busybox/util-linux/hwclock.c

129 lines
2.7 KiB
C

/* vi: set sw=4 ts=4: */
/*
* Mini hwclock implementation for busybox
*
* Copyright (C) 2002 Robert Griebl <griebl@gmx.de>
*
* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
*/
#include <sys/utsname.h>
#include <getopt.h>
#include "libbb.h"
#include "rtc_.h"
#if ENABLE_FEATURE_HWCLOCK_LONG_OPTIONS
# ifndef _GNU_SOURCE
# define _GNU_SOURCE
# endif
#endif
static const char *rtcname;
static time_t read_rtc(int utc)
{
time_t ret;
int fd;
fd = rtc_xopen(rtcname, O_RDONLY);
ret = rtc_read_time(fd, utc);
close(fd);
return ret;
}
static void write_rtc(time_t t, int utc)
{
struct tm tm;
int rtc = rtc_xopen(rtcname, O_WRONLY);
tm = *(utc ? gmtime(&t) : localtime(&t));
tm.tm_isdst = 0;
xioctl(rtc, RTC_SET_TIME, &tm);
close(rtc);
}
static void show_clock(int utc)
{
//struct tm *ptm;
time_t t;
char *cp;
t = read_rtc(utc);
//ptm = localtime(&t); /* Sets 'tzname[]' */
cp = ctime(&t);
if (cp[0])
cp[strlen(cp) - 1] = '\0';
//printf("%s %.6f seconds %s\n", cp, 0.0, utc ? "" : (ptm->tm_isdst ? tzname[1] : tzname[0]));
printf("%s 0.000000 seconds\n", cp);
}
static void to_sys_clock(int utc)
{
struct timeval tv;
const struct timezone tz = { timezone/60 - 60*daylight, 0 };
tv.tv_sec = read_rtc(utc);
tv.tv_usec = 0;
if (settimeofday(&tv, &tz))
bb_perror_msg_and_die("settimeofday() failed");
}
static void from_sys_clock(int utc)
{
struct timeval tv;
gettimeofday(&tv, NULL);
//if (gettimeofday(&tv, NULL))
// bb_perror_msg_and_die("gettimeofday() failed");
write_rtc(tv.tv_sec, utc);
}
#define HWCLOCK_OPT_LOCALTIME 0x01
#define HWCLOCK_OPT_UTC 0x02
#define HWCLOCK_OPT_SHOW 0x04
#define HWCLOCK_OPT_HCTOSYS 0x08
#define HWCLOCK_OPT_SYSTOHC 0x10
#define HWCLOCK_OPT_RTCFILE 0x20
int hwclock_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int hwclock_main(int argc, char **argv)
{
unsigned opt;
int utc;
#if ENABLE_FEATURE_HWCLOCK_LONG_OPTIONS
static const char hwclock_longopts[] ALIGN1 =
"localtime\0" No_argument "l"
"utc\0" No_argument "u"
"show\0" No_argument "r"
"hctosys\0" No_argument "s"
"systohc\0" No_argument "w"
"file\0" Required_argument "f"
;
applet_long_options = hwclock_longopts;
#endif
opt_complementary = "r--ws:w--rs:s--wr:l--u:u--l";
opt = getopt32(argv, "lurswf:", &rtcname);
/* If -u or -l wasn't given check if we are using utc */
if (opt & (HWCLOCK_OPT_UTC | HWCLOCK_OPT_LOCALTIME))
utc = (opt & HWCLOCK_OPT_UTC);
else
utc = rtc_adjtime_is_utc();
if (opt & HWCLOCK_OPT_HCTOSYS)
to_sys_clock(utc);
else if (opt & HWCLOCK_OPT_SYSTOHC)
from_sys_clock(utc);
else
/* default HWCLOCK_OPT_SHOW */
show_clock(utc);
return 0;
}