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@uncnsrd.mt-kisco.ny.us> 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 */
22 #include <sys/types.h>
25 #include "parsedate.h"
29 #define yyparse date_parse
30 #define yylex date_lex
31 #define yyerror date_error
34 /* See the LeapYears table in Convert. */
36 #define END_OF_TIME 2038
37 /* Constants for general time calculations. */
39 #define SECSPERDAY (24L * 60L * 60L)
40 /* Readability for TABLE stuff. */
41 #define HOUR(x) (x * 60)
45 #define IS7BIT(x) ((unsigned int)(x) < 0200)
47 #define SIZEOF(array) ((int)(sizeof array / sizeof array[0]))
48 #define ENDOF(array) (&array[SIZEOF(array)])
52 ** An entry in the lexical lookup table.
54 typedef struct _TABLE {
61 ** Daylight-savings mode: on, off, or not yet known.
63 typedef enum _DSTMODE {
64 DSTon, DSToff, DSTmaybe
68 ** Meridian: am, pm, or 24-hour style.
70 typedef enum _MERIDIAN {
76 ** Global variables. We could get rid of most of them by using a yacc
77 ** union, but this is more efficient. (This routine predates the
78 ** yacc %union construct.)
81 static DSTMODE yyDSTmode;
82 static int yyHaveDate;
84 static int yyHaveTime;
85 static time_t yyTimezone;
88 static time_t yyMinutes;
89 static time_t yyMonth;
90 static time_t yySeconds;
92 static MERIDIAN yyMeridian;
93 static time_t yyRelMonth;
94 static time_t yyRelSeconds;
97 static void date_error(char *);
102 enum _MERIDIAN Meridian;
105 %token tDAY tDAYZONE tMERIDIAN tMONTH tMONTH_UNIT tSEC_UNIT tSNUMBER
106 %token tUNUMBER tZONE
108 %type <Number> tDAYZONE tMONTH tMONTH_UNIT tSEC_UNIT
109 %type <Number> tSNUMBER tUNUMBER tZONE numzone zone
110 %type <Meridian> tMERIDIAN o_merid
121 /* I am compulsive about lint natterings... */
122 if (yyHaveTime == -1) {
139 time : tUNUMBER o_merid {
146 yyMinutes = $1 % 100;
151 | tUNUMBER ':' tUNUMBER o_merid {
157 | tUNUMBER ':' tUNUMBER numzone {
164 | tUNUMBER ':' tUNUMBER ':' tUNUMBER o_merid {
170 | tUNUMBER ':' tUNUMBER ':' tUNUMBER numzone {
189 /* Only allow "GMT+300" and "GMT-0800" */
205 /* Unix and GMT and numeric timezones -- a little confusing. */
207 /* Don't work with negative modulus. */
209 if ($1 > 9999 || (i = $1 % 100) >= 60) {
212 $$ = ($1 / 100) * 60 + i;
215 if ($1 > 9999 || (i = $1 % 100) >= 60) {
218 $$ = -(($1 / 100) * 60 + i);
223 date : tUNUMBER '/' tUNUMBER {
227 | tUNUMBER '/' tUNUMBER '/' tUNUMBER {
243 | tMONTH tUNUMBER ',' tUNUMBER {
252 | tUNUMBER tMONTH tUNUMBER {
257 | tDAY ',' tUNUMBER tMONTH tUNUMBER {
264 rel : tSNUMBER tSEC_UNIT {
265 yyRelSeconds += $1 * $2;
267 | tUNUMBER tSEC_UNIT {
268 yyRelSeconds += $1 * $2;
270 | tSNUMBER tMONTH_UNIT {
271 yyRelMonth += $1 * $2;
273 | tUNUMBER tMONTH_UNIT {
274 yyRelMonth += $1 * $2;
278 o_merid : /* NULL */ {
288 /* Month and day table. */
289 static TABLE MonthDayTable[] = {
290 { "january", tMONTH, 1 },
291 { "february", tMONTH, 2 },
292 { "march", tMONTH, 3 },
293 { "april", tMONTH, 4 },
294 { "may", tMONTH, 5 },
295 { "june", tMONTH, 6 },
296 { "july", tMONTH, 7 },
