2 /* Parse a string into an internal time stamp.
4 Copyright (C) 1999, 2000, 2002, 2003, 2004, 2005, 2006, 2007, 2008
5 Free Software Foundation, Inc.
7 This program is free software: you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3 of the License, or
10 (at your option) any later version.
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with this program. If not, see <http://www.gnu.org/licenses/>. */
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 Modified by Paul Eggert <eggert@twinsun.com> in August 1999 to do
26 the right thing about local DST. Also modified by Paul Eggert
27 <eggert@cs.ucla.edu> in February 2004 to support
28 nanosecond-resolution time stamps, and in October 2004 to support
29 TZ strings in dates. */
31 /* FIXME: Check for arithmetic overflow in all cases, not just
42 /* There's no need to extend the stack, so there's no need to involve
44 #define YYSTACK_USE_ALLOCA 0
46 /* Tell Bison how much stack space is needed. 20 should be plenty for
47 this grammar, which is not right recursive. Beware setting it too
48 high, since that might cause problems on machines whose
49 implementations have lame stack-overflow checking. */
51 #define YYINITDEPTH YYMAXDEPTH
53 /* Since the code of getdate.y is not included in the Emacs executable
54 itself, there is no need to #define static in this file. Even if
55 the code were included in the Emacs executable, it probably
56 wouldn't do any harm to #undef it here; this will only cause
57 problems if we try to write to a static variable, which I don't
58 think this code needs to do. */
72 /* ISDIGIT differs from isdigit, as follows:
73 - Its arg may be any int or unsigned int; it need not be an unsigned char
75 - It's typically faster.
76 POSIX says that only '0' through '9' are digits. Prefer ISDIGIT to
77 isdigit unless it's important to use the locale's definition
78 of `digit' even when the host does not conform to POSIX. */
79 #define ISDIGIT(c) ((unsigned int) (c) - '0' <= 9)
82 # if __GNUC__ < 2 || (__GNUC__ == 2 && __GNUC_MINOR__ < 8) || __STRICT_ANSI__
83 # define __attribute__(x)
87 #ifndef ATTRIBUTE_UNUSED
88 # define ATTRIBUTE_UNUSED __attribute__ ((__unused__))
91 /* Shift A right by B bits portably, by dividing A by 2**B and
92 truncating towards minus infinity. A and B should be free of side
93 effects, and B should be in the range 0 <= B <= INT_BITS - 2, where
94 INT_BITS is the number of useful bits in an int. GNU code can
95 assume that INT_BITS is at least 32.
97 ISO C99 says that A >> B is implementation-defined if A < 0. Some
98 implementations (e.g., UNICOS 9.0 on a Cray Y-MP EL) don't shift
99 right in the usual way when A < 0, so SHR falls back on division if
100 ordinary A >> B doesn't seem to be the usual signed shift. */
104 : (a) / (1 << (b)) - ((a) % (1 << (b)) < 0))
106 #define EPOCH_YEAR 1970
107 #define TM_YEAR_BASE 1900
109 #define HOUR(x) ((x) * 60)
111 /* Lots of this code assumes time_t and time_t-like values fit into
112 long int. It also assumes that signed integer overflow silently
113 wraps around, but there's no portable way to check for that at
115 verify (TYPE_IS_INTEGER (time_t));
116 verify (LONG_MIN <= TYPE_MINIMUM (time_t) && TYPE_MAXIMUM (time_t) <= LONG_MAX);
118 /* An integer value, and the number of digits in its textual
127 /* An entry in the lexical lookup table. */
135 /* Meridian: am, pm, or 24-hour style. */
136 enum { MERam, MERpm, MER24 };
138 enum { BILLION = 1000000000, LOG10_BILLION = 9 };
140 /* Relative times. */
143 /* Relative year, month, day, hour, minutes, seconds, and nanoseconds. */
153 #if HAVE_COMPOUND_LITERALS
154 # define RELATIVE_TIME_0 ((relative_time) { 0, 0, 0, 0, 0, 0, 0 })
156 static relative_time const RELATIVE_TIME_0;
159 /* Information passed to and from the parser. */
162 /* The input string remaining to be parsed. */
165 /* N, if this is the Nth Tuesday. */
166 long int day_ordinal;
168 /* Day of week; Sunday is 0. */
171 /* tm_isdst flag for the local zone. */
174 /* Time zone, in minutes east of UTC. */
177 /* Style used for time. */
180 /* Gregorian year, month, day, hour, minutes, seconds, and nanoseconds. */
