Linux下C开发设置系统时间

/************************************************
设置操作系统时间
参数:*dt数据格式为"2006-4-20 20:30:30"
调用方法:
    char *pt="2006-4-20 20:30:30";
    SetSystemTime(pt);
**************************************************/
int SetSystemTime(char *dt)
{
 struct rtc_time tm;
 struct tm _tm;
 struct timeval tv;
 time_t timep;
 sscanf(dt, "%d-%d-%d %d:%d:%d", &tm.tm_year,
        &tm.tm_mon, &tm.tm_mday,&tm.tm_hour,
        &tm.tm_min, &tm.tm_sec);
 _tm.tm_sec = tm.tm_sec;
 _tm.tm_min = tm.tm_min;
 _tm.tm_hour = tm.tm_hour;
 _tm.tm_mday = tm.tm_mday;
 _tm.tm_mon = tm.tm_mon - 1;
 _tm.tm_year = tm.tm_year - 1900;

 timep = mktime(&_tm);
 tv.tv_sec = timep;
 tv.tv_usec = 0;
 if(settimeofday (&tv, (struct timezone *) 0) < 0)
  printf("Set system datatime error!\n");
 else
  printf("Set system datatime successfully!\n");
}