2 * This code is in the public domain and has no copyright.
4 * This is a plain C recursive-descent translation of an old
5 * public-domain YACC grammar that has been used for parsing dates in
6 * very many open-source projects.
8 * Since the original authors were generous enough to donate their
9 * work to the public domain, I feel compelled to match their
12 * Tim Kientzle, February 2009.
16 * Header comment from original getdate.y:
20 ** Originally written by Steven M. Bellovin <smb@research.att.com> while
21 ** at the University of North Carolina at Chapel Hill. Later tweaked by
22 ** a couple of people on Usenet. Completely overhauled by Rich $alz
23 ** <rsalz@bbn.com> and Jim Berets <jberets@bbn.com> in August, 1990;
25 ** This grammar has 10 shift/reduce conflicts.
27 ** This code is in the public domain and has no copyright.
31 #include <sys/cdefs.h>
32 __FBSDID("$FreeBSD$");
41 #define __LIBARCHIVE_BUILD 1
42 #include "archive_getdate.h"
44 /* Basic time units. */
47 #define HOUR (60L * MINUTE)
48 #define DAY (24L * HOUR)
50 /* Daylight-savings mode: on, off, or not yet known. */
51 enum DSTMODE { DSTon, DSToff, DSTmaybe };
52 /* Meridian: am or pm. */
54 /* Token types returned by nexttoken() */
55 enum { tAGO = 260, tDAY, tDAYZONE, tAMPM, tMONTH, tMONTH_UNIT, tSEC_UNIT,
56 tUNUMBER, tZONE, tDST };
57 struct token { int token; time_t value; };
63 struct token *tokenp; /* Pointer to next token. */
64 /* HaveXxxx counts how many of this kind of phrase we've seen;
65 * it's a fatal error to have more than one time, zone, day,
70 int HaveWeekDay; /* Day of week */
71 int HaveTime; /* Hour/minute/second */
72 int HaveZone; /* timezone and/or DST info */
73 int HaveRel; /* time offset; we can have more than one */
74 /* Absolute time values. */
75 time_t Timezone; /* Seconds offset from GMT */
84 /* Day of week accounting, e.g., "3rd Tuesday" */
85 time_t DayOrdinal; /* "3" in "3rd Tuesday" */
86 time_t DayNumber; /* "Tuesday" in "3rd Tuesday" */
87 /* Relative time values: hour/day/week offsets are measured in
88 * seconds, month/year are counted in months. */
94 * A series of functions that recognize certain common time phrases.
95 * Each function returns 1 if it managed to make sense of some of the
96 * tokens, zero otherwise.
100 * hour:minute or hour:minute:second with optional AM, PM, or numeric
104 timephrase(struct gdstate *gds)
106 if (gds->tokenp[0].token == tUNUMBER
107 && gds->tokenp[1].token == ':'
108 && gds->tokenp[2].token == tUNUMBER
109 && gds->tokenp[3].token == ':'
110 && gds->tokenp[4].token == tUNUMBER) {
111 /* "12:14:18" or "22:08:07" */
113 gds->Hour = gds->tokenp[0].value;
114 gds->Minutes = gds->tokenp[2].value;
115 gds->Seconds = gds->tokenp[4].value;
118 else if (gds->tokenp[0].token == tUNUMBER
119 && gds->tokenp[1].token == ':'
120 && gds->tokenp[2].token == tUNUMBER) {
121 /* "12:14" or "22:08" */
123 gds->Hour = gds->tokenp[0].value;
124 gds->Minutes = gds->tokenp[2].value;
128 else if (gds->tokenp[0].token == tUNUMBER
129 && gds->tokenp[1].token == tAMPM) {
130 /* "7" is a time if it's followed by "am" or "pm" */
132 gds->Hour = gds->tokenp[0].value;
133 gds->Minutes = gds->Seconds = 0;
134 /* We'll handle the AM/PM below. */
137 /* We can't handle this. */
141 if (gds->tokenp[0].token == tAMPM) {
142 /* "7:12pm", "12:20:13am" */
145 if (gds->tokenp[0].value == tPM)
149 if (gds->tokenp[0].token == '+'
150 && gds->tokenp[1].token == tUNUMBER) {
153 gds->DSTmode = DSToff;
154 gds->Timezone = - ((gds->tokenp[1].value / 100) * HOUR
155 + (gds->tokenp[1].value % 100) * MINUTE);
158 if (gds->tokenp[0].token == '-'
159 && gds->tokenp[1].token == tUNUMBER) {
160 /* "19:14:12-0530" */
162 gds->DSTmode = DSToff;
163 gds->Timezone = + ((gds->tokenp[1].value / 100) * HOUR
164 + (gds->tokenp[1].value % 100) * MINUTE);
171 * Timezone name, possibly including DST.