297 { "august", tMONTH, 8 },
298 { "september", tMONTH, 9 },
299 { "october", tMONTH, 10 },
300 { "november", tMONTH, 11 },
301 { "december", tMONTH, 12 },
302 /* The value of the day isn't used... */
303 { "sunday", tDAY, 0 },
304 { "monday", tDAY, 0 },
305 { "tuesday", tDAY, 0 },
306 { "wednesday", tDAY, 0 },
307 { "thursday", tDAY, 0 },
308 { "friday", tDAY, 0 },
309 { "saturday", tDAY, 0 },
312 /* Time units table. */
313 static TABLE UnitsTable[] = {
314 { "year", tMONTH_UNIT, 12 },
315 { "month", tMONTH_UNIT, 1 },
316 { "week", tSEC_UNIT, 7L * 24 * 60 * 60 },
317 { "day", tSEC_UNIT, 1L * 24 * 60 * 60 },
318 { "hour", tSEC_UNIT, 60 * 60 },
319 { "minute", tSEC_UNIT, 60 },
320 { "min", tSEC_UNIT, 60 },
321 { "second", tSEC_UNIT, 1 },
322 { "sec", tSEC_UNIT, 1 },
325 /* Timezone table. */
326 static TABLE TimezoneTable[] = {
327 { "gmt", tZONE, HOUR( 0) }, /* Greenwich Mean */
328 { "ut", tZONE, HOUR( 0) }, /* Universal */
329 { "utc", tZONE, HOUR( 0) }, /* Universal Coordinated */
330 { "cut", tZONE, HOUR( 0) }, /* Coordinated Universal */
331 { "z", tZONE, HOUR( 0) }, /* Greenwich Mean */
332 { "wet", tZONE, HOUR( 0) }, /* Western European */
333 { "bst", tDAYZONE, HOUR( 0) }, /* British Summer */
334 { "nst", tZONE, HOUR(3)+30 }, /* Newfoundland Standard */
335 { "ndt", tDAYZONE, HOUR(3)+30 }, /* Newfoundland Daylight */
336 { "ast", tZONE, HOUR( 4) }, /* Atlantic Standard */
337 { "adt", tDAYZONE, HOUR( 4) }, /* Atlantic Daylight */
338 { "est", tZONE, HOUR( 5) }, /* Eastern Standard */
339 { "edt", tDAYZONE, HOUR( 5) }, /* Eastern Daylight */
340 { "cst", tZONE, HOUR( 6) }, /* Central Standard */
341 { "cdt", tDAYZONE, HOUR( 6) }, /* Central Daylight */
342 { "mst", tZONE, HOUR( 7) }, /* Mountain Standard */
343 { "mdt", tDAYZONE, HOUR( 7) }, /* Mountain Daylight */
344 { "pst", tZONE, HOUR( 8) }, /* Pacific Standard */
345 { "pdt", tDAYZONE, HOUR( 8) }, /* Pacific Daylight */
346 { "yst", tZONE, HOUR( 9) }, /* Yukon Standard */
347 { "ydt", tDAYZONE, HOUR( 9) }, /* Yukon Daylight */
348 { "akst", tZONE, HOUR( 9) }, /* Alaska Standard */
349 { "akdt", tDAYZONE, HOUR( 9) }, /* Alaska Daylight */
350 { "hst", tZONE, HOUR(10) }, /* Hawaii Standard */
351 { "hast", tZONE, HOUR(10) }, /* Hawaii-Aleutian Standard */
352 { "hadt", tDAYZONE, HOUR(10) }, /* Hawaii-Aleutian Daylight */
353 { "ces", tDAYZONE, -HOUR(1) }, /* Central European Summer */
354 { "cest", tDAYZONE, -HOUR(1) }, /* Central European Summer */
355 { "mez", tZONE, -HOUR(1) }, /* Middle European */
356 { "mezt", tDAYZONE, -HOUR(1) }, /* Middle European Summer */
357 { "cet", tZONE, -HOUR(1) }, /* Central European */
358 { "met", tZONE, -HOUR(1) }, /* Middle European */
359 { "eet", tZONE, -HOUR(2) }, /* Eastern Europe */
360 { "msk", tZONE, -HOUR(3) }, /* Moscow Winter */
361 { "msd", tDAYZONE, -HOUR(3) }, /* Moscow Summer */
362 { "wast", tZONE, -HOUR(8) }, /* West Australian Standard */
363 { "wadt", tDAYZONE, -HOUR(8) }, /* West Australian Daylight */
