[unix-history] / usr / src / lib / libc / gen / ctime.c

/*
 * Copyright (c) 1987 Regents of the University of California.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms are permitted
 * provided that this notice is preserved and that due credit is given
 * to the University of California at Berkeley. The name of the University
 * may not be used to endorse or promote products derived from this
 * software without specific written prior permission. This software
 * is provided ``as is'' without express or implied warranty.
 *
 * This code was supplied by Arthur Olson, originally, and has been
 * slightly modified at the University of California.
 */

#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)ctime.c	5.12 (Berkeley) %G%";
#endif /* LIBC_SCCS and not lint */

#include "sys/param.h"
#include "sys/time.h"
#include "tzfile.h"

char *
ctime(t)
time_t *t;
{
	struct tm	*localtime();
	char	*asctime();

	return(asctime(localtime(t)));
}

/*
** A la X3J11
*/

char *
asctime(timeptr)
register struct tm *	timeptr;
{
	static char	wday_name[DAYS_PER_WEEK][3] = {
		"Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"
	};
	static char	mon_name[MONS_PER_YEAR][3] = {
		"Jan", "Feb", "Mar", "Apr", "May", "Jun",
		"Jul", "Aug", "Sep", "Oct", "Nov", "Dec"
	};
	static char	result[26];

	(void) sprintf(result, "%.3s %.3s%3d %02d:%02d:%02d %d\n",
		wday_name[timeptr->tm_wday],
		mon_name[timeptr->tm_mon],
		timeptr->tm_mday, timeptr->tm_hour,
		timeptr->tm_min, timeptr->tm_sec,
		TM_YEAR_BASE + timeptr->tm_year);
	return result;
}

#ifndef TRUE
#define TRUE		1
#define FALSE		0
#endif /* !TRUE */

extern char *		getenv();
extern char *		strcpy();
extern char *		strcat();
struct tm *		offtime();

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 */
};

struct state {
	int		timecnt;
	int		typecnt;
	int		charcnt;
	time_t		ats[TZ_MAX_TIMES];
	unsigned char	types[TZ_MAX_TIMES];
	struct ttinfo	ttis[TZ_MAX_TYPES];
	char		chars[TZ_MAX_CHARS + 1];
};

static struct state	s;

static int		tz_is_set;

char *			tzname[2] = {
	"GMT",
	"GMT"
};

#ifdef USG_COMPAT
time_t			timezone = 0;
int			daylight = 0;
#endif /* USG_COMPAT */

static long
detzcode(codep)
char *	codep;
{
	register long	result;
	register int	i;

	result = 0;
	for (i = 0; i < 4; ++i)
		result = (result << 8) | (codep[i] & 0xff);
	return result;
}

static
tzload(name)
register char *	name;
{
	register int	i;
	register int	fid;

	if (name == 0 && (name = TZDEFAULT) == 0)
		return -1;
	{
		register char *	p;
		register int	doaccess;
		char		fullname[MAXPATHLEN];

		doaccess = name[0] == '/';
		if (!doaccess) {
			if ((p = TZDIR) == 0)
				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.
			*/
			while (*name != '\0')
				if (*name++ == '.')
					doaccess = TRUE;
			name = fullname;
		}
		if (doaccess && access(name, 4) != 0)
			return -1;
		if ((fid = open(name, 0)) == -1)
			return -1;
	}
	{
		register char *			p;
		register struct tzhead *	tzhp;
		char				buf[sizeof s];

		i = read(fid, buf, sizeof buf);
		if (close(fid) != 0 || i < sizeof *tzhp)
			return -1;
		tzhp = (struct tzhead *) buf;
		s.timecnt = (int) detzcode(tzhp->tzh_timecnt);
		s.typecnt = (int) detzcode(tzhp->tzh_typecnt);
		s.charcnt = (int) detzcode(tzhp->tzh_charcnt);
		if (s.timecnt > TZ_MAX_TIMES ||
			s.typecnt == 0 ||
			s.typecnt > TZ_MAX_TYPES ||
			s.charcnt > TZ_MAX_CHARS)
				return -1;
		if (i < sizeof *tzhp +
			s.timecnt * (4 + sizeof (char)) +
			s.typecnt * (4 + 2 * sizeof (char)) +
			s.charcnt * sizeof (char))
				return -1;
		p = buf + sizeof *tzhp;
		for (i = 0; i < s.timecnt; ++i) {
			s.ats[i] = detzcode(p);
			p += 4;
		}
		for (i = 0; i < s.timecnt; ++i)
			s.types[i] = (unsigned char) *p++;
		for (i = 0; i < s.typecnt; ++i) {
			register struct ttinfo *	ttisp;

