c++ - 在 C++ 中使用日期和时间命名日志文件

Question

所以，我想为我正在尝试创建的应用程序创建一个日志文件，但我不知道如何将日志命名为“log/date&time”之类的名称

无论如何，这是我的代码:

#include <iostream>
#include <fstream>
#include <time.h>
#include <stdio.h>
#include <sstream>


using namespace std;


int main (int argc, char *argv[])
{

     time_t t = time(0);
     struct tm * now = localtime( & t );

     char buffer [80];
     strftime (buffer,80,"%Y-%m-%d.",now); //i think i can't just put "log/%Y-%m-%d." there.

     ofstream myfile;
     myfile.open ("log/" + buffer); // this is my problem, i can't put the ' "log/" + ' part there
     if(myfile.is_open())
     {
         cout<<"Success"<<std::endl;
      }

return 0;
}

Answer 1

您应该使用 std::string，它支持通过重载的 operator+ 进行连接。

std::string buffer(80, '\0');
strftime( &buffer[0], buffer.size(), "some format string", now);

/* ... */
std::ofstream myfile( ("log/" + buffer).c_str() ); 
// Remove the (..).c_str() part when working with a C++11 conforming
// standard library implementation