364 { "hkt", tZONE, -HOUR(8) }, /* Hong Kong */
365 { "cct", tZONE, -HOUR(8) }, /* China Coast */
366 { "jst", tZONE, -HOUR(9) }, /* Japan Standard */
367 { "kst", tZONE, -HOUR(9) }, /* Korean Standard */
368 { "kdt", tZONE, -HOUR(9) }, /* Korean Daylight */
369 { "cast", tZONE, -(HOUR(9)+30) }, /* Central Australian Standard */
370 { "cadt", tDAYZONE, -(HOUR(9)+30) }, /* Central Australian Daylight */
371 { "east", tZONE, -HOUR(10) }, /* Eastern Australian Standard */
372 { "eadt", tDAYZONE, -HOUR(10) }, /* Eastern Australian Daylight */
373 { "nzst", tZONE, -HOUR(12) }, /* New Zealand Standard */
374 { "nzdt", tDAYZONE, -HOUR(12) }, /* New Zealand Daylight */
376 /* For completeness we include the following entries. */
379 /* Duplicate names. Either they conflict with a zone listed above
380 * (which is either more likely to be seen or just been in circulation
381 * longer), or they conflict with another zone in this section and
382 * we could not reasonably choose one over the other. */
383 { "fst", tZONE, HOUR( 2) }, /* Fernando De Noronha Standard */
384 { "fdt", tDAYZONE, HOUR( 2) }, /* Fernando De Noronha Daylight */
385 { "bst", tZONE, HOUR( 3) }, /* Brazil Standard */
386 { "est", tZONE, HOUR( 3) }, /* Eastern Standard (Brazil) */
387 { "edt", tDAYZONE, HOUR( 3) }, /* Eastern Daylight (Brazil) */
388 { "wst", tZONE, HOUR( 4) }, /* Western Standard (Brazil) */
389 { "wdt", tDAYZONE, HOUR( 4) }, /* Western Daylight (Brazil) */
390 { "cst", tZONE, HOUR( 5) }, /* Chile Standard */
391 { "cdt", tDAYZONE, HOUR( 5) }, /* Chile Daylight */
392 { "ast", tZONE, HOUR( 5) }, /* Acre Standard */
393 { "adt", tDAYZONE, HOUR( 5) }, /* Acre Daylight */
394 { "cst", tZONE, HOUR( 5) }, /* Cuba Standard */
395 { "cdt", tDAYZONE, HOUR( 5) }, /* Cuba Daylight */
396 { "est", tZONE, HOUR( 6) }, /* Easter Island Standard */
397 { "edt", tDAYZONE, HOUR( 6) }, /* Easter Island Daylight */
398 { "sst", tZONE, HOUR(11) }, /* Samoa Standard */
399 { "ist", tZONE, -HOUR(2) }, /* Israel Standard */
400 { "idt", tDAYZONE, -HOUR(2) }, /* Israel Daylight */
401 { "idt", tDAYZONE, -(HOUR(3)+30) }, /* Iran Daylight */
402 { "ist", tZONE, -(HOUR(3)+30) }, /* Iran Standard */
403 { "cst", tZONE, -HOUR(8) }, /* China Standard */
404 { "cdt", tDAYZONE, -HOUR(8) }, /* China Daylight */
405 { "sst", tZONE, -HOUR(8) }, /* Singapore Standard */
407 /* Dubious (e.g., not in Olson's TIMEZONE package) or obsolete. */
408 { "gst", tZONE, HOUR( 3) }, /* Greenland Standard */
409 { "wat", tZONE, -HOUR(1) }, /* West Africa */
410 { "at", tZONE, HOUR( 2) }, /* Azores */
411 { "gst", tZONE, -HOUR(10) }, /* Guam Standard */
412 { "nft", tZONE, HOUR(3)+30 }, /* Newfoundland */
413 { "idlw", tZONE, HOUR(12) }, /* International Date Line West */
414 { "mewt", tZONE, -HOUR(1) }, /* Middle European Winter */
415 { "mest", tDAYZONE, -HOUR(1) }, /* Middle European Summer */
416 { "swt", tZONE, -HOUR(1) }, /* Swedish Winter */
417 { "sst", tDAYZONE, -HOUR(1) }, /* Swedish Summer */
418 { "fwt", tZONE, -HOUR(1) }, /* French Winter */