			ttisp = &s.ttis[i];
			ttisp->tt_gmtoff = detzcode(p);
			p += 4;
			ttisp->tt_isdst = (unsigned char) *p++;
			ttisp->tt_abbrind = (unsigned char) *p++;
		}
		for (i = 0; i < s.charcnt; ++i)
			s.chars[i] = *p++;
		s.chars[i] = '\0';	/* ensure '\0' at end */
	}
	/*
	** Check that all the local time type indices are valid.
	*/
	for (i = 0; i < s.timecnt; ++i)
		if (s.types[i] >= s.typecnt)
			return -1;
	/*
	** Check that all abbreviation indices are valid.
	*/
	for (i = 0; i < s.typecnt; ++i)
		if (s.ttis[i].tt_abbrind >= s.charcnt)
			return -1;
	/*
	** Set tzname elements to initial values.
	*/
	tzname[0] = tzname[1] = &s.chars[0];
#ifdef USG_COMPAT
	timezone = -s.ttis[0].tt_gmtoff;
	daylight = 0;
#endif /* USG_COMPAT */
	for (i = 1; i < s.typecnt; ++i) {
		register struct ttinfo *	ttisp;

		ttisp = &s.ttis[i];
		if (ttisp->tt_isdst) {
			tzname[1] = &s.chars[ttisp->tt_abbrind];
#ifdef USG_COMPAT
			daylight = 1;
#endif /* USG_COMPAT */ 
		} else {
			tzname[0] = &s.chars[ttisp->tt_abbrind];
#ifdef USG_COMPAT
			timezone = -ttisp->tt_gmtoff;
#endif /* USG_COMPAT */ 
		}
	}
	return 0;
}

static
tzsetkernel()
{
	struct timeval	tv;
	struct timezone	tz;
	char	*_tztab();

	if (gettimeofday(&tv, &tz))
		return -1;
	s.timecnt = 0;		/* UNIX counts *west* of Greenwich */
	s.ttis[0].tt_gmtoff = tz.tz_minuteswest * -SECS_PER_MIN;
	s.ttis[0].tt_abbrind = 0;
	(void)strcpy(s.chars, _tztab(tz.tz_minuteswest, 0));
	tzname[0] = tzname[1] = s.chars;
#ifdef USG_COMPAT
	timezone = tz.tz_minuteswest * 60;
	daylight = tz.tz_dsttime;
#endif /* USG_COMPAT */
	return 0;
}

static
tzsetgmt()
{
	s.timecnt = 0;
	s.ttis[0].tt_gmtoff = 0;
	s.ttis[0].tt_abbrind = 0;
	(void) strcpy(s.chars, "GMT");
	tzname[0] = tzname[1] = s.chars;
#ifdef USG_COMPAT
	timezone = 0;
	daylight = 0;
#endif /* USG_COMPAT */
}

void
tzset()
{
	register char *	name;

	tz_is_set = TRUE;
	name = getenv("TZ");
	if (!name || *name) {			/* did not request GMT */
		if (name && !tzload(name))	/* requested name worked */
			return;
		if (!tzload((char *)0))		/* default name worked */
			return;
		if (!tzsetkernel())		/* kernel guess worked */
			return;
	}
	tzsetgmt();				/* GMT is default */
}

struct tm *
localtime(timep)
time_t *	timep;
{
	register struct ttinfo *	ttisp;
	register struct tm *		tmp;
	register int			i;
	time_t				t;

	if (!tz_is_set)
		(void) tzset();
	t = *timep;
	if (s.timecnt == 0 || t < s.ats[0]) {
		i = 0;
		while (s.ttis[i].tt_isdst)
			if (++i >= s.timecnt) {
				i = 0;
				break;
			}
	} else {
		for (i = 1; i < s.timecnt; ++i)
			if (t < s.ats[i])
				break;
		i = s.types[i - 1];
	}
	ttisp = &s.ttis[i];
	/*
	** To get (wrong) behavior that's compatible with System V Release 2.0
	** you'd replace the statement below with
	**	tmp = offtime((time_t) (t + ttisp->tt_gmtoff), 0L);
	*/
	tmp = offtime(&t, ttisp->tt_gmtoff);
	tmp->tm_isdst = ttisp->tt_isdst;
	tzname[tmp->tm_isdst] = &s.chars[ttisp->tt_abbrind];
	tmp->tm_zone = &s.chars[ttisp->tt_abbrind];
	return tmp;
}

