deno get console input code example

Example 1: deno stdin

async function ask(question: string = '', stdin = Deno.stdin, stdout = Deno.stdout) {
  const buf = new Uint8Array(1024);

  // Write question to console
  await stdout.write(new TextEncoder().encode(question));

  // Read console's input into answer
  const n = <number>await stdin.read(buf);
  const answer = new TextDecoder().decode(buf.subarray(0, n));

  return answer.trim();
}

const answer = await ask(`Tell me your name? `);
console.log(`Your name is ${answer}`);

Example 2: deno stdin

window.onload = async function main() {
  const buf = new Uint8Array(1024);
  /* Reading into `buf` from start.
   * buf.subarray(0, n) is the read result.
   * If n is instead Deno.EOF, then it means that stdin is closed.
   */
  const n = await Deno.stdin.read(buf); 
  if (n == Deno.EOF) {
    console.log("Standard input closed")
  } else {
    console.log("READ:", new TextDecoder().decode(buf.subarray(0, n)));
  }
}