sam.js

let cluster = require('cluster')
let path = require('path') 
let fs = require('fs')
const Readline = require('readline')
var isRunning = false
/**
 * Start a js file
 * @param {String} file `path/to/file`
 */
function start(file) {
  if (isRunning) return
  isRunning = true
  let args = [path.join(__dirname, file), ...process.argv.slice(2)]

  cluster.setupMaster({
    exec: path.join(__dirname, file),
    args: args.slice(1),
  })
  let p = cluster.fork()
  p.on('message', data => {
    console.log('[RECEIVED]', data)
    switch (data) {
      case 'reset':
        p.kill()
        isRunning = false
        start.apply(this, arguments)
        break
      case 'uptime':
        p.send(process.uptime())
        break
    }
  })
  p.on('exit', code => {
    isRunning = false
    console.error('Exited with code:', code)
    if (code === 0) return
    fs.watchFile(args[0], () => {
      fs.unwatchFile(args[0])
      start(file)
    })
  })

}


start('index.js')