lst-0027-book.cpp
// https://godbolt.org/z/6hh5KhExM
#include <iostream> // cin
#include <string>
int main() {
std::string line;
do { // execute getline at least once
std::getline(std::cin, line);
if(!std::cin) break; // error or end of file
} while(line != "quit"); // end on specific input
}