Howto Read From Binary File

[gundalav]

Dear all,

The following code first writes the data
into a binary file. Then reading the file again.

However the output it gives after
reading it is faulty.

How can I correct it?

#include <iostream> 
#include <fstream> 
#include <vector>
#include <iostream> 
#include <fstream>

using namespace std; 

template <class T> T prn_vec(vector<T>& arg) {
    for ( int n=0; n<arg.size() ; n++ ) {
        cout << arg[n] << " ";
    }
	cout << endl;
}

 
int main() 
{ 
	vector <char> digit;
	vector <vector <char> > Repo; 
	
	digit.push_back('0');
	digit.push_back('0');
	digit.push_back('1');
	Repo.push_back(digit);
	digit.clear();
	
	digit.push_back('1');
	digit.push_back('0');
	digit.push_back('1');
	Repo.push_back(digit);
	digit.clear();
	
   
    // Process vector within Repo
    // Write them as binary file
   ofstream out("test.bin", ios::out | ios::binary | ios::app); 
   if(!out) { 
	    cout << "Cannot open file.\n"; 
	    return 1; 
    }
   
	for ( int i=0; i<Repo.size() ; i++ ) {
	  char *array = new char[Repo[i].size()];
       	  prn_vec<char>(Repo[i]);
          out.write((char *) &array, sizeof array); 
        
		delete[] array;
        }

      out.close(); 

    ifstream in("test.bin", ios::in | ios::binary); 
	 if(!in) { 
	    cout << "Cannot open file.\n"; 
	   return 1; 
	 }


     // Reading it
	
	
    cout << endl;
    cout << "READING FROM BINARY FILE AND PRINT" << endl;
    
    char n[3];
    in.read((char *) &n, sizeof n); 
    for(int i = 0; i <4; i++)  {
		cout << n[i] << " ";
   }

    in.close();
    cout << endl;
 
  unlink("test.bin");

  return 0; 
}