Simple Node.js file server

fileserver.js

//
// Very simple Node.js file server by Timur Kristóf
//

var http = require('http');
var url = require('url');
var fs = require('fs');
var mime = require('mime');

// Figure out port number
var portNumber = process.env.PORT || 1337;

// Create HTTP server
var server = http.createServer(function (req, res) {
    // Examine URL, get requested file path
    var currentUrl = url.parse(req.url, true);
    if (currentUrl.pathname === "/" || currentUrl.pathname.indexOf("..") > -1) {
        currentUrl.pathname = "/index.html";
    }
    var filePath = __dirname + currentUrl.pathname;

    //console.log("requested:", req.url, filePath);

    // Check if file exists
    fs.exists(filePath, function (exists) {
        if (!exists) {
            // Return with 404
            res.writeHead(404, { 'Content-Type': 'text/html; charset=utf-8' });
            res.end("There is no such thing on this server.");
            return;
        }

        // Write response head
        res.writeHead(200, { 'Content-Type': mime.lookup(filePath) });

        // Pipe the file stream into the response stream
        var fileStream = fs.createReadStream(filePath);
        fileStream.pipe(res);
    });
});
// Start server
server.listen(portNumber);

console.log("web server listening on: " + portNumber);

package.json

{
  "name": "simple-file-server",
  "description": "The simplest possible file server",
  "author": "Timur Kristóf",
  "version": "1.0.0",
  "dependencies": {
    "mime": "*"
  },
  "engine": "node >= 0.8.0"
}