C语言时间族函数time、localtime、mktime介绍

1.使用time和localtime函数获取时间

#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
/*
struct tm *localtime(const time_t *timer);
*/
int main()
{
	//获取时间
	time_t tt; //时间句柄变量  _int64
	time(&tt); //获取时间句柄
	tm *time = localtime(&tt); //将_int64(time_t)型时间句柄转换成当前时间

	const char* ps[] = {
		"星期日",
		"星期一",
		"星期二",
		"星期三",
		"星期四",
		"星期五",
		"星期六",
	};

	// 输出年月日 时分秒
	printf("%d年%d月%d日 %d时%d分%d秒\n",time->tm_year+1900, time->tm_mon+1,time->tm_mday,
		time->tm_hour,time->tm_min,time->tm_sec);

	//输出当前时星期几
	printf("当前是%s\n",ps[time->tm_wday]);

	return 0;
}

2.使用mktime将当前时间转化成时间句柄

#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
/*
struct tm
{
int tm_sec;   // seconds after the minute - [0, 60] including leap second
int tm_min;   // minutes after the hour - [0, 59]
int tm_hour;  // hours since midnight - [0, 23]
int tm_mday;  // day of the month - [1, 31]
int tm_mon;   // months since January - [0, 11]
int tm_year;  // years since 1900
int tm_wday;  // days since Sunday - [0, 6]
int tm_yday;  // days since January 1 - [0, 365]
int tm_isdst; // daylight savings time flag
};
*/
int main()
{
	time_t tt;//定义时间句柄变量
	tm time = {59,35,14,29,0,2020-1900,3,29,0};//当前时间
	tt = mktime(&time);//当前时间转换时间句柄

	return 0;
}