synchronous_getline.js

// from https://stackoverflow.com/questions/43638105/how-to-get-synchronous-readline-or-simulate-it-using-async-in-nodejs

const readline=require('readline')
const rl = readline.createInterface({ input: process.stdin , output: process.stdout });

const getLine = (function () {
  const getLineGen = (async function* () {
    for await (const line of rl) {
      yield line;
    }
  })();
  return async () => ((await getLineGen.next()).value);
})();

const main = async () => {
  const a = await getLine()
  const b = await getLine()
  console.log('first two lines', a, b);
  const lines = []
  while ((line = await getLine())){
    lines.push(line)
  }
  console.log('rest', lines)
  process.exit(0);
};

main();