struct tm *
gmtime(clock)
time_t *	clock;
{
	register struct tm *	tmp;

	tmp = offtime(clock, 0L);
	tzname[0] = "GMT";
	tmp->tm_zone = "GMT";		/* UCT ? */
	return tmp;
}

static int	mon_lengths[2][MONS_PER_YEAR] = {
	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 int	year_lengths[2] = {
	DAYS_PER_NYEAR, DAYS_PER_LYEAR
};

struct tm *
offtime(clock, offset)
time_t *	clock;
long		offset;
{
	register struct tm *	tmp;
	register long		days;
	register long		rem;
	register int		y;
	register int		yleap;
	register int *		ip;
	static struct tm	tm;

	tmp = &tm;
	days = *clock / SECS_PER_DAY;
	rem = *clock % SECS_PER_DAY;
	rem += offset;
	while (rem < 0) {
		rem += SECS_PER_DAY;
		--days;
	}
	while (rem >= SECS_PER_DAY) {
		rem -= SECS_PER_DAY;
		++days;
	}
	tmp->tm_hour = (int) (rem / SECS_PER_HOUR);
	rem = rem % SECS_PER_HOUR;
	tmp->tm_min = (int) (rem / SECS_PER_MIN);
	tmp->tm_sec = (int) (rem % SECS_PER_MIN);
	tmp->tm_wday = (int) ((EPOCH_WDAY + days) % DAYS_PER_WEEK);
	if (tmp->tm_wday < 0)
		tmp->tm_wday += DAYS_PER_WEEK;
	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_zone = "";
	tmp->tm_gmtoff = offset;
	return tmp;
}
Commit	Line	Data
b8f253e8	1	/*
5d10bbb4	2	* Copyright (c) 1987 Regents of the University of California.
83b522e6 KB	3	* All rights reserved.
	4	*
	5	* Redistribution and use in source and binary forms are permitted
	6	* provided that this notice is preserved and that due credit is given
	7	* to the University of California at Berkeley. The name of the University
	8	* may not be used to endorse or promote products derived from this
	9	* software without specific written prior permission. This software
	10	* is provided ``as is'' without express or implied warranty.
	11	*
	12	* This code was supplied by Arthur Olson, originally, and has been
	13	* slightly modified at the University of California.
b8f253e8 KM	14	*/
b8f253e8 KM	15
f60731f0	16	#if defined(LIBC_SCCS) && !defined(lint)
83b522e6 KB	17	static char sccsid[] = "@(#)ctime.c 5.12 (Berkeley) %G%";
83b522e6 KB	18	#endif /* LIBC_SCCS and not lint */
b8f253e8	19
e747b257	20	#include "sys/param.h"
5d10bbb4	21	#include "sys/time.h"
e747b257	22	#include "tzfile.h"
674afc9d	23
e747b257 KB	24	char *
	25	ctime(t)
	26	time_t *t;
674afc9d	27	{
e747b257 KB	28	struct tm *localtime();
	29	char *asctime();
	30
	31	return(asctime(localtime(t)));
	32	}
674afc9d BJ	33
674afc9d BJ	34	/*
e747b257 KB	35	** A la X3J11
e747b257 KB	36	*/
bdea7503	37
e747b257 KB	38	char *
	39	asctime(timeptr)
	40	register struct tm * timeptr;
	41	{
	42	static char wday_name[DAYS_PER_WEEK][3] = {
	43	"Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"
	44	};
	45	static char mon_name[MONS_PER_YEAR][3] = {
	46	"Jan", "Feb", "Mar", "Apr", "May", "Jun",
	47	"Jul", "Aug", "Sep", "Oct", "Nov", "Dec"
	48	};
	49	static char result[26];
bdea7503	50
36ce8be7	51	(void) sprintf(result, "%.3s %.3s%3d %02d:%02d:%02d %d\n",
e747b257 KB	52	wday_name[timeptr->tm_wday],
	53	mon_name[timeptr->tm_mon],
	54	timeptr->tm_mday, timeptr->tm_hour,
	55	timeptr->tm_min, timeptr->tm_sec,
