Here, we will see how to develop a C++ program to copy the contents of one file into another file. Given a text file, extract contents from it and copy the contents into another new file. After this, display the contents of the new file.
Approach:
- Open the first file which contains data. For example, a file named “file1.txt” contains three strings on three separate lines “Programming Tutorials”, “By Geeks for geeks” and “Happy Coding!”.
- Open the second file to copy the data from the first file.
- Extract the contents of the first file line by line and write the same content to the second file named “file2.txt” via while loop.
- Extract the contents of the second file and display it via the while loop.
C++
// C++ to demonstrate copying // the contents of one file // into another file #include <bits/stdc++.h> using namespace std;
int main()
{ // filestream variables
fstream f1;
fstream f2;
string ch;
// opening first file to read the content
f1.open( "file1.txt" , ios::in);
// opening second file to write
// the content copied from
// first file
f2.open( "file2.txt" , ios::out);
while (!f1.eof()) {
// extracting the content of
// first file line by line
getline(f1, ch);
// writing content to second
// file line by line
f2 << ch << endl;
}
// closing the files
f1.close();
f2.close();
// opening second file to read the content
f2.open( "file2.txt" , ios::in);
while (!f2.eof()) {
// extracting the content of
// second file line by
// line
getline(f2, ch);
// displaying content
cout << ch << endl;
}
// closing file
f2.close();
return 0;
} |
Output:
Programming Tutorials By Geeks for geeks Happy Coding!