Watch the filesystem using NSFW from the command line

nsfw-watcher.js

#!/usr/bin/env node

const nsfw = require('nsfw')
const process = require('process')
const path = require('path')

if (process.argv.length == 0) {
  console.log(`Usage: ${process.argv[0]} [path]`)
  process.exit(0)
}

var pathParam
if (process.argv.length > 2) {
  pathParam = process.argv[2]
} else {
  pathParam = '.'
}

watch(pathParam, 100)

function watch(pathParam, howLong, json) {
  const absolutePath = path.resolve(pathParam)
  console.log(`Watching ${absolutePath} for ${howLong} seconds`)
  nsfw(absolutePath,
    function(events) {
      for(var i = 0; i < events.length; i++) {
        const e = events[i]
        var output = [ `${actionNames[e.action]}` ]
        const file = e.file || e.oldFile
        if (file) {
          output.push(`${path.join(e.directory, file)}`)
        } else {
          output.push(e.directory)
        }
        if (e.newFile) output.push(`to ${path.join(e.directory, e.newFile)}`)
        console.log(output.join(' '))
      }
    })
    .then(function(watcher) {
      return watcher.start();
    })
    .then(function() {
      setTimeout(function() { process.exit(1) }, howLong * 1000)
    })
}

var actionNames = [ 'Created ', 'Deleted ', 'Modified', 'Renamed ' ]

Hi thanks for this code, can you please let me know how I can access nsfw when running this from command line. I have done
npm install -g nsfw
but still getting error of
Cannot find module "nsfw"