Typical top of a tool script

tool.js

/* global __dirname, process */

var fs = require('fs');
var ndjson = require('ndjson');
var through2 = require('through2');
var callNextTick = require('call-next-tick');

if (process.argv.length < 3) {
  console.log(
    'Usage: node tools/toolname.js <export something.ndjson> > new_file.ndjson'
  );
  process.exit();
}