busybox/libbb/rtc.c

/*
 * Common RTC functions
 *
 * 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;
}
1	/*
2	* Common RTC functions
3	*
4	* Licensed under GPLv2, see file LICENSE in this tarball for details.
5	*/
6
7	#include "libbb.h"
8	#include "rtc_.h"
9
10	#if ENABLE_FEATURE_HWCLOCK_ADJTIME_FHS
11	# define ADJTIME_PATH "/var/lib/hwclock/adjtime"
12	#else
13	# define ADJTIME_PATH "/etc/adjtime"
14	#endif
15
16	int FAST_FUNC rtc_adjtime_is_utc(void)
17	{
18	int utc = 0;
19	FILE *f = fopen_for_read(ADJTIME_PATH);
20
21	if (f) {
22	char buffer[128];
23
24	while (fgets(buffer, sizeof(buffer), f)) {
25	int len = strlen(buffer);
26
27	while (len && isspace(buffer[len - 1]))
28	len--;
29
30	buffer[len] = 0;
31
32	if (strncmp(buffer, "UTC", 3) == 0) {
33	utc = 1;
34	break;
35	}
36	}
37	fclose(f);
38	}
39
40	return utc;
41	}
42
43	int FAST_FUNC rtc_xopen(const char **default_rtc, int flags)
44	{
45	int rtc;
46
47	if (!*default_rtc) {
48	*default_rtc = "/dev/rtc";
49	rtc = open(*default_rtc, flags);
50	if (rtc >= 0)
51	return rtc;
52	*default_rtc = "/dev/rtc0";
53	rtc = open(*default_rtc, flags);
54	if (rtc >= 0)
55	return rtc;
56	*default_rtc = "/dev/misc/rtc";
57	}
58
59	return xopen(*default_rtc, flags);
60	}
61
62	void FAST_FUNC rtc_read_tm(struct tm *ptm, int fd)
63	{
64	memset(ptm, 0, sizeof(*ptm));
65	xioctl(fd, RTC_RD_TIME, ptm);
66	ptm->tm_isdst = -1; /* "not known" */
67	}
68
69	time_t FAST_FUNC rtc_tm2time(struct tm *ptm, int utc)
70	{
71	char oldtz = oldtz; / for compiler */
72	time_t t;
73
74	if (utc) {
75	oldtz = getenv("TZ");
76	putenv((char*)"TZ=UTC0");
77	tzset();
78	}
79
80	t = mktime(ptm);
81
82	if (utc) {
83	unsetenv("TZ");
84	if (oldtz)
85	putenv(oldtz - 3);
86	tzset();
87	}
88
89	return t;
90	}