Thread: A program that copies a file and then outputs the copy in binary formate

For copying a file I've used this code:


#include <fstream>

int main()
{
std::ifstream file("C:/Kopia.dat");
std::ofstream file2("C:/KopiaAvKopia.dat");

int x = sizeof file;

char c[x];
file >> c;

file2 << c;

return 0;

}


The problem here is that the program only reads the first characters before a space comes from "file" into the "c"-array. Thus, it only copies those characters into "file2".

What I'm asking for is help with this copying process, so that it can copy everything from "file". I also would like the copied characters to be outputted in binary formate to "file2".

You need to open the files in binary mode. Try something like -

Code:

#include <fstream>

using namespace std;

int main()
{	
	ifstream in("C:/Kopia.dat",ios::binary);
	ofstream out("C:/KopiaAvKopia.dat",ios::binary);

	out << in.rdbuf();

	return 0;
}

>>int x = sizeof file;

should be int x=sizeof(file);

First off, you only need parentheses with primitive types. Secondly you can't use sizeof to get the length of files, it'll return the sizeof the ifstream object. Thirdly, even if it did return the length of the file (or you obtained it by some other method such as ifstream::seekg() and ifstream::tellg()), initialising a stack based array with a variable is not legal C++ (although some compilers let you do it). You'd need to dynamically allocate memory or use something like a std::vector.

>> && << ignore spaces and '\n'
use get/put

If you were reading/writing in binary mode, you'd use fstream::read() and fstream::write(), not get/put.