%{ /* Parse a string into an internal time stamp. Copyright 1999, 2000 Free Software Foundation, Inc. This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ /* Originally written by Steven M. Bellovin while at the University of North Carolina at Chapel Hill. Later tweaked by a couple of people on Usenet. Completely overhauled by Rich $alz and Jim Berets in August, 1990. Modified by Paul Eggert in August 1999 to do the right thing about local DST. Unlike previous versions, this version is reentrant. */ #ifdef HAVE_CONFIG_H # include # ifdef HAVE_ALLOCA_H # include # endif #endif /* Since the code of getdate.y is not included in the Emacs executable itself, there is no need to #define static in this file. Even if the code were included in the Emacs executable, it probably wouldn't do any harm to #undef it here; this will only cause problems if we try to write to a static variable, which I don't think this code needs to do. */ #ifdef emacs # undef static #endif #include #if HAVE_STDLIB_H # include /* for `free'; used by Bison 1.27 */ #endif #if STDC_HEADERS || (! defined isascii && ! HAVE_ISASCII) # define IN_CTYPE_DOMAIN(c) 1 #else # define IN_CTYPE_DOMAIN(c) isascii (c) #endif #define ISSPACE(c) (IN_CTYPE_DOMAIN (c) && isspace (c)) #define ISALPHA(c) (IN_CTYPE_DOMAIN (c) && isalpha (c)) #define ISLOWER(c) (IN_CTYPE_DOMAIN (c) && islower (c)) #define ISDIGIT_LOCALE(c) (IN_CTYPE_DOMAIN (c) && isdigit (c)) /* ISDIGIT differs from ISDIGIT_LOCALE, as follows: - Its arg may be any int or unsigned int; it need not be an unsigned char. - It's guaranteed to evaluate its argument exactly once. - It's typically faster. Posix 1003.2-1992 section 2.5.2.1 page 50 lines 1556-1558 says that only '0' through '9' are digits. Prefer ISDIGIT to ISDIGIT_LOCALE unless it's important to use the locale's definition of `digit' even when the host does not conform to Posix. */ #define ISDIGIT(c) ((unsigned) (c) - '0' <= 9) #if STDC_HEADERS || HAVE_STRING_H # include #endif #if __GNUC__ < 2 || (__GNUC__ == 2 && __GNUC_MINOR__ < 8) || __STRICT_ANSI__ # define __attribute__(x) #endif #ifndef ATTRIBUTE_UNUSED # define ATTRIBUTE_UNUSED __attribute__ ((__unused__)) #endif #define EPOCH_YEAR 1970 #define TM_YEAR_BASE 1900 #define HOUR(x) ((x) * 60) /* An entry in the lexical lookup table. */ typedef struct { char const *name; int type; int value; } table; /* Meridian: am, pm, or 24-hour style. */ enum { MERam, MERpm, MER24 }; /* Information passed to and from the parser. */ struct parser_control { /* The input string remaining to be parsed. */ const char *input; /* N, if this is the Nth Tuesday. */ int day_ordinal; /* Day of week; Sunday is 0. */ int day_number; /* tm_isdst flag for the local zone. */ int local_isdst; /* Time zone, in minutes east of UTC. */ int time_zone; /* Style used for time. */ int meridian; /* Gregorian year, month, day, hour, minutes, and seconds. */ int year; int