186 struct timespec seconds; /* includes nanoseconds */
188 /* Relative year, month, day, hour, minutes, seconds, and nanoseconds. */
191 /* Presence or counts of nonterminals of various flavors parsed so far. */
196 size_t local_zones_seen;
201 /* Table of local time zone abbrevations, terminated by a null entry. */
202 table local_time_zone_table[3];
206 static int yylex (union YYSTYPE *, parser_control *);
207 static int yyerror (parser_control const *, char const *);
208 static long int time_zone_hhmm (textint, long int);
210 /* Extract into *PC any date and time info from a string of digits
211 of the form e.g., YYYYMMDD, YYMMDD, HHMM, HH (and sometimes YYY,
214 digits_to_date_time (parser_control *pc, textint text_int)
216 if (pc->dates_seen && ! pc->year.digits
217 && ! pc->rels_seen && (pc->times_seen || 2 < text_int.digits))
221 if (4 < text_int.digits)
224 pc->day = text_int.value % 100;
225 pc->month = (text_int.value / 100) % 100;
226 pc->year.value = text_int.value / 10000;
227 pc->year.digits = text_int.digits - 4;
232 if (text_int.digits <= 2)
234 pc->hour = text_int.value;
239 pc->hour = text_int.value / 100;
240 pc->minutes = text_int.value % 100;
242 pc->seconds.tv_sec = 0;
243 pc->seconds.tv_nsec = 0;
244 pc->meridian = MER24;
249 /* Increment PC->rel by FACTOR * REL (FACTOR is 1 or -1). */
251 apply_relative_time (parser_control *pc, relative_time rel, int factor)
253 pc->rel.ns += factor * rel.ns;
254 pc->rel.seconds += factor * rel.seconds;
255 pc->rel.minutes += factor * rel.minutes;
256 pc->rel.hour += factor * rel.hour;
257 pc->rel.day += factor * rel.day;
258 pc->rel.month += factor * rel.month;
259 pc->rel.year += factor * rel.year;
260 pc->rels_seen = true;
263 /* Set PC-> hour, minutes, seconds and nanoseconds members from arguments. */
265 set_hhmmss (parser_control *pc, long int hour, long int minutes,
266 time_t sec, long int nsec)
269 pc->minutes = minutes;
270 pc->seconds.tv_sec = sec;
271 pc->seconds.tv_nsec = nsec;
276 /* We want a reentrant parser, even if the TZ manipulation and the calls to
277 localtime and gmtime are not reentrant. */
279 %parse-param { parser_control *pc }
280 %lex-param { parser_control *pc }
282 /* This grammar has 20 shift/reduce conflicts. */
289 struct timespec timespec;
295 %token tYEAR_UNIT tMONTH_UNIT tHOUR_UNIT tMINUTE_UNIT tSEC_UNIT
296 %token <intval> tDAY_UNIT
298 %token <intval> tDAY tDAYZONE tLOCAL_ZONE tMERIDIAN
299 %token <intval> tMONTH tORDINAL tZONE
301 %token <textintval> tSNUMBER tUNUMBER
302 %token <timespec> tSDECIMAL_NUMBER tUDECIMAL_NUMBER
304 %type <intval> o_colon_minutes o_merid
305 %type <timespec> seconds signed_seconds unsigned_seconds
307 %type <rel> relunit relunit_snumber
320 pc->timespec_seen = true;
331 { pc->times_seen++; }
333 { pc->local_zones_seen++; }
335 { pc->zones_seen++; }
337 { pc->dates_seen++; }
348 set_hhmmss (pc, $1.value, 0, 0, 0);
351 | tUNUMBER ':' tUNUMBER o_merid
353 set_hhmmss (pc, $1.value, $3.value, 0, 0);
356 | tUNUMBER ':' tUNUMBER tSNUMBER o_colon_minutes
358 set_hhmmss (pc, $1.value, $3.value, 0, 0);
359 pc->meridian = MER24;
361 pc->time_zone = time_zone_hhmm ($4, $5);
363 | tUNUMBER ':' tUNUMBER ':' unsigned_seconds o_merid
365 set_hhmmss (pc, $1.value, $3.value, $5.tv_sec, $5.tv_nsec);
368 | tUNUMBER ':' tUNUMBER ':' unsigned_seconds tSNUMBER o_colon_minutes
370 set_hhmmss (pc, $1.value, $3.value, $5.tv_sec, $5.tv_nsec);
371 pc->meridian = MER24;
373 pc->time_zone = time_zone_hhmm ($6, $7);
380 pc->local_isdst = $1;
381 pc->dsts_seen += (0 < $1);
386 pc->dsts_seen += (0 < $1) + 1;
392 { pc->time_zone = $1; }
393 | tZONE relunit_snumber
394 { pc->time_zone = $1;
395 apply_relative_time (pc, $2, 1); }
396 | tZONE tSNUMBER o_colon_minutes
397 { pc->time_zone = $1 + time_zone_hhmm ($2, $3); }
399 { pc->time_zone = $1 + 60; }
401 { pc->time_zone = $1 + 60; }
417 pc->day_ordinal = $1;
422 pc->day_ordinal = $1.value;
428 tUNUMBER '/' tUNUMBER
430 pc->month = $1.value;
433 | tUNUMBER '/' tUNUMBER '/' tUNUMBER
435 /* Interpret as YYYY/MM/DD if the first value has 4 or more digits,
436 otherwise as MM/DD/YY.
