Parse User Input in Node.js with readline

don't understand how u used rl.input

I can't find .input even in documentation

oh, I think I have to make an extended interface, listener must be put on stdin. Sorry for misunderstanding. Typescript sometimes is tricky ))

I am using node v18.13.0 and copied your code example with promisified readline from the github and got an error. Started googing around and found example on this page https://www.typeerror.org/docs/node/readline which changes your import:

import readline from "node:readline/promises";

to

import * as readline from "node:readline/promises";

and it worked.

Just a note for future self and others.

Ok - the import was not a problem, in your code example you have

const rl = readline.createInterface({ terminal: true, input: process.stdin, output: process.stdin, });

So both input and output maps to process.stdin, the output should be mapped to process.stdout.

I can't get this example to work, and show keypress events. The only way I got it to show keypress events was:

import readline from "node:readline"; import { stdin as input, stdout as output } from "node:process";

const rl = readline.createInterface({ terminal: true, input, output }); readline.emitKeypressEvents(input, rl); process.stdin.on("keypress", (key, seq) => console.log(key, seq));

I have rebuilt this using v18.13.0. And you're right Xavier, although in the video I correctly had output mapped to stdout, in the repo it's mapped to stdin - I've fixed that now!

Here's the version using event listeners and not promises that is in the middle of the video. Hopefully that helps the last commenter.

import readline from "node:readline";

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

let input = "";

rl.input.on("keypress", (event, rl) => {
  if (rl.name === "return") {
    console.log(`Your name is ${input}.`);
  } else {
    input += event;
  }
});

and here is the promises version (which is also available in the repo but the output is fixed now)

import readline from "node:readline/promises";

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

const answer = await rl.question("What is your name?");

console.log(`Your name is ${answer}.`);

const answer2 = await rl.question("Where do you live? ");

console.log(`You live in ${answer2}.`);
rl.close();

Hope that helps and reach out again if I can help more!

Kevin.