	56	TM_YEAR_BASE + timeptr->tm_year);
	57	return result;
	58	}
7f253f66	59
e747b257 KB	60	#ifndef TRUE
	61	#define TRUE 1
	62	#define FALSE 0
	63	#endif /* !TRUE */
	64
	65	extern char * getenv();
	66	extern char * strcpy();
	67	extern char * strcat();
	68	struct tm * offtime();
	69
	70	struct ttinfo { /* time type information */
	71	long tt_gmtoff; /* GMT offset in seconds */
	72	int tt_isdst; /* used to set tm_isdst */
	73	int tt_abbrind; /* abbreviation list index */
4e884c92 RE	74	};
4e884c92 RE	75
e747b257 KB	76	struct state {
	77	int timecnt;
	78	int typecnt;
	79	int charcnt;
	80	time_t ats[TZ_MAX_TIMES];
	81	unsigned char types[TZ_MAX_TIMES];
	82	struct ttinfo ttis[TZ_MAX_TYPES];
	83	char chars[TZ_MAX_CHARS + 1];
7f253f66 SL	84	};
7f253f66 SL	85
e747b257 KB	86	static struct state s;
	87
	88	static int tz_is_set;
	89
	90	char * tzname[2] = {
	91	"GMT",
	92	"GMT"
674afc9d BJ	93	};
674afc9d BJ	94
e747b257 KB	95	#ifdef USG_COMPAT
	96	time_t timezone = 0;
	97	int daylight = 0;
	98	#endif /* USG_COMPAT */
674afc9d	99
e747b257 KB	100	static long
	101	detzcode(codep)
	102	char * codep;
674afc9d	103	{
e747b257 KB	104	register long result;
e747b257 KB	105	register int i;
674afc9d	106
e747b257 KB	107	result = 0;
	108	for (i = 0; i < 4; ++i)
	109	result = (result << 8) \| (codep[i] & 0xff);
	110	return result;
674afc9d BJ	111	}
674afc9d BJ	112
674afc9d	113	static
e747b257 KB	114	tzload(name)
e747b257 KB	115	register char * name;
674afc9d	116	{
e747b257 KB	117	register int i;
e747b257 KB	118	register int fid;
674afc9d	119
e747b257 KB	120	if (name == 0 && (name = TZDEFAULT) == 0)
	121	return -1;
	122	{
	123	register char * p;
	124	register int doaccess;
	125	char fullname[MAXPATHLEN];
674afc9d	126
e747b257 KB	127	doaccess = name[0] == '/';
	128	if (!doaccess) {
	129	if ((p = TZDIR) == 0)
	130	return -1;
	131	if ((strlen(p) + strlen(name) + 1) >= sizeof fullname)
	132	return -1;
	133	(void) strcpy(fullname, p);
	134	(void) strcat(fullname, "/");
	135	(void) strcat(fullname, name);
	136	/*
	137	** Set doaccess if '.' (as in "../") shows up in name.
	138	*/
	139	while (*name != '\0')
	140	if (*name++ == '.')
	141	doaccess = TRUE;
	142	name = fullname;
	143	}
	144	if (doaccess && access(name, 4) != 0)
	145	return -1;
	146	if ((fid = open(name, 0)) == -1)
	147	return -1;
674afc9d	148	}
e747b257 KB	149	{
	150	register char * p;
	151	register struct tzhead * tzhp;
	152	char buf[sizeof s];
674afc9d	153
e747b257 KB	154	i = read(fid, buf, sizeof buf);
	155	if (close(fid) != 0 \|\| i < sizeof *tzhp)
	156	return -1;
	157	tzhp = (struct tzhead *) buf;
	158	s.timecnt = (int) detzcode(tzhp->tzh_timecnt);
	159	s.typecnt = (int) detzcode(tzhp->tzh_typecnt);
	160	s.charcnt = (int) detzcode(tzhp->tzh_charcnt);
	161	if (s.timecnt > TZ_MAX_TIMES \|\|
	162	s.typecnt == 0 \|\|
	163	s.typecnt > TZ_MAX_TYPES \|\|
	164	s.charcnt > TZ_MAX_CHARS)
	165	return -1;
	166	if (i < sizeof *tzhp +
	167	s.timecnt * (4 + sizeof (char)) +
	168	s.typecnt * (4 + 2 * sizeof (char)) +
	169	s.charcnt * sizeof (char))
	170	return -1;
	171	p = buf + sizeof *tzhp;
