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localtime.c
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localtime.c
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/*
** This file is in the public domain, so clarified as of
** 1996-06-05 by Arthur David Olson.
*/
#ifndef lint
#ifndef NOID
static char elsieid[] = "@(#)localtime.c 8.17";
#endif /* !defined NOID */
#endif /* !defined lint */
/*
** Leap second handling from Bradley White.
** POSIX-style TZ environment variable handling from Guy Harris.
*/
/*LINTLIBRARY*/
#include "private.h"
#include "tzfile.h"
#include "fcntl.h"
#include "float.h" /* for FLT_MAX and DBL_MAX */
#ifndef TZ_ABBR_MAX_LEN
#define TZ_ABBR_MAX_LEN 16
#endif /* !defined TZ_ABBR_MAX_LEN */
#ifndef TZ_ABBR_CHAR_SET
#define TZ_ABBR_CHAR_SET \
"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789 :+-._"
#endif /* !defined TZ_ABBR_CHAR_SET */
#ifndef TZ_ABBR_ERR_CHAR
#define TZ_ABBR_ERR_CHAR '_'
#endif /* !defined TZ_ABBR_ERR_CHAR */
/*
** SunOS 4.1.1 headers lack O_BINARY.
*/
#ifdef O_BINARY
#define OPEN_MODE (O_RDONLY | O_BINARY)
#endif /* defined O_BINARY */
#ifndef O_BINARY
#define OPEN_MODE O_RDONLY
#endif /* !defined O_BINARY */
#ifndef WILDABBR
/*
** Someone might make incorrect use of a time zone abbreviation:
** 1. They might reference tzname[0] before calling tzset (explicitly
** or implicitly).
** 2. They might reference tzname[1] before calling tzset (explicitly
** or implicitly).
** 3. They might reference tzname[1] after setting to a time zone
** in which Daylight Saving Time is never observed.
** 4. They might reference tzname[0] after setting to a time zone
** in which Standard Time is never observed.
** 5. They might reference tm.TM_ZONE after calling offtime.
** What's best to do in the above cases is open to debate;
** for now, we just set things up so that in any of the five cases
** WILDABBR is used. Another possibility: initialize tzname[0] to the
** string "tzname[0] used before set", and similarly for the other cases.
** And another: initialize tzname[0] to "ERA", with an explanation in the
** manual page of what this "time zone abbreviation" means (doing this so
** that tzname[0] has the "normal" length of three characters).
*/
#define WILDABBR " "
#endif /* !defined WILDABBR */
static char wildabbr[] = WILDABBR;
static const char gmt[] = "GMT";
/*
** The DST rules to use if TZ has no rules and we can't load TZDEFRULES.
** We default to US rules as of 1999-08-17.
** POSIX 1003.1 section 8.1.1 says that the default DST rules are
** implementation dependent; for historical reasons, US rules are a
** common default.
*/
#ifndef TZDEFRULESTRING
#define TZDEFRULESTRING ",M4.1.0,M10.5.0"
#endif /* !defined TZDEFDST */
struct ttinfo { /* time type information */
long tt_gmtoff; /* UTC offset in seconds */
int tt_isdst; /* used to set tm_isdst */
int tt_abbrind; /* abbreviation list index */
int tt_ttisstd; /* TRUE if transition is std time */
int tt_ttisgmt; /* TRUE if transition is UTC */
};
struct lsinfo { /* leap second information */
time_t ls_trans; /* transition time */
long ls_corr; /* correction to apply */
};
#define BIGGEST(a, b) (((a) > (b)) ? (a) : (b))
#ifdef TZNAME_MAX
#define MY_TZNAME_MAX TZNAME_MAX
#endif /* defined TZNAME_MAX */
#ifndef TZNAME_MAX
#define MY_TZNAME_MAX 255
#endif /* !defined TZNAME_MAX */
struct state {
int leapcnt;
int timecnt;
int typecnt;
int charcnt;
int goback;
int goahead;
time_t ats[TZ_MAX_TIMES];
unsigned char types[TZ_MAX_TIMES];
struct ttinfo ttis[TZ_MAX_TYPES];
char chars[BIGGEST(BIGGEST(TZ_MAX_CHARS + 1, sizeof gmt),
(2 * (MY_TZNAME_MAX + 1)))];
struct lsinfo lsis[TZ_MAX_LEAPS];
};
struct rule {
int r_type; /* type of rule--see below */
int r_day; /* day number of rule */
int r_week; /* week number of rule */
int r_mon; /* month number of rule */
long r_time; /* transition time of rule */
};