174 zonephrase(struct gdstate *gds)
176 if (gds->tokenp[0].token == tZONE
177 && gds->tokenp[1].token == tDST) {
179 gds->Timezone = gds->tokenp[0].value;
180 gds->DSTmode = DSTon;
185 if (gds->tokenp[0].token == tZONE) {
187 gds->Timezone = gds->tokenp[0].value;
188 gds->DSTmode = DSToff;
193 if (gds->tokenp[0].token == tDAYZONE) {
195 gds->Timezone = gds->tokenp[0].value;
196 gds->DSTmode = DSTon;
204 * Year/month/day in various combinations.
207 datephrase(struct gdstate *gds)
209 if (gds->tokenp[0].token == tUNUMBER
210 && gds->tokenp[1].token == '/'
211 && gds->tokenp[2].token == tUNUMBER
212 && gds->tokenp[3].token == '/'
213 && gds->tokenp[4].token == tUNUMBER) {
217 if (gds->tokenp[0].value >= 13) {
218 /* First number is big: 2004/01/29, 99/02/17 */
219 gds->Year = gds->tokenp[0].value;
220 gds->Month = gds->tokenp[2].value;
221 gds->Day = gds->tokenp[4].value;
222 } else if ((gds->tokenp[4].value >= 13)
223 || (gds->tokenp[2].value >= 13)) {
224 /* Last number is big: 01/07/98 */
225 /* Middle number is big: 01/29/04 */
226 gds->Month = gds->tokenp[0].value;
227 gds->Day = gds->tokenp[2].value;
228 gds->Year = gds->tokenp[4].value;
230 /* No significant clues: 02/03/04 */
231 gds->Month = gds->tokenp[0].value;
232 gds->Day = gds->tokenp[2].value;
233 gds->Year = gds->tokenp[4].value;
239 if (gds->tokenp[0].token == tUNUMBER
240 && gds->tokenp[1].token == '/'
241 && gds->tokenp[2].token == tUNUMBER) {
245 gds->Month = gds->tokenp[0].value;
246 gds->Day = gds->tokenp[2].value;
251 if (gds->tokenp[0].token == tUNUMBER
252 && gds->tokenp[1].token == '-'
253 && gds->tokenp[2].token == tUNUMBER
254 && gds->tokenp[3].token == '-'
255 && gds->tokenp[4].token == tUNUMBER) {
256 /* ISO 8601 format. yyyy-mm-dd. */
260 gds->Year = gds->tokenp[0].value;
261 gds->Month = gds->tokenp[2].value;
262 gds->Day = gds->tokenp[4].value;
267 if (gds->tokenp[0].token == tUNUMBER
268 && gds->tokenp[1].token == '-'
269 && gds->tokenp[2].token == tMONTH
270 && gds->tokenp[3].token == '-'
271 && gds->tokenp[4].token == tUNUMBER) {
275 if (gds->tokenp[0].value > 31) {
276 /* e.g. 1992-Jun-17 */
277 gds->Year = gds->tokenp[0].value;
278 gds->Month = gds->tokenp[2].value;
279 gds->Day = gds->tokenp[4].value;
281 /* e.g. 17-JUN-1992. */
282 gds->Day = gds->tokenp[0].value;
283 gds->Month = gds->tokenp[2].value;
284 gds->Year = gds->tokenp[4].value;
290 if (gds->tokenp[0].token == tMONTH
291 && gds->tokenp[1].token == tUNUMBER
292 && gds->tokenp[2].token == ','
293 && gds->tokenp[3].token == tUNUMBER) {
294 /* "June 17, 2001" */
