You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
59 lines
1.5 KiB
59 lines
1.5 KiB
3 years ago
|
/*
|
||
|
|
* linux/kernel/mktime.c
|
||
|
|
*
|
||
|
|
* (C) 1991 Linus Torvalds
|
||
|
|
*/
|
||
|
|
|
||
|
|
#include <time.h>
|
||
|
|
|
||
|
|
/*
|
||
|
|
* This isn't the library routine, it is only used in the kernel.
|
||
|
|
* as such, we don't care about years<1970 etc, but assume everything
|
||
|
|
* is ok. Similarly, TZ etc is happily ignored. We just do everything
|
||
|
|
* as easily as possible. Let's find something public for the library
|
||
|
|
* routines (although I think minix times is public).
|
||
|
|
*/
|
||
|
|
/*
|
||
|
|
* PS. I hate whoever though up the year 1970 - couldn't they have gotten
|
||
|
|
* a leap-year instead? I also hate Gregorius, pope or no. I'm grumpy.
|
||
|
|
*/
|
||
|
|
#define MINUTE 60
|
||
|
|
#define HOUR (60*MINUTE)
|
||
|
|
#define DAY (24*HOUR)
|
||
|
|
#define YEAR (365*DAY)
|
||
|
|
|
||
|
|
/* interestingly, we assume leap-years */
|
||
|
|
static int month[12] = {
|
||
|
|
0,
|
||
|
|
DAY*(31),
|
||
|
|
DAY*(31+29),
|
||
|
|
DAY*(31+29+31),
|
||
|
|
DAY*(31+29+31+30),
|
||
|
|
DAY*(31+29+31+30+31),
|
||
|
|
DAY*(31+29+31+30+31+30),
|
||
|
|
DAY*(31+29+31+30+31+30+31),
|
||
|
|
DAY*(31+29+31+30+31+30+31+31),
|
||
|
|
DAY*(31+29+31+30+31+30+31+31+30),
|
||
|
|
DAY*(31+29+31+30+31+30+31+31+30+31),
|
||
|
|
DAY*(31+29+31+30+31+30+31+31+30+31+30)
|
||
|
|
};
|
||
|
|
|
||
|
|
long kernel_mktime(struct tm * tm)
|
||
|
|
{
|
||
|
|
long res;
|
||
|
|
int year;
|
||
|
|
if (tm->tm_year < 70 ) tm->tm_year += 100; /* gohigh */
|
||
|
|
year = tm->tm_year - 70;
|
||
|
|
/* magic offsets (y+1) needed to get leapyears right.*/
|
||
|
|
res = YEAR*year + DAY*((year+1)/4);
|
||
|
|
res += month[tm->tm_mon];
|
||
|
|
/* and (y+2) here. If it wasn't a leap-year, we have to adjust */
|
||
|
|
if (tm->tm_mon>1 && ((year+2)%4))
|
||
|
|
res -= DAY;
|
||
|
|
res += DAY*(tm->tm_mday-1);
|
||
|
|
res += HOUR*tm->tm_hour;
|
||
|
|
res += MINUTE*tm->tm_min;
|
||
|
|
res += tm->tm_sec;
|
||
|
|
return res;
|
||
|
|
}
|