437 The goal in recognizing YYYY/MM/DD is solely to support legacy
438 machine-generated dates like those in an RCS log listing. If
439 you want portability, use the ISO 8601 format. */
443 pc->month = $3.value;
448 pc->month = $1.value;
453 | tUNUMBER tSNUMBER tSNUMBER
455 /* ISO 8601 format. YYYY-MM-DD. */
457 pc->month = -$2.value;
460 | tUNUMBER tMONTH tSNUMBER
462 /* e.g. 17-JUN-1992. */
465 pc->year.value = -$3.value;
466 pc->year.digits = $3.digits;
468 | tMONTH tSNUMBER tSNUMBER
470 /* e.g. JUN-17-1992. */
473 pc->year.value = -$3.value;
474 pc->year.digits = $3.digits;
481 | tMONTH tUNUMBER ',' tUNUMBER
492 | tUNUMBER tMONTH tUNUMBER
502 { apply_relative_time (pc, $1, -1); }
504 { apply_relative_time (pc, $1, 1); }
509 { $$ = RELATIVE_TIME_0; $$.year = $1; }
510 | tUNUMBER tYEAR_UNIT
511 { $$ = RELATIVE_TIME_0; $$.year = $1.value; }
513 { $$ = RELATIVE_TIME_0; $$.year = 1; }
514 | tORDINAL tMONTH_UNIT
515 { $$ = RELATIVE_TIME_0; $$.month = $1; }
516 | tUNUMBER tMONTH_UNIT
517 { $$ = RELATIVE_TIME_0; $$.month = $1.value; }
519 { $$ = RELATIVE_TIME_0; $$.month = 1; }
521 { $$ = RELATIVE_TIME_0; $$.day = $1 * $2; }
523 { $$ = RELATIVE_TIME_0; $$.day = $1.value * $2; }
525 { $$ = RELATIVE_TIME_0; $$.day = $1; }
526 | tORDINAL tHOUR_UNIT
527 { $$ = RELATIVE_TIME_0; $$.hour = $1; }
528 | tUNUMBER tHOUR_UNIT
529 { $$ = RELATIVE_TIME_0; $$.hour = $1.value; }
531 { $$ = RELATIVE_TIME_0; $$.hour = 1; }
532 | tORDINAL tMINUTE_UNIT
533 { $$ = RELATIVE_TIME_0; $$.minutes = $1; }
534 | tUNUMBER tMINUTE_UNIT
535 { $$ = RELATIVE_TIME_0; $$.minutes = $1.value; }
537 { $$ = RELATIVE_TIME_0; $$.minutes = 1; }
539 { $$ = RELATIVE_TIME_0; $$.seconds = $1; }
541 { $$ = RELATIVE_TIME_0; $$.seconds = $1.value; }
542 | tSDECIMAL_NUMBER tSEC_UNIT
543 { $$ = RELATIVE_TIME_0; $$.seconds = $1.tv_sec; $$.ns = $1.tv_nsec; }
544 | tUDECIMAL_NUMBER tSEC_UNIT
545 { $$ = RELATIVE_TIME_0; $$.seconds = $1.tv_sec; $$.ns = $1.tv_nsec; }
547 { $$ = RELATIVE_TIME_0; $$.seconds = 1; }
553 { $$ = RELATIVE_TIME_0; $$.year = $1.value; }
554 | tSNUMBER tMONTH_UNIT
555 { $$ = RELATIVE_TIME_0; $$.month = $1.value; }
557 { $$ = RELATIVE_TIME_0; $$.day = $1.value * $2; }
558 | tSNUMBER tHOUR_UNIT
559 { $$ = RELATIVE_TIME_0; $$.hour = $1.value; }
560 | tSNUMBER tMINUTE_UNIT
561 { $$ = RELATIVE_TIME_0; $$.minutes = $1.value; }
563 { $$ = RELATIVE_TIME_0; $$.seconds = $1.value; }
566 seconds: signed_seconds | unsigned_seconds;
571 { $$.tv_sec = $1.value; $$.tv_nsec = 0; }
577 { $$.tv_sec = $1.value; $$.tv_nsec = 0; }
582 { digits_to_date_time (pc, $1); }
586 tUNUMBER relunit_snumber
588 /* Hybrid all-digit and relative offset, so that we accept e.g.,
589 "YYYYMMDD +N days" as well as "YYYYMMDD N days". */
590 digits_to_date_time (pc, $1);
591 apply_relative_time (pc, $2, 1);
611 static table const meridian_table[] =
613 { "AM", tMERIDIAN, MERam },
614 { "A.M.", tMERIDIAN, MERam },
615 { "PM", tMERIDIAN, MERpm },
616 { "P.M.", tMERIDIAN, MERpm },
620 static table const dst_table[] =
625 static table const month_and_day_table[] =
627 { "JANUARY", tMONTH, 1 },
628 { "FEBRUARY", tMONTH, 2 },
629 { "MARCH", tMONTH, 3 },
630 { "APRIL", tMONTH, 4 },
631 { "MAY", tMONTH, 5 },
632 { "JUNE", tMONTH, 6 },
633 { "JULY", tMONTH, 7 },
634 { "AUGUST", tMONTH, 8 },
635 { "SEPTEMBER",tMONTH, 9 },
636 { "SEPT", tMONTH, 9 },
637 { "OCTOBER", tMONTH, 10 },
638 { "NOVEMBER", tMONTH, 11 },
639 { "DECEMBER", tMONTH, 12 },
640 { "SUNDAY", tDAY, 0 },
641 { "MONDAY", tDAY, 1 },
642 { "TUESDAY", tDAY, 2 },
644 { "WEDNESDAY",tDAY, 3 },
645 { "WEDNES", tDAY, 3 },
