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Arquivotheca.SunOS-4.1.3/lib/libc/gen/common/localtime.c
seta75D 2e8a93c394 Init
2021-10-11 18:20:23 -03:00

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#if !defined(lint) && defined(SCCSIDS)
static char sccsid[] = "@(#)localtime.c 1.1 92/07/30 SMI"; /* from Arthur Olson's 6.1 */
#endif
/*LINTLIBRARY*/
#include <tzfile.h>
#include <time.h>
#include <string.h>
#include <ctype.h>
#include <stdio.h> /* for NULL */
#include <fcntl.h>
#include <sys/param.h> /* for MAXPATHLEN */
#define FILENAME_MAX MAXPATHLEN
#ifdef __STDC__
#define P(s) s
#else /* !defined __STDC__ */
/*
** Memory management functions
*/
extern char * calloc();
extern char * malloc();
/*
** Communication with the environment
*/
extern char * getenv();
#define ASTERISK *
#define P(s) (/ASTERISK s ASTERISK/)
#define const
#endif /* !defined __STDC__ */
#ifndef TRUE
#define TRUE 1
#define FALSE 0
#endif /* !defined TRUE */
#define ACCESS_MODE O_RDONLY
#define OPEN_MODE O_RDONLY
/*
** 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).
*/
static const char *WILDABBR = " ";
static const char *GMT = "GMT";
struct ttinfo { /* time type information */
long tt_gmtoff; /* GMT 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 */
};
struct state {
int timecnt;
int typecnt;
int charcnt;
time_t *ats;
unsigned char *types;
struct ttinfo *ttis;
char *chars;
};
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 int allocall P((register struct state * sp));
static long detzcode P((const char * codep));
static void freeall P((register struct state * sp));
static const char * getzname P((const char * strp));
static const char * getnum P((const char * strp, int * nump, int min,
int max));
static const char * getsecs P((const char * strp, long * secsp));
static const char * getoffset P((const char * strp, long * offsetp));
static const char * getrule P((const char * strp, struct rule * rulep));
static void gmtload P((struct state * sp));
static void gmtsub P((const time_t * timep, long offset,
struct tm * tmp));
static void localsub P((const time_t * timep, long offset,
struct tm * tmp));
static void normalize P((int * tensptr, int * unitsptr, int base));
static void settzname P((void));
static time_t time1 P((struct tm * tmp, void (* funcp)(),
long offset));
static time_t time2 P((struct tm *tmp, void (* funcp)(),
long offset, int * okayp));
static void timesub P((const time_t * timep, long offset,
struct tm * tmp));
static int tmcomp P((const struct tm * atmp,
const struct tm * btmp));
static time_t transtime P((time_t janfirst, int year,
const struct rule * rulep, long offset));
static int tzload P((const char * name, struct state * sp));
static int tzparse P((const char * name, struct state * sp,
int lastditch));
static struct state * lclptr;
static struct state * gmtptr;
static int lcl_is_set;
static int gmt_is_set;
#ifdef S5EMUL
char * tzname[2] = {
"GMT",
" ",
};
time_t timezone = 0;
time_t altzone = 0;
int daylight = 0;
#endif /* defined S5EMUL */
static long
detzcode(codep)
const char * const codep;
{
register long result;
register int i;
result = 0;
for (i = 0; i < 4; ++i)
result = (result << 8) | (codep[i] & 0xff);
return result;
}
/*
** Free up existing items pointed to by the specified "state" structure,
** and allocate new ones of sizes specified by that "state" structure.
** Return 0 on success; return -1 and free all previously-allocated items
** on failure.
*/
static int
allocall(sp)
register struct state * const sp;
{
freeall(sp);
if (sp->timecnt != 0) {
sp->ats = (time_t *)calloc((unsigned)sp->timecnt,
(unsigned)sizeof (time_t));
if (sp->ats == NULL)
return -1;
sp->types =
(unsigned char *)calloc((unsigned)sp->timecnt,
(unsigned)sizeof (unsigned char));
if (sp->types == NULL) {
freeall(sp);
return -1;
}
}
sp->ttis =
(struct ttinfo *)calloc((unsigned)sp->typecnt,
(unsigned)sizeof (struct ttinfo));
if (sp->ttis == NULL) {
freeall(sp);
return -1;
}
sp->chars = (char *)calloc((unsigned)sp->charcnt + 1,
(unsigned)sizeof (char));
if (sp->chars == NULL) {
freeall(sp);
return -1;
}
return 0;
