node-hid-input

Node.js binding for reading text inputs on Linux, such as barcode scanners.

Why another...?

Features:

• [x] First class TypeScript support
• [x] Node-API addon for better parsing of input_event
• [x] Supports exclusive (EVIOCGRAB) open
• [x] Mocking interface for better unit testing, even on platforms other than Linux

Installation

npm install --save hid-input

Build from source

npm install --save hid-input --build-from-source

Additional build dependencies are required on different platforms:

Debian/Ubuntu

sudo apt install -y build-essential cmake ninja-build

macOS

brew install cmake ninja

Usage

import { createInput, listInputs } from 'hid-input';

const inputs = await listInputs();
console.log(inputs);

const reader = createInput(inputs[0].path);
reader.once('open', ()=>{
  console.log('device opened');
});
reader.on('data', (input) => {
  console.log(`- scanned: ${input}`);
});

APIs

listInputs()

• Returns: Promise<InputDevice[]>
  • path - string Path to the device
  • name - string Human readable name of the deivce

List HID input devices available on this machine.

createInput(path[, options])

• path - string
• options - Object
  • exclusive - boolean Whether to prevent the device from being opened by other processes before getting closed
• Returns: HidInputStream

Opens an input stream of device path. Available devices along with paths can be retrieved with listInputs().

createMockInput(path)

• path - string
• Returns: HidInputStream

Opens a mocking stream by listening on a newly created UNIX domain socket path.

After the stream is open, you can emulate inputs with nc -U <path>.

Class: HidInputStream

• Extends fs.Readable

A readable stream in Object mode.

Event: open

Event: close

Event: data

• input - string Input read from the device

close()

Close the stream and release any underlying resources.

License

MIT License