diff options
Diffstat (limited to 'libc/msdos/time.c')
| -rw-r--r-- | libc/msdos/time.c | 63 |
1 files changed, 63 insertions, 0 deletions
diff --git a/libc/msdos/time.c b/libc/msdos/time.c new file mode 100644 index 0000000..0a66da8 --- /dev/null +++ b/libc/msdos/time.c @@ -0,0 +1,63 @@ + +#include <time.h> + +static int mdays[13] = { 0,31,31+28,31+28+31,31+28+31+30, + 31+28+31+30+31,31+28+31+30+31+30,31+28+31+30+31+30+31, + 31+28+31+30+31+30+31+31,31+28+31+30+31+30+31+31+30, + 31+28+31+30+31+30+31+31+30+31,31+28+31+30+31+30+31+31+30+31+30, + 365 }; + +#define SECSPERHOUR (60*60) +#define SECSPERDAY (SECSPERHOUR*24L) + +/**************************************** + * Return the number of seconds that have elapsed since the start + * of 1970. + * Input: + * timer pointer to where to store result (or NULL) + * Output: + * *timer = result (unless timer == NULL) + * Returns: + * time + */ + +static long get_time(ah) +{ +#asm +#if !__FIST_ARG_IN_AX__ + mov bx,sp + mov ax,[bx+2] +#endif + mov ah,al + int $21 + mov ax,dx + mov dx,cx +#endasm +} + +time_t time(timer) +time_t *timer; +{ + unsigned day,month,year; + long rv; + time_t t; + + rv = get_time(0x2C); + rv >>= 8; t = (rv & 0xFF); + rv >>= 8; t += (rv & 0xFF)*60; + rv >>= 8; t += (rv & 0xFF)*3600; + + rv = get_time(0x2A); + day = (rv & 0xFF); + rv >>= 8; month = (rv & 0xFF) -1; + rv >>= 8; year = (rv & 0xFFFF) - 1970; + + if (month <= 1 || year & 3) /* if before Feb or not a leap year */ + day--; /* don't add day for leap year */ + day += mdays[month]; /* day in year */ + day += (year + 3) >> 2; /* add a day for each leap year */ + t += ((year * 365L) + day) * SECSPERDAY; + if (timer) + *timer = t; + return t; +} |