298 gds->Month = gds->tokenp[0].value;
299 gds->Day = gds->tokenp[1].value;
300 gds->Year = gds->tokenp[3].value;
305 if (gds->tokenp[0].token == tMONTH
306 && gds->tokenp[1].token == tUNUMBER) {
310 gds->Month = gds->tokenp[0].value;
311 gds->Day = gds->tokenp[1].value;
316 if (gds->tokenp[0].token == tUNUMBER
317 && gds->tokenp[1].token == tMONTH
318 && gds->tokenp[2].token == tUNUMBER) {
323 gds->Day = gds->tokenp[0].value;
324 gds->Month = gds->tokenp[1].value;
325 gds->Year = gds->tokenp[2].value;
330 if (gds->tokenp[0].token == tUNUMBER
331 && gds->tokenp[1].token == tMONTH) {
335 gds->Day = gds->tokenp[0].value;
336 gds->Month = gds->tokenp[1].value;
345 * Relative time phrase: "tomorrow", "yesterday", "+1 hour", etc.
348 relunitphrase(struct gdstate *gds)
350 if (gds->tokenp[0].token == '-'
351 && gds->tokenp[1].token == tUNUMBER
352 && gds->tokenp[2].token == tSEC_UNIT) {
355 gds->RelSeconds -= gds->tokenp[1].value * gds->tokenp[2].value;
359 if (gds->tokenp[0].token == '+'
360 && gds->tokenp[1].token == tUNUMBER
361 && gds->tokenp[2].token == tSEC_UNIT) {
364 gds->RelSeconds += gds->tokenp[1].value * gds->tokenp[2].value;
368 if (gds->tokenp[0].token == tUNUMBER
369 && gds->tokenp[1].token == tSEC_UNIT) {
372 gds->RelSeconds += gds->tokenp[0].value * gds->tokenp[1].value;
376 if (gds->tokenp[0].token == '-'
377 && gds->tokenp[1].token == tUNUMBER
378 && gds->tokenp[2].token == tMONTH_UNIT) {
381 gds->RelMonth -= gds->tokenp[1].value * gds->tokenp[2].value;
385 if (gds->tokenp[0].token == '+'
386 && gds->tokenp[1].token == tUNUMBER
387 && gds->tokenp[2].token == tMONTH_UNIT) {
390 gds->RelMonth += gds->tokenp[1].value * gds->tokenp[2].value;
394 if (gds->tokenp[0].token == tUNUMBER
395 && gds->tokenp[1].token == tMONTH_UNIT) {
398 gds->RelMonth += gds->tokenp[0].value * gds->tokenp[1].value;
402 if (gds->tokenp[0].token == tSEC_UNIT) {
403 /* "now", "tomorrow" */
405 gds->RelSeconds += gds->tokenp[0].value;
409 if (gds->tokenp[0].token == tMONTH_UNIT) {
412 gds->RelMonth += gds->tokenp[0].value;
420 * Day of the week specification.
423 dayphrase(struct gdstate *gds)
425 if (gds->tokenp[0].token == tDAY) {
426 /* "tues", "wednesday," */
429 gds->DayNumber = gds->tokenp[0].value;
431 if (gds->tokenp[0].token == ',')
435 if (gds->tokenp[0].token == tUNUMBER
436 && gds->tokenp[1].token == tDAY) {
437 /* "second tues" "3 wed" */
439 gds->DayOrdinal = gds->tokenp[0].value;
440 gds->DayNumber = gds->tokenp[1].value;
448 * Try to match a phrase using one of the above functions.
449 * This layer also deals with a couple of generic issues.