	172	for (i = 0; i < s.timecnt; ++i) {
	173	s.ats[i] = detzcode(p);
	174	p += 4;
	175	}
	176	for (i = 0; i < s.timecnt; ++i)
	177	s.types[i] = (unsigned char) *p++;
	178	for (i = 0; i < s.typecnt; ++i) {
	179	register struct ttinfo * ttisp;
674afc9d	180
e747b257 KB	181	ttisp = &s.ttis[i];
	182	ttisp->tt_gmtoff = detzcode(p);
	183	p += 4;
	184	ttisp->tt_isdst = (unsigned char) *p++;
	185	ttisp->tt_abbrind = (unsigned char) *p++;
	186	}
	187	for (i = 0; i < s.charcnt; ++i)
	188	s.chars[i] = *p++;
	189	s.chars[i] = '\0'; /* ensure '\0' at end */
	190	}
	191	/*
	192	** Check that all the local time type indices are valid.
	193	*/
	194	for (i = 0; i < s.timecnt; ++i)
	195	if (s.types[i] >= s.typecnt)
	196	return -1;
674afc9d	197	/*
e747b257 KB	198	** Check that all abbreviation indices are valid.
	199	*/
	200	for (i = 0; i < s.typecnt; ++i)
	201	if (s.ttis[i].tt_abbrind >= s.charcnt)
	202	return -1;
	203	/*
	204	** Set tzname elements to initial values.
	205	*/
	206	tzname[0] = tzname[1] = &s.chars[0];
	207	#ifdef USG_COMPAT
689df48b	208	timezone = -s.ttis[0].tt_gmtoff;
e747b257 KB	209	daylight = 0;
	210	#endif /* USG_COMPAT */
	211	for (i = 1; i < s.typecnt; ++i) {
	212	register struct ttinfo * ttisp;
674afc9d	213
e747b257 KB	214	ttisp = &s.ttis[i];
	215	if (ttisp->tt_isdst) {
	216	tzname[1] = &s.chars[ttisp->tt_abbrind];
	217	#ifdef USG_COMPAT
	218	daylight = 1;
	219	#endif /* USG_COMPAT */
	220	} else {
	221	tzname[0] = &s.chars[ttisp->tt_abbrind];
	222	#ifdef USG_COMPAT
689df48b	223	timezone = -ttisp->tt_gmtoff;
e747b257 KB	224	#endif /* USG_COMPAT */
	225	}
	226	}
	227	return 0;
	228	}
674afc9d	229
5d10bbb4 KB	230	static
	231	tzsetkernel()
	232	{
	233	struct timeval tv;
	234	struct timezone tz;
2555d7f3	235	char *_tztab();
5d10bbb4 KB	236
	237	if (gettimeofday(&tv, &tz))
	238	return -1;
	239	s.timecnt = 0; /* UNIX counts west of Greenwich */
	240	s.ttis[0].tt_gmtoff = tz.tz_minuteswest * -SECS_PER_MIN;
	241	s.ttis[0].tt_abbrind = 0;
2555d7f3	242	(void)strcpy(s.chars, _tztab(tz.tz_minuteswest, 0));
5d10bbb4 KB	243	tzname[0] = tzname[1] = s.chars;
	244	#ifdef USG_COMPAT
	245	timezone = tz.tz_minuteswest * 60;
	246	daylight = tz.tz_dsttime;
	247	#endif /* USG_COMPAT */
	248	return 0;
	249	}
	250
e747b257 KB	251	static
	252	tzsetgmt()
	253	{
	254	s.timecnt = 0;
	255	s.ttis[0].tt_gmtoff = 0;
	256	s.ttis[0].tt_abbrind = 0;
	257	(void) strcpy(s.chars, "GMT");
	258	tzname[0] = tzname[1] = s.chars;
	259	#ifdef USG_COMPAT
	260	timezone = 0;
	261	daylight = 0;
	262	#endif /* USG_COMPAT */
	263	}
674afc9d	264
e747b257 KB	265	void
	266	tzset()
	267	{
	268	register char * name;
	269
	270	tz_is_set = TRUE;
	271	name = getenv("TZ");
5d10bbb4 KB	272	if (!name \|\| name) { / did not request GMT */
	273	if (name && !tzload(name)) /* requested name worked */
	274	return;
	275	if (!tzload((char )0)) / default name worked */
	276	return;
	277	if (!tzsetkernel()) /* kernel guess worked */
	278	return;
	279	}
	280	tzsetgmt(); /* GMT is default */
674afc9d BJ	281	}
674afc9d BJ	282
e747b257 KB	283	struct tm *
	284	localtime(timep)
