linux 在程序里修改系统时间

int main(void)
{
    char t_string[] = "2012-04-28 22:30:00";
    struct tm time_tm;
    struct timeval time_tv;
    time_t timep;
    int ret = 0;

    sscanf(t_string, "%d-%d-%d %d:%d:%d", &time_tm.tm_year, &time_tm.tm_mon, &time_tm.tm_mday, &time_tm.tm_hour, &time_tm.tm_min, &time_tm.tm_sec);
    time_tm.tm_year -= 1900;
    time_tm.tm_mon -= 1;
    time_tm.tm_wday = 0;
    time_tm.tm_yday = 0;
    time_tm.tm_isdst = 0;

    timep = mktime(&time_tm);
    time_tv.tv_sec = timep;
    time_tv.tv_usec = 0;

    ret = settimeofday(&time_tv, NULL);
    if(ret != 0)
    {
        fprintf(stderr, "settimeofday failed\n");
        return -1;
    }
    return 0;
}