452 phrase(struct gdstate *gds)
462 if (relunitphrase(gds)) {
463 if (gds->tokenp[0].token == tAGO) {
464 gds->RelSeconds = -gds->RelSeconds;
465 gds->RelMonth = -gds->RelMonth;
471 /* Bare numbers sometimes have meaning. */
472 if (gds->tokenp[0].token == tUNUMBER) {
473 if (gds->HaveTime && !gds->HaveYear && !gds->HaveRel) {
475 gds->Year = gds->tokenp[0].value;
480 if(gds->tokenp[0].value > 10000) {
485 gds->Day= (gds->tokenp[0].value)%100;
486 gds->Month= (gds->tokenp[0].value/100)%100;
487 gds->Year = gds->tokenp[0].value/10000;
492 if (gds->tokenp[0].value < 24) {
494 gds->Hour = gds->tokenp[0].value;
501 if ((gds->tokenp[0].value / 100 < 24)
502 && (gds->tokenp[0].value % 100 < 60)) {
503 /* "513" is same as "5:13" */
504 gds->Hour = gds->tokenp[0].value / 100;
505 gds->Minutes = gds->tokenp[0].value % 100;
516 * A dictionary of time words.
518 static struct LEXICON {
523 } const TimeWords[] = {
525 { 0, "am", tAMPM, tAM },
526 { 0, "pm", tAMPM, tPM },
529 { 3, "january", tMONTH, 1 },
530 { 3, "february", tMONTH, 2 },
531 { 3, "march", tMONTH, 3 },
532 { 3, "april", tMONTH, 4 },
533 { 3, "may", tMONTH, 5 },
534 { 3, "june", tMONTH, 6 },
535 { 3, "july", tMONTH, 7 },
536 { 3, "august", tMONTH, 8 },
537 { 3, "september", tMONTH, 9 },
538 { 3, "october", tMONTH, 10 },
539 { 3, "november", tMONTH, 11 },
540 { 3, "december", tMONTH, 12 },
542 /* Days of the week. */
543 { 2, "sunday", tDAY, 0 },
544 { 3, "monday", tDAY, 1 },
545 { 2, "tuesday", tDAY, 2 },
546 { 3, "wednesday", tDAY, 3 },
547 { 2, "thursday", tDAY, 4 },
548 { 2, "friday", tDAY, 5 },
549 { 2, "saturday", tDAY, 6 },
551 /* Timezones: Offsets are in seconds. */
552 { 0, "gmt", tZONE, 0*HOUR }, /* Greenwich Mean */
553 { 0, "ut", tZONE, 0*HOUR }, /* Universal (Coordinated) */
554 { 0, "utc", tZONE, 0*HOUR },
555 { 0, "wet", tZONE, 0*HOUR }, /* Western European */
556 { 0, "bst", tDAYZONE, 0*HOUR }, /* British Summer */
557 { 0, "wat", tZONE, 1*HOUR }, /* West Africa */
558 { 0, "at", tZONE, 2*HOUR }, /* Azores */
559 /* { 0, "bst", tZONE, 3*HOUR }, */ /* Brazil Standard: Conflict */
560 /* { 0, "gst", tZONE, 3*HOUR }, */ /* Greenland Standard: Conflict*/
561 { 0, "nft", tZONE, 3*HOUR+30*MINUTE }, /* Newfoundland */
562 { 0, "nst", tZONE, 3*HOUR+30*MINUTE }, /* Newfoundland Standard */
563 { 0, "ndt", tDAYZONE, 3*HOUR+30*MINUTE }, /* Newfoundland Daylight */
564 { 0, "ast", tZONE, 4*HOUR }, /* Atlantic Standard */
565 { 0, "adt", tDAYZONE, 4*HOUR }, /* Atlantic Daylight */
