Question

‘cout is an output stream object that is attached to the process’s standard output device,often to the terminal from which the program is run’-my book says so.Just curious about the following:

Is there any case where cout is made to be attached to any other output devices such as may be printer?Or it is like cout refers to monitor and cin to keyboard all the time.

Answer 1

cin is the standard input, and while most systems get their input from the keyboard it is not necessary. cout is standard output, most systems again have stdout (standard output) set to console. But you can redirect it.

For instance to file:

  std::ofstream file;
  file.open ("test.txt"); // open file

  std::streambuf *orig_out = std::cout.rdbuf();     // save cout 
  std::streambuf *buf = file.rdbuf();   // get file's streambuf
  std::cout.rdbuf(buf);         // redirect cout to file
  std::cout << "This is written to the file";
  std::cout.rdbuf(orig_out);        // restore cout's original output

  file.close(); // close file