/* * date.c -- * Functions for the built-in type "AbsoluteTime". * Functions for the built-in type "RelativeTime". * Functions for the built-in type "TimeInterval". * * Notes: * This code is actually (almost) unused. * It needs to be integrated with Time and struct trange. * * XXX This code needs to be rewritten to work with the "new" definitions * XXX in h/tim.h. Look for int32's, int, long, etc. in the code. The * XXX definitions in h/tim.h may need to be rethought also. */ #include #include #include #include #include #include #include "tmp/postgres.h" #include "tmp/miscadmin.h" #include "utils/log.h" #include "utils/nabstime.h" RcsId("$Header: /private/postgres/src/utils/adt/RCS/date.c,v 1.25 1992/06/18 18:16:01 mer Exp $"); #define TM_YEAR_BASE 1900 /* compatible to UNIX time */ #define EPOCH_YEAR 1970 /* compatible to UNIX time */ #define YEAR_MAX 2038 /* otherwise overflow */ #define YEAR_MIN 1902 /* otherwise overflow */ #define DAYS_PER_LYEAR 366 #define DAYS_PER_NYEAR 365 #define HOURS_PER_DAY 24 #define MINS_PER_HOUR 60 #define SECS_PER_MIN 60 #define MAX_LONG 2147483647 /* 2^31 */ /* absolute time definitions */ #define TIME_NOW_STR "now" /* represents time now */ #define TIME_EPOCH_STR "epoch" /* Jan 1 00:00:00 1970 GMT */ #define TIME_EPOCH_STR_LEN (sizeof(TIME_EPOCH_STR)-1) #ifndef INVALID_ABSTIME #define INVALID_ABSTIME MAX_LONG #endif !INVALID_ABSTIME /* -2145916801 invalid time representation */ /* Dec 31 23:59:59 1901 */ #define INVALID_ABSTIME_STR "Undefined AbsTime" #define INVALID_ABSTIME_STR_LEN (sizeof(INVALID_ABSTIME_STR)-1) /* * Unix epoch is Jan 1 00:00:00 1970. Postgres knows about times * sixty-eight years on either side of that. */ #define MAX_ABSTIME 2147483647 /* Jan 19 03:14:07 2038 GMT */ #define MIN_ABSTIME (0) /* Jan 1 00:00:00 1970 */ /* relative time definitions */ #define MAX_RELTIME 2144448000 /* about 68 years, compatible to absolute time */ #define INVALID_RELTIME MAX_LONG /* invalid reltime representation */ #define INVALID_RELTIME_STR "Undefined RelTime" #define INVALID_RELTIME_STR_LEN (sizeof(INVALID_RELTIME_STR)-1) #define RELTIME_LABEL '@' #define RELTIME_PAST "ago" #define DIRMAXLEN (sizeof(RELTIME_PAST)-1) #define InAbsTimeInterval(T) \ ((int32)(T) <= MAX_ABSTIME && (int32)(T) >= MIN_ABSTIME) #define InRelTimeInterval(T) \ ((int32)(T) <= MAX_RELTIME && (int32)(T) >= - MAX_RELTIME) #define IsCharDigit(C) isdigit(C) #define IsCharA_Z(C) isalpha(C) #define IsSpace(C) ((C) == ' ') #define IsNull(C) ((C) == NULL) #define T_INTERVAL_INVAL 0 /* data represents no valid interval */ #define T_INTERVAL_VALID 1 /* data represents a valid interval */ #define T_INTERVAL_UNCOM 2 /* data represents an uncomplete interval */ #define T_INTERVAL_LEN 47 /* 2+20+1+1+1+20+2 : ['...' '...'] */ #define INVALID_INTERVAL_STR "Undefined Range" #define INVALID_INTERVAL_STR_LEN (sizeof(INVALID_INTERVAL_STR)-1) static char *month_name[] = { "Jan","Feb","Mar","Apr","May","Jun","Jul", "Aug","Sep","Oct","Nov","Dec" }; static int day_tab[2][12] = { {31,28,31,30,31,30,31,31,30,31,30,31}, {31,29,31,30,31,30,31,31,30,31,30,31} }; static char *unit_tab[] = { "second", "seconds", "minute", "minutes", "hour", "hours", "day", "days", "week", "weeks", "month", "months", "year", "years"}; #define UNITMAXLEN 