}
/*
** Free all the items pointed to by the specified "state" structure (except for
** "chars", which might have other references to it), and zero out all the
** pointers to those items.
*/
static void
freeall(sp)
register struct state * const sp;
{
if (sp->ttis) {
free((char *)sp->ttis);
sp->ttis = 0;
}
if (sp->types) {
free((char *)sp->types);
sp->types = 0;
}
if (sp->ats) {
free((char *)sp->ats);
sp->ats = 0;
}
}
#ifdef S5EMUL
static void
settzname()
{
register const struct state * const sp = lclptr;
register int i;
tzname[0] = GMT;
tzname[1] = WILDABBR;
daylight = 0;
timezone = 0;
altzone = 0;
if (sp == NULL)
return;
for (i = 0; i < sp->typecnt; ++i) {
register const struct ttinfo * const ttisp = &sp->ttis[i];
tzname[ttisp->tt_isdst] =
(char *) &sp->chars[ttisp->tt_abbrind];
if (ttisp->tt_isdst)
daylight = 1;
if (i == 0 || !ttisp->tt_isdst)
timezone = -(ttisp->tt_gmtoff);
if (i == 0 || ttisp->tt_isdst)
altzone = -(ttisp->tt_gmtoff);
}
/*
** 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] =
(char *) &sp->chars[ttisp->tt_abbrind];
}
}
#endif
/*
** Maximum size of a time zone file.
*/
#define MAX_TZFILESZ (sizeof (struct tzhead) + \
TZ_MAX_TIMES * (4 + sizeof (char)) + \
TZ_MAX_TYPES * (4 + 2 * sizeof (char)) + \
TZ_MAX_CHARS * sizeof (char) + \
TZ_MAX_LEAPS * 2 * 4 + \
TZ_MAX_TYPES * sizeof (char))
static int
tzload(name, sp)
register const char * name;
register struct state * const sp;
{
register const char * p;
register int i;
register int fid;
if (name == NULL && (name = TZDEFAULT) == NULL)
return -1;
{
register int doaccess;
char fullname[FILENAME_MAX + 1];
if (name[0] == ':')
++name;
doaccess = name[0] == '/';
if (!doaccess) {
if ((p = TZDIR) == NULL)
return -1;
if ((strlen(p) + strlen(name) + 1) >= sizeof fullname)
return -1;
(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, ACCESS_MODE) != 0)
return -1;
if ((fid = open(name, OPEN_MODE)) == -1)
return -1;
}
{
register const struct tzhead * tzhp;
char buf[MAX_TZFILESZ];
int leapcnt;
int ttisstdcnt;
i = read(fid, buf, sizeof buf);
if (close(fid) != 0 || i < sizeof *tzhp)
return -1;
tzhp = (struct tzhead *) buf;
ttisstdcnt = (int) detzcode(tzhp->tzh_ttisstdcnt);
leapcnt = (int) detzcode(tzhp->tzh_leapcnt);
sp->timecnt = (int) detzcode(tzhp->tzh_timecnt);
sp->typecnt = (int) detzcode(tzhp->tzh_typecnt);
sp->charcnt = (int) detzcode(tzhp->tzh_charcnt);
if (leapcnt < 0 || 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))
return -1;
if (i < sizeof *tzhp +
sp->timecnt * (4 + sizeof (char)) +
sp->typecnt * (4 + 2 * sizeof (char)) +
sp->charcnt * sizeof (char) +
leapcnt * 2 * 4 +
ttisstdcnt * sizeof (char))
return -1;
if (allocall(sp) < 0)
return -1;
p = buf + sizeof *tzhp;
for (i = 0; i < sp->timecnt; ++i) {
sp->ats[i] = detzcode(p);
p += 4;
}
for (i = 0; i < sp->timecnt; ++i) {
sp->types[i] = (unsigned char) *p++;
if (sp->types[i] >= sp->typecnt)
return -1;
}
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)
return -1;
ttisp->tt_abbrind = (unsigned char) *p++;
if (ttisp->tt_abbrind < 0 ||
ttisp->tt_abbrind > sp->charcnt)
return -1;
}
for (i = 0; i < sp->charcnt; ++i)
sp->chars[i] = *p++;
sp->chars[i] = '\0'; /* ensure '\0' at end */
p += (4 + 4) * leapcnt; /* skip leap seconds list */
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)
return -1;
}
}
}
return 0;
}