419 { "fst", tDAYZONE, -HOUR(1) }, /* French Summer */
420 { "bt", tZONE, -HOUR(3) }, /* Baghdad */
421 { "it", tZONE, -(HOUR(3)+30) }, /* Iran */
422 { "zp4", tZONE, -HOUR(4) }, /* USSR Zone 3 */
423 { "zp5", tZONE, -HOUR(5) }, /* USSR Zone 4 */
424 { "ist", tZONE, -(HOUR(5)+30) }, /* Indian Standard */
425 { "zp6", tZONE, -HOUR(6) }, /* USSR Zone 5 */
426 { "nst", tZONE, -HOUR(7) }, /* North Sumatra */
427 { "sst", tZONE, -HOUR(7) }, /* South Sumatra */
428 { "jt", tZONE, -(HOUR(7)+30) }, /* Java (3pm in Cronusland!) */
429 { "nzt", tZONE, -HOUR(12) }, /* New Zealand */
430 { "idle", tZONE, -HOUR(12) }, /* International Date Line East */
431 { "cat", tZONE, HOUR(10) }, /* -- expired 1967 */
432 { "nt", tZONE, HOUR(11) }, /* -- expired 1967 */
433 { "ahst", tZONE, HOUR(10) }, /* -- expired 1983 */
434 { "hdt", tDAYZONE, HOUR(10) }, /* -- expired 1986 */
448 ToSeconds(time_t Hours, time_t Minutes, time_t Seconds, MERIDIAN Meridian)
450 if (Minutes < 0 || Minutes > 59 || Seconds < 0 || Seconds > 61)
452 if (Meridian == MER24) {
453 if (Hours < 0 || Hours > 23)
457 if (Hours < 1 || Hours > 12)
461 if (Meridian == MERpm)
464 return (Hours * 60L + Minutes) * 60L + Seconds;
469 Convert(time_t Month, time_t Day, time_t Year,
470 time_t Hours, time_t Minutes, time_t Seconds,
471 MERIDIAN Meridian, DSTMODE dst)
473 static int DaysNormal[13] = {
474 0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31
476 static int DaysLeap[13] = {
477 0, 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31
479 static int LeapYears[] = {
480 1972, 1976, 1980, 1984, 1988, 1992, 1996,
481 2000, 2004, 2008, 2012, 2016, 2020, 2024, 2028, 2032, 2036
485 register time_t Julian;
495 for (mp = DaysNormal, yp = LeapYears; yp < ENDOF(LeapYears); yp++)
500 if (Year < EPOCH || Year > END_OF_TIME
501 || Month < 1 || Month > 12
502 /* NOSTRICT *//* conversion from long may lose accuracy */
503 || Day < 1 || Day > mp[(int)Month])
506 Julian = Day - 1 + (Year - EPOCH) * 365;
507 for (yp = LeapYears; yp < ENDOF(LeapYears); yp++, Julian++)
510 for (i = 1; i < Month; i++)
512 Julian *= SECSPERDAY;
513 Julian += yyTimezone * 60L;
514 if ((tod = ToSeconds(Hours, Minutes, Seconds, Meridian)) < 0)
518 if (dst == DSTon || (dst == DSTmaybe && localtime(&tod)->tm_isdst))
519 Julian -= DST_OFFSET * 60L * 60L;
525 DSTcorrect(time_t Start, time_t Future)
530 StartDay = (localtime(&Start)->tm_hour + 1) % 24;
531 FutureDay = (localtime(&Future)->tm_hour + 1) % 24;
532 return (Future - Start) + (StartDay - FutureDay) * DST_OFFSET * 60L * 60L;
537 RelativeMonth(time_t Start, time_t RelMonth)
543 tm = localtime(&Start);
544 Month = 12 * tm->tm_year + tm->tm_mon + RelMonth;
546 Month = Month % 12 + 1;
547 return DSTcorrect(Start,
548 Convert(Month, (time_t)tm->tm_mday, Year,
549 (time_t)tm->tm_hour, (time_t)tm->tm_min, (time_t)tm->tm_sec,
555 LookupWord(char *buff, register int length)
565 /* See if we have an abbreviation for a month. */
566 if (length == 3 || (length == 4 && p[3] == '.'))
