如何用time_t改变日期和时间的格式？

Question

time_t now = time(0);  
std::string h = std::string (ctime (&now));

std::cout << "\nh: " << h;

我收到的当前输出是：Thu Sep 14 10:58:26 2017

我希望输出为 2017-08-26-16-10-56

我可以对该输出做什么？

Answer 1

使用strftime，像这样：

strftime (buffer, 80,"%Y-%m-%d-%H-%M-%S",timeinfo);

完整代码：

#include <cstdio>
#include <ctime>

int main ()
{
  time_t rawtime;
  struct tm * timeinfo;
  char buffer [80];

  time (&rawtime);
  timeinfo = localtime (&rawtime);

  strftime (buffer, 80,"%Y-%m-%d-%H-%M-%S",timeinfo);
  puts (buffer);

  return 0;
}

输出：

2017-09-14-14-41-19

Answer 2

使用std::put_time

#include <iomanip>

time_t now = time(0);
std::string h = std::put_time(localtime(&now), "%F-%H-%M-%S");
std::cout << "\nh: " << h;

输出

h: 2017-09-14-05-54-02

更好的是，使用std::chrono

#include <iostream>
#include <iomanip>
#include <chrono>
using namespace std;

int main() {
    auto now = chrono::system_clock::to_time_t(chrono::system_clock::now());
    cout << put_time(localtime(&now), "%F-%H-%M-%S") << endl;
    return 0;
}

如何用time_t改变日期和时间的格式？

How to change the format of date and time with time_t?

c++

date

time

formatting

time-t