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' && !isdigit(c) && c != ',' && c != '-' &&
c != '+')
++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 || !isdigit(*strp))
return NULL;
num = 0;
while ((c = *strp) != '\0' && isdigit(c)) {
num = num * 10 + (c - '0');
if (num > max)
return NULL; /* illegal value */
++strp;
}
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;
strp = getnum(strp, &num, 0, HOURSPERDAY);
if (strp == NULL)
return NULL;
*secsp = num * SECSPERHOUR;
if (*strp == ':') {
++strp;
strp = getnum(strp, &num, 0, MINSPERHOUR - 1);
if (strp == NULL)
return NULL;
*secsp += num * SECSPERMIN;
if (*strp == ':') {
++strp;
strp = getnum(strp, &num, 0, SECSPERMIN - 1);
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;
if (*strp == '-') {
neg = 1;
++strp;
} else if (isdigit(*strp) || *strp++ == '+')
neg = 0;
else return NULL; /* illegal offset */
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 (isdigit(*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 GMT, in a year, the
** year, a rule, and the offset from GMT 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;
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 GMT 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 GMT.
*/
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;
int stdlen;
int dstlen;
long stdoffset;
long dstoffset;
register time_t * atp;
register unsigned char * typep;
register char * cp;
freeall(sp); /* */
stdname = name;
if (lastditch) {
stdlen = strlen(name); /* length of standard zone name */
name += stdlen;
if (stdlen >= sizeof sp->chars)
stdlen = (sizeof sp->chars) - 1;
} else {
name = getzname(name);
stdlen = name - stdname;
if (stdlen < 3)
return -1;
}
if (*name == '\0')
stdoffset = 0;
else {
name = getoffset(name, &stdoffset);
if (name == NULL)
return -1;
}
if (*name != '\0') {
dstname = name;
name = getzname(name);
dstlen = name - dstname; /* length of DST zone name */
if (dstlen < 3)
return -1;
if (*name != '\0' && *name != ',' && *name != ';') {
name = getoffset(name, &dstoffset);
if (name == NULL)
return -1;
} else dstoffset = stdoffset - SECSPERHOUR;
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)
return -1;
if (*name != '\0')
return -1;
sp->typecnt = 2; /* standard time and DST */
/*
** Two transitions per year, from EPOCH_YEAR to 2037.
*/
sp->timecnt = 2 * (2037 - EPOCH_YEAR + 1);
if (sp->timecnt > TZ_MAX_TIMES)
return -1;
sp->charcnt = stdlen + 1 + dstlen + 1;
if (allocall(sp) < 0)
return -1;
sp->ttis[0].tt_gmtoff = -dstoffset;
sp->ttis[0].tt_isdst = 1;
sp->ttis[0].tt_abbrind = stdlen + 1;
sp->ttis[1].tt_gmtoff = -stdoffset;
sp->ttis[1].tt_isdst = 0;
sp->ttis[1].tt_abbrind = 0;
atp = sp->ats;
typep = sp->types;
janfirst = 0;
for (year = EPOCH_YEAR; year <= 2037; ++year) {
starttime = transtime(janfirst, year, &start,
stdoffset);
endtime = transtime(janfirst, year, &end,
dstoffset);
if (starttime > endtime) {
*atp++ = endtime;
*typep++ = 1; /* DST ends */
*atp++ = starttime;
*typep++ = 0; /* DST begins */
} else {
*atp++ = starttime;
*typep++ = 0; /* DST begins */
*atp++ = endtime;
*typep++ = 1; /* DST ends */
}
janfirst +=
year_lengths[isleap(year)] * SECSPERDAY;
}
} else {
int sawstd;
int sawdst;
long stdfix;
long dstfix;
long oldfix;
int isdst;
register int i;
if (*name != '\0')
return -1;
if (tzload(TZDEFRULES, sp) != 0) {
freeall(sp);
return -1;
