4 ** Originally written by Steven M. Bellovin <smb@research.att.com> while
5 ** at the University of North Carolina at Chapel Hill. Later tweaked by
6 ** a couple of people on Usenet. Completely overhauled by Rich $alz
7 ** <rsalz@osf.org> and Jim Berets <jberets@bbn.com> in August, 1990.
8 ** Further revised (removed obsolete constructs and cleaned up timezone
9 ** names) in August, 1991, by Rich. Paul Eggert <eggert@twinsun.com>
10 ** helped in September, 1992. Art Cancro <ajc@citadel.org> cleaned
11 ** it up for ANSI C in December, 1999.
13 ** This grammar has six shift/reduce conflicts.
15 ** This code is in the public domain and has no copyright.
17 /* SUPPRESS 530 *//* Empty body for statement */
18 /* SUPPRESS 593 on yyerrlab *//* Label was not used */
19 /* SUPPRESS 593 on yynewstate *//* Label was not used */
20 /* SUPPRESS 595 on yypvt *//* Automatic variable may be used before set */
26 #include <sys/types.h>
30 # if !STDC_HEADERS && HAVE_MEMORY_H
39 #include "parsedate.h"
43 #define yyparse date_parse
44 #define yylex date_lex
45 #define yyerror date_error
48 /* See the LeapYears table in Convert. */
50 #define END_OF_TIME 2038
51 /* Constants for general time calculations. */
53 #define SECSPERDAY (24L * 60L * 60L)
54 /* Readability for TABLE stuff. */
55 #define HOUR(x) (x * 60)
59 #define IS7BIT(x) ((unsigned int)(x) < 0200)
61 #define SIZEOF(array) ((int)(sizeof array / sizeof array[0]))
62 #define ENDOF(array) (&array[SIZEOF(array)])
66 ** An entry in the lexical lookup table.
68 typedef struct _TABLE {
75 ** Daylight-savings mode: on, off, or not yet known.
77 typedef enum _DSTMODE {
78 DSTon, DSToff, DSTmaybe
82 ** Meridian: am, pm, or 24-hour style.
84 typedef enum _MERIDIAN {
90 ** Global variables. We could get rid of most of them by using a yacc
91 ** union, but this is more efficient. (This routine predates the
92 ** yacc %union construct.)
94 static const char *yyInput;
95 static DSTMODE yyDSTmode;
96 static int yyHaveDate;
98 static int yyHaveTime;
99 static time_t yyTimezone;
101 static time_t yyHour;
102 static time_t yyMinutes;
103 static time_t yyMonth;
104 static time_t yySeconds;
105 static time_t yyYear;
106 static MERIDIAN yyMeridian;
107 static time_t yyRelMonth;
108 static time_t yyRelSeconds;
111 static void date_error(char *);
116 enum _MERIDIAN Meridian;
119 %token tDAY tDAYZONE tMERIDIAN tMONTH tMONTH_UNIT tSEC_UNIT tSNUMBER
120 %token tUNUMBER tZONE
122 %type <Number> tDAYZONE tMONTH tMONTH_UNIT tSEC_UNIT
123 %type <Number> tSNUMBER tUNUMBER tZONE numzone zone
124 %type <Meridian> tMERIDIAN o_merid
135 /* I am compulsive about lint natterings... */
136 if (yyHaveTime == -1) {
153 time : tUNUMBER o_merid {
160 yyMinutes = $1 % 100;
165 | tUNUMBER ':' tUNUMBER o_merid {
171 | tUNUMBER ':' tUNUMBER numzone {
178 | tUNUMBER ':' tUNUMBER ':' tUNUMBER o_merid {
184 | tUNUMBER ':' tUNUMBER ':' tUNUMBER numzone {
203 /* Only allow "GMT+300" and "GMT-0800" */
219 /* Unix and GMT and numeric timezones -- a little confusing. */
221 /* Don't work with negative modulus. */
223 if ($1 > 9999 || (i = $1 % 100) >= 60) {
226 $$ = ($1 / 100) * 60 + i;
229 if ($1 > 9999 || (i = $1 % 100) >= 60) {
232 $$ = -(($1 / 100) * 60 + i);
237 date : tUNUMBER '/' tUNUMBER {
