CODEWITHSUNDEEP
node.js
user7816795
user7816795

Reputation: 81

How do I detect whether a key is pressed in node.js?

I have a little utility written in node.js that does some real-time data capture. I'd like to augment it so it also records whether a particular key is pressed on the keyboard at which time during the capture. (This allows me to "mark" the time in the data capture when some event happened).

But how do I detect whether a given key is pressed/down on the keyboard from node.js? Something like readline won't work because it's line-based, and waits until CR is entered. (The capture needs to continue in real time.) Instead, it needs to access the keyboard on a fairly low level to get "the state of key X right now", returning pressed or not-pressed.

Is there such a thing in node.js?

Upvotes: 6

Views: 12054

Answers (3)

user3209882
user3209882

Reputation: 51

iohook support only nodejs v8.x - v15.x

readline support current nodejs v19.x

Try install readline with command: npm I readline

var readline = require('readline');

readline.emitKeypressEvents(process.stdin);

if (process.stdin.isTTY)
    process.stdin.setRawMode(true);

console.log('press q to exit, or any key to print log');

process.stdin.on('keypress', (chunk, key) => {
  if (key && key.name == 'q'){
    process.exit();
  }
  console.log({key});
});

Upvotes: 4

Bob
Bob

Reputation: 1679

From here ;

let readline = require('readline');

readline.emitKeypressEvents(process.stdin);

process.stdin.on('keypress', (ch, key) => {
  console.log('got "keypress"', ch, key);
  if (key && key.ctrl && key.name == 'c') {
    process.stdin.pause();
  }
});

process.stdin.setRawMode(true);

Upvotes: 1

Joviallix
Joviallix

Reputation: 1069

Just use iohook npm module. This is example: 

const iohook = require('iohook');
iohook.on("keypress", event => {
  console.log(event);
  // {keychar: 'f', keycode: 19, rawcode: 15, type: 'keypress'}
});
iohook.start();

But this is question is duplicate for this question

Upvotes: 3

Related Questions