fs-watch-stream

The NodeJs library that watch for changes of sets of files and stream out their differences. It usable, for example, for streaming server logs to browser in real time.

Type definition:

type fsWatchStream = (
  filesList: { [string]: string }[],
  callback: (err: Error, res: string) => void
) => void

Example with web sockets

const fsWatchStream = require('fs-watch-stream')
const WebSocket = require('ws')

const wss = new WebSocket.Server({ port: 8080 })

fsWatchStream([
  { system: '/var/log/system.log' },
  { wifi: '/var/log/wifi.log' }
], (err, res) => {
  if (err) throw err
  wss.clients.forEach(client => client.send(res))
})