241 | tUNUMBER '/' tUNUMBER '/' tUNUMBER {
257 | tMONTH tUNUMBER ',' tUNUMBER {
266 | tUNUMBER tMONTH tUNUMBER {
271 | tDAY ',' tUNUMBER tMONTH tUNUMBER {
278 rel : tSNUMBER tSEC_UNIT {
279 yyRelSeconds += $1 * $2;
281 | tUNUMBER tSEC_UNIT {
282 yyRelSeconds += $1 * $2;
284 | tSNUMBER tMONTH_UNIT {
285 yyRelMonth += $1 * $2;
287 | tUNUMBER tMONTH_UNIT {
288 yyRelMonth += $1 * $2;
292 o_merid : /* NULL */ {
302 /* Month and day table. */
303 static TABLE MonthDayTable[] = {
304 { "january", tMONTH, 1 },
305 { "february", tMONTH, 2 },
306 { "march", tMONTH, 3 },
307 { "april", tMONTH, 4 },
308 { "may", tMONTH, 5 },
309 { "june", tMONTH, 6 },
310 { "july", tMONTH, 7 },
311 { "august", tMONTH, 8 },
312 { "september", tMONTH, 9 },
313 { "october", tMONTH, 10 },
314 { "november", tMONTH, 11 },
315 { "december", tMONTH, 12 },
316 /* The value of the day isn't used... */
317 { "sunday", tDAY, 0 },
318 { "monday", tDAY, 0 },
319 { "tuesday", tDAY, 0 },
320 { "wednesday", tDAY, 0 },
321 { "thursday", tDAY, 0 },
322 { "friday", tDAY, 0 },
323 { "saturday", tDAY, 0 },
326 /* Time units table. */
327 static TABLE UnitsTable[] = {
328 { "year", tMONTH_UNIT, 12 },
329 { "month", tMONTH_UNIT, 1 },
330 { "week", tSEC_UNIT, 7L * 24 * 60 * 60 },
331 { "day", tSEC_UNIT, 1L * 24 * 60 * 60 },
332 { "hour", tSEC_UNIT, 60 * 60 },
333 { "minute", tSEC_UNIT, 60 },
334 { "min", tSEC_UNIT, 60 },
335 { "second", tSEC_UNIT, 1 },
336 { "sec", tSEC_UNIT, 1 },
339 /* Timezone table. */
340 static TABLE TimezoneTable[] = {
341 { "gmt", tZONE, HOUR( 0) }, /* Greenwich Mean */
342 { "ut", tZONE, HOUR( 0) }, /* Universal */
343 { "utc", tZONE, HOUR( 0) }, /* Universal Coordinated */
344 { "cut", tZONE, HOUR( 0) }, /* Coordinated Universal */
345 { "z", tZONE, HOUR( 0) }, /* Greenwich Mean */
346 { "wet", tZONE, HOUR( 0) }, /* Western European */
347 { "bst", tDAYZONE, HOUR( 0) }, /* British Summer */
348 { "nst", tZONE, HOUR(3)+30 }, /* Newfoundland Standard */
349 { "ndt", tDAYZONE, HOUR(3)+30 }, /* Newfoundland Daylight */
350 { "ast", tZONE, HOUR( 4) }, /* Atlantic Standard */
351 { "adt", tDAYZONE, HOUR( 4) }, /* Atlantic Daylight */
352 { "est", tZONE, HOUR( 5) }, /* Eastern Standard */
353 { "edt", tDAYZONE, HOUR( 5) }, /* Eastern Daylight */
354 { "cst", tZONE, HOUR( 6) }, /* Central Standard */
355 { "cdt", tDAYZONE, HOUR( 6) }, /* Central Daylight */
356 { "mst", tZONE, HOUR( 7) }, /* Mountain Standard */
357 { "mdt", tDAYZONE, HOUR( 7) }, /* Mountain Daylight */
358 { "pst", tZONE, HOUR( 8) }, /* Pacific Standard */
359 { "pdt", tDAYZONE, HOUR( 8) }, /* Pacific Daylight */
360 { "yst", tZONE, HOUR( 9) }, /* Yukon Standard */
361 { "ydt", tDAYZONE, HOUR( 9) }, /* Yukon Daylight */
362 { "akst", tZONE, HOUR( 9) }, /* Alaska Standard */
363 { "akdt", tDAYZONE, HOUR( 9) }, /* Alaska Daylight */
364 { "hst", tZONE, HOUR(10) }, /* Hawaii Standard */
365 { "hast", tZONE, HOUR(10) }, /* Hawaii-Aleutian Standard */
366 { "hadt", tDAYZONE, HOUR(10) }, /* Hawaii-Aleutian Daylight */
367 { "ces", tDAYZONE, -HOUR(1) }, /* Central European Summer */
368 { "cest", tDAYZONE, -HOUR(1) }, /* Central European Summer */
369 { "mez", tZONE, -HOUR(1) }, /* Middle European */
370 { "mezt", tDAYZONE, -HOUR(1) }, /* Middle European Summer */