#define JULIAN_DAY 0 /* Jn - Julian day */
#define DAY_OF_YEAR 1 /* n - day of year */
#define MONTH_NTH_DAY_OF_WEEK 2 /* Mm.n.d - month, week, day of week */
/*
** Prototypes for static functions.
*/
static long detzcode(const char * codep);
static time_t detzcode64(const char * codep);
static int differ_by_repeat(time_t t1, time_t t0);
static const char * getzname(const char * strp);
static const char * getqzname(const char * strp, const int delim);
static const char * getnum(const char * strp, int * nump, int min,
int max);
static const char * getsecs(const char * strp, long * secsp);
static const char * getoffset(const char * strp, long * offsetp);
static const char * getrule(const char * strp, struct rule * rulep);
static void gmtload(struct state * sp);
static struct tm * gmtsub(const time_t * timep, long offset,
struct tm * tmp);
static struct tm * localsub(const time_t * timep, long offset,
struct tm * tmp);
static int increment_overflow(int * number, int delta);
static int leaps_thru_end_of(int y);
static int long_increment_overflow(long * number, int delta);
static int long_normalize_overflow(long * tensptr,
int * unitsptr, int base);
static int normalize_overflow(int * tensptr, int * unitsptr,
int base);
static void settzname(void);
static time_t time1(struct tm * tmp,
struct tm * (*funcp)(const time_t *,
long, struct tm *),
long offset);
static time_t time2(struct tm *tmp,
struct tm * (*funcp)(const time_t *,
long, struct tm*),
long offset, int * okayp);
static time_t time2sub(struct tm *tmp,
struct tm * (*funcp)(const time_t *,
long, struct tm*),
long offset, int * okayp, int do_norm_secs);
static struct tm * timesub(const time_t * timep, long offset,
const struct state * sp, struct tm * tmp);
static int tmcomp(const struct tm * atmp,
const struct tm * btmp);
static time_t transtime(time_t janfirst, int year,
const struct rule * rulep, long offset);
static int typesequiv(const struct state * sp, int a, int b);
static int tzload(const char * name, struct state * sp,
int doextend);
static int tzparse(const char * name, struct state * sp,
int lastditch);
#ifdef ALL_STATE
static struct state * lclptr;
static struct state * gmtptr;
#endif /* defined ALL_STATE */
#ifndef ALL_STATE
static struct state lclmem;
static struct state gmtmem;
#define lclptr (&lclmem)
#define gmtptr (&gmtmem)
#endif /* State Farm */
#ifndef TZ_STRLEN_MAX
#define TZ_STRLEN_MAX 255
#endif /* !defined TZ_STRLEN_MAX */
static char lcl_TZname[TZ_STRLEN_MAX + 1];
static int lcl_is_set;
static int gmt_is_set;
char * tzname[2] = {
wildabbr,
wildabbr
};
/*
** Section 4.12.3 of X3.159-1989 requires that
** Except for the strftime function, these functions [asctime,
** ctime, gmtime, localtime] return values in one of two static
** objects: a broken-down time structure and an array of char.
** Thanks to Paul Eggert for noting this.
*/
static struct tm tm;
#ifdef USG_COMPAT
time_t timezone = 0;
int daylight = 0;
#endif /* defined USG_COMPAT */
#ifdef ALTZONE
time_t altzone = 0;
#endif /* defined ALTZONE */
static long
detzcode(codep)
const char * const codep;
{
register long result;
register int i;
result = (codep[0] & 0x80) ? ~0L : 0;
for (i = 0; i < 4; ++i)
result = (result << 8) | (codep[i] & 0xff);
return result;
}
static time_t
detzcode64(codep)
const char * const codep;
{
register time_t result;
register int i;
result = (codep[0] & 0x80) ? (~(int_fast64_t) 0) : 0;
for (i = 0; i < 8; ++i)
result = result * 256 + (codep[i] & 0xff);
return result;
}
static void
settzname(void)
{
register struct state * const sp = lclptr;
register int i;
tzname[0] = wildabbr;
tzname[1] = wildabbr;
#ifdef USG_COMPAT
daylight = 0;
timezone = 0;
#endif /* defined USG_COMPAT */
#ifdef ALTZONE
altzone = 0;
#endif /* defined ALTZONE */
#ifdef ALL_STATE
if (sp == NULL) {
tzname[0] = tzname[1] = gmt;
return;