566 { 0, "est", tZONE, 5*HOUR }, /* Eastern Standard */
567 { 0, "edt", tDAYZONE, 5*HOUR }, /* Eastern Daylight */
568 { 0, "cst", tZONE, 6*HOUR }, /* Central Standard */
569 { 0, "cdt", tDAYZONE, 6*HOUR }, /* Central Daylight */
570 { 0, "mst", tZONE, 7*HOUR }, /* Mountain Standard */
571 { 0, "mdt", tDAYZONE, 7*HOUR }, /* Mountain Daylight */
572 { 0, "pst", tZONE, 8*HOUR }, /* Pacific Standard */
573 { 0, "pdt", tDAYZONE, 8*HOUR }, /* Pacific Daylight */
574 { 0, "yst", tZONE, 9*HOUR }, /* Yukon Standard */
575 { 0, "ydt", tDAYZONE, 9*HOUR }, /* Yukon Daylight */
576 { 0, "hst", tZONE, 10*HOUR }, /* Hawaii Standard */
577 { 0, "hdt", tDAYZONE, 10*HOUR }, /* Hawaii Daylight */
578 { 0, "cat", tZONE, 10*HOUR }, /* Central Alaska */
579 { 0, "ahst", tZONE, 10*HOUR }, /* Alaska-Hawaii Standard */
580 { 0, "nt", tZONE, 11*HOUR }, /* Nome */
581 { 0, "idlw", tZONE, 12*HOUR }, /* Intl Date Line West */
582 { 0, "cet", tZONE, -1*HOUR }, /* Central European */
583 { 0, "met", tZONE, -1*HOUR }, /* Middle European */
584 { 0, "mewt", tZONE, -1*HOUR }, /* Middle European Winter */
585 { 0, "mest", tDAYZONE, -1*HOUR }, /* Middle European Summer */
586 { 0, "swt", tZONE, -1*HOUR }, /* Swedish Winter */
587 { 0, "sst", tDAYZONE, -1*HOUR }, /* Swedish Summer */
588 { 0, "fwt", tZONE, -1*HOUR }, /* French Winter */
589 { 0, "fst", tDAYZONE, -1*HOUR }, /* French Summer */
590 { 0, "eet", tZONE, -2*HOUR }, /* Eastern Eur, USSR Zone 1 */
591 { 0, "bt", tZONE, -3*HOUR }, /* Baghdad, USSR Zone 2 */
592 { 0, "it", tZONE, -3*HOUR-30*MINUTE },/* Iran */
593 { 0, "zp4", tZONE, -4*HOUR }, /* USSR Zone 3 */
594 { 0, "zp5", tZONE, -5*HOUR }, /* USSR Zone 4 */
595 { 0, "ist", tZONE, -5*HOUR-30*MINUTE },/* Indian Standard */
596 { 0, "zp6", tZONE, -6*HOUR }, /* USSR Zone 5 */
597 /* { 0, "nst", tZONE, -6.5*HOUR }, */ /* North Sumatra: Conflict */
598 /* { 0, "sst", tZONE, -7*HOUR }, */ /* So Sumatra, USSR 6: Conflict */
599 { 0, "wast", tZONE, -7*HOUR }, /* West Australian Standard */
600 { 0, "wadt", tDAYZONE, -7*HOUR }, /* West Australian Daylight */
601 { 0, "jt", tZONE, -7*HOUR-30*MINUTE },/* Java (3pm in Cronusland!)*/
602 { 0, "cct", tZONE, -8*HOUR }, /* China Coast, USSR Zone 7 */
603 { 0, "jst", tZONE, -9*HOUR }, /* Japan Std, USSR Zone 8 */
604 { 0, "cast", tZONE, -9*HOUR-30*MINUTE },/* Ctrl Australian Std */
605 { 0, "cadt", tDAYZONE, -9*HOUR-30*MINUTE },/* Ctrl Australian Daylt */
606 { 0, "east", tZONE, -10*HOUR }, /* Eastern Australian Std */