646 { "THURSDAY", tDAY, 4 },
648 { "THURS", tDAY, 4 },
649 { "FRIDAY", tDAY, 5 },
650 { "SATURDAY", tDAY, 6 },
654 static table const time_units_table[] =
656 { "YEAR", tYEAR_UNIT, 1 },
657 { "MONTH", tMONTH_UNIT, 1 },
658 { "FORTNIGHT",tDAY_UNIT, 14 },
659 { "WEEK", tDAY_UNIT, 7 },
660 { "DAY", tDAY_UNIT, 1 },
661 { "HOUR", tHOUR_UNIT, 1 },
662 { "MINUTE", tMINUTE_UNIT, 1 },
663 { "MIN", tMINUTE_UNIT, 1 },
664 { "SECOND", tSEC_UNIT, 1 },
665 { "SEC", tSEC_UNIT, 1 },
669 /* Assorted relative-time words. */
670 static table const relative_time_table[] =
672 { "TOMORROW", tDAY_UNIT, 1 },
673 { "YESTERDAY",tDAY_UNIT, -1 },
674 { "TODAY", tDAY_UNIT, 0 },
675 { "NOW", tDAY_UNIT, 0 },
676 { "LAST", tORDINAL, -1 },
677 { "THIS", tORDINAL, 0 },
678 { "NEXT", tORDINAL, 1 },
679 { "FIRST", tORDINAL, 1 },
680 /*{ "SECOND", tORDINAL, 2 }, */
681 { "THIRD", tORDINAL, 3 },
682 { "FOURTH", tORDINAL, 4 },
683 { "FIFTH", tORDINAL, 5 },
684 { "SIXTH", tORDINAL, 6 },
685 { "SEVENTH", tORDINAL, 7 },
686 { "EIGHTH", tORDINAL, 8 },
687 { "NINTH", tORDINAL, 9 },
688 { "TENTH", tORDINAL, 10 },
689 { "ELEVENTH", tORDINAL, 11 },
690 { "TWELFTH", tORDINAL, 12 },
695 /* The universal time zone table. These labels can be used even for
696 time stamps that would not otherwise be valid, e.g., GMT time
697 stamps in London during summer. */
698 static table const universal_time_zone_table[] =
700 { "GMT", tZONE, HOUR ( 0) }, /* Greenwich Mean */
701 { "UT", tZONE, HOUR ( 0) }, /* Universal (Coordinated) */
702 { "UTC", tZONE, HOUR ( 0) },
706 /* The time zone table. This table is necessarily incomplete, as time
707 zone abbreviations are ambiguous; e.g. Australians interpret "EST"
708 as Eastern time in Australia, not as US Eastern Standard Time.
709 You cannot rely on getdate to handle arbitrary time zone
710 abbreviations; use numeric abbreviations like `-0500' instead. */
711 static table const time_zone_table[] =
713 { "WET", tZONE, HOUR ( 0) }, /* Western European */
714 { "WEST", tDAYZONE, HOUR ( 0) }, /* Western European Summer */
715 { "BST", tDAYZONE, HOUR ( 0) }, /* British Summer */
716 { "ART", tZONE, -HOUR ( 3) }, /* Argentina */
717 { "BRT", tZONE, -HOUR ( 3) }, /* Brazil */
718 { "BRST", tDAYZONE, -HOUR ( 3) }, /* Brazil Summer */
719 { "NST", tZONE, -(HOUR ( 3) + 30) }, /* Newfoundland Standard */
720 { "NDT", tDAYZONE,-(HOUR ( 3) + 30) }, /* Newfoundland Daylight */
721 { "AST", tZONE, -HOUR ( 4) }, /* Atlantic Standard */
722 { "ADT", tDAYZONE, -HOUR ( 4) }, /* Atlantic Daylight */
723 { "CLT", tZONE, -HOUR ( 4) }, /* Chile */
724 { "CLST", tDAYZONE, -HOUR ( 4) }, /* Chile Summer */
725 { "EST", tZONE, -HOUR ( 5) }, /* Eastern Standard */
726 { "EDT", tDAYZONE, -HOUR ( 5) }, /* Eastern Daylight */
727 { "CST", tZONE, -HOUR ( 6) }, /* Central Standard */
728 { "CDT", tDAYZONE, -HOUR ( 6) }, /* Central Daylight */
729 { "MST", tZONE, -HOUR ( 7) }, /* Mountain Standard */
730 { "MDT", tDAYZONE, -HOUR ( 7) }, /* Mountain Daylight */
731 { "PST", tZONE, -HOUR ( 8) }, /* Pacific Standard */
732 { "PDT", tDAYZONE, -HOUR ( 8) }, /* Pacific Daylight */
733 { "AKST", tZONE, -HOUR ( 9) }, /* Alaska Standard */
734 { "AKDT", tDAYZONE, -HOUR ( 9) }, /* Alaska Daylight */
735 { "HST", tZONE, -HOUR (10) }, /* Hawaii Standard */
736 { "HAST", tZONE, -HOUR (10) }, /* Hawaii-Aleutian Standard */
737 { "HADT", tDAYZONE, -HOUR (10) }, /* Hawaii-Aleutian Daylight */
738 { "SST", tZONE, -HOUR (12) }, /* Samoa Standard */
739 { "WAT", tZONE, HOUR ( 1) }, /* West Africa */
740 { "CET", tZONE, HOUR ( 1) }, /* Central European */
