hush/libbb/rtc.c

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/*
* Common RTC functions
2008-12-07 00:52:58 +00:00
*
* Licensed under GPLv2, see file LICENSE in this tarball for details.
*/
#include "libbb.h"
#include "rtc_.h"
#if ENABLE_FEATURE_HWCLOCK_ADJTIME_FHS
# define ADJTIME_PATH "/var/lib/hwclock/adjtime"
#else
# define ADJTIME_PATH "/etc/adjtime"
#endif
int FAST_FUNC rtc_adjtime_is_utc(void)
{
int utc = 0;
FILE *f = fopen_for_read(ADJTIME_PATH);
if (f) {
char buffer[128];
while (fgets(buffer, sizeof(buffer), f)) {
int len = strlen(buffer);
while (len && isspace(buffer[len - 1]))
len--;
buffer[len] = 0;
if (strncmp(buffer, "UTC", 3) == 0) {
utc = 1;
break;
}
}
fclose(f);
}
return utc;
}
int FAST_FUNC rtc_xopen(const char **default_rtc, int flags)
{
int rtc;
if (!*default_rtc) {
*default_rtc = "/dev/rtc";
rtc = open(*default_rtc, flags);
if (rtc >= 0)
return rtc;
*default_rtc = "/dev/rtc0";
rtc = open(*default_rtc, flags);
if (rtc >= 0)
return rtc;
*default_rtc = "/dev/misc/rtc";
}
return xopen(*default_rtc, flags);
}
void FAST_FUNC rtc_read_tm(struct tm *ptm, int fd)
{
memset(ptm, 0, sizeof(*ptm));
xioctl(fd, RTC_RD_TIME, ptm);
ptm->tm_isdst = -1; /* "not known" */
}
time_t FAST_FUNC rtc_tm2time(struct tm *ptm, int utc)
{
char *oldtz = oldtz; /* for compiler */
time_t t;
if (utc) {
oldtz = getenv("TZ");
putenv((char*)"TZ=UTC0");
tzset();
}
t = mktime(ptm);
if (utc) {
unsetenv("TZ");
if (oldtz)
putenv(oldtz - 3);
tzset();
}
return t;
}