607 { 0, "eadt", tDAYZONE, -10*HOUR }, /* Eastern Australian Daylt */
608 { 0, "gst", tZONE, -10*HOUR }, /* Guam Std, USSR Zone 9 */
609 { 0, "nzt", tZONE, -12*HOUR }, /* New Zealand */
610 { 0, "nzst", tZONE, -12*HOUR }, /* New Zealand Standard */
611 { 0, "nzdt", tDAYZONE, -12*HOUR }, /* New Zealand Daylight */
612 { 0, "idle", tZONE, -12*HOUR }, /* Intl Date Line East */
614 { 0, "dst", tDST, 0 },
617 { 4, "years", tMONTH_UNIT, 12 },
618 { 5, "months", tMONTH_UNIT, 1 },
619 { 9, "fortnights", tSEC_UNIT, 14 * DAY },
620 { 4, "weeks", tSEC_UNIT, 7 * DAY },
621 { 3, "days", tSEC_UNIT, DAY },
622 { 4, "hours", tSEC_UNIT, HOUR },
623 { 3, "minutes", tSEC_UNIT, MINUTE },
624 { 3, "seconds", tSEC_UNIT, 1 },
626 /* Relative-time words. */
627 { 0, "tomorrow", tSEC_UNIT, DAY },
628 { 0, "yesterday", tSEC_UNIT, -DAY },
629 { 0, "today", tSEC_UNIT, 0 },
630 { 0, "now", tSEC_UNIT, 0 },
631 { 0, "last", tUNUMBER, -1 },
632 { 0, "this", tSEC_UNIT, 0 },
633 { 0, "next", tUNUMBER, 2 },
634 { 0, "first", tUNUMBER, 1 },
635 { 0, "1st", tUNUMBER, 1 },
636 /* { 0, "second", tUNUMBER, 2 }, */
637 { 0, "2nd", tUNUMBER, 2 },
638 { 0, "third", tUNUMBER, 3 },
639 { 0, "3rd", tUNUMBER, 3 },
640 { 0, "fourth", tUNUMBER, 4 },
641 { 0, "4th", tUNUMBER, 4 },
642 { 0, "fifth", tUNUMBER, 5 },
643 { 0, "5th", tUNUMBER, 5 },
644 { 0, "sixth", tUNUMBER, 6 },
645 { 0, "seventh", tUNUMBER, 7 },
646 { 0, "eighth", tUNUMBER, 8 },
647 { 0, "ninth", tUNUMBER, 9 },
648 { 0, "tenth", tUNUMBER, 10 },
649 { 0, "eleventh", tUNUMBER, 11 },
650 { 0, "twelfth", tUNUMBER, 12 },
651 { 0, "ago", tAGO, 1 },
653 /* Military timezones. */
654 { 0, "a", tZONE, 1*HOUR },
655 { 0, "b", tZONE, 2*HOUR },
656 { 0, "c", tZONE, 3*HOUR },
657 { 0, "d", tZONE, 4*HOUR },
658 { 0, "e", tZONE, 5*HOUR },
659 { 0, "f", tZONE, 6*HOUR },
660 { 0, "g", tZONE, 7*HOUR },
661 { 0, "h", tZONE, 8*HOUR },
662 { 0, "i", tZONE, 9*HOUR },
663 { 0, "k", tZONE, 10*HOUR },
664 { 0, "l", tZONE, 11*HOUR },
665 { 0, "m", tZONE, 12*HOUR },
666 { 0, "n", tZONE, -1*HOUR },
667 { 0, "o", tZONE, -2*HOUR },
668 { 0, "p", tZONE, -3*HOUR },
669 { 0, "q", tZONE, -4*HOUR },
670 { 0, "r", tZONE, -5*HOUR },
671 { 0, "s", tZONE, -6*HOUR },
672 { 0, "t", tZONE, -7*HOUR },
673 { 0, "u", tZONE, -8*HOUR },
674 { 0, "v", tZONE, -9*HOUR },
675 { 0, "w", tZONE, -10*HOUR },
676 { 0, "x", tZONE, -11*HOUR },
677 { 0, "y", tZONE, -12*HOUR },
678 { 0, "z", tZONE, 0*HOUR },
686 * = A number from 0 to 99, which means a year from 1970 to 2069, or
687 * = The actual year (>=100).
