3 * March 2005: Further modified and simplified by Tim Kientzle:
4 * Eliminate minutes-based calculations (just do everything in
5 * seconds), have lexer only recognize unsigned integers (handle '+'
6 * and '-' characters in grammar), combine tables into one table with
7 * explicit abbreviation notes, do am/pm adjustments in the grammar
8 * (eliminate some state variables and post-processing). Among other
9 * things, these changes eliminated two shift/reduce conflicts. (Went
11 * All of Tim Kientzle's changes to this file are public domain.
15 ** Originally written by Steven M. Bellovin <smb@research.att.com> while
16 ** at the University of North Carolina at Chapel Hill. Later tweaked by
17 ** a couple of people on Usenet. Completely overhauled by Rich $alz
18 ** <rsalz@bbn.com> and Jim Berets <jberets@bbn.com> in August, 1990;
20 ** This grammar has 10 shift/reduce conflicts.
22 ** This code is in the public domain and has no copyright.
24 /* SUPPRESS 287 on yaccpar_sccsid *//* Unused static variable */
25 /* SUPPRESS 288 on yyerrlab *//* Label unused */
28 #include <sys/cdefs.h>
29 __FBSDID("$FreeBSD$");
38 #define yyparse getdate_yyparse
39 #define yylex getdate_yylex
40 #define yyerror getdate_yyerror
42 static int yyparse(void);
43 static int yylex(void);
44 static int yyerror(const char *);
46 time_t get_date(char *);
49 #define HOUR(x) ((time_t)(x) * 60)
50 #define SECSPERDAY (24L * 60L * 60L)
53 ** Daylight-savings mode: on, off, or not yet known.
55 typedef enum _DSTMODE {
56 DSTon, DSToff, DSTmaybe
60 ** Meridian: am or pm.
65 ** Global variables. We could get rid of most of these by using a good
66 ** union as the yacc stack. (This routine was originally written before
67 ** yacc had the %union construct.) Maybe someday; right now we only use
68 ** the %union very rarely.
72 static DSTMODE yyDSTmode;
73 static time_t yyDayOrdinal;
74 static time_t yyDayNumber;
75 static int yyHaveDate;
78 static int yyHaveTime;
79 static int yyHaveZone;
80 static time_t yyTimezone;
83 static time_t yyMinutes;
84 static time_t yyMonth;
85 static time_t yySeconds;
87 static time_t yyRelMonth;
88 static time_t yyRelSeconds;
96 %token tAGO tDAY tDAYZONE tAMPM tMONTH tMONTH_UNIT tSEC_UNIT tUNUMBER
99 %type <Number> tDAY tDAYZONE tMONTH tMONTH_UNIT
100 %type <Number> tSEC_UNIT tUNUMBER tZONE tAMPM
108 item : time { yyHaveTime++; }
109 | zone { yyHaveZone++; }
110 | date { yyHaveDate++; }
111 | day { yyHaveDay++; }
112 | rel { yyHaveRel++; }
116 time : tUNUMBER tAMPM {
127 /* "7:12:18" "19:17" */
130 /* "7:12pm", "12:20:13am" */
136 | bare_time '+' tUNUMBER {
