一、时间函数

       time_t time(time_t *t);

       char *asctime(const struct tm *tm);

       char *asctime_r(const struct tm *tm, char *buf);

       char *ctime(const time_t *timep);

       char *ctime_r(const time_t *timep, char *buf);

       struct tm *gmtime(const time_t *timep); //获取的为英国时间

       struct tm *gmtime_r(const time_t *timep, struct tm *result);

       struct tm *localtime(const time_t *timep);      //获取的为本地时间,注意与英国时间的区别。

       struct tm *localtime_r(const time_t *timep, struct tm *result);

       time_t mktime(struct tm *tm);

       double difftime(time_t time1, time_t time0);

       int gettimeofday(struct timeval *tv, struct timezone *tz);

       int settimeofday(const struct timeval *tv , const struct timezone *tz);

二、设置和获取时间

#include <stdio.h>

#include <time.h>

int main(void)

{

       time_t t1;

       time_t t2;

       struct tm *my_tm;

       char buf[128] = {0};

       //自Epoch (00:00:00 UTC, January 1,1970)的秒数