Bjarne Stroustrup “Programming Principles and Practice Using C++”
Chapter 10 Exercise 9
Using std_lib_facilities.h by Bjarne Stroustrup.
[code language=”cpp”]
// Philipp Siedler
// Bjarne Stroustrup’s PPP
// Chapter 10 Exercise 9
#include "std_lib_facilities.h"
void read_file(string& _input, ofstream& _ost) {
ifstream ist{ _input };
string result;
if (!ist) error("can’t open input file ", _input);
ist.exceptions(ist.exceptions() | ios_base::badbit);
ist >> result;
while (true) {
_ost << result << endl;
if (ist.eof()) {
break;
}
else {
ist >> result;
}
}
}
void write_file(string& _output, string& _input_1, string& _input_2) {
ofstream ost{ _output };
if (!ost) error("can’t open output file", _output);
read_file(_input_1, ost);
read_file(_input_2, ost);
}
void calculate() {
string input_1 = "input/ch10_9_input_1.txt";
string input_2 = "input/ch10_9_input_2.txt";
string output = "output/ch10_9_output_1+2.txt";
cout << "Combining files " << input_1 << " & " << input_2 << "…";
write_file(output, input_1, input_2);
cout << " Done!" << endl;
cout << output << " successfully written." << endl;
}
int main()
try
{
calculate();
keep_window_open();
}
catch (runtime_error e) {
cout << e.what() << endl;
keep_window_open();
}
catch (…) {
cout << "Exiting" << endl;
keep_window_open();
}
[/code]
Output: Combining files input/ch10_9_input_1.txt & input/ch10_9_input_2.txt... Done! output/ch10_9_output_1+2.txt successfully written. Please enter a character to exit
Input-File 1: ch10_9_input_1.txt this is a test
Input-File 2: ch10_9_input_2.txt and so is this
Output-File: ch10_9_output_1+2.txt this is a test and so is this
