The following code example is taken from the book
 
  The C++ Standard Library - A Tutorial and Reference, 2nd Edition
 by Nicolai M. Josuttis, Addison Wesley Longman, 2012
 
  Copyright © 2012 by Pearson Education, Inc. and Nicolai M. Josuttis
// header files for file I/O
#include <fstream>
#include <iostream>
using namespace std;
// for all filenames passed as command-line arguments
// - open, print contents, and close file
int main (int argc, char* argv[])
{
    ifstream file;
    // for all command-line arguments
    for (int i=1; i<argc; ++i) {
        // open file
        file.open(argv[i]);
        // write file contents to cout
        char c;
        while (file.get(c)) {
            cout.put(c);
        }
        // close file
        file.close();
    }
}