binary input/output

Bjarne Stroustrup “Programming Principles and Practice Using C++”
Chapter 11 Exercise 9 IO
Using std_lib_facilities.h by Bjarne Stroustrup.

[code language=”cpp”]
// Philipp Siedler
// Bjarne Stroustrup’s PPP
// Chapter 11 Exercise 9 IO

#include "std_lib_facilities.h"

int main()
try
{
//open an istream for binary input from a file:
cout << "Please enter input file name\n";
string iname;
cin >> iname;
ifstream ifs{ iname.c_str(), ios_base::binary }; //note: stream mode
//binary tells the stream not to try anything clever with the bytes

if (!ifs) error("can’t open input file", iname);

//open an ostream for binary output to a file:
cout << "Please enter output file name\n";
string oname;
cin >> oname;
ofstream ofs{ oname }; //note: stream mode // oname.c_str(), ios_base::binary
//binary tells the stream not to try anything clever with the bytes

if (!ofs) error("can’t open output file", oname);
vector<int> v;

//read from binary file:
for (int x; ifs.read(as_bytes(x), sizeof(int));) { //note: reading bytes
v.push_back(x);
//cout << x << endl;
}

//…do something…

//write to binary file:
for (int x : v) { //char x : v
ofs.write(as_bytes(x), sizeof(int)); //note: writing bytes
}

//return 0;
keep_window_open();
}
catch (runtime_error e) {
cout << e.what() << endl;
keep_window_open();
}
catch (…) {
cout << "Exiting" << endl;
keep_window_open();
}
[/code]

Output:
Please enter input file name
ch10_9_input_1.txt
Please enter output file name
ch10_9_output_1.txt
Please enter a character to exit
Input-File: ch10_9_input_1.txt
this is a test
Output-File: ch10_9_output_1.txt
this is a te

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