139 yyTimezone = - ($3 % 100 + ($3 / 100) * 60);
141 | bare_time '-' tUNUMBER {
142 /* "19:14:12-0530" */
144 yyTimezone = + ($3 % 100 + ($3 / 100) * 60);
148 bare_time : tUNUMBER ':' tUNUMBER {
153 | tUNUMBER ':' tUNUMBER ':' tUNUMBER {
179 /* "tue," "wednesday," */
184 /* "second tues" "3 wed" */
190 date : tUNUMBER '/' tUNUMBER {
195 | tUNUMBER '/' tUNUMBER '/' tUNUMBER {
197 /* First number is big: 2004/01/29, 99/02/17 */
201 } else if (($5 >= 13) || ($3 >= 13)) {
202 /* Last number is big: 01/07/98 */
203 /* Middle number is big: 01/29/04 */
208 /* No significant clues: 02/03/04 */
214 | tUNUMBER '-' tUNUMBER '-' tUNUMBER {
215 /* ISO 8601 format. yyyy-mm-dd. */
220 | tUNUMBER '-' tMONTH '-' tUNUMBER {
222 /* e.g. 1992-Jun-17 */
227 /* e.g. 17-JUN-1992. */
238 | tMONTH tUNUMBER ',' tUNUMBER {
239 /* "June 17, 2001" */
249 | tUNUMBER tMONTH tUNUMBER {
258 yyRelSeconds = -yyRelSeconds;
259 yyRelMonth = -yyRelMonth;
264 relunit : '-' tUNUMBER tSEC_UNIT {
266 yyRelSeconds -= $2 * $3;
268 | '+' tUNUMBER tSEC_UNIT {
270 yyRelSeconds += $2 * $3;
272 | tUNUMBER tSEC_UNIT {
274 yyRelSeconds += $1 * $2;
280 | '-' tUNUMBER tMONTH_UNIT {
282 yyRelMonth -= $2 * $3;
284 | '+' tUNUMBER tMONTH_UNIT {
286 yyRelMonth += $2 * $3;
288 | tUNUMBER tMONTH_UNIT {
290 yyRelMonth += $1 * $2;
299 if (yyHaveTime && yyHaveDate && !yyHaveRel)
306 yyMonth= ($1/100)%100;
310 /* "513" is same as "5:13" */
318 yyMinutes = $1 % 100;
329 static struct TABLE {
334 } const TimeWords[] = {
336 { 0, "am", tAMPM, tAM },
337 { 0, "pm", tAMPM, tPM },
340 { 3, "january", tMONTH, 1 },
341 { 3, "february", tMONTH, 2 },
342 { 3, "march", tMONTH, 3 },
343 { 3, "april", tMONTH, 4 },
344 { 3, "may", tMONTH, 5 },
345 { 3, "june", tMONTH, 6 },
346 { 3, "july", tMONTH, 7 },
347 { 3, "august", tMONTH, 8 },
348 { 3, "september", tMONTH, 9 },
349 { 3, "october", tMONTH, 10 },
350 { 3, "november", tMONTH, 11 },
351 { 3, "december", tMONTH, 12 },
353 /* Days of the week. */
354 { 2, "sunday", tDAY, 0 },
355 { 3, "monday", tDAY, 1 },
356 { 2, "tuesday", tDAY, 2 },
357 { 3, "wednesday", tDAY, 3 },
358 { 2, "thursday", tDAY, 4 },
359 { 2, "friday", tDAY, 5 },
360 { 2, "saturday", tDAY, 6 },
362 /* Timezones: Offsets are in minutes. */
363 { 0, "gmt", tZONE, HOUR( 0) }, /* Greenwich Mean */
364 { 0, "ut", tZONE, HOUR( 0) }, /* Universal (Coordinated) */
365 { 0, "utc", tZONE, HOUR( 0) },
366 { 0, "wet", tZONE, HOUR( 0) }, /* Western European */
367 { 0, "bst", tDAYZONE, HOUR( 0) }, /* British Summer */
368 { 0, "wat", tZONE, HOUR( 1) }, /* West Africa */
369 { 0, "at", tZONE, HOUR( 2) }, /* Azores */
370 /* { 0, "bst", tZONE, HOUR( 3) }, */ /* Brazil Standard: Conflict */
