All built-in function and javascript source in Node.js

get-node

#!/usr/bin/env node

//all built-in module and lib/*.js,expcept node.js
['constants','io_watcher','timer','buffer','cares','child_process','evals','fs','net','http_parser','signal_watcher','stdio','os'].forEach(function(v){
  console.log('built-in module:\t' + v);
  console.dir(require('sys').inspect(process.binding(v)));
});
console.log('all javascript from built-in module natives,expect node.js');
var sources = process.binding('natives');
Object.keys(sources).forEach(function(key){
  console.log('\n\n**************************************************')
  console.log('Source of lib/' + key + '.js');
  console.log('**************************************************\n\n')
  console.log(sources[key]);
});

Please explain above code and what it does ?
I want to get all built-in functions in node js using terminal cmd, so plz help me