}
/*
** Discard zone abbreviations from file, and allocate
** space for the ones from TZ.
*/
free(sp->chars);
sp->charcnt = stdlen + 1 + dstlen + 1;
sp->chars = (char *)calloc((unsigned)sp->charcnt,
(unsigned)sizeof (char));
/*
** Compute the difference between the real and
** prototype standard and summer time offsets
** from GMT, and put the real standard and summer
** time offsets into the rules in place of the
** prototype offsets.
*/
sawstd = FALSE;
sawdst = FALSE;
stdfix = 0;
dstfix = 0;
for (i = 0; i < sp->typecnt; ++i) {
if (sp->ttis[i].tt_isdst) {
oldfix = dstfix;
dstfix =
sp->ttis[i].tt_gmtoff + dstoffset;
if (sawdst && (oldfix != dstfix))
return -1;
sp->ttis[i].tt_gmtoff = -dstoffset;
sp->ttis[i].tt_abbrind = stdlen + 1;
sawdst = TRUE;
} else {
oldfix = stdfix;
stdfix =
sp->ttis[i].tt_gmtoff + stdoffset;
if (sawstd && (oldfix != stdfix))
return -1;
sp->ttis[i].tt_gmtoff = -stdoffset;
sp->ttis[i].tt_abbrind = 0;
sawstd = TRUE;
}
}
/*
** Make sure we have both standard and summer time.
*/
if (!sawdst || !sawstd)
return -1;
/*
** Now correct the transition times by shifting
** them by the difference between the real and
** prototype offsets. Note that this difference
** can be different in standard and summer time;
** the prototype probably has a 1-hour difference
** between standard and summer time, but a different
** difference can be specified in TZ.
*/
isdst = FALSE; /* we start in standard time */
for (i = 0; i < sp->timecnt; ++i) {
register const struct ttinfo * ttisp;
/*
** If summer time is in effect, and the
** transition time was not specified as
** standard time, add the summer time
** offset to the transition time;
** otherwise, add the standard time offset
** to the transition time.
*/
ttisp = &sp->ttis[sp->types[i]];
sp->ats[i] +=
(isdst && !ttisp->tt_ttisstd) ?
dstfix : stdfix;
isdst = ttisp->tt_isdst;
}
}
} else {
dstlen = 0;
sp->typecnt = 1; /* only standard time */
sp->timecnt = 0;
sp->charcnt = stdlen + 1;
if (allocall(sp) < 0)
return -1;
sp->ttis[0].tt_gmtoff = -stdoffset;
sp->ttis[0].tt_isdst = 0;
sp->ttis[0].tt_abbrind = 0;
}
cp = sp->chars;
(void) strncpy(cp, stdname, stdlen);
cp += stdlen;
*cp++ = '\0';
if (dstlen != 0) {
(void) strncpy(cp, dstname, dstlen);
*(cp + dstlen) = '\0';
}
return 0;
}
static void
gmtload(sp)
struct state * const sp;
{
if (tzload(GMT, sp) != 0)
(void) tzparse(GMT, sp, TRUE);
}
void
tzsetwall()
{
lcl_is_set = TRUE;
if (lclptr == NULL) {
lclptr = (struct state *) calloc(1, (unsigned)sizeof *lclptr);
if (lclptr == NULL) {
#ifdef S5EMUL
settzname(); /* all we can do */
#endif
return;
}
}
if (tzload((char *) NULL, lclptr) != 0)
gmtload(lclptr);
#ifdef S5EMUL
settzname();
#endif
}
void
tzset()
{
register const char * name;
name = getenv("TZ");
if (name == NULL) {
tzsetwall();
return;
}
lcl_is_set = TRUE;
if (lclptr == NULL) {
lclptr = (struct state *) calloc(1, (unsigned)sizeof *lclptr);
if (lclptr == NULL) {
#ifdef S5EMUL
settzname(); /* all we can do */
#endif
return;