	285	time_t * timep;
674afc9d	286	{
e747b257 KB	287	register struct ttinfo * ttisp;
	288	register struct tm * tmp;
	289	register int i;
	290	time_t t;
	291
	292	if (!tz_is_set)
	293	(void) tzset();
	294	t = *timep;
	295	if (s.timecnt == 0 \|\| t < s.ats[0]) {
	296	i = 0;
	297	while (s.ttis[i].tt_isdst)
	298	if (++i >= s.timecnt) {
	299	i = 0;
	300	break;
	301	}
	302	} else {
	303	for (i = 1; i < s.timecnt; ++i)
	304	if (t < s.ats[i])
	305	break;
	306	i = s.types[i - 1];
674afc9d	307	}
e747b257 KB	308	ttisp = &s.ttis[i];
	309	/*
	310	** To get (wrong) behavior that's compatible with System V Release 2.0
	311	** you'd replace the statement below with
	312	** tmp = offtime((time_t) (t + ttisp->tt_gmtoff), 0L);
	313	*/
	314	tmp = offtime(&t, ttisp->tt_gmtoff);
	315	tmp->tm_isdst = ttisp->tt_isdst;
	316	tzname[tmp->tm_isdst] = &s.chars[ttisp->tt_abbrind];
	317	tmp->tm_zone = &s.chars[ttisp->tt_abbrind];
	318	return tmp;
674afc9d BJ	319	}
674afc9d BJ	320
e747b257 KB	321	struct tm *
	322	gmtime(clock)
	323	time_t * clock;
674afc9d	324	{
e747b257 KB	325	register struct tm * tmp;
	326
	327	tmp = offtime(clock, 0L);
	328	tzname[0] = "GMT";
	329	tmp->tm_zone = "GMT"; /* UCT ? */
	330	return tmp;
674afc9d BJ	331	}
674afc9d BJ	332
e747b257 KB	333	static int mon_lengths[2][MONS_PER_YEAR] = {
	334	31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31,
	335	31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31
	336	};
	337
	338	static int year_lengths[2] = {
	339	DAYS_PER_NYEAR, DAYS_PER_LYEAR
	340	};
	341
	342	struct tm *
	343	offtime(clock, offset)
	344	time_t * clock;
	345	long offset;
674afc9d	346	{
e747b257 KB	347	register struct tm * tmp;
	348	register long days;
	349	register long rem;
	350	register int y;
	351	register int yleap;
	352	register int * ip;
	353	static struct tm tm;
	354
	355	tmp = &tm;
	356	days = *clock / SECS_PER_DAY;
	357	rem = *clock % SECS_PER_DAY;
	358	rem += offset;
	359	while (rem < 0) {
	360	rem += SECS_PER_DAY;
	361	--days;
	362	}
	363	while (rem >= SECS_PER_DAY) {
	364	rem -= SECS_PER_DAY;
	365	++days;
	366	}
	367	tmp->tm_hour = (int) (rem / SECS_PER_HOUR);
	368	rem = rem % SECS_PER_HOUR;
	369	tmp->tm_min = (int) (rem / SECS_PER_MIN);
	370	tmp->tm_sec = (int) (rem % SECS_PER_MIN);
	371	tmp->tm_wday = (int) ((EPOCH_WDAY + days) % DAYS_PER_WEEK);
	372	if (tmp->tm_wday < 0)
	373	tmp->tm_wday += DAYS_PER_WEEK;
	374	y = EPOCH_YEAR;
	375	if (days >= 0)
	376	for ( ; ; ) {
	377	yleap = isleap(y);
	378	if (days < (long) year_lengths[yleap])
	379	break;
	380	++y;
	381	days = days - (long) year_lengths[yleap];
	382	}
	383	else do {
	384	--y;
	385	yleap = isleap(y);
	386	days = days + (long) year_lengths[yleap];
	387	} while (days < 0);
	388	tmp->tm_year = y - TM_YEAR_BASE;
	389	tmp->tm_yday = (int) days;
	390	ip = mon_lengths[yleap];
	391	for (tmp->tm_mon = 0; days >= (long) ip[tmp->tm_mon]; ++(tmp->tm_mon))
	392	days = days - (long) ip[tmp->tm_mon];
	393	tmp->tm_mday = (int) (days + 1);
	394	tmp->tm_isdst = 0;
	395	tmp->tm_zone = "";
	396	tmp->tm_gmtoff = offset;
	397	return tmp;
674afc9d	398	}