File Names as Input

//Reads three numbers from the file specified by the user,

//sums the numbers, and writes the sum to another file

//specified by the user.

#include <fstream>

#include <iostream>

#include <cstdlib>

int main( )

{

using namespace std;

char in_file_name[16], out_file_name[16];

ifstream in_stream;

ofstream out_stream;

cout << "I will sum three numbers taken from an input\n"

<< "file and write the sum to an output file.\n";

cout << "Enter the input file name (maximum of 15 characters):\n";

cin >> in_file_name;

cout << "Enter the output file name (maximum of 15 characters):\n";

cin >> out_file_name;

cout << "I will read numbers from the file "

<< in_file_name << " and\n"

<< "place the sum in the file "

<< out_file_name << endl;

in_stream.open(in_file_name);

if (in_stream.fail( ))

{

cout << "Input file opening failed.\n";

exit(1);

}

out_stream.open(out_file_name);

if (out_stream.fail( ))

{

cout << "Output file opening failed.\n";

exit(1);

}

int first, second, third;

in_stream >> first >> second >> third;

out_stream << "The sum of the first 3\n"

<< "numbers in " << in_file_name << endl

<< "is " << (first + second + third)

<< endl;

in_stream.close( );

out_stream.close( );

cout << "End of Program.\n";

return 0;

}