}
}
if (*name == '\0') {
/*
** User wants it fast rather than right.
*/
lclptr->timecnt = 0;
lclptr->typecnt = 1;
lclptr->charcnt = sizeof GMT;
if (allocall(lclptr) < 0)
return;
lclptr->ttis[0].tt_gmtoff = 0;
lclptr->ttis[0].tt_abbrind = 0;
(void) strcpy(lclptr->chars, GMT);
} else if (tzload(name, lclptr) != 0)
if (name[0] == ':' || tzparse(name, lclptr, FALSE) != 0)
(void) tzparse(name, lclptr, TRUE);
#ifdef S5EMUL
settzname();
#endif
}
/*
** The easy way to behave "as if no library function calls" localtime
** is to not call it--so we drop its guts into "localsub", which can be
** freely called. (And no, the PANS doesn't require the above behavior--
** but it *is* desirable.)
**
** The unused offset argument is for the benefit of mktime variants.
*/
static struct tm tm;
/*ARGSUSED*/
static void
localsub(timep, offset, tmp)
const time_t * const timep;
const long offset;
struct tm * const tmp;
{
register const struct state * sp;
register const struct ttinfo * ttisp;
register int i;
const time_t t = *timep;
if (!lcl_is_set)
tzset();
sp = lclptr;
if (sp == NULL) {
gmtsub(timep, offset, tmp);
return;
}
if (sp->timecnt == 0 || t < sp->ats[0]) {
i = 0;
while (sp->ttis[i].tt_isdst)
if (++i >= sp->typecnt) {
i = 0;
break;
}
} else {
for (i = 1; i < sp->timecnt; ++i)
if (t < sp->ats[i])
break;
i = sp->types[i - 1];
}
ttisp = &sp->ttis[i];
timesub(&t, ttisp->tt_gmtoff, tmp);
tmp->tm_isdst = ttisp->tt_isdst;
#ifdef S5EMUL
tzname[tmp->tm_isdst] = (char *) &sp->chars[ttisp->tt_abbrind];
#endif /* S5EMUL */
tmp->tm_zone = &sp->chars[ttisp->tt_abbrind];
}
struct tm *
localtime(timep)
const time_t * const timep;
{
localsub(timep, 0L, &tm);
return &tm;
}
/*
** gmtsub is to gmtime as localsub is to localtime.
*/
static void
gmtsub(timep, offset, tmp)
const time_t * const timep;
const long offset;
struct tm * const tmp;
{
if (!gmt_is_set) {
gmt_is_set = TRUE;
gmtptr = (struct state *) calloc(1, (unsigned)sizeof *gmtptr);
if (gmtptr != NULL)
gmtload(gmtptr);
}
timesub(timep, offset, tmp);