371 /* { 0, "gst", tZONE, HOUR( 3) }, */ /* Greenland Standard: Conflict*/
372 { 0, "nft", tZONE, HOUR(3)+30 }, /* Newfoundland */
373 { 0, "nst", tZONE, HOUR(3)+30 }, /* Newfoundland Standard */
374 { 0, "ndt", tDAYZONE, HOUR(3)+30 }, /* Newfoundland Daylight */
375 { 0, "ast", tZONE, HOUR( 4) }, /* Atlantic Standard */
376 { 0, "adt", tDAYZONE, HOUR( 4) }, /* Atlantic Daylight */
377 { 0, "est", tZONE, HOUR( 5) }, /* Eastern Standard */
378 { 0, "edt", tDAYZONE, HOUR( 5) }, /* Eastern Daylight */
379 { 0, "cst", tZONE, HOUR( 6) }, /* Central Standard */
380 { 0, "cdt", tDAYZONE, HOUR( 6) }, /* Central Daylight */
381 { 0, "mst", tZONE, HOUR( 7) }, /* Mountain Standard */
382 { 0, "mdt", tDAYZONE, HOUR( 7) }, /* Mountain Daylight */
383 { 0, "pst", tZONE, HOUR( 8) }, /* Pacific Standard */
384 { 0, "pdt", tDAYZONE, HOUR( 8) }, /* Pacific Daylight */
385 { 0, "yst", tZONE, HOUR( 9) }, /* Yukon Standard */
386 { 0, "ydt", tDAYZONE, HOUR( 9) }, /* Yukon Daylight */
387 { 0, "hst", tZONE, HOUR(10) }, /* Hawaii Standard */
388 { 0, "hdt", tDAYZONE, HOUR(10) }, /* Hawaii Daylight */
389 { 0, "cat", tZONE, HOUR(10) }, /* Central Alaska */
390 { 0, "ahst", tZONE, HOUR(10) }, /* Alaska-Hawaii Standard */
391 { 0, "nt", tZONE, HOUR(11) }, /* Nome */
392 { 0, "idlw", tZONE, HOUR(12) }, /* Intl Date Line West */
393 { 0, "cet", tZONE, -HOUR(1) }, /* Central European */
394 { 0, "met", tZONE, -HOUR(1) }, /* Middle European */
395 { 0, "mewt", tZONE, -HOUR(1) }, /* Middle European Winter */
396 { 0, "mest", tDAYZONE, -HOUR(1) }, /* Middle European Summer */
397 { 0, "swt", tZONE, -HOUR(1) }, /* Swedish Winter */
398 { 0, "sst", tDAYZONE, -HOUR(1) }, /* Swedish Summer */
399 { 0, "fwt", tZONE, -HOUR(1) }, /* French Winter */
400 { 0, "fst", tDAYZONE, -HOUR(1) }, /* French Summer */
401 { 0, "eet", tZONE, -HOUR(2) }, /* Eastern Eur, USSR Zone 1 */
402 { 0, "bt", tZONE, -HOUR(3) }, /* Baghdad, USSR Zone 2 */
403 { 0, "it", tZONE, -HOUR(3)-30 },/* Iran */
404 { 0, "zp4", tZONE, -HOUR(4) }, /* USSR Zone 3 */
405 { 0, "zp5", tZONE, -HOUR(5) }, /* USSR Zone 4 */
406 { 0, "ist", tZONE, -HOUR(5)-30 },/* Indian Standard */
407 { 0, "zp6", tZONE, -HOUR(6) }, /* USSR Zone 5 */
408 /* { 0, "nst", tZONE, -HOUR(6.5) }, */ /* North Sumatra: Conflict */
409 /* { 0, "sst", tZONE, -HOUR(7) }, */ /* So Sumatra, USSR 6: Conflict */
410 { 0, "wast", tZONE, -HOUR(7) }, /* West Australian Standard */
411 { 0, "wadt", tDAYZONE, -HOUR(7) }, /* West Australian Daylight */
412 { 0, "jt", tZONE, -HOUR(7)-30 },/* Java (3pm in Cronusland!)*/
413 { 0, "cct", tZONE, -HOUR(8) }, /* China Coast, USSR Zone 7 */
