async/await 標準入力読み込み

stdin_read.js

process.stdin.resume();
process.stdin.setEncoding('utf8');
// Here your code !

function getStdin() {
    return new Promise((resolve, reject) => {
        let input_string = '';
        process.stdin.on('data', function(chunk) {
          input_string += chunk;
        });
         
        process.stdin.on('end', function() {
            resolve(input_string);
        });
    });
}

async function main() {
  let input_string = await getStdin();
  console.log(input_string);
}

main();