567 for (tp = MonthDayTable; tp < ENDOF(MonthDayTable); tp++) {
569 if (c == q[0] && p[1] == q[1] && p[2] == q[2]) {
570 yylval.Number = tp->value;
575 for (tp = MonthDayTable; tp < ENDOF(MonthDayTable); tp++)
576 if (c == tp->name[0] && strcmp(p, tp->name) == 0) {
577 yylval.Number = tp->value;
581 /* Try for a timezone. */
582 for (tp = TimezoneTable; tp < ENDOF(TimezoneTable); tp++)
583 if (c == tp->name[0] && p[1] == tp->name[1]
584 && strcmp(p, tp->name) == 0) {
585 yylval.Number = tp->value;
589 /* Try the units table. */
590 for (tp = UnitsTable; tp < ENDOF(UnitsTable); tp++)
591 if (c == tp->name[0] && strcmp(p, tp->name) == 0) {
592 yylval.Number = tp->value;
596 /* Strip off any plural and try the units table again. */
597 if (--length > 0 && p[length] == 's') {
599 for (tp = UnitsTable; tp < ENDOF(UnitsTable); tp++)
600 if (c == tp->name[0] && strcmp(p, tp->name) == 0) {
602 yylval.Number = tp->value;
609 /* Drop out any periods. */
610 for (p = buff, q = (char*)buff; *q; q++)
615 /* Try the meridians. */
616 if (buff[1] == 'm' && buff[2] == '\0') {
617 if (buff[0] == 'a') {
618 yylval.Meridian = MERam;
621 if (buff[0] == 'p') {
622 yylval.Meridian = MERpm;
627 /* If we saw any periods, try the timezones again. */
628 if (p - buff != length) {
630 for (p = buff, tp = TimezoneTable; tp < ENDOF(TimezoneTable); tp++)
631 if (c == tp->name[0] && p[1] == tp->name[1]
632 && strcmp(p, tp->name) == 0) {
633 yylval.Number = tp->value;
638 /* Unknown word -- assume GMT timezone. */
652 register int nesting;
655 /* Get first character after the whitespace. */
657 while (isspace(*yyInput))
661 /* Ignore RFC 822 comments, typically time zone names. */
664 for (nesting = 1; (c = *++yyInput) != RPAREN || --nesting; )
667 else if (!IS7BIT(c) || c == '\0' || c == '\r'
668 || (c == '\\' && ((c = *++yyInput) == '\0' || !IS7BIT(c))))
669 /* Lexical error: bad comment. */
675 if (isdigit(c) || c == '-' || c == '+') {
676 if (c == '-' || c == '+') {
677 sign = c == '-' ? -1 : 1;
679 if (!isdigit(*yyInput))
680 /* Skip the plus or minus sign. */
685 for (i = 0; (c = *yyInput++) != '\0' && isdigit(c); )
686 i = 10 * i + c - '0';
688 yylval.Number = sign < 0 ? -i : i;
689 return sign ? tSNUMBER : tUNUMBER;
694 for (p = buff; (c = *yyInput++) == '.' || isalpha(c); )
695 if (p < &buff[sizeof buff - 1])
696 *p++ = isupper(c) ? tolower(c) : c;
699 return LookupWord(buff, p - buff);
710 extern int date_parse(void);
719 yyDSTmode = DSTmaybe;
730 if (date_parse() || yyHaveTime > 1 || yyHaveDate > 1)
733 if (yyHaveDate || yyHaveTime) {
734 Start = Convert(yyMonth, yyDay, yyYear, yyHour, yyMinutes, yySeconds,
735 yyMeridian, yyDSTmode);
742 Start += yyRelSeconds;
744 Start += RelativeMonth(Start, yyRelMonth);
746 /* Have to do *something* with a legitimate -1 so it's distinguishable
747 * from the error return value. (Alternately could set errno on error.) */
748 return Start == -1 ? 0 : Start;
760 main(int ac, char *av[])
769 (void)printf("Enter date, or blank line to exit.\n\t> ");
771 (void)printf("\t> ");
772 (void)fflush(stdout);
773 if (gets(buff) == NULL || buff[0] == '\n')
776 if (strcmp(buff, "yydebug") == 0) {
778 printf("yydebug = %s\n", yydebug ? "on" : "off");
782 d = parsedate(buff, (TIMEINFO *)NULL);
784 (void)printf("Bad format - couldn't convert.\n");
786 (void)printf("%s", ctime(&d));