month; int day; int hour; int minutes; int seconds; /* Relative year, month, day, hour, minutes, and seconds. */ int rel_year; int rel_month; int rel_day; int rel_hour; int rel_minutes; int rel_seconds; /* Counts of nonterminals of various flavors parsed so far. */ int dates_seen; int days_seen; int local_zones_seen; int rels_seen; int times_seen; int zones_seen; /* Table of local time zone abbrevations, terminated by a null entry. */ table local_time_zone_table[3]; }; #define PC (* (struct parser_control *) parm) #define YYLEX_PARAM parm #define YYPARSE_PARAM parm #define YYSTYPE int static int yyerror (); static int yylex (); %} /* We want a reentrant parser. */ %pure_parser /* This grammar has 13 shift/reduce conflicts. */ %expect 13 %token tAGO tDAY tDAY_UNIT tDAYZONE tDST tHOUR_UNIT tID %token tLOCAL_ZONE tMERIDIAN tMINUTE_UNIT tMONTH tMONTH_UNIT %token tSEC_UNIT tSNUMBER tUNUMBER tYEAR_UNIT tZONE %% spec: /* empty */ | spec item ; item: time { PC.times_seen++; } | local_zone { PC.local_zones_seen++; } | zone { PC.zones_seen++; } | date { PC.dates_seen++; } | day { PC.days_seen++; } | rel { PC.rels_seen++; } | number ; time: tUNUMBER tMERIDIAN { PC.hour = $1; PC.minutes = 0; PC.seconds = 0; PC.meridian = $2; } | tUNUMBER ':' tUNUMBER o_merid { PC.hour = $1; PC.minutes = $3; PC.seconds = 0; PC.meridian = $4; } | tUNUMBER ':' tUNUMBER tSNUMBER { PC.hour = $1; PC.minutes = $3; PC.meridian = MER24; PC.zones_seen++; PC.time_zone = $4 % 100 + ($4 / 100) * 60; } | tUNUMBER ':' tUNUMBER ':' tUNUMBER o_merid { PC.hour = $1; PC.minutes = $3; PC.seconds = $5; PC.meridian = $6; } | tUNUMBER ':' tUNUMBER ':' tUNUMBER tSNUMBER { PC.hour = $1; PC.minutes = $3; PC.seconds = $5; PC.meridian = MER24; PC.zones_seen++; PC.time_zone = $6 % 100 + ($6 / 100) * 60; } ; local_zone: tLOCAL_ZONE { PC.local_isdst = $1; } | tLOCAL_ZONE tDST { PC.local_isdst = $1 < 0 ? 1 : $1 + 1; } ; zone: tZONE { PC.time_zone = $1; } | tDAYZONE { PC.time_zone = $1 + 60; } | tZONE tDST { PC.time_zone = $1 + 60; } ; day: tDAY { PC.day_ordinal = 1; PC.day_number = $1; } | tDAY ',' { PC.day_ordinal = 1; PC.day_number = $1; } | tUNUMBER tDAY { PC.day_ordinal = $1; PC.day_number = $2; } ; date: tUNUMBER '/' tUNUMBER { PC.month = $1; PC.day = $3; } | tUNUMBER '/' tUNUMBER '/' tUNUMBER { /* Interpret as YYYY/MM/DD if 1000 <= $1, otherwise as MM/DD/YY. The goal in recognizing YYYY/MM/DD is solely to support legacy machine-generated dates like those in an RCS log listing. If you want portability, use the ISO 8601 format. */ if (1000 <= $1) { PC.year = $1; PC.month = $3; PC.day = $5; } else { PC.month = $1; PC.day = $3; PC.year = $5; } } | tUNUMBER tSNUMBER tSNUMBER { /* ISO 8601 format. YYYY-MM-DD. */ PC.year = $1; PC.month = -$2; PC.day = -$3; } | tUNUMBER tMONTH tSNUMBER { /* e.g. 17-JUN-1992. */ PC.day = $1; PC.month = $2; PC.year = -$3; } | tMONTH tUNUMBER { PC.month = $1; PC.day = $2; } | tMONTH tUNUMBER ',' tUNUMBER { PC.month = $1; PC.day = $2; PC.year = $4; } | tUNUMBER tMONTH { PC.month = $2; PC.day = $1; } | tUNUMBER tMONTH tUNUMBER { PC.month = $2; PC.day = $1; PC.year = $3; } ; rel: relunit tAGO { PC.rel_seconds = -PC.rel_seconds; PC.rel_minutes = -PC.rel_minutes; PC.rel_hour = -PC.rel_hour; PC.rel_day = -PC.rel_day; PC.rel_month = -PC.rel_month; PC.rel_year = -PC.rel_year; } | relunit ; relunit: tUNUMBER tYEAR_UNIT { PC.rel_year += $1 * $2; } | tSNUMBER tYEAR_UNIT { PC.rel_year += $1 * $2; } | tYEAR_UNIT { PC.rel_year += $1; } | tUNUMBER tMONTH_UNIT { PC.rel_month += $1 * $2; } | tSNUMBER tMONTH_UNIT { PC.rel_month += $1 * $2; } | tMONTH_UNIT { PC.rel_month += $1; } | tUNUMBER tDAY_UNIT { PC.rel_day += $1 * $2; } | tSNUMBER tDAY_UNIT { PC.rel_day += $1 * $2; } | tDAY_UNIT { PC.rel_day += $1; } | tUNUMBER tHOUR_UNIT { PC.rel_hour += $1 * $2; } | tSNUMBER tHOUR_UNIT { PC.rel_hour += $1 * $2; } | tHOUR_UNIT { PC.rel_hour += $1; } | tUNUMBER tMINUTE_UNIT { PC.rel_minutes += $1 * $2; } | tSNUMBER tMINUTE_UNIT { PC.rel_minutes += $1 * $2; } | tMINUTE_UNIT { PC.rel_minutes += $1; } | tUNUMBER tSEC_UNIT { PC.rel_seconds += $1 * $2; } | tSNUMBER tSEC_UNIT { PC.rel_seconds += $1 * $2; } | tSEC_UNIT { PC.rel_seconds += $1; } ; number: tUNUMBER { if (PC.dates_seen && ! PC.rels_seen && (PC.times_seen || 100 <= $1)) PC.year = $1; else { if (10000 < $1) { PC.dates_seen++; PC.day = $1 % 100; PC.month = ($1 / 100) % 100; PC.year = $1 / 10000; } else { PC.times_seen++; if ($1 < 100) { PC.hour = $1; PC.minutes = 0; } else { PC.hour = $1 / 100; PC.minutes = $1 % 100; } PC.seconds = 0; PC.meridian = MER24; } } } ; o_merid: /* empty */ { $$ = MER24; } | tMERIDIAN { $$ = $1; } ; %% /* Include this file down here because bison inserts code above which may define-away `const'. We want the prototype for get_date to have the same signature as the function definition. */ #include "getdate.h" #ifndef gmtime struct tm *gmtime (); #endif #ifndef localtime struct tm *localtime (); #endif #ifndef mktime time_t mktime (); #endif static table const meridian_table[] = { { "AM", tMERIDIAN, MERam }, { "A.M.", tMERIDIAN, MERam }, { "PM", tMERIDIAN, MERpm }, { "P.M.", tMERIDIAN, MERpm }, { 0, 0, 0 } }; static table const dst_table[] = { { "DST", tDST, 0 } }; static table const month_and_day_table[] = { { "JANUARY", tMONTH, 1 }, { "FEBRUARY", tMONTH, 2 }, { "MARCH", tMONTH, 3 }, { "APRIL", tMONTH, 4 }, { "MAY", tMONTH, 5 }, { "JUNE", tMONTH, 6 }, { "JULY", tMONTH, 7 }, { "AUGUST", tMONTH, 8 }, { "SEPTEMBER",tMONTH, 9 }, { "SEPT", tMONTH, 9 }, { "OCTOBER", tMONTH, 10 }, { "NOVEMBER", tMONTH, 11 }, { "DECEMBER", tMONTH, 12 }, { "SUNDAY", tDAY, 0 }, { "MONDAY", tDAY, 1 }, { "TUESDAY", tDAY, 2 }, { "TUES", tDAY, 2 }, { "WEDNESDAY",tDAY, 3 }, { "WEDNES", tDAY, 3 }, { "THURSDAY", tDAY, 4 }, { "THUR", tDAY, 4 }, { "THURS", tDAY, 4 }, { "FRIDAY", tDAY, 5 }, { "SATURDAY", tDAY, 6 }, { 0, 0, 0 } }; static