linux timeval如何转换为其他格式

Linux??timeval????????????,?????????????????:

1. ???time_t:timeval?????tv_sec?????????time_t??,???1970?1?1???????

2. ??????:????ctime()???timeval???????????????

3. ???tm???:????gmtime()?localtime()???timeval??????tm???,???????????

4. ?????:???timeval?????tv_sec????1000???tv_usec????1000,??????

??????:

#include 
#include 

int main() {
    struct timeval tv;
    gettimeofday(&tv, NULL);

    time_t sec = tv.tv_sec;
    printf("tv_sec: %ld\n", sec);

    char *str = ctime(&tv.tv_sec);
    printf("ctime: %s", str);

    struct tm *tm = gmtime(&tv.tv_sec);
    printf("gmtime: %d-d-d d:d:d\n",
           tm->tm_year + 1900, tm->tm_mon + 1, tm->tm_mday,
           tm->tm_hour, tm->tm_min, tm->tm_sec);

    long long ms = (long long)tv.tv_sec * 1000 + tv.tv_usec / 1000;
    printf("milliseconds: %lld\n", ms);

    return 0;
}

??????????timeval???????????,????????????????