}
#endif /* defined ALL_STATE */
/*
** And to get the latest zone names into tzname. . .
*/
for (i = 0; i < sp->timecnt; ++i) {
register const struct ttinfo * const ttisp =
&sp->ttis[
sp->types[i]];
tzname[ttisp->tt_isdst] =
&sp->chars[ttisp->tt_abbrind];
#ifdef USG_COMPAT
if (ttisp->tt_isdst)
daylight = 1;
if (!ttisp->tt_isdst)
timezone = -(ttisp->tt_gmtoff);
#endif /* defined USG_COMPAT */
#ifdef ALTZONE
if (ttisp->tt_isdst)
altzone = -(ttisp->tt_gmtoff);
#endif /* defined ALTZONE */
}
/*
** Finally, scrub the abbreviations.
** First, replace bogus characters.
*/
for (i = 0; i < sp->charcnt; ++i)
if (strchr(TZ_ABBR_CHAR_SET, sp->chars[i]) == NULL)
sp->chars[i] = TZ_ABBR_ERR_CHAR;
/*
** Second, truncate long abbreviations.
*/
for (i = 0; i < sp->typecnt; ++i) {
register const struct ttinfo * const ttisp = &sp->ttis[i];
register char * cp = &sp->chars[ttisp->tt_abbrind];
if (strlen(cp) > TZ_ABBR_MAX_LEN &&
strcmp(cp, GRANDPARENTED) != 0)
*(cp + TZ_ABBR_MAX_LEN) = '\0';
}
}
static int
differ_by_repeat(t1, t0)
const time_t t1;
const time_t t0;
{
if (TYPE_INTEGRAL(time_t) &&
TYPE_BIT(time_t) - TYPE_SIGNED(time_t) < SECSPERREPEAT_BITS)
return 0;
return t1 - t0 == SECSPERREPEAT;
}
static int
tzload(name, sp, doextend)
register const char * name;
register struct state * const sp;
register const int doextend;
{
register const char * p;
register int i;
register int fid;
register int stored;
register int nread;
typedef union {
struct tzhead tzhead;
char buf[2 * sizeof(struct tzhead) +
2 * sizeof *sp +
4 * TZ_MAX_TIMES];
} u_t;
#ifdef ALL_STATE
register u_t * up;
up = (u_t *) calloc(1, sizeof *up);
if (up == NULL)
return -1;
#else /* !defined ALL_STATE */
u_t u;
register u_t * const up = &u;
#endif /* !defined ALL_STATE */
sp->goback = sp->goahead = FALSE;
if (name == NULL && (name = TZDEFAULT) == NULL)
goto oops;
{
register int doaccess;
/*
** Section 4.9.1 of the C standard says that
** "FILENAME_MAX expands to an integral constant expression
** that is the size needed for an array of char large enough
** to hold the longest file name string that the implementation
** guarantees can be opened."
*/
char fullname[FILENAME_MAX + 1];
if (name[0] == ':')
++name;
doaccess = name[0] == '/';
if (!doaccess) {
if ((p = TZDIR) == NULL)
goto oops;
if ((strlen(p) + strlen(name) + 1) >= sizeof fullname)
goto oops;
(void) strcpy(fullname, p);
(void) strcat(fullname, "/");
(void) strcat(fullname, name);
