4.4BSD/usr/src/contrib/rcs-V5.6/src/maketime.c
#
/*
* MAKETIME derive 32-bit time value from TM structure.
*
* Usage:
* int zone; Minutes west of GMT, or
* 48*60 for localtime
* time_t t;
* struct tm *tp; Pointer to TM structure from <time.h>
* t = maketime(tp,zone);
*
* Returns:
* -1 if failure; parameter out of range or nonsensical.
* else time-value.
* Notes:
* This code is quasi-public; it may be used freely in like software.
* It is not to be sold, nor used in licensed software without
* permission of the author.
* For everyone's benefit, please report bugs and improvements!
* Copyright 1981 by Ken Harrenstien, SRI International.
* (ARPANET: KLH @ SRI)
*/
/* $Log: maketime.c,v $
* Revision 5.3 1991/08/19 03:13:55 eggert
* Add setfiledate, str2time, TZ_must_be_set.
*
* Revision 5.2 1990/11/01 05:03:30 eggert
* Remove lint.
*
* Revision 5.1 1990/10/04 06:30:13 eggert
* Calculate the GMT offset of 'xxx LT' as of xxx, not as of now.
* Don't assume time_t is 32 bits. Fix bugs near epoch and near end of time.
*
* Revision 5.0 1990/08/22 08:12:38 eggert
* Switch to GMT and fix the bugs exposed thereby.
* Permit dates past 1999/12/31. Ansify and Posixate.
*
* Revision 1.8 88/11/08 13:54:53 narten
* allow negative timezones (-24h <= x <= 24h)
*
* Revision 1.7 88/08/28 14:47:52 eggert
* Allow cc -R. Remove unportable "#endif XXX"s.
*
* Revision 1.6 87/12/18 17:05:58 narten
* include rcsparam.h
*
* Revision 1.5 87/12/18 11:35:51 narten
* maketime.c: fixed USG code - you have tgo call "tzset" in order to have
* "timezone" set. ("localtime" calls it, but it's probably better not to
* count on "localtime" having been called.)
*
* Revision 1.4 87/10/18 10:26:57 narten
* Updating version numbers. Changes relative to 1.0 are actually
* relative to 1.2
*
* Revision 1.3 87/09/24 13:58:45 narten
* Sources now pass through lint (if you ignore printf/sprintf/fprintf
* warnings)
*
* Revision 1.2 87/03/27 14:21:48 jenkins
* Port to suns
*
* Revision 1.2 83/12/05 10:12:56 wft
* added cond. compilation for USG Unix; long timezone;
*
* Revision 1.1 82/05/06 11:38:00 wft
* Initial revision
*
*/
#include "rcsbase.h"
libId(maketId, "$Id: maketime.c,v 5.3 1991/08/19 03:13:55 eggert Exp $")
static struct tm const *time2tm P((time_t));
#define given(v) (0 <= (v)) /* Negative values are unspecified. */
static int const daytb[] = {
/* # days in year thus far, indexed by month (0-12!!) */
0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 365
};
static time_t
maketime(atm,zone)
struct tm const *atm;
int zone;
{
register struct tm const *tp;
register int i;
int year, yday, mon, day, hour, min, sec, leap, localzone;
int attempts;
time_t t, tres;
attempts = 2;
localzone = zone==48*60;
tres = -1;
year = mon = day = 0; /* Keep lint happy. */
do {
if (localzone || !given(atm->tm_year)) {
if (tres == -1)
if ((tres = time((time_t*)0)) == -1)
return -1;
tp = time2tm(tres);
/* Get breakdowns of default time, adjusting to zone. */
year = tp->tm_year; /* Use to set up defaults */
yday = tp->tm_yday;
mon = tp->tm_mon;
day = tp->tm_mday;
hour = tp->tm_hour;
min = tp->tm_min;
if (localzone) {
tp = localtime(&tres);
zone =
min - tp->tm_min + 60*(
hour - tp->tm_hour + 24*(
/* If years differ, it's by one day. */
year - tp->tm_year
? year - tp->tm_year
: yday - tp->tm_yday));
}
/* Adjust the default day, month and year according to zone. */
if ((min -= zone) < 0) {
if (hour-(59-min)/60 < 0 && --day <= 0) {
if (--mon < 0) {
--year;
mon = 11;
}
day = daytb[mon+1] - daytb[mon] + (mon==1&&!(year&3));
}
} else
if (
24 <= hour+min/60 &&
daytb[mon+1] - daytb[mon] + (mon==1&&!(year&3)) < ++day
) {
if (11 < ++mon) {
++year;
mon = 0;
}
day = 1;
}
}
if (zone < -24*60 || 24*60 < zone)
return -1;
#ifdef DEBUG
printf("first YMD: %d %d %d\n",year,mon,day);
#endif
tp = atm;
/* First must find date, using specified year, month, day.
* If one of these is unspecified, it defaults either to the
* current date (if no more global spec was given) or to the
* zero-value for that spec (i.e. a more global spec was seen).
* Reject times that do not fit in time_t,
* without assuming that time_t is 32 bits or is signed.
*/
if (given(tp->tm_year))
{
year = tp->tm_year;
mon = 0; /* Since year was given, default */
day = 1; /* for remaining specs is zero */
}
if (year < 69) /* 1969/12/31 OK in some timezones. */
return -1; /* ERR: year out of range */
leap = !(year&3) && (year%100 || !((year+300)%400));
year -= 70; /* UNIX time starts at 1970 */
/*
* Find day of year.