414 { 0, "jst", tZONE, -HOUR(9) }, /* Japan Std, USSR Zone 8 */
415 { 0, "cast", tZONE, -HOUR(9)-30 },/* Central Australian Std */
416 { 0, "cadt", tDAYZONE, -HOUR(9)-30 },/* Central Australian Daylt */
417 { 0, "east", tZONE, -HOUR(10) }, /* Eastern Australian Std */
418 { 0, "eadt", tDAYZONE, -HOUR(10) }, /* Eastern Australian Daylt */
419 { 0, "gst", tZONE, -HOUR(10) }, /* Guam Std, USSR Zone 9 */
420 { 0, "nzt", tZONE, -HOUR(12) }, /* New Zealand */
421 { 0, "nzst", tZONE, -HOUR(12) }, /* New Zealand Standard */
422 { 0, "nzdt", tDAYZONE, -HOUR(12) }, /* New Zealand Daylight */
423 { 0, "idle", tZONE, -HOUR(12) }, /* Intl Date Line East */
425 { 0, "dst", tDST, 0 },
428 { 4, "years", tMONTH_UNIT, 12 },
429 { 5, "months", tMONTH_UNIT, 1 },
430 { 9, "fortnights", tSEC_UNIT, 14 * 24 * 60 * 60 },
431 { 4, "weeks", tSEC_UNIT, 7 * 24 * 60 * 60 },
432 { 3, "days", tSEC_UNIT, 1 * 24 * 60 * 60 },
433 { 4, "hours", tSEC_UNIT, 60 * 60 },
434 { 3, "minutes", tSEC_UNIT, 60 },
435 { 3, "seconds", tSEC_UNIT, 1 },
437 /* Relative-time words. */
438 { 0, "tomorrow", tSEC_UNIT, 1 * 24 * 60 * 60 },
439 { 0, "yesterday", tSEC_UNIT, -1 * 24 * 60 * 60 },
440 { 0, "today", tSEC_UNIT, 0 },
441 { 0, "now", tSEC_UNIT, 0 },
442 { 0, "last", tUNUMBER, -1 },
443 { 0, "this", tSEC_UNIT, 0 },
444 { 0, "next", tUNUMBER, 2 },
445 { 0, "first", tUNUMBER, 1 },
446 { 0, "1st", tUNUMBER, 1 },
447 /* { 0, "second", tUNUMBER, 2 }, */
448 { 0, "2nd", tUNUMBER, 2 },
449 { 0, "third", tUNUMBER, 3 },
450 { 0, "3rd", tUNUMBER, 3 },
451 { 0, "fourth", tUNUMBER, 4 },
452 { 0, "4th", tUNUMBER, 4 },
453 { 0, "fifth", tUNUMBER, 5 },
454 { 0, "5th", tUNUMBER, 5 },
455 { 0, "sixth", tUNUMBER, 6 },
456 { 0, "seventh", tUNUMBER, 7 },
457 { 0, "eighth", tUNUMBER, 8 },
458 { 0, "ninth", tUNUMBER, 9 },
459 { 0, "tenth", tUNUMBER, 10 },
460 { 0, "eleventh", tUNUMBER, 11 },
461 { 0, "twelfth", tUNUMBER, 12 },
462 { 0, "ago", tAGO, 1 },
464 /* Military timezones. */
465 { 0, "a", tZONE, HOUR( 1) },
466 { 0, "b", tZONE, HOUR( 2) },
467 { 0, "c", tZONE, HOUR( 3) },
468 { 0, "d", tZONE, HOUR( 4) },
469 { 0, "e", tZONE, HOUR( 5) },
470 { 0, "f", tZONE, HOUR( 6) },
471 { 0, "g", tZONE, HOUR( 7) },
472 { 0, "h", tZONE, HOUR( 8) },
473 { 0, "i", tZONE, HOUR( 9) },
474 { 0, "k", tZONE, HOUR( 10) },
475 { 0, "l", tZONE, HOUR( 11) },
476 { 0, "m", tZONE, HOUR( 12) },
477 { 0, "n", tZONE, HOUR(- 1) },
478 { 0, "o", tZONE, HOUR(- 2) },
479 { 0, "p", tZONE, HOUR(- 3) },
480 { 0, "q", tZONE, HOUR(- 4) },
481 { 0, "r", tZONE, HOUR(- 5) },
482 { 0, "s", tZONE, HOUR(- 6) },
483 { 0, "t", tZONE, HOUR(- 7) },