/*
** Could get fancy here and deliver something such as
** "GMT+xxxx" or "GMT-xxxx" if offset is non-zero,
** but this is no time for a treasure hunt.
*/
if (offset != 0)
tmp->tm_zone = WILDABBR;
else {
if (gmtptr == NULL)
tmp->tm_zone = GMT;
else tmp->tm_zone = gmtptr->chars;
}
}
struct tm *
gmtime(timep)
const time_t * const timep;
{
gmtsub(timep, 0L, &tm);
return &tm;
}
struct tm *
offtime(timep, offset)
const time_t * const timep;
const long offset;
{
gmtsub(timep, offset, &tm);
return &tm;
}
static void
timesub(timep, offset, tmp)
const time_t * const timep;
const long offset;
register struct tm * const tmp;
{
register long days;
register long rem;
register int y;
register int yleap;
register const int * ip;
days = *timep / SECSPERDAY;
rem = *timep % SECSPERDAY;
rem += offset;
while (rem < 0) {
rem += SECSPERDAY;
--days;
}
while (rem >= SECSPERDAY) {
rem -= SECSPERDAY;
++days;
}
tmp->tm_hour = (int) (rem / SECSPERHOUR);
rem = rem % SECSPERHOUR;
tmp->tm_min = (int) (rem / SECSPERMIN);
tmp->tm_sec = (int) (rem % SECSPERMIN);
tmp->tm_wday = (int) ((EPOCH_WDAY + days) % DAYSPERWEEK);
if (tmp->tm_wday < 0)
tmp->tm_wday += DAYSPERWEEK;
y = EPOCH_YEAR;
if (days >= 0)
for ( ; ; ) {
yleap = isleap(y);
if (days < (long) year_lengths[yleap])
break;
++y;
days = days - (long) year_lengths[yleap];
}
else do {
--y;
yleap = isleap(y);
days = days + (long) year_lengths[yleap];
} while (days < 0);
tmp->tm_year = y - TM_YEAR_BASE;
tmp->tm_yday = (int) days;
ip = mon_lengths[yleap];
for (tmp->tm_mon = 0; days >= (long) ip[tmp->tm_mon]; ++(tmp->tm_mon))
days = days - (long) ip[tmp->tm_mon];
tmp->tm_mday = (int) (days + 1);
tmp->tm_isdst = 0;
tmp->tm_gmtoff = offset;
}
/*
** Adapted from code provided by Robert Elz, who writes:
** The "best" way to do mktime I think is based on an idea of Bob
** Kridle's (so its said...) from a long time ago. (mtxinu!kridle now).
** It does a binary search of the time_t space. Since time_t's are
** just 32 bits, its a max of 32 iterations (even at 64 bits it
** would still be very reasonable).
*/
#ifndef WRONG
#define WRONG (-1)
#endif /* !defined WRONG */
static void
normalize(tensptr, unitsptr, base)
int * const tensptr;
int * const unitsptr;
const int base;
{
if (*unitsptr >= base) {
*tensptr += *unitsptr / base;
*unitsptr %= base;
} else if (*unitsptr < 0) {
--*tensptr;
*unitsptr += base;
if (*unitsptr < 0) {
*tensptr -= 1 + (-*unitsptr) / base;
*unitsptr = base - (-*unitsptr) % base;
}
}
}
static int
tmcomp(atmp, btmp)
register const struct tm * const atmp;
register const struct tm * const btmp;
{
register int result;
if ((result = (atmp->tm_year - btmp->tm_year)) == 0 &&
(result = (atmp->tm_mon - btmp->tm_mon)) == 0 &&
(result = (atmp->tm_mday - btmp->tm_mday)) == 0 &&
(result = (atmp->tm_hour - btmp->tm_hour)) == 0 &&
(result = (atmp->tm_min - btmp->tm_min)) == 0)
result = atmp->tm_sec - btmp->tm_sec;
return result;
}
static time_t
time2(tmp, funcp, offset, okayp)
struct tm * const tmp;
void (* const funcp)();
const long offset;
int * const okayp;
{
register const struct state * sp;
register int dir;
register int bits;
register int i, j ;
register int saved_seconds;
time_t newt;
time_t t;
struct tm yourtm, mytm;
*okayp = FALSE;
yourtm = *tmp;
if (yourtm.tm_sec >= SECSPERMIN + 2 || yourtm.tm_sec < 0)
normalize(&yourtm.tm_min, &yourtm.tm_sec, SECSPERMIN);
normalize(&yourtm.tm_hour, &yourtm.tm_min, MINSPERHOUR);
normalize(&yourtm.tm_mday, &yourtm.tm_hour, HOURSPERDAY);
normalize(&yourtm.tm_year, &yourtm.tm_mon, MONSPERYEAR);
while (yourtm.tm_mday <= 0) {
--yourtm.tm_year;
yourtm.tm_mday +=
year_lengths[isleap(yourtm.tm_year + TM_YEAR_BASE)];
}
for ( ; ; ) {
i = mon_lengths[isleap(yourtm.tm_year +
TM_YEAR_BASE)][yourtm.tm_mon];
if (yourtm.tm_mday <= i)
break;
yourtm.tm_mday -= i;
if (++yourtm.tm_mon >= MONSPERYEAR) {
yourtm.tm_mon = 0;
++yourtm.tm_year;
}
}
saved_seconds = yourtm.tm_sec;
yourtm.tm_sec = 0;
