nodejs how to read keystrokes from stdin

Question

For those finding this answer since this capability was stripped from tty, here's how to get a raw character stream from stdin:

var stdin = process.stdin;

// without this, we would only get streams once enter is pressed
stdin.setRawMode( true );

// resume stdin in the parent process (node app won't quit all by itself
// unless an error or process.exit() happens)
stdin.resume();

// i don't want binary, do you?
stdin.setEncoding( 'utf8' );

// on any data into stdin
stdin.on( 'data', function( key ){
  // ctrl-c ( end of text )
  if ( key === '\u0003' ) {
    process.exit();
  }
  // write the key to stdout all normal like
  process.stdout.write( key );
});

pretty simple - basically just like process.stdin's documentation but using setRawMode( true ) to get a raw stream, which is harder to identify in the documentation.

You can achieve it this way, if you switch to raw mode:

var stdin = process.openStdin(); 
require('tty').setRawMode(true);    

stdin.on('keypress', function (chunk, key) {
  process.stdout.write('Get Chunk: ' + chunk + '\n');
  if (key && key.ctrl && key.name == 'c') process.exit();
});

In node >= v6.1.0:

const readline = require('readline');

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

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

See https://github.com/nodejs/node/issues/6626

This version uses the keypress module and supports node.js version 0.10, 0.8 and 0.6 as well as iojs 2.3. Be sure to run npm install --save keypress.

var keypress = require('keypress')
  , tty = require('tty');

// make `process.stdin` begin emitting "keypress" events
keypress(process.stdin);

// listen for the "keypress" event
process.stdin.on('keypress', function (ch, key) {
  console.log('got "keypress"', key);
  if (key && key.ctrl && key.name == 'c') {
    process.stdin.pause();
  }
});

if (typeof process.stdin.setRawMode == 'function') {
  process.stdin.setRawMode(true);
} else {
  tty.setRawMode(true);
}
process.stdin.resume();