C에서 getline()을 사용하여 사용자 입력의 전체 행을 읽는 방법은 무엇입니까?

#include <iostream>
#include <cstdlib>
#include <cstring>
#include <fstream>

using namespace std;

int main()
{
    char x;

    cout << "Would you like to write to a file?" << endl;
    cin >> x;
    if (x == 'y' || x == 'Y')
    {
        string response;  // Changed data type to string
        cout << "What would you like to write?" << endl;
        getline(cin, response);  // Using getline() now

        ofstream file;
        file.open("Characters.txt");
        file << strlen(response) << " Characters." << endl;
        file << endl;
        file << response;

        file.close();

        cout << "Done. \a" << endl;
    }
    else
    {
        cout << "K, Bye." << endl;
    }

    return 0;
}