*/
{
if (given(tp->tm_mon))
{ mon = tp->tm_mon; /* Month was specified */
day = 1; /* so set remaining default */
}
if (11 < (unsigned)mon)
return -1; /* ERR: bad month */
if (given(tp->tm_mday)) day = tp->tm_mday;
if(day < 1
|| (((daytb[mon+1]-daytb[mon]) < day)
&& (day!=29 || mon!=1 || !leap) ))
return -1; /* ERR: bad day */
yday = daytb[mon] /* Add # of days in months so far */
+ ((leap /* Leap year, and past Feb? If */
&& mon>1)? 1:0) /* so, add leap day for this year */
+ day-1; /* And finally add # days this mon */
}
if (leap+365 <= (unsigned)yday)
return -1; /* ERR: bad YDAY */
if (year < 0) {
if (yday != 364)
return -1; /* ERR: too early */
t = -1;
} else {
tres = year*365; /* Get # days of years so far */
if (tres/365 != year)
return -1; /* ERR: overflow */
t = tres
+ ((year+1)>>2) /* plus # of leap days since 1970 */
+ yday; /* and finally add # days this year */
if (t+4 < tres)
return -1; /* ERR: overflow */
}
tres = t;
if (given(i = tp->tm_wday)) /* Check WDAY if present */
if (i != (tres+4)%7) /* 1970/01/01 was Thu = 4 */
return -1; /* ERR: bad WDAY */
#ifdef DEBUG
printf("YMD: %d %d %d, T=%ld\n",year,mon,day,tres);
#endif
/*
* Now determine time. If not given, default to zeros
* (since time is always the least global spec)
*/
tres *= 86400L; /* Get # seconds (24*60*60) */
if (tres/86400L != t)
return -1; /* ERR: overflow */
hour = min = sec = 0;
if (given(tp->tm_hour)) hour = tp->tm_hour;
if (given(tp->tm_min )) min = tp->tm_min;
if (given(tp->tm_sec )) sec = tp->tm_sec;
if (60 <= (unsigned)min || 60 < (unsigned)sec)
return -1; /* ERR: MS out of range */
if (24 <= (unsigned)hour)
if(hour != 24 || (min+sec) !=0) /* Allow 24:00 */
return -1; /* ERR: H out of range */
t = tres;
tres += sec + 60L*(zone + min + 60*hour);
#ifdef DEBUG
printf("HMS: %d %d %d T=%ld\n",hour,min,sec,tres);
#endif
if (!localzone) /* check for overflow */
return (year<0 ? (tres<0||86400L<=tres) : tres<t) ? -1 : tres;
/* Check results; LT may have had a different GMT offset back then. */
tp = localtime(&tres);
if (given(atm->tm_sec) && atm->tm_sec != tp->tm_sec)
return -1; /* If seconds don't match, we're in trouble. */
if (!(
given(atm->tm_min) && atm->tm_min != tp->tm_min ||
given(atm->tm_hour) && atm->tm_hour != tp->tm_hour ||
given(atm->tm_mday) && atm->tm_mday != tp->tm_mday ||
given(atm->tm_mon) && atm->tm_mon != tp->tm_mon ||
given(atm->tm_year) && atm->tm_year != tp->tm_year
))
return tres; /* Everything matches. */
} while (--attempts);
return -1;
}
/*
* Convert Unix time to struct tm format.
* Use Coordinated Universal Time (UTC) if version 5 or newer;
* use local time otherwise.
*/
static struct tm const *
time2tm(unixtime)
time_t unixtime;
{
struct tm const *tm;
# if TZ_must_be_set
static char const *TZ;
if (!TZ && !(TZ = getenv("TZ")))
faterror("TZ is not set");
# endif
if (!(tm = (RCSversion<VERSION(5) ? localtime : gmtime)(&unixtime)))
faterror("UTC is not available; perhaps TZ is not set?");
return tm;
}
/*
* Convert Unix time to RCS format.
* For compatibility with older versions of RCS,
* dates before AD 2000 are stored without the leading "19".
*/
void
time2date(unixtime,date)
time_t unixtime;
char date[datesize];
{
register struct tm const *tm = time2tm(unixtime);
VOID sprintf(date, DATEFORM,
tm->tm_year + (tm->tm_year<100 ? 0 : 1900),
tm->tm_mon+1, tm->tm_mday,
tm->tm_hour, tm->tm_min, tm->tm_sec
);
}
static time_t
str2time(source)
char const *source;
/* Parse a free-format date in SOURCE, yielding a Unix format time. */
{
int zone;
time_t unixtime;
struct tm parseddate;
if (!partime(source, &parseddate, &zone))
faterror("can't parse date/time: %s", source);
if ((unixtime = maketime(&parseddate, zone)) == -1)
faterror("bad date/time: %s", source);
return unixtime;
}
void
str2date(source, target)
char const *source;
char target[datesize];
/* Parse a free-format date in SOURCE, convert it
* into RCS internal format, and store the result into TARGET.
*/
{
time2date(str2time(source), target);
}
int
setfiledate(file, date)
char const *file, date[datesize];
/* Set the access and modification time of FILE to DATE. */
{
static struct utimbuf times; /* static so unused fields are zero */
char datebuf[datesize];
if (!date)
return 0;
times.actime = times.modtime = str2time(date2str(date, datebuf));
return utime(file, ×);
}