/*
** Set doaccess if '.' (as in "../") shows up in name.
*/
if (strchr(name, '.') != NULL)
doaccess = TRUE;
name = fullname;
}
if (doaccess && access(name, R_OK) != 0)
goto oops;
if ((fid = open(name, OPEN_MODE)) == -1)
goto oops;
}
nread = read(fid, up->buf, sizeof up->buf);
if (close(fid) < 0 || nread <= 0)
goto oops;
for (stored = 4; stored <= 8; stored *= 2) {
int ttisstdcnt;
int ttisgmtcnt;
ttisstdcnt = (int) detzcode(up->tzhead.tzh_ttisstdcnt);
ttisgmtcnt = (int) detzcode(up->tzhead.tzh_ttisgmtcnt);
sp->leapcnt = (int) detzcode(up->tzhead.tzh_leapcnt);
sp->timecnt = (int) detzcode(up->tzhead.tzh_timecnt);
sp->typecnt = (int) detzcode(up->tzhead.tzh_typecnt);
sp->charcnt = (int) detzcode(up->tzhead.tzh_charcnt);
p = up->tzhead.tzh_charcnt + sizeof up->tzhead.tzh_charcnt;
if (sp->leapcnt < 0 || sp->leapcnt > TZ_MAX_LEAPS ||
sp->typecnt <= 0 || sp->typecnt > TZ_MAX_TYPES ||
sp->timecnt < 0 || sp->timecnt > TZ_MAX_TIMES ||
sp->charcnt < 0 || sp->charcnt > TZ_MAX_CHARS ||
(ttisstdcnt != sp->typecnt && ttisstdcnt != 0) ||
(ttisgmtcnt != sp->typecnt && ttisgmtcnt != 0))
goto oops;
if (nread - (p - up->buf) <
sp->timecnt * stored + /* ats */
sp->timecnt + /* types */
sp->typecnt * 6 + /* ttinfos */
sp->charcnt + /* chars */
sp->leapcnt * (stored + 4) + /* lsinfos */
ttisstdcnt + /* ttisstds */
ttisgmtcnt) /* ttisgmts */
goto oops;
for (i = 0; i < sp->timecnt; ++i) {
sp->ats[i] = (stored == 4) ?
detzcode(p) : detzcode64(p);
p += stored;
}
for (i = 0; i < sp->timecnt; ++i) {
sp->types[i] = (unsigned char) *p++;
if (sp->types[i] >= sp->typecnt)
goto oops;
}
for (i = 0; i < sp->typecnt; ++i) {
register struct ttinfo * ttisp;
ttisp = &sp->ttis[i];
ttisp->tt_gmtoff = detzcode(p);
p += 4;
ttisp->tt_isdst = (unsigned char) *p++;
if (ttisp->tt_isdst != 0 && ttisp->tt_isdst != 1)
goto oops;
ttisp->tt_abbrind = (unsigned char) *p++;
if (ttisp->tt_abbrind < 0 ||
ttisp->tt_abbrind > sp->charcnt)
goto oops;
}
for (i = 0; i < sp->charcnt; ++i)
sp->chars[i] = *p++;
sp->chars[i] = '\0'; /* ensure '\0' at end */
for (i = 0; i < sp->leapcnt; ++i) {
register struct lsinfo * lsisp;
lsisp = &sp->lsis[i];
lsisp->ls_trans = (stored == 4) ?
detzcode(p) : detzcode64(p);
p += stored;
lsisp->ls_corr = detzcode(p);
p += 4;
}
for (i = 0; i < sp->typecnt; ++i) {
register struct ttinfo * ttisp;
ttisp = &sp->ttis[i];
if (ttisstdcnt == 0)
ttisp->tt_ttisstd = FALSE;
else {
ttisp->tt_ttisstd = *p++;
if (ttisp->tt_ttisstd != TRUE &&
ttisp->tt_ttisstd != FALSE)
goto oops;
}
}
for (i = 0; i < sp->typecnt; ++i) {
register struct ttinfo * ttisp;
ttisp = &sp->ttis[i];
if (ttisgmtcnt == 0)
ttisp->tt_ttisgmt = FALSE;
else {
ttisp->tt_ttisgmt = *p++;
if (ttisp->tt_ttisgmt != TRUE &&
ttisp->tt_ttisgmt != FALSE)
goto oops;
}
}
/*
** Out-of-sort ats should mean we're running on a
** signed time_t system but using a data file with
** unsigned values (or vice versa).
*/
for (i = 0; i < sp->timecnt - 2; ++i)
if (sp->ats[i] > sp->ats[i + 1]) {
++i;
if (TYPE_SIGNED(time_t)) {
/*
** Ignore the end (easy).
*/
sp->timecnt = i;
} else {
/*
** Ignore the beginning (harder).
*/
register int j;
for (j = 0; j + i < sp->timecnt; ++j) {
sp->ats[j] = sp->ats[j + i];
sp->types[j] = sp->types[j + i];
}
sp->timecnt = j;
}
break;
}
/*
** If this is an old file, we're done.
*/
if (up->tzhead.tzh_version[0] == '\0')
break;
nread -= p - up->buf;
for (i = 0; i < nread; ++i)
up->buf[i] = p[i];