/*
** Calculate the number of magnitude bits in a time_t
** (this works regardless of whether time_t is
** signed or unsigned, though lint complains if unsigned).
*/
for (bits = 0, t = 1; t > 0; ++bits, t <<= 1)
;
/*
** If time_t is signed, then 0 is the median value,
** if time_t is unsigned, then 1 << bits is median.
*/
t = (t < 0) ? 0 : ((time_t) 1 << bits);
for ( ; ; ) {
(*funcp)(&t, offset, &mytm);
dir = tmcomp(&mytm, &yourtm);
if (dir != 0) {
if (bits-- < 0)
return WRONG;
if (bits < 0)
--t;
else if (dir > 0)
t -= (time_t) 1 << bits;
else t += (time_t) 1 << bits;
continue;
}
if (yourtm.tm_isdst < 0 || mytm.tm_isdst == yourtm.tm_isdst)
break;
/*
** Right time, wrong type.
** Hunt for right time, right type.
** It's okay to guess wrong since the guess
** gets checked.
*/
sp = (const struct state *)
((funcp == localsub) ? lclptr : gmtptr);
if (sp == NULL)
return WRONG;
for (i = 0; i < sp->typecnt; ++i) {
if (sp->ttis[i].tt_isdst != yourtm.tm_isdst)
continue;
for (j = 0; j < sp->typecnt; ++j) {
if (sp->ttis[j].tt_isdst == yourtm.tm_isdst)
continue;
newt = t + sp->ttis[j].tt_gmtoff -
sp->ttis[i].tt_gmtoff;
(*funcp)(&newt, offset, &mytm);
if (tmcomp(&mytm, &yourtm) != 0)
continue;
if (mytm.tm_isdst != yourtm.tm_isdst)
continue;
/*
** We have a match.
*/
t = newt;
goto label;
}
}
return WRONG;
}
label:
t += saved_seconds;
(*funcp)(&t, offset, tmp);
*okayp = TRUE;
return t;
}
static time_t
time1(tmp, funcp, offset)
struct tm * const tmp;
void (* const funcp)();
const long offset;
{
register time_t t;
register const struct state * sp;
register int samei, otheri;
int okay;
if (tmp->tm_isdst > 1)
tmp->tm_isdst = 1;
t = time2(tmp, funcp, offset, &okay);
if (okay || tmp->tm_isdst < 0)
return t;
/*
** We're supposed to assume that somebody took a time of one type
** and did some math on it that yielded a "struct tm" that's bad.
** We try to divine the type they started from and adjust to the
** type they need.
*/
sp = (const struct state *) ((funcp == localsub) ? lclptr : gmtptr);
if (sp == NULL)
return WRONG;
for (samei = 0; samei < sp->typecnt; ++samei) {
if (sp->ttis[samei].tt_isdst != tmp->tm_isdst)
continue;
for (otheri = 0; otheri < sp->typecnt; ++otheri) {
if (sp->ttis[otheri].tt_isdst == tmp->tm_isdst)
continue;
tmp->tm_sec += sp->ttis[otheri].tt_gmtoff -
sp->ttis[samei].tt_gmtoff;
tmp->tm_isdst = !tmp->tm_isdst;
t = time2(tmp, funcp, offset, &okay);
if (okay)
return t;
tmp->tm_sec -= sp->ttis[otheri].tt_gmtoff -
sp->ttis[samei].tt_gmtoff;
tmp->tm_isdst = !tmp->tm_isdst;
}
}
return WRONG;
}
time_t
mktime(tmp)
struct tm * const tmp;
{
return time1(tmp, localsub, 0L);
}
time_t
timelocal(tmp)
struct tm * const tmp;
{
tmp->tm_isdst = -1;
return mktime(tmp);
}
time_t
timegm(tmp)
struct tm * const tmp;
{
return time1(tmp, gmtsub, 0L);
}
time_t
timeoff(tmp, offset)
struct tm * const tmp;
const long offset;
{
return time1(tmp, gmtsub, offset);
}
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