741 { "CEST", tDAYZONE, HOUR ( 1) }, /* Central European Summer */
742 { "MET", tZONE, HOUR ( 1) }, /* Middle European */
743 { "MEZ", tZONE, HOUR ( 1) }, /* Middle European */
744 { "MEST", tDAYZONE, HOUR ( 1) }, /* Middle European Summer */
745 { "MESZ", tDAYZONE, HOUR ( 1) }, /* Middle European Summer */
746 { "EET", tZONE, HOUR ( 2) }, /* Eastern European */
747 { "EEST", tDAYZONE, HOUR ( 2) }, /* Eastern European Summer */
748 { "CAT", tZONE, HOUR ( 2) }, /* Central Africa */
749 { "SAST", tZONE, HOUR ( 2) }, /* South Africa Standard */
750 { "EAT", tZONE, HOUR ( 3) }, /* East Africa */
751 { "MSK", tZONE, HOUR ( 3) }, /* Moscow */
752 { "MSD", tDAYZONE, HOUR ( 3) }, /* Moscow Daylight */
753 { "IST", tZONE, (HOUR ( 5) + 30) }, /* India Standard */
754 { "SGT", tZONE, HOUR ( 8) }, /* Singapore */
755 { "KST", tZONE, HOUR ( 9) }, /* Korea Standard */
756 { "JST", tZONE, HOUR ( 9) }, /* Japan Standard */
757 { "GST", tZONE, HOUR (10) }, /* Guam Standard */
758 { "NZST", tZONE, HOUR (12) }, /* New Zealand Standard */
759 { "NZDT", tDAYZONE, HOUR (12) }, /* New Zealand Daylight */
763 /* Military time zone table. */
764 static table const military_table[] =
766 { "A", tZONE, -HOUR ( 1) },
767 { "B", tZONE, -HOUR ( 2) },
768 { "C", tZONE, -HOUR ( 3) },
769 { "D", tZONE, -HOUR ( 4) },
770 { "E", tZONE, -HOUR ( 5) },
771 { "F", tZONE, -HOUR ( 6) },
772 { "G", tZONE, -HOUR ( 7) },
773 { "H", tZONE, -HOUR ( 8) },
774 { "I", tZONE, -HOUR ( 9) },
775 { "K", tZONE, -HOUR (10) },
776 { "L", tZONE, -HOUR (11) },
777 { "M", tZONE, -HOUR (12) },
778 { "N", tZONE, HOUR ( 1) },
779 { "O", tZONE, HOUR ( 2) },
780 { "P", tZONE, HOUR ( 3) },
781 { "Q", tZONE, HOUR ( 4) },
782 { "R", tZONE, HOUR ( 5) },
783 { "S", tZONE, HOUR ( 6) },
784 { "T", tZONE, HOUR ( 7) },
785 { "U", tZONE, HOUR ( 8) },
786 { "V", tZONE, HOUR ( 9) },
787 { "W", tZONE, HOUR (10) },
788 { "X", tZONE, HOUR (11) },
789 { "Y", tZONE, HOUR (12) },
790 { "Z", tZONE, HOUR ( 0) },
796 /* Convert a time zone expressed as HH:MM into an integer count of
797 minutes. If MM is negative, then S is of the form HHMM and needs
798 to be picked apart; otherwise, S is of the form HH. */
801 time_zone_hhmm (textint s, long int mm)
804 return (s.value / 100) * 60 + s.value % 100;
806 return s.value * 60 + (s.negative ? -mm : mm);
810 to_hour (long int hours, int meridian)
814 default: /* Pacify GCC. */
816 return 0 <= hours && hours < 24 ? hours : -1;
818 return 0 < hours && hours < 12 ? hours : hours == 12 ? 0 : -1;
820 return 0 < hours && hours < 12 ? hours + 12 : hours == 12 ? 12 : -1;
825 to_year (textint textyear)
827 long int year = textyear.value;
832 /* XPG4 suggests that years 00-68 map to 2000-2068, and
833 years 69-99 map to 1969-1999. */
834 else if (textyear.digits == 2)
835 year += year < 69 ? 2000 : 1900;
841 lookup_zone (parser_control const *pc, char const *name)
845 for (tp = universal_time_zone_table; tp->name; tp++)
846 if (strcmp (name, tp->name) == 0)
849 /* Try local zone abbreviations before those in time_zone_table, as
850 the local ones are more likely to be right. */
851 for (tp = pc->local_time_zone_table; tp->name; tp++)
852 if (strcmp (name, tp->name) == 0)
855 for (tp = time_zone_table; tp->name; tp++)
856 if (strcmp (name, tp->name) == 0)
863 /* Yield the difference between *A and *B,
864 measured in seconds, ignoring leap seconds.
865 The body of this function is taken directly from the GNU C Library;
866 see src/strftime.c. */
868 tm_diff (struct tm const *a, struct tm const *b)
870 /* Compute intervening leap days correctly even if year is negative.
