fileio2.cpp

// This program shows how C++-based file I/O works.
// It will open a file, read in the first two strings, and print them to the screen.

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

// we want to use parameters
int main(int argc, char** argv) {
    // verify the correct number of parameters
    if (argc != 2) {
        cout << "Must supply the input file name as the one and only parameter" << endl;
        exit(1);
    }

    // attempt to open the supplied file
    ifstream file(argv[1], ifstream::binary);
    // report any problems opening the file and then exit
    if (!file.is_open()) {
        cout << "Unable to open file '" << argv[1] << "'." << endl;
        exit(2);
    }

    // read in two strings
    string s1, s2;
    file >> s1;
    file >> s2;

    // output those strings
    cout << s1 << endl;
    cout << s2 << endl;

    // close the file before exiting
    file.close();
}