Trailing-Edge
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PDP-10 Archives
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SRI_NIC_PERM_FS_1_19910112
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kcc-5/lib/timemk.c
There are 4 other files named timemk.c in the archive. Click here to see a list.
/*
** TIME_MAKE derive 32-bit time value from TMX structure.
**
** Copyright (c) 1980, 1987 by Ken Harrenstien, SRI International.
**
** 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!
** (Internet: <[email protected]>)
**
** Usage:
** #include <timex.h>
** time_t time_make(struct tmx *tp);
**
** Returns:
** A time_t value.
** Will fail if parameters are out of range or nonsensical; the
** return value will be (time_t)-1 and tmx_err will be set in the
** tmx structure to point at a constant error-message string. Note
** that tmx_err is not touched otherwise!
*/
#include <timex.h>
/* Days in year thus far, indexed by month (0-12!!) Assumes non-leap year. */
static int daytb[] = {
0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 365
};
#define TERR(str) { tp->tmx_err = str; return -1; }
time_t
time_make(tp)
register struct tmx *tp;
{
register int i;
struct tm *tmp;
int year, mon, day, yday, wday, dst, leap, minzone;
long seczone;
time_t tres, curtim;
if (tp->tm.tm_year == TMX_NULL
|| tp->tm.tm_mon == TMX_NULL
|| tp->tm.tm_mday == TMX_NULL) {
time(&curtim);
tmp = localtime(&curtim); /* Get breakdowns of current time */
year = tmp->tm_year; /* Get defaults to use */
mon = tmp->tm_mon;
day = tmp->tm_mday;
#ifdef DEBUG
printf("first YMD: %d %d %d, T=%ld\n",year,mon,day,curtim);
#endif
}
/* 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).
* Start with year... note 32 bits can only handle 135 years.
*/
if (tp->tm.tm_year == TMX_NULL)
tp->tm.tm_year = year; /* Set to default */
else {
if ((year = tp->tm.tm_year) >= 1900) /* Allow full yr # */
year = (tp->tm.tm_year -= 1900); /* by making kosher */
mon = 0; /* Since year was given, default */
day = 1; /* for remaining specs is zero */
}
if (year < 70 || 70+134 < year) /* Check range */
TERR("year out of range")
leap = year&03 ? 0 : 1; /* See if leap year */
year -= 70; /* UNIX time starts at 1970 */
/*
* Find day of year.
* YDAY is used only if it exists and either the month or day-of-month
* is missing.
*/
if (tp->tm.tm_yday != TMX_NULL
&& (tp->tm.tm_mon == TMX_NULL || tp->tm.tm_mday == TMX_NULL))
yday = tp->tm.tm_yday;
else {
if (tp->tm.tm_mon == TMX_NULL)
tp->tm.tm_mon = mon; /* Set month from default */
else {
mon = tp->tm.tm_mon; /* Month was specified */
day = 1; /* so set remaining default */
}
if (mon < 0 || 11 < mon)
TERR("month out of range")
if (tp->tm.tm_mday == TMX_NULL)
tp->tm.tm_mday = day; /* Set day from default */
else day = tp->tm.tm_mday;
if (day < 1
|| (((daytb[mon+1]-daytb[mon]) < day)
&& (day!=29 || mon!=1 || !leap) ))
TERR("day out of range")
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 1 /* Optional */
if (tp->tm.tm_yday == TMX_NULL) /* Confirm that YDAY correct */
tp->tm.tm_yday = yday; /* Not specified, just set */
else if (tp->tm.tm_yday != yday)
TERR("yday conflict")
#endif
}
if (yday < 0 || (leap?366:365) <= yday)
TERR("yday out of range") /* ERR: bad YDAY or maketime bug */
tres = year*365 /* Get # days of years so far */
+ ((year+1)>>2) /* plus # of leap days since 1970 */
+ yday; /* and finally add # days this year */
#if 1 /* Optional */
wday = (tres+4)%7; /* Derive day-of-week */
if ((i = tp->tm.tm_wday) != TMX_NULL) { /* Check WDAY if present */
if (i < 0 || 6 < i /* Ensure within range */
|| i != wday) /* Matches? Jan 1,1970 was Thu = 4 */
TERR("wday conflict")
} else tp->tm.tm_wday = wday;
#endif
#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 ((i = tp->tm.tm_min) == TMX_NULL) tp->tm.tm_min = i = 0;
if (i < 0 || 60 <= i) TERR("min out of range")
if ((i = tp->tm.tm_sec) == TMX_NULL) tp->tm.tm_sec = i = 0;
if (i < 0 || 60 <= i) TERR("sec out of range")
if ((i = tp->tm.tm_hour) == TMX_NULL) tp->tm.tm_hour = i = 0;
if (i < 0 || 24 <= i)
if (i != 24 || (tp->tm.tm_min+tp->tm.tm_sec) !=0) /* 24:00 OK */
TERR("hour out of range")
#ifdef DEBUG
printf("HMS: %d %d %d T=%ld\n",
tp->tm.tm_hour, tp->tm.tm_min, tp->tm.tm_sec, tres);
#endif
tres += tp->tm.tm_sec /* Add in # secs of time */
+ 60L * (tp->tm.tm_min + 60L * tp->tm.tm_hour);
/*
** We now have the local date/time and must make final
** adjustment for the specified time zone, to get GMT.
** If no zone is specified, the local time-zone is assumed.
*/
if (tp->tmz.tmz_secwest == TMX_NULL) { /* If unspecified */
if ((i = tp->tmz.tmz_minwest)==TMX_NULL)
i = 1; /* Use local zone */
tp->tmz.tmz_secwest = (i == 1 ? 1 : i*60L);
}
if (tp->tmz.tmz_secwest == 1) { /* Forcing use of local zone? */
time_lzone(&tp->tmz); /* then set to local zone */
}
if (tp->tmz.tmz_secwest < -(12*60*60L)
|| 12*60*60L < tp->tmz.tmz_secwest)
TERR("zone out of range")
/* See if must apply Daylight Saving Time shift.
* Note that if DST is specified, validity is not checked.
*/
if((dst = tp->tm.tm_isdst) == TMX_NULL) { /* Must we figure it out? */
struct tmz lz;
time_lzone(&lz); /* Get our local tz stuff */
if (lz.tmz_secwest == tp->tmz.tmz_secwest) { /* Same as local? */
curtim = tres + lz.tmz_secwest; /* Yes, get equiv local */
dst = localtime(&curtim)->tm_isdst; /* time, and ask. */
} else dst = 0; /* No, cannot determine if OK. */
tp->tm.tm_isdst = dst;
}
tres += tp->tmz.tmz_secwest - (dst==1 ? 3600 : 0); /* Add in zone adj */
tp->tmx_err = 0; /* Won! Clear error message ptr */
return tres;
}