You can look at the following documentation and example:
http://www.cplusplus.com/doc/tutorial/files/
Edit upon recommendation:
In the provided link below they explain how to open and close a text file, read lines and write lines and several other functionalities. For completeness of this answer an example will be given below:
// writing on a text file
#include <iostream>
#include <fstream>
using namespace std;
int main () {
ofstream myfile ("example.txt");
if (myfile.is_open())
{
myfile << "This is a line.\n";
myfile << "This is another line.\n";
myfile.close();
}
else cout << "Unable to open file";
return 0;
}
The above script will write the 2 lines into the text file named example.txt.
You can then read these lines with a somewhat similar script:
// reading a text file
#include <iostream>
#include <fstream>
#include <string>
using namespace std;
int main () {
string line;
ifstream myfile ("example.txt");
if (myfile.is_open())
{
while ( getline (myfile,line) )
{
cout << line << '\n';
}
myfile.close();
}
else cout << "Unable to open file";
return 0;
}
Best regards
Ruud