371 { "cet", tZONE, -HOUR(1) }, /* Central European */
372 { "met", tZONE, -HOUR(1) }, /* Middle European */
373 { "eet", tZONE, -HOUR(2) }, /* Eastern Europe */
374 { "msk", tZONE, -HOUR(3) }, /* Moscow Winter */
375 { "msd", tDAYZONE, -HOUR(3) }, /* Moscow Summer */
376 { "wast", tZONE, -HOUR(8) }, /* West Australian Standard */
377 { "wadt", tDAYZONE, -HOUR(8) }, /* West Australian Daylight */
378 { "hkt", tZONE, -HOUR(8) }, /* Hong Kong */
379 { "cct", tZONE, -HOUR(8) }, /* China Coast */
380 { "jst", tZONE, -HOUR(9) }, /* Japan Standard */
381 { "kst", tZONE, -HOUR(9) }, /* Korean Standard */
382 { "kdt", tZONE, -HOUR(9) }, /* Korean Daylight */
383 { "cast", tZONE, -(HOUR(9)+30) }, /* Central Australian Standard */
384 { "cadt", tDAYZONE, -(HOUR(9)+30) }, /* Central Australian Daylight */
385 { "east", tZONE, -HOUR(10) }, /* Eastern Australian Standard */
386 { "eadt", tDAYZONE, -HOUR(10) }, /* Eastern Australian Daylight */
387 { "nzst", tZONE, -HOUR(12) }, /* New Zealand Standard */
388 { "nzdt", tDAYZONE, -HOUR(12) }, /* New Zealand Daylight */
390 /* For completeness we include the following entries. */
393 /* Duplicate names. Either they conflict with a zone listed above
394 * (which is either more likely to be seen or just been in circulation
395 * longer), or they conflict with another zone in this section and
396 * we could not reasonably choose one over the other. */
397 { "fst", tZONE, HOUR( 2) }, /* Fernando De Noronha Standard */
398 { "fdt", tDAYZONE, HOUR( 2) }, /* Fernando De Noronha Daylight */
399 { "bst", tZONE, HOUR( 3) }, /* Brazil Standard */
400 { "est", tZONE, HOUR( 3) }, /* Eastern Standard (Brazil) */
401 { "edt", tDAYZONE, HOUR( 3) }, /* Eastern Daylight (Brazil) */
402 { "wst", tZONE, HOUR( 4) }, /* Western Standard (Brazil) */
403 { "wdt", tDAYZONE, HOUR( 4) }, /* Western Daylight (Brazil) */
404 { "cst", tZONE, HOUR( 5) }, /* Chile Standard */
405 { "cdt", tDAYZONE, HOUR( 5) }, /* Chile Daylight */
406 { "ast", tZONE, HOUR( 5) }, /* Acre Standard */
407 { "adt", tDAYZONE, HOUR( 5) }, /* Acre Daylight */
408 { "cst", tZONE, HOUR( 5) }, /* Cuba Standard */
409 { "cdt", tDAYZONE, HOUR( 5) }, /* Cuba Daylight */
410 { "est", tZONE, HOUR( 6) }, /* Easter Island Standard */
411 { "edt", tDAYZONE, HOUR( 6) }, /* Easter Island Daylight */
412 { "sst", tZONE, HOUR(11) }, /* Samoa Standard */
413 { "ist", tZONE, -HOUR(2) }, /* Israel Standard */
414 { "idt", tDAYZONE, -HOUR(2) }, /* Israel Daylight */
415 { "idt", tDAYZONE, -(HOUR(3)+30) }, /* Iran Daylight */
416 { "ist", tZONE, -(HOUR(3)+30) }, /* Iran Standard */
417 { "cst", tZONE, -HOUR(8) }, /* China Standard */
418 { "cdt", tDAYZONE, -HOUR(8) }, /* China Daylight */
419 { "sst", tZONE, -HOUR(8) }, /* Singapore Standard */
421 /* Dubious (e.g., not in Olson's TIMEZONE package) or obsolete. */
422 { "gst", tZONE, HOUR( 3) }, /* Greenland Standard */
423 { "wat", tZONE, -HOUR(1) }, /* West Africa */
424 { "at", tZONE, HOUR( 2) }, /* Azores */
425 { "gst", tZONE, -HOUR(10) }, /* Guam Standard */
426 { "nft", tZONE, HOUR(3)+30 }, /* Newfoundland */
427 { "idlw", tZONE, HOUR(12) }, /* International Date Line West */
428 { "mewt", tZONE, -HOUR(1) }, /* Middle European Winter */
