file_server.js

/**
 Write an HTTP server that serves the same text file for each request
 it receives.

 You will be provided with the location of the file to serve as the
 first command-line argument. You must use the `fs.createReadStream()`
 method to stream the file contents to the response.

 Your server should listen on port 8000.

 ----------------------------------------------------------------------
 HINTS:

 The `http` core module has a method named `http.createServer()` that
 takes a callback function. Unlike most callbacks in Node, the callback
 used by `createServer()` is called more than once. Every connection
 received by your server triggers another call to the callback. The
 callback function has the signature:

 function (request, response) { ... }

 Where the two arguments are objects representing the HTTP request
 and the corresponding response for this request. `request` is used to
 fetch properties, such as the header and query-string from the request
 while `response` if for sending data to the client, both headers and
 body.

 Both `request` and `response` are also Node streams! Which means that
 you can use the streaming abstractions to send and receive data if
 they suit your use-case.

 `http.createServer()` also returns an instance of your `server`. You
 must call `server.listen(portNumber)` to start listening on a
 particular port.

 A typical Node HTTP server looks like this:

 var http = require('http')
 var server = http.createServer(function (req, res) {
    // request handling logic...
  })
 server.listen(8000)

 Documentation on the `http` module can be found by pointing your
 browser here:
 /home/anca/lib/node_modules/learnyounode/node_apidoc/http.html

 The `fs` core module also has some streaming APIs for files. You will
 need to use `fs.createReadStream()` method to create a stream
 representing the file you are given as a command-line argument. The
 method returns a stream object which you can use `src.pipe(dst)` to
 pipe the data from the `src` stream to the `dst` stream. In this way
 you can connect a filesystem stream with an HTTP response stream.

 ----------------------------------------------------------------------
 */


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

var server = http.createServer(function(req, res) {
	var readStream = fs.createReadStream(process.argv[2]);
	readStream.pipe(res);

	readStream.on('error', function(err) {
		res.end(err);
	});

});

server.listen(8000);