871 Take care to avoid int overflow in leap day calculations. */
872 int a4 = SHR (a->tm_year, 2) + SHR (TM_YEAR_BASE, 2) - ! (a->tm_year & 3);
873 int b4 = SHR (b->tm_year, 2) + SHR (TM_YEAR_BASE, 2) - ! (b->tm_year & 3);
874 int a100 = a4 / 25 - (a4 % 25 < 0);
875 int b100 = b4 / 25 - (b4 % 25 < 0);
876 int a400 = SHR (a100, 2);
877 int b400 = SHR (b100, 2);
878 int intervening_leap_days = (a4 - b4) - (a100 - b100) + (a400 - b400);
879 long int ayear = a->tm_year;
880 long int years = ayear - b->tm_year;
881 long int days = (365 * years + intervening_leap_days
882 + (a->tm_yday - b->tm_yday));
883 return (60 * (60 * (24 * days + (a->tm_hour - b->tm_hour))
884 + (a->tm_min - b->tm_min))
885 + (a->tm_sec - b->tm_sec));
887 #endif /* ! HAVE_TM_GMTOFF */
890 lookup_word (parser_control const *pc, char *word)
899 /* Make it uppercase. */
900 for (p = word; *p; p++)
902 unsigned char ch = *p;
906 for (tp = meridian_table; tp->name; tp++)
907 if (strcmp (word, tp->name) == 0)
910 /* See if we have an abbreviation for a month. */
911 wordlen = strlen (word);
912 abbrev = wordlen == 3 || (wordlen == 4 && word[3] == '.');
914 for (tp = month_and_day_table; tp->name; tp++)
915 if ((abbrev ? strncmp (word, tp->name, 3) : strcmp (word, tp->name)) == 0)
918 if ((tp = lookup_zone (pc, word)))
921 if (strcmp (word, dst_table[0].name) == 0)
924 for (tp = time_units_table; tp->name; tp++)
925 if (strcmp (word, tp->name) == 0)
928 /* Strip off any plural and try the units table again. */
929 if (word[wordlen - 1] == 'S')
931 word[wordlen - 1] = '\0';
932 for (tp = time_units_table; tp->name; tp++)
933 if (strcmp (word, tp->name) == 0)
935 word[wordlen - 1] = 'S'; /* For "this" in relative_time_table. */
938 for (tp = relative_time_table; tp->name; tp++)
939 if (strcmp (word, tp->name) == 0)
942 /* Military time zones. */
944 for (tp = military_table; tp->name; tp++)
945 if (word[0] == tp->name[0])
948 /* Drop out any periods and try the time zone table again. */
949 for (period_found = false, p = q = word; (*p = *q); q++)
954 if (period_found && (tp = lookup_zone (pc, word)))
961 yylex (YYSTYPE *lvalp, parser_control *pc)
968 while (c = *pc->input, c_isspace (c))
971 if (ISDIGIT (c) || c == '-' || c == '+')
975 unsigned long int value;
976 if (c == '-' || c == '+')
978 sign = c == '-' ? -1 : 1;
979 while (c = *++pc->input, c_isspace (c))
982 /* skip the '-' sign */
988 for (value = 0; ; value *= 10)
990 unsigned long int value1 = value + (c - '0');
997 if (ULONG_MAX / 10 < value)
1000 if ((c == '.' || c == ',') && ISDIGIT (p[1]))
1005 unsigned long int value1;
1007 /* Check for overflow when converting value to time_t. */
1022 if (value != value1)
1025 /* Accumulate fraction, to ns precision. */
1028 for (digits = 2; digits <= LOG10_BILLION; digits++)
1035 /* Skip excess digits, truncating toward -Infinity. */
1037 for (; ISDIGIT (*p); p++)
1043 while (ISDIGIT (*p))
1046 /* Adjust to the timespec convention, which is that
1047 tv_nsec is always a positive offset even if tv_sec is
1057 lvalp->timespec.tv_sec = s;
1058 lvalp->timespec.tv_nsec = ns;
1060 return sign ? tSDECIMAL_NUMBER : tUDECIMAL_NUMBER;
1064 lvalp->textintval.negative = sign < 0;
1067 lvalp->textintval.value = - value;
1068 if (0 < lvalp->textintval.value)
1073 lvalp->textintval.value = value;
1074 if (lvalp->textintval.value < 0)
1077 lvalp->textintval.digits = p - pc->input;
1079 return sign ? tSNUMBER : tUNUMBER;
1091 if (p < buff + sizeof buff - 1)
1095 while (c_isalpha (c) || c == '.');
1098 tp = lookup_word (pc, buff);
1101 lvalp->intval = tp->value;
1106 return *pc->input++;
1122 /* Do nothing if the parser reports an error. */
1124 yyerror (parser_control const *pc ATTRIBUTE_UNUSED,
1125 char const *s ATTRIBUTE_UNUSED)
1130 /* If *TM0 is the old and *TM1 is the new value of a struct tm after
1131 passing it to mktime, return true if it's OK that mktime returned T.
1132 It's not OK if *TM0 has out-of-range members. */
1135 mktime_ok (struct tm const *tm0, struct tm const *tm1, time_t t)
1137 if (t == (time_t) -1)
1139 /* Guard against falsely reporting an error when parsing a time
1140 stamp that happens to equal (time_t) -1, on a host that
1141 supports such a time stamp. */
1142 tm1 = localtime (&t);
1147 return ! ((tm0->tm_sec ^ tm1->tm_sec)
1148 | (tm0->tm_min ^ tm1->tm_min)
1149 | (tm0->tm_hour ^ tm1->tm_hour)
1150 | (tm0->tm_mday ^ tm1->tm_mday)
1151 | (tm0->tm_mon ^ tm1->tm_mon)
1152 | (tm0->tm_year ^ tm1->tm_year));
1155 /* A reasonable upper bound for the size of ordinary TZ strings.
1156 Use heap allocation if TZ's length exceeds this. */
1157 enum { TZBUFSIZE = 100 };
1159 /* Return a copy of TZ, stored in TZBUF if it fits, and heap-allocated
1162 get_tz (char tzbuf[TZBUFSIZE])
1164 char *tz = getenv ("TZ");
1167 size_t tzsize = strlen (tz) + 1;
1168 tz = (tzsize <= TZBUFSIZE
1169 ? memcpy (tzbuf, tz, tzsize)
1170 : xmemdup (tz, tzsize));
1175 /* Parse a date/time string, storing the resulting time value into *RESULT.