484 { 0, "u", tZONE, HOUR(- 8) },
485 { 0, "v", tZONE, HOUR(- 9) },
486 { 0, "w", tZONE, HOUR(-10) },
487 { 0, "x", tZONE, HOUR(-11) },
488 { 0, "y", tZONE, HOUR(-12) },
489 { 0, "z", tZONE, HOUR( 0) },
500 yyerror(const char *s)
507 ToSeconds(time_t Hours, time_t Minutes, time_t Seconds)
509 if (Minutes < 0 || Minutes > 59 || Seconds < 0 || Seconds > 59)
511 if (Hours < 0 || Hours > 23)
513 return (Hours * 60L + Minutes) * 60L + Seconds;
518 * A number from 0 to 99, which means a year from 1970 to 2069, or
519 * The actual year (>=100). */
521 Convert(time_t Month, time_t Day, time_t Year,
522 time_t Hours, time_t Minutes, time_t Seconds, DSTMODE DSTmode)
524 static int DaysInMonth[12] = {
525 31, 0, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31
535 DaysInMonth[1] = Year % 4 == 0 && (Year % 100 != 0 || Year % 400 == 0)
537 /* Checking for 2038 bogusly assumes that time_t is 32 bits. But
538 I'm too lazy to try to check for time_t overflow in another way. */
539 if (Year < EPOCH || Year > 2038
540 || Month < 1 || Month > 12
541 /* Lint fluff: "conversion from long may lose accuracy" */
542 || Day < 1 || Day > DaysInMonth[(int)--Month])
546 for (i = 0; i < Month; i++)
547 Julian += DaysInMonth[i];
548 for (i = EPOCH; i < Year; i++)
549 Julian += 365 + (i % 4 == 0);
550 Julian *= SECSPERDAY;
551 Julian += yyTimezone * 60L;
552 if ((tod = ToSeconds(Hours, Minutes, Seconds)) < 0)
556 || (DSTmode == DSTmaybe && localtime(&Julian)->tm_isdst))
563 DSTcorrect(time_t Start, time_t Future)
568 StartDay = (localtime(&Start)->tm_hour + 1) % 24;
569 FutureDay = (localtime(&Future)->tm_hour + 1) % 24;
570 return (Future - Start) + (StartDay - FutureDay) * 60L * 60L;
575 RelativeDate(time_t Start, time_t DayOrdinal, time_t DayNumber)
581 tm = localtime(&now);
582 now += SECSPERDAY * ((DayNumber - tm->tm_wday + 7) % 7);
583 now += 7 * SECSPERDAY * (DayOrdinal <= 0 ? DayOrdinal : DayOrdinal - 1);
584 return DSTcorrect(Start, now);
589 RelativeMonth(time_t Start, time_t RelMonth)
597 tm = localtime(&Start);
598 Month = 12 * (tm->tm_year + 1900) + tm->tm_mon + RelMonth;
600 Month = Month % 12 + 1;
601 return DSTcorrect(Start,
602 Convert(Month, (time_t)tm->tm_mday, Year,
603 (time_t)tm->tm_hour, (time_t)tm->tm_min, (time_t)tm->tm_sec,
614 while (isspace((unsigned char)*yyInput))
617 /* Skip parenthesized comments. */
618 if (*yyInput == '(') {
632 /* Try the next token in the word table first. */
633 /* This allows us to match "2nd", for example. */
636 const struct TABLE *tp;
639 /* Force to lowercase and strip '.' characters. */
641 && (isalnum((unsigned char)*src) || *src == '.')