/*
** If this is a narrow integer time_t system, we're done.
*/
if (stored >= (int) sizeof(time_t) && TYPE_INTEGRAL(time_t))
break;
}
if (doextend && nread > 2 &&
up->buf[0] == '\n' && up->buf[nread - 1] == '\n' &&
sp->typecnt + 2 <= TZ_MAX_TYPES) {
struct state ts;
register int result;
up->buf[nread - 1] = '\0';
result = tzparse(&up->buf[1], &ts, FALSE);
if (result == 0 && ts.typecnt == 2 &&
sp->charcnt + ts.charcnt <= TZ_MAX_CHARS) {
for (i = 0; i < 2; ++i)
ts.ttis[i].tt_abbrind +=
sp->charcnt;
for (i = 0; i < ts.charcnt; ++i)
sp->chars[sp->charcnt++] =
ts.chars[i];
i = 0;
while (i < ts.timecnt &&
ts.ats[i] <=
sp->ats[sp->timecnt - 1])
++i;
while (i < ts.timecnt &&
sp->timecnt < TZ_MAX_TIMES) {
sp->ats[sp->timecnt] =
ts.ats[i];
sp->types[sp->timecnt] =
sp->typecnt +
ts.types[i];
++sp->timecnt;
++i;
}
sp->ttis[sp->typecnt++] = ts.ttis[0];
sp->ttis[sp->typecnt++] = ts.ttis[1];
}
}
if (sp->timecnt > 1) {
for (i = 1; i < sp->timecnt; ++i)
if (typesequiv(sp, sp->types[i], sp->types[0]) &&
differ_by_repeat(sp->ats[i], sp->ats[0])) {
sp->goback = TRUE;
break;
}
for (i = sp->timecnt - 2; i >= 0; --i)
if (typesequiv(sp, sp->types[sp->timecnt - 1],
sp->types[i]) &&
differ_by_repeat(sp->ats[sp->timecnt - 1],
sp->ats[i])) {
sp->goahead = TRUE;
break;
}
}
#ifdef ALL_STATE
(void) free((void *) up);
#endif /* defined ALL_STATE */
return 0;
oops:
#ifdef ALL_STATE
(void) free((void *) up);
#endif /* defined ALL_STATE */
return -1;
}
static int
typesequiv(sp, a, b)
const struct state * const sp;
const int a;
const int b;
{
register int result;
if (sp == NULL ||
a < 0 || a >= sp->typecnt ||
b < 0 || b >= sp->typecnt)
result = FALSE;
else {
register const struct ttinfo * ap = &sp->ttis[a];
register const struct ttinfo * bp = &sp->ttis[b];
result = ap->tt_gmtoff == bp->tt_gmtoff &&
ap->tt_isdst == bp->tt_isdst &&
ap->tt_ttisstd == bp->tt_ttisstd &&
ap->tt_ttisgmt == bp->tt_ttisgmt &&
strcmp(&sp->chars[ap->tt_abbrind],
&sp->chars[bp->tt_abbrind]) == 0;
}
return result;
}
static const int mon_lengths[2][MONSPERYEAR] = {
{ 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 const int year_lengths[2] = {
DAYSPERNYEAR, DAYSPERLYEAR
};
/*
** Given a pointer into a time zone string, scan until a character that is not
** a valid character in a zone name is found. Return a pointer to that
** character.
*/
static const char *
getzname(strp)
register const char * strp;
{
register char c;
while ((c = *strp) != '\0' && !is_digit(c) && c != ',' && c != '-' &&
c != '+')
++strp;
return strp;
}
/*
** Given a pointer into an extended time zone string, scan until the ending
** delimiter of the zone name is located. Return a pointer to the delimiter.
**
** As with getzname above, the legal character set is actually quite
** restricted, with other characters producing undefined results.
** We don't do any checking here; checking is done later in common-case code.
*/
static const char *
getqzname(register const char *strp, const int delim)
{
register int c;
while ((c = *strp) != '\0' && c != delim)
++strp;
return strp;