7 /* max length of a unit name */ /* table of seconds per unit (month = 30 days, year = 365 days) */ static int sec_tab[] = { 1,1, 60, 60, 3600, 3600, 86400, 86400, 604800, 604800, 2592000, 2592000, 31536000, 31536000 }; /* maximal values (in seconds) per unit which can be represented */ static int unit_max_quantity[] = { 2144448000, 2144448000, 35740800, 35740800, 595680, 595680, 24820, 24820, 3545, 3545, 827, 827, 68, 68 }; #ifdef linux struct tm *CurrentLocalTime = 0; #else struct timeb *TimeDifferenceFromGMT = NULL; #endif static bool TimeDiffIsInited = false; static char *timezonename = NULL; /* * Function prototypes -- internal to this file only */ int isabstime ARGS((char *datestring , struct tm *brokentime )); int correct_month ARGS((char month [], int *num )); int isleap ARGS((int year )); int timeinsec ARGS((struct tm *t , AbsoluteTime *seconds )); int isreltime ARGS((char *timestring , int *sign , long *quantity , int *unitnr )); int correct_unit ARGS((char unit [], int *unptr )); int correct_dir ARGS((char direction [], int *signptr )); int istinterval ARGS((char *i_string , AbsoluteTime *i_start , AbsoluteTime *i_end )); char *timenowout ARGS((void )); AbsoluteTime timenow ARGS((void )); RelativeTime intervalrel ARGS((TimeInterval interval )); int ininterval ARGS((int32 t , TimeInterval interval )); AbsoluteTime timemi ARGS((AbsoluteTime AbsTime_t1 , RelativeTime RelTime_t2 )); char *tintervalout ARGS((TimeInterval interval )); TimeInterval tintervalin ARGS((char *intervalstr )); int32 intervaleq ARGS((TimeInterval i1 , TimeInterval i2 )); int32 intervalleneq ARGS((TimeInterval i , RelativeTime t )); int32 intervallenne ARGS((TimeInterval i , RelativeTime t )); int32 intervallenlt ARGS((TimeInterval i , RelativeTime t )); int32 intervallengt ARGS((TimeInterval i , RelativeTime t )); int32 intervallenle ARGS((TimeInterval i , RelativeTime t )); int32 intervallenge ARGS((TimeInterval i , RelativeTime t )); int32 intervalct ARGS((TimeInterval i1 , TimeInterval i2 )); int32 intervalov ARGS((TimeInterval i1 , TimeInterval i2 )); AbsoluteTime intervalstart ARGS((TimeInterval i )); AbsoluteTime intervalend ARGS((TimeInterval i )); /* ========== USER I/O ROUTINES ========== */ /* * abstimein - converts a time string to an internal format * checks syntax and range of datetime, * returns time as long integer in respect of GMT */ AbsoluteTime abstimein(datetime) char *datetime; { int which; AbsoluteTime time_; struct tm brokentime; if ( TimeDiffIsInited == false ) { #ifdef linux time_t ti; CurrentLocalTime = (struct tm *) malloc (sizeof(struct tm)); time(&ti); memcpy(CurrentLocalTime, localtime(&ti), sizeof(struct tm)); timezonename = tzname[CurrentLocalTime -> tm_isdst]; #else TimeDifferenceFromGMT = (struct timeb *) malloc( sizeof(struct timeb)); ftime(TimeDifferenceFromGMT); timezonename = (char *) timezone ( TimeDifferenceFromGMT->timezone, TimeDifferenceFromGMT->dstflag ) ; #endif TimeDiffIsInited = true; } which = isabstime(datetime, &brokentime); switch (which) { case 3: /* epoch */ time_ = MIN_ABSTIME; break; case 2: /* now */ time_ = GetCurrentTransactionStartTime(); break; case 1: /* from user */ (void) timeinsec(&brokentime, &time_); /* user inputs in local time, we need to store things * in GMT so that