642 && i < sizeof(buff)-1) {
644 if (isupper((unsigned char)*src))
645 buff[i++] = tolower((unsigned char)*src);
654 * Find the first match. If the word can be
655 * abbreviated, make sure we match at least
656 * the minimum abbreviation.
658 for (tp = TimeWords; tp->name; tp++) {
659 size_t abbrev = tp->abbrev;
661 abbrev = strlen(tp->name);
662 if (strlen(buff) >= abbrev
663 && strncmp(tp->name, buff, strlen(buff))
665 /* Skip over token. */
667 /* Return the match. */
668 yylval.Number = tp->value;
675 * Not in the word table, maybe it's a number. Note:
676 * Because '-' and '+' have other special meanings, I
677 * don't deal with signed numbers here.
679 if (isdigit((unsigned char)(c = *yyInput))) {
680 for (yylval.Number = 0; isdigit((unsigned char)(c = *yyInput++)); )
681 yylval.Number = 10 * yylval.Number + c - '0';
690 #define TM_YEAR_ORIGIN 1900
692 /* Yield A - B, measured in seconds. */
694 difftm (struct tm *a, struct tm *b)
696 int ay = a->tm_year + (TM_YEAR_ORIGIN - 1);
697 int by = b->tm_year + (TM_YEAR_ORIGIN - 1);
699 /* difference in day of year */
700 a->tm_yday - b->tm_yday
701 /* + intervening leap days */
702 + ((ay >> 2) - (by >> 2))
704 + ((ay/100 >> 2) - (by/100 >> 2))
705 /* + difference in years * 365 */
706 + (long)(ay-by) * 365
708 return (60*(60*(24*days + (a->tm_hour - b->tm_hour))
709 + (a->tm_min - b->tm_min))
710 + (a->tm_sec - b->tm_sec));
717 struct tm gmt, *gmt_ptr;
723 memset(&gmt, 0, sizeof(gmt));
726 (void)time (&nowtime);
728 gmt_ptr = gmtime (&nowtime);
729 if (gmt_ptr != NULL) {
730 /* Copy, in case localtime and gmtime use the same buffer. */
734 if (! (tm = localtime (&nowtime)))
738 tzone = difftm (&gmt, tm) / 60;
740 /* This system doesn't understand timezones; fake it. */
745 yyYear = tm->tm_year + 1900;
746 yyMonth = tm->tm_mon + 1;
749 yyDSTmode = DSTmaybe;
762 || yyHaveTime > 1 || yyHaveZone > 1
763 || yyHaveDate > 1 || yyHaveDay > 1)
766 if (yyHaveDate || yyHaveTime || yyHaveDay) {
767 Start = Convert(yyMonth, yyDay, yyYear,
768 yyHour, yyMinutes, yySeconds, yyDSTmode);
774 Start -= ((tm->tm_hour * 60L + tm->tm_min) * 60L) + tm->tm_sec;
777 Start += yyRelSeconds;
778 Start += RelativeMonth(Start, yyRelMonth);
780 if (yyHaveDay && !yyHaveDate) {
781 tod = RelativeDate(Start, yyDayOrdinal, yyDayNumber);
785 /* Have to do *something* with a legitimate -1 so it's
786 * distinguishable from the error return value. (Alternately
787 * could set errno on error.) */
788 return Start == -1 ? 0 : Start;
796 main(int argc, char **argv)
800 while (*++argv != NULL) {
801 (void)printf("Input: %s\n", *argv);
804 (void)printf("Bad format - couldn't convert.\n");
806 (void)printf("Output: %s\n", ctime(&d));
811 #endif /* defined(TEST) */