table const time_units_table[] = { { "YEAR", tYEAR_UNIT, 1 }, { "MONTH", tMONTH_UNIT, 1 }, { "FORTNIGHT",tDAY_UNIT, 14 }, { "WEEK", tDAY_UNIT, 7 }, { "DAY", tDAY_UNIT, 1 }, { "HOUR", tHOUR_UNIT, 1 }, { "MINUTE", tMINUTE_UNIT, 1 }, { "MIN", tMINUTE_UNIT, 1 }, { "SECOND", tSEC_UNIT, 1 }, { "SEC", tSEC_UNIT, 1 }, { 0, 0, 0 } }; /* Assorted relative-time words. */ static table const relative_time_table[] = { { "TOMORROW", tMINUTE_UNIT, 24 * 60 }, { "YESTERDAY",tMINUTE_UNIT, - (24 * 60) }, { "TODAY", tMINUTE_UNIT, 0 }, { "NOW", tMINUTE_UNIT, 0 }, { "LAST", tUNUMBER, -1 }, { "THIS", tUNUMBER, 0 }, { "NEXT", tUNUMBER, 1 }, { "FIRST", tUNUMBER, 1 }, /*{ "SECOND", tUNUMBER, 2 }, */ { "THIRD", tUNUMBER, 3 }, { "FOURTH", tUNUMBER, 4 }, { "FIFTH", tUNUMBER, 5 }, { "SIXTH", tUNUMBER, 6 }, { "SEVENTH", tUNUMBER, 7 }, { "EIGHTH", tUNUMBER, 8 }, { "NINTH", tUNUMBER, 9 }, { "TENTH", tUNUMBER, 10 }, { "ELEVENTH", tUNUMBER, 11 }, { "TWELFTH", tUNUMBER, 12 }, { "AGO", tAGO, 1 }, { 0, 0, 0 } }; /* The time zone table. This table is necessarily incomplete, as time zone abbreviations are ambiguous; e.g. Australians interpret "EST" as Eastern time in Australia, not as US Eastern Standard Time. You cannot rely on getdate to handle arbitrary time zone abbreviations; use numeric abbreviations like `-0500' instead. */ static table const time_zone_table[] = { { "GMT", tZONE, HOUR ( 0) }, /* Greenwich Mean */ { "UT", tZONE, HOUR ( 0) }, /* Universal (Coordinated) */ { "UTC", tZONE, HOUR ( 0) }, { "WET", tZONE, HOUR ( 0) }, /* Western European */ { "WEST", tDAYZONE, HOUR ( 0) }, /* Western European Summer */ { "BST", tDAYZONE, HOUR ( 0) }, /* British Summer */ { "ART", tZONE, -HOUR ( 3) }, /* Argentina */ { "BRT", tZONE, -HOUR ( 3) }, /* Brazil */ { "BRST", tDAYZONE, -HOUR ( 3) }, /* Brazil Summer */ { "NST", tZONE, -(HOUR ( 3) + 30) }, /* Newfoundland Standard */ { "NDT", tDAYZONE,-(HOUR ( 3) + 30) }, /* Newfoundland Daylight */ { "AST", tZONE, -HOUR ( 4) }, /* Atlantic Standard */ { "ADT", tDAYZONE, -HOUR ( 4) }, /* Atlantic Daylight */ { "CLT", tZONE, -HOUR ( 4) }, /* Chile */ { "CLST", tDAYZONE, -HOUR ( 4) }, /* Chile Summer */ { "EST", tZONE, -HOUR ( 5) }, /* Eastern Standard */ { "EDT", tDAYZONE, -HOUR ( 5) }, /* Eastern Daylight */ { "CST", tZONE, -HOUR ( 6) }, /* Central Standard */ { "CDT", tDAYZONE, -HOUR ( 6) }, /* Central Daylight */ { "MST", tZONE, -HOUR ( 7) }, /* Mountain Standard */ { "MDT", tDAYZONE, -HOUR ( 7) }, /* Mountain Daylight */ { "PST", tZONE, -HOUR ( 8) }, /* Pacific Standard */ { "PDT", tDAYZONE, -HOUR ( 8) }, /* Pacific Daylight */ { "AKST", tZONE, -HOUR ( 9) }, /* Alaska Standard */ { "AKDT", tDAYZONE, -HOUR ( 9) }, /* Alaska Daylight */ { "HST", tZONE, -HOUR (10) }, /* Hawaii Standard */ { "HAST", tZONE, -HOUR (10) }, /* Hawaii-Aleutian Standard */ { "HADT", tDAYZONE, -HOUR (10) }, /* Hawaii-Aleutian Daylight */ { "SST", tZONE, -HOUR (12) }, /* Samoa Standard */ { "WAT", tZONE, HOUR ( 1) }, /* West Africa */ { "CET", tZONE, HOUR ( 1) }, /* Central European */ { "CEST", tDAYZONE, HOUR ( 1) }, /* Central European Summer */ { "MET", tZONE, HOUR ( 1) }, /* Middle European */ { "MEZ", tZONE, HOUR ( 1) }, /* Middle European */ { "MEST", tDAYZONE, HOUR ( 1) }, /* Middle European Summer */ { "MESZ", tDAYZONE, HOUR ( 1) }, /* Middle European Summer */ { "EET", tZONE, HOUR ( 2) }, /* Eastern European */ { "EEST", tDAYZONE, HOUR ( 2) }, /* Eastern European Summer */ { "CAT", tZONE, HOUR ( 2) }, /* Central Africa */ { "SAST", tZONE, HOUR ( 2) }, /* South Africa Standard */ { "EAT", tZONE, HOUR ( 3) }, /* East Africa */ { "MSK", tZONE, HOUR ( 3) }, /* Moscow */ { "MSD", tDAYZONE, HOUR ( 3) }, /* Moscow Daylight */ { "IST", tZONE, (HOUR ( 5) + 30) }, /* India Standard */ { "SGT", tZONE, HOUR ( 8) }, /* Singapore */ { "KST", tZONE, HOUR ( 9) }, /* Korea Standard */ { "JST", tZONE, HOUR ( 9) }, /* Japan Standard */ { "GST", tZONE, HOUR (10) }, /* Guam Standard */ { "NZST", tZONE, HOUR (12) }, /* New Zealand Standard */ { "NZDT", tDAYZONE, HOUR (12) }, /* New Zealand Daylight */ { 0, 0, 0 } }; /* Military time zone table. */ static table const military_table[] = { { "A", tZONE, -HOUR ( 1) }, { "B", tZONE, -HOUR ( 2) }, { "C", tZONE, -HOUR ( 3) }, { "D", tZONE, -HOUR ( 4) }, { "E", tZONE, -HOUR ( 5) }, { "F", tZONE, -HOUR ( 6) }, { "G", tZONE, -HOUR ( 7) }, { "H", tZONE, -HOUR ( 8) }, { "I", tZONE, -HOUR ( 9) }, { "K", tZONE, -HOUR (10) }, { "L", tZONE, -HOUR (11) }, { "M", tZONE, -HOUR (12) }, { "N", tZONE, HOUR ( 1) }, { "O", tZONE, HOUR ( 2) }, { "P", tZONE, HOUR ( 3) }, { "Q", tZONE, HOUR ( 4) }, { "R", tZONE, HOUR ( 5) }, { "S", tZONE, HOUR ( 6) }, { "T", tZONE, HOUR ( 7) }, { "U", tZONE, HOUR ( 8) }, { "V", tZONE, HOUR ( 9) }, { "W", tZONE, HOUR (10) }, { "X", tZONE, HOUR (11) }, { "Y", tZONE, HOUR (12) }, { "Z", tZONE, HOUR ( 0) }, { 0, 0, 0 } }; static int to_hour (int hours, int meridian) { switch (meridian) { case MER24: return 0 <= hours && hours < 24 ? hours : -1; case MERam: return 0 < hours && hours < 12 ? hours : hours == 12 ? 0 : -1; case MERpm: return 0 < hours && hours < 12 ? hours + 12 : hours == 12 ? 12 : -1; default: abort (); } /* NOTREACHED */ } static int to_year (int year) { if (year < 0) year = -year; /* XPG4 suggests that years 00-68 map to 2000-2068, and years 69-99 map to 1969-1999. */ if (year < 69) year += 2000; else if (year < 100) year += 1900; return year; } static table const * lookup_zone (struct parser_control const *pc, char const *name) { table const *tp; /* Try local zone abbreviations first; they're more likely to be right. */ for (tp = pc->local_time_zone_table; tp->name; tp++) if (strcmp (name, tp->name) == 0) return tp; for (tp = time_zone_table; tp->name; tp++) if (strcmp (name, tp->name) == 0) return tp; return 0; } #if ! HAVE_TM_GMTOFF /* Yield the difference between *A and *B, measured