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

//--------------------------- convertString ----------------------------------
// Convert a string object into a character array (actually char*)

char* convertString(string s) {
   int length = s.length();

   // allocate memory one longer than length to store null character
   // which is required at the end of char arrays so they display correctly
   char* charString = new char[length+1];
   s.copy(charString, length, 0);
   charString[length] = '\0';                   // put null char at array end
   return charString;
}

//---------------------------------- main ------------------------------------
// Allow user to enter a filename from standard input

int main() {
   string s;
   cout << "please enter filename:  ";
   cin >> s;
   char* filename = convertString(s);

   ifstream infile(filename);               // constructor opens file
   if (!infile) {
      cerr << "File could not be opened." << endl;
      return 1;
      }

   // simple example of use to read ints until eof and display
   int n;
   for (;;) {
      infile >> n;
      if (infile.eof()) break;
      cout << n << endl;
   }

   delete [] filename;                      // clean up memory
   filename = NULL;
   return 0;
}