1176 The string itself is pointed to by P. Return true if successful.
1177 P can be an incomplete or relative time specification; if so, use
1178 *NOW as the basis for the returned time. */
1180 get_date (struct timespec *result, char const *p, struct timespec const *now)
1184 struct tm const *tmp;
1188 struct timespec gettime_buffer;
1190 bool tz_was_altered = false;
1192 char tz0buf[TZBUFSIZE];
1197 gettime (&gettime_buffer);
1198 now = &gettime_buffer;
1201 Start = now->tv_sec;
1202 Start_ns = now->tv_nsec;
1204 tmp = localtime (&now->tv_sec);
1208 while (c = *p, c_isspace (c))
1211 if (strncmp (p, "TZ=\"", 4) == 0)
1213 char const *tzbase = p + 4;
1217 for (s = tzbase; *s; s++, tzsize++)
1221 if (! (*s == '\\' || *s == '"'))
1228 char tz1buf[TZBUFSIZE];
1229 bool large_tz = TZBUFSIZE < tzsize;
1231 tz0 = get_tz (tz0buf);
1232 z = tz1 = large_tz ? xmalloc (tzsize) : tz1buf;
1233 for (s = tzbase; *s != '"'; s++)
1234 *z++ = *(s += *s == '\\');
1236 setenv_ok = setenv ("TZ", tz1, 1) == 0;
1241 tz_was_altered = true;
1246 /* As documented, be careful to treat the empty string just like
1247 a date string of "0". Without this, an empty string would be
1248 declared invalid when parsed during a DST transition. */
1253 pc.year.value = tmp->tm_year;
1254 pc.year.value += TM_YEAR_BASE;
1256 pc.month = tmp->tm_mon + 1;
1257 pc.day = tmp->tm_mday;
1258 pc.hour = tmp->tm_hour;
1259 pc.minutes = tmp->tm_min;
1260 pc.seconds.tv_sec = tmp->tm_sec;
1261 pc.seconds.tv_nsec = Start_ns;
1262 tm.tm_isdst = tmp->tm_isdst;
1264 pc.meridian = MER24;
1265 pc.rel = RELATIVE_TIME_0;
1266 pc.timespec_seen = false;
1267 pc.rels_seen = false;
1271 pc.local_zones_seen = 0;
1275 #if HAVE_STRUCT_TM_TM_ZONE
1276 pc.local_time_zone_table[0].name = tmp->tm_zone;
1277 pc.local_time_zone_table[0].type = tLOCAL_ZONE;
1278 pc.local_time_zone_table[0].value = tmp->tm_isdst;
1279 pc.local_time_zone_table[1].name = NULL;
1281 /* Probe the names used in the next three calendar quarters, looking
1282 for a tm_isdst different from the one we already have. */
1285 for (quarter = 1; quarter <= 3; quarter++)
1287 time_t probe = Start + quarter * (90 * 24 * 60 * 60);
1288 struct tm const *probe_tm = localtime (&probe);
1289 if (probe_tm && probe_tm->tm_zone
1290 && probe_tm->tm_isdst != pc.local_time_zone_table[0].value)
1293 pc.local_time_zone_table[1].name = probe_tm->tm_zone;
1294 pc.local_time_zone_table[1].type = tLOCAL_ZONE;
1295 pc.local_time_zone_table[1].value = probe_tm->tm_isdst;
1296 pc.local_time_zone_table[2].name = NULL;
1305 # if !HAVE_DECL_TZNAME
1306 extern char *tzname[];
1309 for (i = 0; i < 2; i++)
1311 pc.local_time_zone_table[i].name = tzname[i];
1312 pc.local_time_zone_table[i].type = tLOCAL_ZONE;
1313 pc.local_time_zone_table[i].value = i;
1315 pc.local_time_zone_table[i].name = NULL;
1318 pc.local_time_zone_table[0].name = NULL;
1322 if (pc.local_time_zone_table[0].name && pc.local_time_zone_table[1].name
1323 && ! strcmp (pc.local_time_zone_table[0].name,
1324 pc.local_time_zone_table[1].name))
1326 /* This locale uses the same abbrevation for standard and
1327 daylight times. So if we see that abbreviation, we don't
1328 know whether it's daylight time. */
1329 pc.local_time_zone_table[0].value = -1;
1330 pc.local_time_zone_table[1].name = NULL;
1333 if (yyparse (&pc) != 0)
1336 if (pc.timespec_seen)
1337 *result = pc.seconds;
1340 if (1 < (pc.times_seen | pc.dates_seen | pc.days_seen | pc.dsts_seen
1341 | (pc.local_zones_seen + pc.zones_seen)))
1344 tm.tm_year = to_year (pc.year) - TM_YEAR_BASE;
1345 tm.tm_mon = pc.month - 1;
1346 tm.tm_mday = pc.day;
1347 if (pc.times_seen || (pc.rels_seen && ! pc.dates_seen && ! pc.days_seen))
1349 tm.tm_hour = to_hour (pc.hour, pc.meridian);
1352 tm.tm_min = pc.minutes;
1353 tm.tm_sec = pc.seconds.tv_sec;
1357 tm.tm_hour = tm.tm_min = tm.tm_sec = 0;
1358 pc.seconds.tv_nsec = 0;
1361 /* Let mktime deduce tm_isdst if we have an absolute time stamp. */
1362 if (pc.dates_seen | pc.days_seen | pc.times_seen)
1365 /* But if the input explicitly specifies local time with or without
1366 DST, give mktime that information. */
1367 if (pc.local_zones_seen)