}
/*
** Given a pointer into a time zone string, extract a number from that string.
** Check that the number is within a specified range; if it is not, return
** NULL.
** Otherwise, return a pointer to the first character not part of the number.
*/
static const char *
getnum(strp, nump, min, max)
register const char * strp;
int * const nump;
const int min;
const int max;
{
register char c;
register int num;
if (strp == NULL || !is_digit(c = *strp))
return NULL;
num = 0;
do {
num = num * 10 + (c - '0');
if (num > max)
return NULL; /* illegal value */
c = *++strp;
} while (is_digit(c));
if (num < min)
return NULL; /* illegal value */
*nump = num;
return strp;
}
/*
** Given a pointer into a time zone string, extract a number of seconds,
** in hh[:mm[:ss]] form, from the string.
** If any error occurs, return NULL.
** Otherwise, return a pointer to the first character not part of the number
** of seconds.
*/
static const char *
getsecs(strp, secsp)
register const char * strp;
long * const secsp;
{
int num;
/*
** `HOURSPERDAY * DAYSPERWEEK - 1' allows quasi-Posix rules like
** "M10.4.6/26", which does not conform to Posix,
** but which specifies the equivalent of
** ``02:00 on the first Sunday on or after 23 Oct''.
*/
strp = getnum(strp, &num, 0, HOURSPERDAY * DAYSPERWEEK - 1);
if (strp == NULL)
return NULL;
*secsp = num * (long) SECSPERHOUR;
if (*strp == ':') {
++strp;
strp = getnum(strp, &num, 0, MINSPERHOUR - 1);
if (strp == NULL)
return NULL;
*secsp += num * SECSPERMIN;
if (*strp == ':') {
++strp;
/* `SECSPERMIN' allows for leap seconds. */
strp = getnum(strp, &num, 0, SECSPERMIN);
if (strp == NULL)
return NULL;
*secsp += num;
}
}
return strp;
}
/*
** Given a pointer into a time zone string, extract an offset, in
** [+-]hh[:mm[:ss]] form, from the string.
** If any error occurs, return NULL.
** Otherwise, return a pointer to the first character not part of the time.
*/
static const char *
getoffset(strp, offsetp)
register const char * strp;
long * const offsetp;
{
register int neg = 0;
if (*strp == '-') {
neg = 1;
++strp;
} else if (*strp == '+')
++strp;
strp = getsecs(strp, offsetp);
if (strp == NULL)
return NULL; /* illegal time */
if (neg)
*offsetp = -*offsetp;
return strp;
}
/*
** Given a pointer into a time zone string, extract a rule in the form
** date[/time]. See POSIX section 8 for the format of "date" and "time".
** If a valid rule is not found, return NULL.
** Otherwise, return a pointer to the first character not part of the rule.
*/
static const char *
getrule(strp, rulep)
const char * strp;
register struct rule * const rulep;
{
if (*strp == 'J') {
/*
** Julian day.
*/
rulep->r_type = JULIAN_DAY;
++strp;
strp = getnum(strp, &rulep->r_day, 1, DAYSPERNYEAR);
} else if (*strp == 'M') {
/*
** Month, week, day.
*/
rulep->r_type = MONTH_NTH_DAY_OF_WEEK;
++strp;
strp = getnum(strp, &rulep->r_mon, 1, MONSPERYEAR);
if (strp == NULL)
return NULL;
if (*strp++ != '.')
return NULL;
strp = getnum(strp, &rulep->r_week, 1, 5);
if (strp == NULL)
return NULL;
if (*strp++ != '.')
return NULL;
strp = getnum(strp, &rulep->r_day, 0, DAYSPERWEEK - 1);
} else if (is_digit(*strp)) {
/*
** Day of year.
*/
rulep->r_type = DAY_OF_YEAR;
strp = getnum(strp, &rulep->r_day, 0, DAYSPERLYEAR - 1);
} else return NULL; /* invalid format */
if (strp == NULL)
return NULL;
if (*strp == '/') {
/*
** Time specified.
*/
++strp;
strp = getsecs(strp, &rulep->r_time);
} else rulep->r_time = 2 * SECSPERHOUR; /* default = 2:00:00 */
return strp;
}
/*
** Given the Epoch-relative time of January 1, 00:00:00 UTC, in a year, the
** year, a rule, and the offset from UTC at the time that rule takes effect,
** calculate the Epoch-relative time that rule takes effect.
*/
static time_t
transtime(janfirst, year, rulep, offset)
const time_t janfirst;
const int year;
register const struct rule * const rulep;
const long offset;
{
register int leapyear;
register time_t value;
register int i;
int d, m1, yy0, yy1, yy2, dow;
INITIALIZE(value);
leapyear = isleap(year);
switch (rulep->r_type) {
case JULIAN_DAY:
/*
** Jn - Julian day, 1 == January 1, 60 == March 1 even in leap
** years.
** In non-leap years, or if the day number is 59 or less, just
** add SECSPERDAY times the day number-1 to the time of
** January 1, midnight, to get the day.
*/
value = janfirst + (rulep->r_day - 1) * SECSPERDAY;
if (leapyear && rulep->r_day >= 60)
value += SECSPERDAY;
break;
case DAY_OF_YEAR:
/*
** n - day of year.
** Just add SECSPERDAY times the day number to the time of
** January 1, midnight, to get the day.
*/
value = janfirst + rulep->r_day * SECSPERDAY;
break;
case MONTH_NTH_DAY_OF_WEEK:
/*
** Mm.n.d - nth "dth day" of month m.
*/
value = janfirst;
for (i = 0; i < rulep->r_mon - 1; ++i)
value += mon_lengths[leapyear][i] * SECSPERDAY;
/*
** Use Zeller's Congruence to get day-of-week of first day of
** month.
*/
m1 = (rulep->r_mon + 9) % 12 + 1;
yy0 = (rulep->r_mon <= 2) ? (year - 1) : year;
yy1 = yy0 / 100;
yy2 = yy0 % 100;
dow = ((26 * m1 - 2) / 10 +
1 + yy2 + yy2 / 4 + yy1 / 4 - 2 * yy1) % 7;
if (dow < 0)
dow += DAYSPERWEEK;
/*
** "dow" is the day-of-week of the first day of the month. Get
** the day-of-month (zero-origin) of the first "dow" day of the
** month.
*/
d = rulep->r_day - dow;
if (d < 0)
d += DAYSPERWEEK;
for (i = 1; i < rulep->r_week; ++i) {
if (d + DAYSPERWEEK >=
mon_lengths[leapyear][rulep->r_mon - 1])
break;
d += DAYSPERWEEK;
}
/*
** "d" is the day-of-month (zero-origin) of the day we want.
*/
value += d * SECSPERDAY;
break;
}
/*
** "value" is the Epoch-relative time of 00:00:00 UTC on the day in
** question. To get the Epoch-relative time of the specified local
** time on that day, add the transition time and the current offset
** from UTC.
*/
return value + rulep->r_time + offset;
}
/*
** Given a POSIX section 8-style TZ string, fill in the rule tables as
** appropriate.
*/
static int
tzparse(name, sp, lastditch)
const char * name;
register struct state * const sp;
const int lastditch;
{
const char * stdname;
const char * dstname;
size_t stdlen;
size_t dstlen;
long stdoffset;
long dstoffset;
register time_t * atp;
register unsigned char * typep;
register char * cp;
register int load_result;
static struct ttinfo zttinfo;
INITIALIZE(dstname);
stdname = name;
if (lastditch) {
stdlen = strlen(name); /* length of standard zone name */
name += stdlen;
if (stdlen >= sizeof sp->chars)
stdlen = (sizeof sp->chars) - 1;
stdoffset = 0;
} else {
if (*name == '<') {
name++;
stdname = name;
name = getqzname(name, '>');
if (*name != '>')
return (-1);
stdlen = name - stdname;
name++;
} else {
name = getzname(name);
stdlen = name - stdname;
}
if (*name == '\0')
return -1;
name = getoffset(name, &stdoffset);
if (name == NULL)
return -1;
}
load_result = tzload(TZDEFRULES, sp, FALSE);
if (load_result != 0)
sp->leapcnt = 0; /* so, we're off a little */
if (*name != '\0') {
if (*name == '<') {
dstname = ++name;
name = getqzname(name, '>');
if (*name != '>')
return -1;
dstlen = name - dstname;
name++;
} else {
dstname = name;
name = getzname(name);
dstlen = name - dstname; /* length of DST zone name */
}
if (*name != '\0' && *name != ',' && *name != ';') {
name = getoffset(name, &dstoffset);
if (name == NULL)
return -1;
} else dstoffset = stdoffset - SECSPERHOUR;
if (*name == '\0' && load_result != 0)
name = TZDEFRULESTRING;
if (*name == ',' || *name == ';') {
struct rule start;
struct rule end;
register int year;
register time_t janfirst;
time_t starttime;
time_t endtime;
++name;
if ((name = getrule(name, &start)) == NULL)
return -1;
if (*name++ != ',')
return -1;
if ((name = getrule(name, &end)) == NULL)