429 { "mest", tDAYZONE, -HOUR(1) }, /* Middle European Summer */
430 { "swt", tZONE, -HOUR(1) }, /* Swedish Winter */
431 { "sst", tDAYZONE, -HOUR(1) }, /* Swedish Summer */
432 { "fwt", tZONE, -HOUR(1) }, /* French Winter */
433 { "fst", tDAYZONE, -HOUR(1) }, /* French Summer */
434 { "bt", tZONE, -HOUR(3) }, /* Baghdad */
435 { "it", tZONE, -(HOUR(3)+30) }, /* Iran */
436 { "zp4", tZONE, -HOUR(4) }, /* USSR Zone 3 */
437 { "zp5", tZONE, -HOUR(5) }, /* USSR Zone 4 */
438 { "ist", tZONE, -(HOUR(5)+30) }, /* Indian Standard */
439 { "zp6", tZONE, -HOUR(6) }, /* USSR Zone 5 */
440 { "nst", tZONE, -HOUR(7) }, /* North Sumatra */
441 { "sst", tZONE, -HOUR(7) }, /* South Sumatra */
442 { "jt", tZONE, -(HOUR(7)+30) }, /* Java (3pm in Cronusland!) */
443 { "nzt", tZONE, -HOUR(12) }, /* New Zealand */
444 { "idle", tZONE, -HOUR(12) }, /* International Date Line East */
445 { "cat", tZONE, HOUR(10) }, /* -- expired 1967 */
446 { "nt", tZONE, HOUR(11) }, /* -- expired 1967 */
447 { "ahst", tZONE, HOUR(10) }, /* -- expired 1983 */
448 { "hdt", tDAYZONE, HOUR(10) }, /* -- expired 1986 */
462 ToSeconds(time_t Hours, time_t Minutes, time_t Seconds, MERIDIAN Meridian)
464 if (Minutes < 0 || Minutes > 59 || Seconds < 0 || Seconds > 61)
466 if (Meridian == MER24) {
467 if (Hours < 0 || Hours > 23)
471 if (Hours < 1 || Hours > 12)
475 if (Meridian == MERpm)
478 return (Hours * 60L + Minutes) * 60L + Seconds;
483 Convert(time_t Month, time_t Day, time_t Year,
484 time_t Hours, time_t Minutes, time_t Seconds,
485 MERIDIAN Meridian, DSTMODE dst)
487 static int DaysNormal[13] = {
488 0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31
490 static int DaysLeap[13] = {
491 0, 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31
493 static int LeapYears[] = {
494 1972, 1976, 1980, 1984, 1988, 1992, 1996,
495 2000, 2004, 2008, 2012, 2016, 2020, 2024, 2028, 2032, 2036
499 register time_t Julian;
509 for (mp = DaysNormal, yp = LeapYears; yp < ENDOF(LeapYears); yp++)
514 if (Year < EPOCH || Year > END_OF_TIME
515 || Month < 1 || Month > 12
516 /* NOSTRICT *//* conversion from long may lose accuracy */
517 || Day < 1 || Day > mp[(int)Month])
520 Julian = Day - 1 + (Year - EPOCH) * 365;
521 for (yp = LeapYears; yp < ENDOF(LeapYears); yp++, Julian++)
524 for (i = 1; i < Month; i++)
526 Julian *= SECSPERDAY;
527 Julian += yyTimezone * 60L;
528 if ((tod = ToSeconds(Hours, Minutes, Seconds, Meridian)) < 0)
532 if (dst == DSTon || (dst == DSTmaybe && localtime(&tod)->tm_isdst))
533 Julian -= DST_OFFSET * 60L * 60L;
539 DSTcorrect(time_t Start, time_t Future)
544 StartDay = (localtime(&Start)->tm_hour + 1) % 24;
545 FutureDay = (localtime(&Future)->tm_hour + 1) % 24;
546 return (Future - Start) + (StartDay - FutureDay) * DST_OFFSET * 60L * 60L;
551 RelativeMonth(time_t Start, time_t RelMonth)
557 tm = localtime(&Start);
558 Month = 12 * tm->tm_year + tm->tm_mon + RelMonth;
560 Month = Month % 12 + 1;
561 return DSTcorrect(Start,
562 Convert(Month, (time_t)tm->tm_mday, Year,
563 (time_t)tm->tm_hour, (time_t)tm->tm_min, (time_t)tm->tm_sec,
569 LookupWord(char *buff, register int length)
579 /* See if we have an abbreviation for a month. */
580 if (length == 3 || (length == 4 && p[3] == '.'))