moving databases across timezones * (amongst other things) behave predictably */ time_ = time_ + #ifdef linux timezone - (CurrentLocalTime -> tm_isdst) * 3600; #else (TimeDifferenceFromGMT->timezone * 60 ) - ( TimeDifferenceFromGMT->dstflag * 3600 ) ; #endif break; case 0: /* error */ time_ = INVALID_ABSTIME; break; } return(time_); } /* * abstimeout - converts the internal time format to a string */ char * abstimeout(datetime) AbsoluteTime datetime; /* seconds in respect of Greenwich Mean Time GMT!! */ { extern struct tm *gmtime(); extern char *asctime(); extern char *index(); extern char *strcpy(); struct tm *brokentime; /*points to static structure in gmtime*/ char *datestring, *p; int i; if ( TimeDiffIsInited == false ) { #ifdef linux time_t ti; CurrentLocalTime = (struct tm *) malloc (sizeof(struct tm)); time(&ti); memcpy(CurrentLocalTime, localtime(&ti), sizeof(struct tm)); timezonename = tzname[CurrentLocalTime -> tm_isdst]; #else TimeDifferenceFromGMT = (struct timeb *) malloc( sizeof(struct timeb)); ftime(TimeDifferenceFromGMT); timezonename = (char *) timezone ( TimeDifferenceFromGMT->timezone, TimeDifferenceFromGMT->dstflag ) ; #endif TimeDiffIsInited = true; } if (datetime == INVALID_ABSTIME) { datestring = (char *) palloc ( INVALID_ABSTIME_STR_LEN +1 ); (void) strcpy(datestring,INVALID_ABSTIME_STR); } else if ( datetime == 0 ) { datestring = (char *)palloc ( TIME_EPOCH_STR_LEN + 1 ); (void) strcpy(datestring, TIME_EPOCH_STR ); } else { /* Using localtime instead of gmtime * does the correct conversion !!! */ char *temp_date_string = NULL; brokentime = localtime((long *) &datetime); temp_date_string = asctime(brokentime); /* add ten to the length because we want to append * the local timezone spec which might be up to GMT+xx:xx */ datestring = (char *)palloc ( strlen ( temp_date_string ) + 10 ); (void) strcpy(datestring, temp_date_string + 4 ); /* skip name of day */ /* change new-line character "\n" at the end to timezone followed by a null */ p = index(datestring,'\n'); *p = ' '; strcpy ( p+1 , timezonename ); } return(datestring); } /* * reltimein - converts a reltime string in an internal format */ int32 /* RelativeTime */ reltimein(timestring) char *timestring; { int error; int32 /* RelativeTime */ timeinsec; int sign, unitnr; long quantity; error = isreltime(timestring, &sign, &quantity, &unitnr); #ifdef DATEDEBUG elog(DEBUG, "reltimein: isreltime(%s) returns error=%d, %d, %d, %d", timestring, error, sign, quantity, unitnr); #endif /* !DATEDEBUG */ if (error != 1) { timeinsec = INVALID_RELTIME; /*invalid time representation */ } else { /* this check is necessary, while no control on overflow */ if (quantity > unit_max_quantity[unitnr] || quantity < 0) { #ifdef DATEDEBUG elog(DEBUG, "reltimein: illegal quantity %d (< %d)", quantity, unit_max_quantity[unitnr]); #endif /* DATEDEBUG */ timeinsec = INVALID_RELTIME; /* illegal quantity */ } else { timeinsec = sign * quantity * sec_tab[unitnr]; #ifdef DATEDEBUG elog(DEBUG, "reltimein: computed timeinsec %d", timeinsec); #endif /* DATEDEBUG */ if (timeinsec > MAX_RELTIME || timeinsec < - MAX_RELTIME) { timeinsec = INVALID_RELTIME; } } } /* if (timeinsec == INVALID_RELTIME) (void) printf("\n\tInvalid RelTime"); */ if (timeinsec == InvalidTime) { elog(WARN, "reltimein: cannot handle reltime of 0 secs, yet"); return(0); } else if (timeinsec == INVALID_ABSTIME) { timeinsec = InvalidTime; } return(timeinsec); } /* * reltimeout - converts the internal format to a reltime string */ char * reltimeout(timevalue) int32 /* RelativeTime */ timevalue; { extern char *sprintf(); char *timestring; long quantity; register int i; int unitnr; timestring = (char *) palloc(Max(strlen(INVALID_RELTIME_STR), UNITMAXLEN)); (void) strcpy(timestring,INVALID_RELTIME_STR); if (timevalue == INVALID_RELTIME) return(timestring); if (timevalue == 0) i = 1; /* unit = 'seconds' */ else for (i = 12; i >= 0; i = i-2) if ((timevalue % sec_tab[i]) == 0) break; /* appropriate unit found */ unitnr = i; quantity = (timevalue / sec_tab[unitnr]); if (quantity > 1 || quantity < -1) unitnr++; /* adjust index for PLURAL of unit */ timestring = (char *) palloc(Max(strlen(INVALID_RELTIME_STR), UNITMAXLEN)); if (quantity >= 0) (void) sprintf( timestring, "%c %u %s", RELTIME_LABEL, quantity, unit_tab[unitnr]); else (void) sprintf( timestring, "%c %u %s %s", RELTIME_LABEL, (quantity * -1), unit_tab[unitnr], RELTIME_PAST); return(timestring); } /* * tintervalin - converts an interval string to an internal format */ TimeInterval tintervalin(intervalstr) char *intervalstr; { int error; AbsoluteTime i_start, i_end; TimeInterval interval; interval = (TimeInterval) palloc(sizeof(TimeIntervalData)); error = istinterval(intervalstr, &i_start, &i_end); if (error == 0) /* not a valid interval NOT IMPLEMENTED */ interval->status = T_INTERVAL_INVAL; else { interval->data[0] = Min(i_start, i_end); interval->data[1] = Max(i_start, i_end); interval->status = T_INTERVAL_VALID; /* suppose valid range*/ if (interval->data[0] == INVALID_ABSTIME || interval->data[1] == INVALID_ABSTIME) interval->status = T_INTERVAL_UNCOM; /* uncomplete */ if (interval->data[0] == INVALID_ABSTIME && interval->data[1] == INVALID_ABSTIME) interval->status = T_INTERVAL_INVAL; /* undefined */ } return(interval); } /* * tintervalout - converts an internal interval format to a string * */ char * tintervalout(interval) TimeInterval interval; { extern char *abstimeout(); extern char *strcat(); extern char *strcpy(); char *i_str, *p; i_str = (char *) palloc( T_INTERVAL_LEN ); /* ['...' '...'] */ p = (char *) palloc(T_INTERVAL_LEN); (void) strcpy(i_str,"[\'"); if (interval->status == T_INTERVAL_INVAL) (void) strcat(i_str,INVALID_INTERVAL_STR); else { p = nabstimeout(interval->data[0]); (void) strcat(i_str,p); (void) strcat(i_str,"\' \'"); p = nabstimeout(interval->data[1]); (void) strcat(i_str,nabstimeout(interval->data[1])); } (void) strcat(i_str,"\']\0"); return(i_str); } /* ========== PUBLIC ROUTINES ========== */ /* * timemi - returns the value of (AbsTime_t1 - RelTime_t2) */ AbsoluteTime timemi(AbsTime_t1, RelTime_t2) AbsoluteTime AbsTime_t1; RelativeTime RelTime_t2; { AbsoluteTime t; if (InAbsTimeInterval(AbsTime_t1) && InRelTimeInterval(RelTime_t2)) { t = AbsTime_t1 - RelTime_t2; if (InAbsTimeInterval(t)) return(t); } return(INVALID_ABSTIME); } /* * timepl - returns the avlue of (AbsTime_t1 + RelTime_t2) */ AbsoluteTime timepl(AbsTime_t1,RelTime_t2) AbsoluteTime AbsTime_t1; RelativeTime RelTime_t2; { AbsoluteTime t; if (InAbsTimeInterval(AbsTime_t1) && InRelTimeInterval(RelTime_t2)) { t = AbsTime_t1 + RelTime_t2; if (InAbsTimeInterval(t)) return(t); } return(INVALID_ABSTIME); } /* * ininterval - returns 1, iff absolute date is in the interval */ int ininterval(t, interval) int32 /* AbsoluteTime */ t; TimeInterval interval; { if (interval->status == T_INTERVAL_VALID) { if (t >= (int32)interval->data[0] && t <= (int32)interval->data[1]) { return(1); /* t in valid interval */ } } return(0); } /* * intervalrel - returns relative time corresponding to interval */ RelativeTime intervalrel(interval) TimeInterval interval; { if (interval->status == T_INTERVAL_VALID) return(timemi(interval->data[1], interval->data[0])); else return(INVALID_RELTIME); } /* * timenow - returns time "now", internal format * * Now AbsoluteTime is time since Jan 1 1970 -mer 7 Feb 1992 */ AbsoluteTime timenow() { struct timeval tp; struct timezone tzp; (void) gettimeofday(&tp, &tzp); return((AbsoluteTime)tp.tv_sec); } /* * timenowout - returns a pointer to "" */ char * timenowout() { extern gettimeofday(); extern struct tm *localtime(); extern char *asctime(); struct timeval *tp; struct timezone *tzp; struct tm *brokentime; long sec; int i; char *datestring; tp = (struct timeval *) palloc(sizeof(struct timeval)); tzp= (struct timezone *) palloc(sizeof(struct timezone)); (void) gettimeofday(tp, tzp); sec = tp->tv_sec; brokentime = (struct tm *) palloc(sizeof(struct tm)); brokentime = localtime(&sec); datestring = asctime(brokentime); for (i=0; i<=3; i++) datestring=datestring++; return(datestring); } /* * reltimeeq - returns 1, iff arguments are equal * reltimene - returns 1, iff arguments are not equal * reltimelt - returns 1, iff t1 less than t2 * reltimegt - returns 1, iff t1 greater than t2 * reltimele - returns 1, iff t1 less than or equal to t2 * reltimege - returns 1, iff t1 greater than or equal to t2 */ int32 reltimeeq(t1,t2) RelativeTime t1,t2; { return(t1 == t2); } int32 reltimene(t1, t2) RelativeTime t1,t2; { return(t1 != t2); } int32 reltimelt(t1, t2) int32 /* RelativeTime */ t1,t2; { return(t1 < t2); } int32 reltimegt(t1, t2) int32 /* RelativeTime */ t1,t2; { return(t1 > t2); } int32 reltimele(t1, t2) int32 /* RelativeTime */ t1,t2; { return(t1 <= t2); } int32 reltimege(t1, t2) int32 /* RelativeTime */ t1,t2; { return(t1 >= t2); } /* * intervaleq - returns 1, iff interval i1 is equal to interval i2 */ int32 intervaleq(i1, i2) TimeInterval i1, i2; { Assert(0); /* XXX */ if (i1->status == T_INTERVAL_INVAL || i2->status == T_INTERVAL_INVAL) return(0); /* invalid interval */ return((i1->data[0] == i2->data[0]) && (i1->data[1] == i2->data[1]) ); } /* * intervalleneq - returns 1, iff length of interval i is equal to * reltime t */ int32 intervalleneq(i,t) TimeInterval i; RelativeTime t; { Assert(0); /* XXX */ if ((i->status == T_INTERVAL_INVAL) || (t == INVALID_RELTIME)) return(0); return ( (intervalrel(i) == t)); } /* * intervallenne - returns 1, iff length of interval i is not equal * to reltime t */ int32 intervallenne(i,t) TimeInterval i; RelativeTime t; { Assert(0); /* XXX */ if ((i->status == T_INTERVAL_INVAL) || (t == INVALID_RELTIME)) return(0); return ( (intervalrel(i) != t)); } /* * intervallenlt - returns 1, iff length of interval i is less than * reltime t */ int32 