Linux下的时间函数：设置及获取时间

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

       t1 = time(&t1);

       printf("%d\n", t1);                       //1355905754

       t2 = time(&t2);

       sleep(1);

       printf("%lf\n", difftime(t2, t1));  //t1,t2相差:1.000000，有时候可以用这个函数来做伪定时器

       printf("%s\n",ctime(&t1));        //Wed Dec 19 16:29:14 2012

       //init tm

       my_tm->tm_year = 2012-1900;

       my_tm->tm_mon = 12-1;

       my_tm->tm_mday = 12;

       my_tm->tm_hour = 12;

       my_tm->tm_min = 12;

       my_tm->tm_sec = 12;

      //设置时间

       t1 = mktime(my_tm);

       //获取时间

       my_tm = localtime(&t1);

       sprintf(buf, "%04d-%02d-%02d  %02d:%02d:%02d",

                     my_tm->tm_year + 1900, my_tm->tm_mon + 1, my_tm->tm_mday, my_tm->tm_hour, my_tm->tm_min, my_tm->tm_sec);

       printf("%s\n", buf);              //2012-12-12  12:12:12

       return 0;

}

     没那么简单，就这么简单！

    幸福很简单，简单到时间一冲即淡，一淡就散！