mktime函数实现获取当前系统时间

#include<stdio.h>
#include<time.h>


char displayTime[14];      


int main( )
{
     time_t timep;
     struct tm *p;


     while(1){
        time(&timep);
        //printf("\rtime():%ld\n",timep);    //打印从1900年到当前的时间的秒数，每一次打印出的时间都不同

        p = localtime(&timep);
        timep = mktime(p);

/************************************以下内容的方法可用在写RTC驱动在LCD上显示*******************************************/

        displayTime[0] = 0x30+ (p->tm_year + 1900) / 1000;                       //年    0x30 = '0'
        displayTime[1] = 0x30+ (p->tm_year + 1900) % 1000 / 100;
        displayTime[2] = 0x30+ (p->tm_year + 1900) % 100 / 10;  
        displayTime[3] = 0x30+(p->tm_year + 1900) % 10;

        displayTime[4] = 0x30+ (p->tm_mon + 1) / 10;                             //月
        displayTime[5] = 0x30+(p->tm_mon + 1) % 10;
  
        displayTime[6] = 0x30+p->tm_mday / 10;                                   //日
        displayTime[7] = 0x30+p->tm_mday % 10;

        displayTime[8] = 0x30+p->tm_hour / 10;                                   //时
        displayTime[9] = 0x30+p->tm_hour % 10;

        displayTime[10] = 0x30+ p->tm_min / 10;                                  //分
        displayTime[11] = 0x30+p->tm_min % 10;

        displayTime[12] = 0x30+p->tm_sec / 10;                                   //秒
        displayTime[13] = 0x30+p->tm_sec % 10;

        printf("\r%d%d%d%d-%d%d-%d%d %d%d:%d%d:%d%d",displayTime[0],displayTime[1],displayTime[2],\
                                                    displayTime[3],displayTime[4],displayTime[5],\
                                                    displayTime[6],displayTime[7],displayTime[8],\
                                                    displayTime[9],displayTime[10],displayTime[11],\
                                                    displayTime[12],displayTime[13]);
/**************************************************以下内容的方法可在写RTC驱动控制台和串口上显示***********************************/
       //printf("\r%4d-%02d-%02d %02d:%02d:%02d",p->tm_year+1900,p->tm_mon+1,p->tm_mday,p->tm_hour,p->tm_min,p->tm_sec);
    }
}





#include<stdio.h>
#include<time.h>


char di