在控制台上显示C ++中.txt文件的动态更改

Question

Here is my requirement: " I need to show to the user on a Console window, the output of a .txt file which will be modified continuously by a Third party application "

I have this code from cplusplus.com :

// reading a text file
#include <iostream>
#include <fstream>
#include <string>
using namespace std;

int main () {
  string line;
  ifstream myfile ("test_results.txt");
  if (myfile.is_open())
  {
    while ( myfile.good() )
    {
      getline (myfile,line);
      cout << line << endl;
    }
    myfile.close();
  }

  else cout << "Unable to open file"; 

  return 0;
}

Do I need any sort of time counter to read that file at certain regular intervals of time? Guide me, thanks in advance...

Answer 1

There are two approaches.

• Platform-dependent

  Use API, like inotify in Linux

• Platform-independent

  Query fs about file modifications, for example using boost::filesystem http://www.boost.org/doc/libs/1_52_0/libs/filesystem/doc/reference.html#last_write_time