// This program demonstrates the return value of the stream
// object error testing member functions.
#include <iostream>
#include <fstream>
using namespace std;

// Function prototype
void showState(fstream &);

int main()
{
   int num = 10;

   // Open the file for output.
   fstream testFile("stuff.dat", ios::out);
   if (testFile.fail())
   {
      cout << "ERROR: Cannot open the file.\n";
      return 0;
   }

   // Write a value to the file.
   cout << "Writing the value " << num << " to the file.\n";
   testFile << num;
   
   // Show the bit states.
   showState(testFile);
   
   // Close the file.
   testFile.close();

   // Reopen the file for input.
   testFile.open("stuff.dat", ios::in);
   if (testFile.fail())
   {
      cout << "ERROR: Cannot open the file.\n";
      return 0;
   }

   // Read the only value from the file.
   cout << "Reading from the file.\n";
   testFile >> num;
   cout << "The value " << num << " was read.\n";
   
   // Show the bit states.
   showState(testFile);
   
   // No more data in the file, but force an invalid read operation.
   cout << "Forcing a bad read operation.\n";
   testFile >> num;
   
   // Show the bit states.
   showState(testFile);
   
   // Close the file.
   testFile.close();
   return 0;
}

//*****************************************************************
// Definition of function showState. This function uses           *
// an fstream reference as its parameter. The return values of    *
// the eof(), fail(), bad(), and good() member functions is       *
// displayed. The clear() function is called before the function  *
// returns.                                                       *
//*****************************************************************

void showState(fstream &file)
{
   cout << "File Status:\n";
   cout << "  eof bit: " << file.eof() << endl;
   cout << "  fail bit: " << file.fail() << endl;
   cout << "  bad bit: " << file.bad() << endl;
   cout << "  good bit: " << file.good() << endl;
   file.clear();  // Clear any bad bits
}