app.js

/**
 *  Tutorial
 *  
 *  Step1. install nodejs & npm (download: http://nodejs.org/download/)
 *
 *  Step2. install express (http://expressjs.com/)
 *         $ sudo npm install express -g
 *
 *  Step3. $ node app 
 *         default port is 3000
 *         default root is this file(app.js) path
 *         
 *         if you want to change port or root folder you can follow this format
 *         $ node app [YOUR_PORT] [YOUR_ROOT (base on app.js file path)] or
 *         $ node app [YOUR_ROOT (base on app.js file path)] [YOUR_PORT]
 *         
 *         SAMPLE: $ node app 8080 www
 *                 $ node app www 8080
 *         server will start on port 8080 and root folder is 'www'
 *
 *         SAMPLE2 $ node app 8080
 *         server will start on port 8080 and root folder is '/'
 *
 *         SAMPLE3 $ node app www
 *         server will start on port 3000 and root folder is 'www'
 */

var express = require('/usr/local/lib/node_modules/express') //mac default npm path
  , http = require('http')
  , path = require('path')
  , myFolder = '/'
  , myPort = 3000;

if(process.argv.length > 2){
  if(!isNaN(process.argv[2])){
    myPort = process.argv[2];
  }else{
    myFolder = process.argv[2];
  }
}

if(process.argv.length > 3){
  if(!isNaN(process.argv[3])){
    myPort = process.argv[3];
  }else{
    myFolder = process.argv[3];
  }
}

var app = express();

app.configure(function(){
  app.set('port', process.env.PORT || myPort);
  app.use(express.favicon());
  app.use(express.logger('dev'));
  app.use(express.static(path.join(__dirname, myFolder)));
  app.use(express.directory(__dirname + '/'+myFolder));
});

app.configure('development', function(){
  app.use(express.errorHandler());
});

http.createServer(app).listen(app.get('port'), function(){
  console.log("Express server listening on port " + app.get('port')+" root folder is '"+__dirname+'/'+myFolder+"'");
});