intervallenlt(i,t) TimeInterval i; RelativeTime t; { Assert(0); /* XXX */ if ((i->status == T_INTERVAL_INVAL) || (t == INVALID_RELTIME)) return(0); return ( (intervalrel(i) < t)); } /* * intervallengt - returns 1, iff length of interval i is greater than * reltime t */ int32 intervallengt(i,t) TimeInterval i; RelativeTime t; { Assert(0); /* XXX */ if ((i->status == T_INTERVAL_INVAL) || (t == INVALID_RELTIME)) return(0); return ( (intervalrel(i) > t)); } /* * intervallenle - returns 1, iff length of interval i is less or equal * than reltime t */ int32 intervallenle(i,t) TimeInterval i; RelativeTime t; { Assert(0); /* XXX */ if ((i->status == T_INTERVAL_INVAL) || (t == INVALID_RELTIME)) return(0); return ( (intervalrel(i) <= t)); } /* * intervallenge - returns 1, iff length of interval i is greater or * equal than reltime t */ int32 intervallenge(i,t) TimeInterval i; RelativeTime t; { Assert(0); /* XXX */ if ((i->status == T_INTERVAL_INVAL) || (t == INVALID_RELTIME)) return(0); return ( (intervalrel(i) >= t)); } /* * intervalct - returns 1, iff interval i1 contains interval i2 */ int32 intervalct(i1,i2) TimeInterval i1, i2; { Assert(0); /* XXX */ if (i1->status == T_INTERVAL_INVAL || i2->status == T_INTERVAL_INVAL) return(0); /* invalid interval */ return((i1->data[0] <= i2->data[0]) && (i1->data[1] >= i2->data[1]) ); } /* * intervalov - returns 1, iff interval i1 (partially) overlaps i2 */ int32 intervalov(i1, i2) TimeInterval i1, i2; { Assert(0); /* XXX */ if (i1->status == T_INTERVAL_INVAL || i2->status == T_INTERVAL_INVAL) return(0); /* invalid interval */ return(ininterval(i2->data[0], i1) || ininterval(i2->data[1], i1) ); } /* * intervalstart - returns the start of interval i */ AbsoluteTime intervalstart(i) TimeInterval i; { return(i->data[0]); } /* * intervalend - returns the end of interval i */ AbsoluteTime intervalend(i) TimeInterval i; { return(i->data[1]); } /* ========== PRIVATE ROUTINES ========== */ /* * These are support routines for the old abstime implementation. As * far as I know they are no longer used... * * correct_month - returns 1, iff month is a correct month descriptor * else 0. * output parameter: * num: points to an integer which is an index * in table month_name[] */ int correct_month(month, num) char month[]; int *num; /* number of month 0,...,11 */ { extern int strncmp(); extern char *month_name[]; int i = 0; while (i <= 11) { if (strncmp(month, month_name[i],3) == 0) { *num = i; return(1); } i++; } return(0); /* invalid month describtion */ } /* * isleap - returns 1, iff year is a leap year */ int isleap(year) int year; { return(year%4 == 0 && year%100 != 0 || year%400 == 0); } /* * timeinsec - returns 1, iff a valid date is given, otherwise 0 * * output parameter * seconds: date in seconds (in respect of GMT!) */ int timeinsec(t, seconds) struct tm *t; AbsoluteTime *seconds; /* absolute time in seconds */ { register long sec; register int year, mon; if (t == NULL) return(0); sec = 0; *seconds = INVALID_ABSTIME; year = t->tm_year + TM_YEAR_BASE; mon = t->tm_mon + 1; /* mon 1,...,12 */ if (year >= EPOCH_YEAR) { /* collect days, maybe also the Feb 29. */ if (isleap(year) && mon > 2) ++sec; for (--year; year >= EPOCH_YEAR; --year) sec += isleap(year) ? DAYS_PER_LYEAR : DAYS_PER_NYEAR; --mon; /* mon 