in seconds, ignoring leap seconds. The body of this function is taken directly from the GNU C Library; see src/strftime.c. */ static int tm_diff (struct tm const *a, struct tm const *b) { /* Compute intervening leap days correctly even if year is negative. Take care to avoid int overflow in leap day calculations, but it's OK to assume that A and B are close to each other. */ int a4 = (a->tm_year >> 2) + (TM_YEAR_BASE >> 2) - ! (a->tm_year & 3); int b4 = (b->tm_year >> 2) + (TM_YEAR_BASE >> 2) - ! (b->tm_year & 3); int a100 = a4 / 25 - (a4 % 25 < 0); int b100 = b4 / 25 - (b4 % 25 < 0); int a400 = a100 >> 2; int b400 = b100 >> 2; int intervening_leap_days = (a4 - b4) - (a100 - b100) + (a400 - b400); int years = a->tm_year - b->tm_year; int days = (365 * years + intervening_leap_days + (a->tm_yday - b->tm_yday)); return (60 * (60 * (24 * days + (a->tm_hour - b->tm_hour)) + (a->tm_min - b->tm_min)) + (a->tm_sec - b->tm_sec)); } #endif /* ! HAVE_TM_GMTOFF */ static table const * lookup_word (struct parser_control const *pc, char *word) { char *p; char *q; size_t wordlen; table const *tp; int i; int abbrev; /* Make it uppercase. */ for (p = word; *p; p++) if (ISLOWER ((unsigned char) *p)) *p = toupper ((unsigned char) *p); for (tp = meridian_table; tp->name; tp++) if (strcmp (word, tp->name) == 0) return tp; /* See if we have an abbreviation for a month. */ wordlen = strlen (word); abbrev = wordlen == 3 || (wordlen == 4 && word[3] == '.'); for (tp = month_and_day_table; tp->name; tp++) if ((abbrev ? strncmp (word, tp->name, 3) : strcmp (word, tp->name)) == 0) return tp; if ((tp = lookup_zone (pc, word))) return tp; if (strcmp (word, dst_table[0].name) == 0) return dst_table; for (tp = time_units_table; tp->name; tp++) if (strcmp (word, tp->name) == 0) return tp; /* Strip off any plural and try the units table again. */ if (word[wordlen - 1] == 'S') { word[wordlen - 1] = '\0'; for (tp = time_units_table; tp->name; tp++) if (strcmp (word, tp->name) == 0) return tp; word[wordlen - 1] = 'S'; /* For "this" in relative_time_table. */ } for (tp = relative_time_table; tp->name; tp++) if (strcmp (word, tp->name) == 0) return tp; /* Military time zones. */ if (wordlen == 1) for (tp = military_table; tp->name; tp++) if (word[0] == tp->name[0]) return tp; /* Drop out any periods and try the time zone table again. */ for (i = 0, p = q = word; (*p = *q); q++) if (*q == '.') i = 1; else p++; if (i && (tp = lookup_zone (pc, word))) return tp; return 0; } static int yylex (YYSTYPE *lvalp, struct parser_control *pc) { unsigned char c; int count; for (;;) { while (c = *pc->input, ISSPACE (c)) pc->input++; if (ISDIGIT (c) || c == '-' || c == '+') { int sign; if (c == '-' || c == '+') { sign = c == '-' ? -1 : 1; if (! ISDIGIT (*++pc->input)) /* skip the '-' sign */ continue; } else sign = 0; for (*lvalp = 0; ISDIGIT (c = *pc->input++);) *lvalp = 10 * *lvalp + (c - '0'); pc->input--; if (sign < 0) *lvalp = - *lvalp; return sign ? tSNUMBER : tUNUMBER; } if (ISALPHA (c)) { char buff[20]; char *p = buff; table const *tp; do { if (p < buff + sizeof buff - 1) *p++ = c; c = *++pc->input; } while (ISALPHA (c) || c == '.'); *p = '\0'; tp = lookup_word (pc, buff); if (! tp) return tID; *lvalp = tp->value; return tp->type; } if (c != '(') return *pc->input++; count = 0; do { c = *pc->input++; if (c == '\0') return c; if (c == '(') count++; else if (c == ')') count--; } while (count > 0); } } /* Do nothing if the parser reports an error. */ static int yyerror (char *s ATTRIBUTE_UNUSED) { return 0; } /* Parse a date/time string P. Return the corresponding time_t value, or (time_t) -1 if there is an error. P can be an incomplete or relative time specification; if so, use *NOW as the basis for the returned time. */ time_t get_date (const char *p, const time_t *now) { time_t Start = now ? *now : time (0); struct tm *tmp = localtime (&Start); struct tm tm; struct tm tm0; struct parser_control pc; if (! tmp) return -1; pc.input = p; pc.year = tmp->tm_year + TM_YEAR_BASE; pc.month = tmp->tm_mon + 1; pc.day = tmp->tm_mday; pc.hour = tmp->tm_hour; pc.minutes = tmp->tm_min; pc.seconds = tmp->tm_sec; tm.tm_isdst = tmp->tm_isdst; pc.meridian = MER24; pc.rel_seconds = 0; pc.rel_minutes = 0; pc.rel_hour = 0; pc.rel_day = 0; pc.rel_month = 0; pc.rel_year = 0; pc.dates_seen = 0; pc.days_seen = 0; pc.rels_seen = 0; pc.times_seen = 0; pc.local_zones_seen = 0; pc.zones_seen = 0; #if HAVE_TM_ZONE pc.local_time_zone_table[0].name = tmp->tm_zone; pc.local_time_zone_table[0].type = tLOCAL_ZONE; pc.local_time_zone_table[0].value = tmp->tm_isdst; pc.local_time_zone_table[1].name = 0; /* Probe the names used in the next three calendar quarters, looking for a tm_isdst different from the one we already have. */ { int quarter; for (quarter = 1; quarter <= 3; quarter++) { time_t probe = Start + quarter * (90 * 24 * 60 * 60); struct tm *probe_tm = localtime (&probe); if (probe_tm && probe_tm->tm_zone && probe_tm->tm_isdst != pc.local_time_zone_table[0].value) { { pc.local_time_zone_table[1].name = probe_tm->tm_zone; pc.local_time_zone_table[1].type = tLOCAL_ZONE; pc.local_time_zone_table[1].value = probe_tm->tm_isdst; pc.local_time_zone_table[2].name = 0; } break; } } } #else #if HAVE_TZNAME { # ifndef tzname extern char *tzname[]; # endif int i; for (i = 0; i < 2; i++) { pc.local_time_zone_table[i].name = tzname[i]; pc.local_time_zone_table[i].type = tLOCAL_ZONE; pc.local_time_zone_table[i].value = i; } pc.local_time_zone_table[i].name = 0; } #else pc.local_time_zone_table[0].name = 0; #endif #endif if (pc.local_time_zone_table[0].name && pc.local_time_zone_table[1].name && ! strcmp (pc.local_time_zone_table[0].name, pc.local_time_zone_table[1].name)) { /* This locale uses the same abbrevation for standard and daylight times. So if we see that abbreviation, we don't know whether