Node js how to get list of keys pressed

Question

I'm writing a command line app using Node.js. I'm trying to get keypresses from stdin. Here's what I've tried so far:

const readline = require('readline');

readline.emitKeypressEvents(process.stdin);
process.stdin.setRawMode(true);

process.stdin.on('keypress', (str, key) => {
  console.log(str)
  console.log(key)
})

This works pretty well. It gets all letters and I can see if some modifiers were pressed such as control/shift. But it doesn't register some key combinations like shift+alt+up. I would like a method to just get a list of keys pressed so I can parse combos like that.

Also, some key combos are registered as ansi escape sequences. For example:

// ctrl+a
{ sequence: '\x01', name: 'a', ctrl: true, meta: false, shift: false }

// ctrl+h
{
  sequence: '\b',
  name: 'backspace',
  ctrl: false,
  meta: false,
  shift: false
}

Here ctrl+a is registered as 'a' with control pressed, but ctrl+h is registered as backspace. In this case I'd like a way to see if ctrl+h was pressed.

Answer 1

The stdin is based on byte streams, so it only responds to bytes. Whether the corresponding keystroke will input bytes depends on a higher layer, such as the operating system. If you want to detect keystrokes, you have to use proprietary APIs from the higher layer.