1368 tm.tm_isdst = pc.local_isdst;
1372 Start = mktime (&tm);
1374 if (! mktime_ok (&tm0, &tm, Start))
1376 if (! pc.zones_seen)
1380 /* Guard against falsely reporting errors near the time_t
1381 boundaries when parsing times in other time zones. For
1382 example, suppose the input string "1969-12-31 23:00:00 -0100",
1383 the current time zone is 8 hours ahead of UTC, and the min
1384 time_t value is 1970-01-01 00:00:00 UTC. Then the min
1385 localtime value is 1970-01-01 08:00:00, and mktime will
1386 therefore fail on 1969-12-31 23:00:00. To work around the
1387 problem, set the time zone to 1 hour behind UTC temporarily
1388 by setting TZ="XXX1:00" and try mktime again. */
1390 long int time_zone = pc.time_zone;
1391 long int abs_time_zone = time_zone < 0 ? - time_zone : time_zone;
1392 long int abs_time_zone_hour = abs_time_zone / 60;
1393 int abs_time_zone_min = abs_time_zone % 60;
1394 char tz1buf[sizeof "XXX+0:00"
1395 + sizeof pc.time_zone * CHAR_BIT / 3];
1396 if (!tz_was_altered)
1397 tz0 = get_tz (tz0buf);
1398 sprintf (tz1buf, "XXX%s%ld:%02d", "-" + (time_zone < 0),
1399 abs_time_zone_hour, abs_time_zone_min);
1400 if (setenv ("TZ", tz1buf, 1) != 0)
1402 tz_was_altered = true;
1404 Start = mktime (&tm);
1405 if (! mktime_ok (&tm0, &tm, Start))
1410 if (pc.days_seen && ! pc.dates_seen)
1412 tm.tm_mday += ((pc.day_number - tm.tm_wday + 7) % 7
1413 + 7 * (pc.day_ordinal - (0 < pc.day_ordinal)));
1415 Start = mktime (&tm);
1416 if (Start == (time_t) -1)
1420 /* Add relative date. */
1421 if (pc.rel.year | pc.rel.month | pc.rel.day)
1423 int year = tm.tm_year + pc.rel.year;
1424 int month = tm.tm_mon + pc.rel.month;
1425 int day = tm.tm_mday + pc.rel.day;
1426 if (((year < tm.tm_year) ^ (pc.rel.year < 0))
1427 | ((month < tm.tm_mon) ^ (pc.rel.month < 0))
1428 | ((day < tm.tm_mday) ^ (pc.rel.day < 0)))
1433 tm.tm_hour = tm0.tm_hour;
1434 tm.tm_min = tm0.tm_min;
1435 tm.tm_sec = tm0.tm_sec;
1436 tm.tm_isdst = tm0.tm_isdst;
1437 Start = mktime (&tm);
1438 if (Start == (time_t) -1)
1442 /* The only "output" of this if-block is an updated Start value,
1443 so this block must follow others that clobber Start. */
1446 long int delta = pc.time_zone * 60;
1448 #ifdef HAVE_TM_GMTOFF
1449 delta -= tm.tm_gmtoff;
1452 struct tm const *gmt = gmtime (&t);
1455 delta -= tm_diff (&tm, gmt);
1458 if ((Start < t1) != (delta < 0))
1459 goto fail; /* time_t overflow */
1463 /* Add relative hours, minutes, and seconds. On hosts that support
1464 leap seconds, ignore the possibility of leap seconds; e.g.,
1465 "+ 10 minutes" adds 600 seconds, even if one of them is a
1466 leap second. Typically this is not what the user wants, but it's
1467 too hard to do it the other way, because the time zone indicator
1468 must be applied before relative times, and if mktime is applied
1469 again the time zone will be lost. */
1471 long int sum_ns = pc.seconds.tv_nsec + pc.rel.ns;
1472 long int normalized_ns = (sum_ns % BILLION + BILLION) % BILLION;
1474 long int d1 = 60 * 60 * pc.rel.hour;
1475 time_t t1 = t0 + d1;
1476 long int d2 = 60 * pc.rel.minutes;
1477 time_t t2 = t1 + d2;
1478 long int d3 = pc.rel.seconds;
1479 time_t t3 = t2 + d3;
1480 long int d4 = (sum_ns - normalized_ns) / BILLION;
1481 time_t t4 = t3 + d4;
1483 if ((d1 / (60 * 60) ^ pc.rel.hour)
1484 | (d2 / 60 ^ pc.rel.minutes)
1485 | ((t1 < t0) ^ (d1 < 0))
1486 | ((t2 < t1) ^ (d2 < 0))
1487 | ((t3 < t2) ^ (d3 < 0))
1488 | ((t4 < t3) ^ (d4 < 0)))
1491 result->tv_sec = t4;
1492 result->tv_nsec = normalized_ns;
1502 ok &= (tz0 ? setenv ("TZ", tz0, 1) : unsetenv ("TZ")) == 0;
1511 main (int ac, char **av)
1515 printf ("Enter date, or blank line to exit.\n\t> ");
1518 buff[BUFSIZ - 1] = '\0';
1519 while (fgets (buff, BUFSIZ - 1, stdin) && buff[0])
1522 struct tm const *tm;
1523 if (! get_date (&d, buff, NULL))
1524 printf ("Bad format - couldn't convert.\n");
1525 else if (! (tm = localtime (&d.tv_sec)))
1527 long int sec = d.tv_sec;
1528 printf ("localtime (%ld) failed\n", sec);
1533 printf ("%04ld-%02d-%02d %02d:%02d:%02d.%09d\n",
1534 tm->tm_year + 1900L, tm->tm_mon + 1, tm->tm_mday,
1535 tm->tm_hour, tm->tm_min, tm->tm_sec, ns);