it's daylight time. */ pc.local_time_zone_table[0].value = -1; pc.local_time_zone_table[1].name = 0; } if (yyparse (&pc) != 0 || 1 < pc.times_seen || 1 < pc.dates_seen || 1 < pc.days_seen || 1 < (pc.local_zones_seen + pc.zones_seen) || (pc.local_zones_seen && 1 < pc.local_isdst)) return -1; tm.tm_year = to_year (pc.year) - TM_YEAR_BASE + pc.rel_year; tm.tm_mon = pc.month - 1 + pc.rel_month; tm.tm_mday = pc.day + pc.rel_day; if (pc.times_seen || (pc.rels_seen && ! pc.dates_seen && ! pc.days_seen)) { tm.tm_hour = to_hour (pc.hour, pc.meridian); if (tm.tm_hour < 0) return -1; tm.tm_min = pc.minutes; tm.tm_sec = pc.seconds; } else { tm.tm_hour = tm.tm_min = tm.tm_sec = 0; } tm.tm_hour += pc.rel_hour; tm.tm_min += pc.rel_minutes; tm.tm_sec += pc.rel_seconds; /* Let mktime deduce tm_isdst if we have an absolute time stamp, or if the relative time stamp mentions days, months, or years. */ if (pc.dates_seen | pc.days_seen | pc.times_seen | pc.rel_day | pc.rel_month | pc.rel_year) tm.tm_isdst = -1; /* But if the input explicitly specifies local time with or without DST, give mktime that information. */ if (pc.local_zones_seen) tm.tm_isdst = pc.local_isdst; tm0 = tm; Start = mktime (&tm); if (Start == (time_t) -1) { /* Guard against falsely reporting errors near the time_t boundaries when parsing times in other time zones. For example, if the min time_t value is 1970-01-01 00:00:00 UTC and we are 8 hours ahead of UTC, then the min localtime value is 1970-01-01 08:00:00; if we apply mktime to 1970-01-01 00:00:00 we will get an error, so we apply mktime to 1970-01-02 08:00:00 instead and adjust the time zone by 24 hours to compensate. This algorithm assumes that there is no DST transition within a day of the time_t boundaries. */ if (pc.zones_seen) { tm = tm0; if (tm.tm_year <= EPOCH_YEAR - TM_YEAR_BASE) { tm.tm_mday++; pc.time_zone += 24 * 60; } else { tm.tm_mday--; pc.time_zone -= 24 * 60; } Start = mktime (&tm); } if (Start == (time_t) -1) return Start; } if (pc.days_seen && ! pc.dates_seen) { tm.tm_mday += ((pc.day_number - tm.tm_wday + 7) % 7 + 7 * (pc.day_ordinal - (0 < pc.day_ordinal))); Start = mktime (&tm); if (Start == (time_t) -1) return Start; } if (pc.zones_seen) { int delta = pc.time_zone * 60; #ifdef HAVE_TM_GMTOFF delta -= tm.tm_gmtoff; #else struct tm *gmt = gmtime (&Start); if (! gmt) return -1; delta -= tm_diff (&tm, gmt); #endif if ((Start < Start - delta) != (delta < 0)) return -1; /* time_t overflow */ Start -= delta; } return Start; } #if TEST #include int main (int ac, char **av) { char buff[BUFSIZ]; time_t d; printf ("Enter date, or blank line to exit.\n\t> "); fflush (stdout); buff[BUFSIZ - 1] = 0; while (fgets (buff, BUFSIZ - 1, stdin) && buff[0]) { d = get_date (buff, 0); if (d == (time_t) -1) printf ("Bad format - couldn't convert.\n"); else printf ("%s", ctime (&d)); printf ("\t> "); fflush (stdout); } return 0; } #endif /* defined TEST */