0,...,11 */ while(--mon >= 0) sec += day_tab[0][mon]; sec += t->tm_mday - 1; sec = HOURS_PER_DAY * sec + t->tm_hour; sec = MINS_PER_HOUR * sec + t->tm_min; sec = SECS_PER_MIN * sec + t->tm_sec; /* year >= EPOCH_YEAR ==> sec >= 0 , otherwise overflow!! */ if (sec >= 0 && sec <= MAX_ABSTIME) { *seconds = sec; /* seconds in respect of */ return(1); /* Greenwich Mean Time GMT */ } else return(0); } else { /* collect days, maby also the Feb 29. */ if(isleap(year) && mon <= 2) ++sec; for (++year; year < EPOCH_YEAR; ++year) sec += isleap(year) ? DAYS_PER_LYEAR : DAYS_PER_NYEAR; --mon; /* mon 0,...,11 */ while(++mon <= 11) sec += day_tab[0][mon]; sec += day_tab[isleap(t->tm_year)][t->tm_mon] - t->tm_mday; sec = HOURS_PER_DAY * sec + (24 - (t->tm_hour + 1)); sec = MINS_PER_HOUR * sec + (60 - (t->tm_min + 1)); sec = SECS_PER_MIN * sec + (60 - t->tm_sec); sec = -sec; /* year was less then EPOCH_YEAR !! */ /* year < EPOCH_YEAR ==> sec < 0 , otherwise overflow!! */ if (sec < 0 && sec >= MIN_ABSTIME) { *seconds = sec; /* seconds in respect of */ return(1); /* Greenwich Mean Time GMT */ } else return(0); } } /* * isreltime - returns 1, iff datestring is of type reltime * 2, iff datestring is 'invalid time' identifier * 0, iff datestring contains a syntax error * * output parameter: * sign = -1, iff direction is 'ago' * else sign = 1. * quantity : quantity of unit * unitnr : 0 or 1 ... sec * 2 or 3 ... min * 4 or 5 ... hour * 6 or 7 ... day * 8 or 9 ... week * 10 or 11... month * 12 or 13... year * * * Relative time: * * `@' ` ' Quantity ` ' Unit [ ` ' Direction] * * OR `Undefined RelTime' (see also INVALID_RELTIME_STR) * * where * Quantity is `1', `2', ... * Unit is `second', `minute', `hour', `day', `week', * `month' (30-days), or `year' (365-days), * or PLURAL of these units. * Direction is `ago' * * VALID time less or equal `@ 68 years' * */ int isreltime(timestring, sign, quantity, unitnr) char *timestring; int *sign, *unitnr; long *quantity; { extern int strncmp(); extern char *strcpy(); register char *p; register char c; int i; char unit[UNITMAXLEN] ; char direction[DIRMAXLEN]; int localSign; int localUnitNumber; long localQuantity; if (!PointerIsValid(sign)) { sign = &localSign; } if (!PointerIsValid(unitnr)) { unitnr = &localUnitNumber; } if (!PointerIsValid(quantity)) { quantity = &localQuantity; } unit[0] = '\0'; direction[0] = '\0'; p = timestring; /* skip leading blanks */ while (c = *p) { if (c != ' ') break; p++; } /* Test whether 'invalid time' identifier or not */ if (!strncmp(INVALID_RELTIME_STR,p,strlen(INVALID_RELTIME_STR) + 1)) return(2); /* correct 'invalid time' identifier found */ /* handle label of relative time */ if (c != RELTIME_LABEL) return(0); /*syntax error*/ c = *++p; if (c != ' ') return(0); /*syntax error*/ p++; /* handle the quantity */ *quantity = 0; for (;;) { c = *p; if (isdigit(c)) { *quantity = *quantity * 10 + (c -'0'); p++; } else { if (c == ' ' ) break; /* correct quantity found */ else return(0); /* syntax error */ } } /* handle unit */ p++; i = 0; for (;;) { c = *p; if (c >= 'a' && c <= 'z' && i <= (UNITMAXLEN - 1)) { unit[i] = c; p++; i++; } else { if ((c == ' ' || c == '\0') && correct_unit(unit, unitnr)) break; /* correct unit found */ else return(0); /* syntax error */ } } /* handle