Copy contents of One File to another C++

'Copy file in C++' program is given below.

Copies content of file 'a' to file 'b'.

#include <iostream>

#include <fstream>

using namespace std;

int main(){

char line[100];

ifstream is("a.txt");

ofstream os("b.txt");

if (is.is_open()){

while (!is.eof()){

is.getline(line,100,'\n');

os << line << endl;

}

}

else{

cout << "a.txt couldn't be opened. Creat and write something in a.txt, and try again." << endl;

}

return 0;

}

See a better program:
Copy one file to another file C++