C++ Writing to file and Console Output at the same time with simple code

问题

I am trying to write the following entire function to a text file while still maintaining its console output functionality without having code redundancy. Is there a simple way to post an entire method's result to a file and console at the same time?

#include<iostream>
#include<fstream>
  void sports(){
      cout<<"\nGame_Code\t\tGane\t\tCost\t\tStart Time\n";
      cout<<"\nSP-9651\t\t Game 1 \t\t60\t\t08:00";
      cout<<"\nSP-9652\t\t Game 2 \t\t60\t\t09:15";
      cout<<"\nSP-9653\t\t Game 3 \t\t55\t\t09:55";
      cout<<"\nSP-9654\t\t Game 4 \t\t55\t\t11:00";
      cout<<"\nSP-9655\t\t Game 5 \t\t50\t\t13:00";
      cout<<"\nSP-9657\t\t Game 7 \t\t45\t\t19:45";
      cout<<"\nSP-9659\t\t Game 8 \t\t70\t\t22:45";
      cout<<"\n\n";
     } 
    int main(){
    //This is for console output
    sports();
    }

回答1:

Streams can be passed to functions. So have a print function that does both outputs.

void print(std::ostream &os1, std::ostream &os2, const std::string &str)
{
    os1 << str;
    o22 << str;
}

void sports()
{
    std::fstream file("filename");

    print(std::cout, file, "\nSP-9651\t\t Game 1 \t\t60\t\t08:00");
    print(std::cout, file, "\nSP-9652\t\t Game 2 \t\t60\t\t09:00");
    print(std::cout, file, "\nSP-9653\t\t Game 3 \t\t60\t\t10:00");
    //... etc
}

int main()
{
    sports();
    return 0;
}

回答2:

Yes, you can return std::string from the function and save it to a variable. Then you can use that variable to print it on the console or/and on a file.

std::string sports(){
  std::stringstream ss;
  ss<<"\nGame_Code\t\tGane\t\tCost\t\tStart Time\n";
  // ...
  return ss.str();
 }

The function should have only one purpose. In your case, that purpose is to create the string.Single responsibility principle.

回答3:

   #include<iostream>
   #include<fstream>
   using namespace std;
  void sports(){
      ofstream fs("abc");
      cout<<"\nGame_Code\t\tGane\t\tCost\t\tStart Time\n";
      fs<<"\nGame_Code\t\tGane\t\tCost\t\tStart Time\n";

     } 
    int main(){
    //This is for console output
    sports();
    }

回答4:

You can write simple function to club it ??

#include<iostream>
#include<fstream>
using namespace std;

  void myoutput( fstream &fs, string str)
  {
      cout << str;
      fs << str;

  }
  void sports(){
      fstream fs("abc");
      myoutput(fs,"\nGame_Code\t\tGane\t\tCost\t\tStart Time\n ..");

     } 
    int main(){
    //This is for console output
    sports();
    }

回答5:

I suggest using a function, that writes both - to a file and cout. My example function just takes text. All given text is appended to the file:

void dual_write(const std::string& text) {
    // Print to console
    std::cout << text;

    // Print to file (append)
    std::ofstream file("out.txt", std::ios_base::app);
    file << text;
}

Call it via dual_write("\nGame_Code\t\tGane\t\tCost\t\tStart Time\n"); and so on.

来源：https://stackoverflow.com/questions/49938086/c-writing-to-file-and-console-output-at-the-same-time-with-simple-code

标签

c++

fstream

ofstream