581 for (tp = MonthDayTable; tp < ENDOF(MonthDayTable); tp++) {
583 if (c == q[0] && p[1] == q[1] && p[2] == q[2]) {
584 yylval.Number = tp->value;
589 for (tp = MonthDayTable; tp < ENDOF(MonthDayTable); tp++)
590 if (c == tp->name[0] && strcmp(p, tp->name) == 0) {
591 yylval.Number = tp->value;
595 /* Try for a timezone. */
596 for (tp = TimezoneTable; tp < ENDOF(TimezoneTable); tp++)
597 if (c == tp->name[0] && p[1] == tp->name[1]
598 && strcmp(p, tp->name) == 0) {
599 yylval.Number = tp->value;
603 /* Try the units table. */
604 for (tp = UnitsTable; tp < ENDOF(UnitsTable); tp++)
605 if (c == tp->name[0] && strcmp(p, tp->name) == 0) {
606 yylval.Number = tp->value;
610 /* Strip off any plural and try the units table again. */
611 if (--length > 0 && p[length] == 's') {
613 for (tp = UnitsTable; tp < ENDOF(UnitsTable); tp++)
614 if (c == tp->name[0] && strcmp(p, tp->name) == 0) {
616 yylval.Number = tp->value;
623 /* Drop out any periods. */
624 for (p = buff, q = (char*)buff; *q; q++)
629 /* Try the meridians. */
630 if (buff[1] == 'm' && buff[2] == '\0') {
631 if (buff[0] == 'a') {
632 yylval.Meridian = MERam;
635 if (buff[0] == 'p') {
636 yylval.Meridian = MERpm;
641 /* If we saw any periods, try the timezones again. */
642 if (p - buff != length) {
644 for (p = buff, tp = TimezoneTable; tp < ENDOF(TimezoneTable); tp++)
645 if (c == tp->name[0] && p[1] == tp->name[1]
646 && strcmp(p, tp->name) == 0) {
647 yylval.Number = tp->value;
652 /* Unknown word -- assume GMT timezone. */
666 register int nesting;
669 /* Get first character after the whitespace. */
671 while (isspace(*yyInput))
675 /* Ignore RFC 822 comments, typically time zone names. */
678 for (nesting = 1; (c = *++yyInput) != RPAREN || --nesting; )
681 else if (!IS7BIT(c) || c == '\0' || c == '\r'
682 || (c == '\\' && ((c = *++yyInput) == '\0' || !IS7BIT(c))))
683 /* Lexical error: bad comment. */
689 if (isdigit(c) || c == '-' || c == '+') {
690 if (c == '-' || c == '+') {
691 sign = c == '-' ? -1 : 1;
693 if (!isdigit(*yyInput))
694 /* Skip the plus or minus sign. */
699 for (i = 0; (c = *yyInput++) != '\0' && isdigit(c); )
700 i = 10 * i + c - '0';
702 yylval.Number = sign < 0 ? -i : i;
703 return sign ? tSNUMBER : tUNUMBER;
708 for (p = buff; (c = *yyInput++) == '.' || isalpha(c); )
709 if (p < &buff[sizeof buff - 1])
710 *p++ = isupper(c) ? tolower(c) : c;
713 return LookupWord(buff, p - buff);
722 parsedate(const char *p)
724 extern int date_parse(void);
727 yyInput = p; /* well, its supposed to be const... */
733 yyDSTmode = DSTmaybe;
744 if (date_parse() || yyHaveTime > 1 || yyHaveDate > 1)
747 if (yyHaveDate || yyHaveTime) {
748 Start = Convert(yyMonth, yyDay, yyYear, yyHour, yyMinutes, yySeconds,
749 yyMeridian, yyDSTmode);
756 Start += yyRelSeconds;
758 Start += RelativeMonth(Start, yyRelMonth);
760 /* Have to do *something* with a legitimate -1 so it's distinguishable
761 * from the error return value. (Alternately could set errno on error.) */
762 return Start == -1 ? 0 : Start;
774 main(int ac, char *av[])
783 (void)printf("Enter date, or blank line to exit.\n\t> ");
785 (void)printf("\t> ");
786 (void)fflush(stdout);
787 if (fgets(buff, sizeof buff, stdin) == NULL || buff[0] == '\n')
790 if (strcmp(buff, "yydebug") == 0) {
792 printf("yydebug = %s\n", yydebug ? "on" : "off");
796 d = parsedate(buff, (TIMEINFO *)NULL);
798 (void)printf("Bad format - couldn't convert.\n");
800 (void)printf("%s", ctime(&d));