690 Convert(time_t Month, time_t Day, time_t Year,
691 time_t Hours, time_t Minutes, time_t Seconds,
692 time_t Timezone, enum DSTMODE DSTmode)
694 signed char DaysInMonth[12] = {
695 31, 0, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31
704 DaysInMonth[1] = Year % 4 == 0 && (Year % 100 != 0 || Year % 400 == 0)
706 /* Checking for 2038 bogusly assumes that time_t is 32 bits. But
707 I'm too lazy to try to check for time_t overflow in another way. */
708 if (Year < EPOCH || Year > 2038
709 || Month < 1 || Month > 12
710 /* Lint fluff: "conversion from long may lose accuracy" */
711 || Day < 1 || Day > DaysInMonth[(int)--Month]
712 || Hours < 0 || Hours > 23
713 || Minutes < 0 || Minutes > 59
714 || Seconds < 0 || Seconds > 59)
718 for (i = 0; i < Month; i++)
719 Julian += DaysInMonth[i];
720 for (i = EPOCH; i < Year; i++)
721 Julian += 365 + (i % 4 == 0);
724 Julian += Hours * HOUR + Minutes * MINUTE + Seconds;
726 || (DSTmode == DSTmaybe && localtime(&Julian)->tm_isdst))
733 DSTcorrect(time_t Start, time_t Future)
738 StartDay = (localtime(&Start)->tm_hour + 1) % 24;
739 FutureDay = (localtime(&Future)->tm_hour + 1) % 24;
740 return (Future - Start) + (StartDay - FutureDay) * HOUR;
745 RelativeDate(time_t Start, time_t zone, int dstmode,
746 time_t DayOrdinal, time_t DayNumber)
754 now += DAY * ((DayNumber - tm->tm_wday + 7) % 7);
755 now += 7 * DAY * (DayOrdinal <= 0 ? DayOrdinal : DayOrdinal - 1);
756 if (dstmode == DSTmaybe)
757 return DSTcorrect(Start, now);
763 RelativeMonth(time_t Start, time_t Timezone, time_t RelMonth)
771 tm = localtime(&Start);
772 Month = 12 * (tm->tm_year + 1900) + tm->tm_mon + RelMonth;
774 Month = Month % 12 + 1;
775 return DSTcorrect(Start,
776 Convert(Month, (time_t)tm->tm_mday, Year,
777 (time_t)tm->tm_hour, (time_t)tm->tm_min, (time_t)tm->tm_sec,
778 Timezone, DSTmaybe));
785 nexttoken(const char **in, time_t *value)
791 while (isspace((unsigned char)**in))
794 /* Skip parenthesized comments. */
809 /* Try the next token in the word table first. */
810 /* This allows us to match "2nd", for example. */
812 const char *src = *in;
813 const struct LEXICON *tp;
816 /* Force to lowercase and strip '.' characters. */
818 && (isalnum((unsigned char)*src) || *src == '.')
819 && i < sizeof(buff)-1) {
821 if (isupper((unsigned char)*src))
822 buff[i++] = tolower((unsigned char)*src);
831 * Find the first match. If the word can be
832 * abbreviated, make sure we match at least
833 * the minimum abbreviation.
835 for (tp = TimeWords; tp->name; tp++) {
836 size_t abbrev = tp->abbrev;
838 abbrev = strlen(tp->name);
839 if (strlen(buff) >= abbrev
840 && strncmp(tp->name, buff, strlen(buff))
842 /* Skip over token. */
844 /* Return the match. */
852 * Not in the word table, maybe it's a number. Note:
853 * Because '-' and '+' have other special meanings, I
854 * don't deal with signed numbers here.
856 if (isdigit((unsigned char)(c = **in))) {
857 for (*value = 0; isdigit((unsigned char)(c = *(*in)++)); )
858 *value = 10 * *value + c - '0';
867 #define TM_YEAR_ORIGIN 1900
869 /* Yield A - B, measured in seconds. */
871 difftm (struct tm *a, struct tm *b)
873 int ay = a->tm_year + (TM_YEAR_ORIGIN - 1);
874 int by = b->tm_year + (TM_YEAR_ORIGIN - 1);
876 /* difference in day of year */
877 a->tm_yday - b->tm_yday
878 /* + intervening leap days */
879 + ((ay >> 2) - (by >> 2))
881 + ((ay/100 >> 2) - (by/100 >> 2))
882 /* + difference in years * 365 */
883 + (long)(ay-by) * 365
885 return (days * DAY + (a->tm_hour - b->tm_hour) * HOUR
886 + (a->tm_min - b->tm_min) * MINUTE
887 + (a->tm_sec - b->tm_sec));
892 * The public function.