optional direction */ if (c == ' ') p++; i = 0; *sign = 1; for (;;) { c = *p; if (c >= 'a' && c <= 'z' && i <= (DIRMAXLEN - 1)) { direction[i] = c; p++; i++; } else { if ((c == ' ' || c == NULL) && i == 0) { *sign = 1; break; /* no direction specified */ } if ((c == ' ' || c == '\0') && i != 0) { direction[i] = '\0'; correct_dir(direction, sign); break; /* correct direction found */ } else return(0); /* syntax error*/ } } return(1); } /* * correct_unit - returns 1, iff unit is a correct unit description * * output parameter: * unptr: points to an integer which is the appropriate unit number * (see function isreltime()) */ int correct_unit(unit, unptr) char unit[]; int *unptr; { int j = 0; while (j >= 0) { if (strncmp(unit, unit_tab[j], strlen(unit_tab[j])) == 0) { *unptr = j; return(1); } j++; } return (0); /* invalid unit descriptor */ } /* * correct_dir - returns 1, iff direction is a correct identifier * * output parameter: * signptr: points to -1 if dir corresponds to past tense * else to 1 */ int correct_dir(direction,signptr) char direction[]; int *signptr; { *signptr = 1; if (strncmp(RELTIME_PAST, direction, strlen(RELTIME_PAST)+1) == 0) { *signptr = -1; return(1); } else return (0); /* invalid direction descriptor */ } /* * istinterval - returns 1, iff i_string is a valid interval descr. * 0, iff i_string is NOT a valid interval desc. * 2, iff any time is INVALID_ABSTIME * * output parameter: * i_start, i_end: interval margins * * Time interval: * `[' {` '} `'' `'' {` '} `'' `'' {` '} `]' * * OR `Undefined Range' (see also INVALID_INTERVAL_STR) * * where satisfies the syntax of absolute time. * * e.g. [ ' Jan 18 1902' 'Jan 1 00:00:00 1970'] */ int istinterval(i_string, i_start, i_end) char *i_string; AbsoluteTime *i_start, *i_end; { extern AbsoluteTime abstimein(); register char *p,*p1; register char c; p = i_string; /* skip leading blanks up to '[' */ while (c = *p) { if ( IsSpace(c)) p++; else if (c != '[') return(0); /* syntax error */ else break; } p++; /* skip leading blanks up to "'" */ while (c = *p) { if (IsSpace(c)) p++; else if (c != '\'') return (0); /* syntax error */ else break; } p++; if (strncmp(INVALID_INTERVAL_STR,p,strlen(INVALID_INTERVAL_STR)) == 0) return(0); /* undefined range, handled like a syntax err.*/ /* search for the end of the first date and change it to a NULL*/ p1 = p; while (c = *p1) { if ( c == '\'') { *p1 = NULL; break; } p1++; } /* get the first date */ *i_start = nabstimein(p); /* first absolute date */ /* rechange NULL at the end of the first date to a "'" */ *p1 = '\''; p = ++p1; /* skip blanks up to "'", beginning of second date*/ while (c = *p) { if (IsSpace(c)) p++; else if (c != '\'') return (0); /* syntax error */ else break; } p++; /* search for the end of the second date and change it to a NULL*/ p1 = p; while (c = *p1) { if ( c == '\'') { *p1 = NULL; break; } p1++; } /* get the second date */ *i_end = nabstimein(p); /* second absolute date */ /* rechange NULL at the end of the first date to a ''' */ *p1 = '\''; p = ++p1; /* skip blanks up to ']'*/ while (c = *p) { if ( IsSpace(c)) p++; else if (c != ']') return(0); /*syntax error */ else break; } p++; c = *p; if ( ! IsNull(c)) return (0); /* syntax error */ /* it seems to be a valid interval */ return(1); }