesterday },
878 { "noon", date_noon },
879 { "midnight", date_midnight },
880 { "tea", date_tea },
881 { "PM", date_pm },
882 { "AM", date_am },
883 { "never", date_never },
884 { "now", date_now },
885 { NULL }
886 };
887
888 static const char *number_name[] = {
889 "zero", "one", "two", "three", "four",
890 "five", "six", "seven", "eight", "nine", "ten",
891 };
892
893 static const struct typelen {
894 const char *type;
895 int length;
896 } typelen[] = {
897 { "seconds", 1 },
898 { "minutes", 60 },
899 { "hours", 60*60 },
900 { "days", 24*60*60 },
901 { "weeks", 7*24*60*60 },
902 { NULL }
903 };
904
905 static const char *approxidate_alpha(const char *date, struct tm *tm, struct tm *now, int *num, int *touched)
906 {
907 const struct typelen *tl;
908 const struct special *s;
909 const char *end = date;
910 int i;
911
912 while (isalpha(*++end))
913 ;
914
915 for (i = 0; i < 12; i++) {
916 int match = match_string(date, month_names[i]);
917 if (match >= 3) {
918 tm->tm_mon = i;
919 *touched = 1;
920 return end;
921 }
922 }
923
924 for (s = special; s->name; s++) {
925 int len = strlen(s->name);
926 if (match_string(date, s->name) == len) {
927 s->fn(tm, now, num);
928 *touched = 1;
929 return end;
930 }
931 }
932
933 if (!*num) {
934 for (i = 1; i < 11; i++) {
935 int len = strlen(number_name[i]);
936 if (match_string(date, number_name[i]) == len) {
937 *num = i;
938 *touched = 1;
939 return end;
940 }
941 }
942 if (match_string(date, "last") == 4) {
943 *num = 1;
944 *touched = 1;
945 }
946 return end;
947 }
948
949 tl = typelen;
950 while (tl->type) {
951 int len = strlen(tl->type);
952 if (match_string(date, tl->type) >= len-1) {
953 update_tm(tm, now, tl->length * *num);
954 *num = 0;
955 *touched = 1;
956 return end;
957 }
958 tl++;
959 }
960
961 for (i = 0; i < 7; i++) {
962 int match = match_string(date, weekday_names[i]);
963 if (match >= 3) {
964 int diff, n = *num -1;
965 *num = 0;
966
967 diff = tm->tm_wday - i;
968 if (diff <= 0)
969 n++;
970 diff += 7*n;
971
972 update_tm(tm, now, diff * 24 * 60 * 60);
973 *touched = 1;
974 return end;
975 }
976 }
977
978 if (match_string(date, "months") >= 5) {
979 int n;
980 update_tm(tm, now, 0); /* fill in date fields if needed */
981 n = tm->tm_mon - *num;
982 *num = 0;
983 while (n < 0) {
984 n += 12;
985 tm->tm_year--;
986 }
987 tm->tm_mon = n;
988 *touched = 1;
989 return end;
990 }
991
992 if (match_string(date, "years") >= 4) {
993 update_tm(tm, now, 0); /* fill in date fields if needed */
994 tm->tm_year -= *num;
995 *num = 0;
996 *touched = 1;
997 return end;
998 }
999
1000 return end;
1001 }
1002
1003 static const char *approxidate_digit(const char *date, struct tm *tm, int *num)
1004 {
1005 char *end;
1006 unsigned long number = strtoul(date, &end, 10);
1007
1008 switch (*end) {
1009 case ':':
1010 case '.':
1011 case '/':
1012 case '-':
1013 if (isdigit(end[1])) {
1014 int match = match_multi_number(number, *end, date, end, tm);
1015 if (match)
1016 return date + match;
1017 }
1018 }
1019
1020 /* Accept zero-padding only for small numbers ("Dec 02", never "Dec 0002") */
1021 if (date[0] != '0' || end - date <= 2)
1022 *num = number;
1023 return end;
1024 }
1025
1026 /*
1027 * Do we have a pending number at the end, or when
1028 * we see a new one? Let's assume it's a month day,
1029 * as in "Dec 6, 1992"
1030 */
1031 static void pending_number(struct tm *tm, int *num)
1032 {
1033 int number = *num;
1034
1035 if (number) {
1036 *num = 0;
1037 if (tm->tm_mday < 0 && number < 32)
1038 tm->tm_mday = number;
1039 else if (tm->tm_mon < 0 && number < 13)
1040 tm->tm_mon = number-1;
1041 else if (tm->tm_year < 0) {
1042 if (number > 1969 && number < 2100)
1043 tm->tm_year = number - 1900;
1044 else if (number > 69 && number < 100)
1045 tm->tm_year = number;
1046 else if (number < 38)
1047 tm->tm_year = 100 + number;
1048 /* We screw up for number = 00 ? */
1049 }
1050 }
1051 }
1052
1053 static unsigned long approxidate_str(const char *date,
1054 const struct timeval *tv,
1055 int *error_ret)
1056 {
1057 int number = 0;
1058 int touched = 0;
1059 struct tm tm, now;
1060 time_t time_sec;
1061
1062 time_sec = tv->tv_sec;
1063 localtime_r(&time_sec, &tm);
1064 now = tm;
1065
1066 tm.tm_year = -1;
1067 tm.tm_mon = -1;
1068 tm.tm_mday = -1;
1069
1070 for (;;) {
1071 unsigned char c = *date;
1072 if (!c)
1073 break;
1074 date++;
1075 if (isdigit(c)) {
1076 pending_number(&tm, &number);
1077 date = approxidate_digit(date-1, &tm, &number);
1078 touched = 1;
1079 continue;
1080 }
1081 if (isalpha(c))
1082 date = approxidate_alpha(date-1, &tm, &now, &number, &touched);
1083 }
1084 pending_number(&tm, &number);
1085 if (!touched)
1086 *error_ret = 1;
1087 return update_tm(&tm, &now, 0);
1088 }
1089
1090 unsigned long approxidate_relative(const char *date, const struct timeval *tv)
1091 {
1092 unsigned long timestamp;
1093 int offset;
1094 int errors = 0;
1095
1096 if (!parse_date_basic(date, &timestamp, &offset))
1097 return timestamp;
1098 return approxidate_str(date, tv, &errors);
1099 }
1100
1101 unsigned long approxidate_careful(const char *date, int *error_ret)
1102 {
1103 struct timeval tv;
1104 unsigned long timestamp;
1105 int offset;
1106 int dummy = 0;
1107 if (!error_ret)
1108 error_ret = &dummy;
1109
1110 if (!parse_date_basic(date, &timestamp, &offset)) {
1111 *error_ret = 0;
1112 return timestamp;
1113 }
1114
1115 gettimeofday(&tv, NULL);
1116 return approxidate_str(date, &tv, error_ret);
1117 }
1118
1119 int date_overflows(unsigned long t)
1120 {
1121 time_t sys;
1122
1123 /* If we overflowed our unsigned long, that's bad... */
1124 if (t == ULONG_MAX)
1125 return 1;
1126
1127 /*
1128 * ...but we also are going to feed the result to system
1129 * functions that expect time_t, which is often "signed long".
1130 * Make sure that we fit into time_t, as well.
1131 */
1132 sys = t;
1133 return t != sys || (t < 1) != (sys < 1);
1134 }
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