Is it possible to automatically install the required modules for a node.js script?

Is it possible to automatically download the required modules for a node.js script? I'm wondering if it's possible to generate a list of required modules for a node.js script (like the one below), and install them automatically, instead of installing them manually, one-by-one (using npm).

#!/usr/bin/env node

var DNode = require('dnode');
var sys = require('sys');
var fs = require('fs');
var http = require('http');

var html = fs.readFileSync(__dirname + '/web.html');
var js = require('dnode/web').source();

//the rest of this script is omitted.

Yes, there is a great piece of code called NPM for exactly this: https://npmjs.org/

You specify dependent packages in a package.json file (see the docs for syntax) and you can use npm install . to pull them in all at once, and then require them from your script.

Package.json syntax page: https://npmjs.org/doc/json.html

I writed a script for that.

(function(){
    var r=require;
    require=function (n){
        try{
            return r(n)
        }
        catch(e){
            r('child_process').exec('npm i ' + n,function (err,body){
                try{

                    console.log('Module "' +n + '"" not found, try to install. Please restart the app\n' + body )
                    return r(n);
                }
                catch(e){
                }
            })
        }
    }
})()