894 * TODO: tokens[] array should be dynamically sized.
897 __archive_get_date(time_t now, const char *p)
899 struct token tokens[256];
901 struct token *lasttoken;
903 struct tm local, *tm;
904 struct tm gmt, *gmt_ptr;
909 /* Clear out the parsed token array. */
910 memset(tokens, 0, sizeof(tokens));
911 /* Initialize the parser state. */
912 memset(&_gds, 0, sizeof(_gds));
915 /* Look up the current time. */
916 memset(&local, 0, sizeof(local));
917 tm = localtime (&now);
922 /* Look up UTC if we can and use that to determine the current
923 * timezone offset. */
924 memset(&gmt, 0, sizeof(gmt));
925 gmt_ptr = gmtime (&now);
926 if (gmt_ptr != NULL) {
927 /* Copy, in case localtime and gmtime use the same buffer. */
931 tzone = difftm (&gmt, &local);
933 /* This system doesn't understand timezones; fake it. */
938 /* Tokenize the input string. */
940 while ((lasttoken->token = nexttoken(&p, &lasttoken->value)) != 0) {
942 if (lasttoken > tokens + 255)
945 gds->tokenp = tokens;
947 /* Match phrases until we run out of input tokens. */
948 while (gds->tokenp < lasttoken) {
953 /* Use current local timezone if none was specified. */
954 if (!gds->HaveZone) {
955 gds->Timezone = tzone;
956 gds->DSTmode = DSTmaybe;
959 /* If a timezone was specified, use that for generating the default
960 * time components instead of the local timezone. */
961 if (gds->HaveZone && gmt_ptr != NULL) {
962 now -= gds->Timezone;
963 gmt_ptr = gmtime (&now);
966 now += gds->Timezone;
970 gds->Year = local.tm_year + 1900;
972 gds->Month = local.tm_mon + 1;
974 gds->Day = local.tm_mday;
975 /* Note: No default for hour/min/sec; a specifier that just
976 * gives date always refers to 00:00 on that date. */
978 /* If we saw more than one time, timezone, weekday, year, month,
979 * or day, then give up. */
980 if (gds->HaveTime > 1 || gds->HaveZone > 1 || gds->HaveWeekDay > 1
981 || gds->HaveYear > 1 || gds->HaveMonth > 1 || gds->HaveDay > 1)
984 /* Compute an absolute time based on whatever absolute information
986 if (gds->HaveYear || gds->HaveMonth || gds->HaveDay
987 || gds->HaveTime || gds->HaveWeekDay) {
988 Start = Convert(gds->Month, gds->Day, gds->Year,
989 gds->Hour, gds->Minutes, gds->Seconds,
990 gds->Timezone, gds->DSTmode);
996 Start -= local.tm_hour * HOUR + local.tm_min * MINUTE
1000 /* Add the relative offset. */
1001 Start += gds->RelSeconds;
1002 Start += RelativeMonth(Start, gds->Timezone, gds->RelMonth);
1004 /* Adjust for day-of-week offsets. */
1005 if (gds->HaveWeekDay
1006 && !(gds->HaveYear || gds->HaveMonth || gds->HaveDay)) {
1007 tod = RelativeDate(Start, gds->Timezone,
1008 gds->DSTmode, gds->DayOrdinal, gds->DayNumber);
1012 /* -1 is an error indicator, so return 0 instead of -1 if
1013 * that's the actual time. */
1014 return Start == -1 ? 0 : Start;
1022 main(int argc, char **argv)
1025 time_t now = time(NULL);
1027 while (*++argv != NULL) {
1028 (void)printf("Input: %s\n", *argv);
1029 d = get_date(now, *argv);
1031 (void)printf("Bad format - couldn't convert.\n");
1033 (void)printf("Output: %s\n", ctime(&d));
1038 #endif /* defined(TEST) */