ForEachLine() in node.js - node.js

Question

Referring to slide no 35 in ppt on slideshare
When I run this code
var server = my_http.createServer();
server.on("request", function(request,response){
var chunks = [];
output = fs.createWriteStream("./output");
request.on("data",function(chunk){
chunks = forEachLine(chunks.concat(chunk),function(line){
output.write(parseInt(line,10)*2);
output.write("\n");
})
});
request.on("end",function(){
response.writeHeader(200,{"Content-Type":"plain/text"})
response.end("OK\n");
output.end()
server.close()
})
});
server.listen("8080");
I get error as
chunks = forEachLine(chunks.concat(chunk),function(line){
^
ReferenceError: forEachLine is not defined
Of course I unserstand that I need to include some library but when I googled this I found nothing . Since I am complete newbie to this I have absolutely no idea how to resolve it.
Any suggestions will be appreciable.
EDIT
Using the suggested answer I am getting error as
events.js:72
throw er; // Unhandled 'error' event
^
TypeError: Invalid non-string/buffer chunk
at validChunk (_stream_writable.js:150:14)
at WriteStream.Writable.write (_stream_writable.js:179:12)
at /var/www/html/experimentation/nodejs/first.js:18:20
at Array.forEach (native)
at forEachLine (/var/www/html/experimentation/nodejs/first.js:8:60)
at IncomingMessage.<anonymous> (/var/www/html/experimentation/nodejs/first.js:17:18)
at IncomingMessage.EventEmitter.emit (events.js:95:17)
at IncomingMessage.<anonymous> (_stream_readable.js:736:14)
at IncomingMessage.EventEmitter.emit (events.js:92:17)
at emitReadable_ (_stream_readable.js:408:10)
Thanks

Answer 1

See proxy_stream.js
function forEachLine(chunks, callback) {
var buffer = chunks.join("")
buffer.substr(0, buffer.lastIndexOf("\n")).split("\n").forEach(callback)
return buffer.substr(buffer.lastIndexOf("\n") + 1).split("\n")
}
The link to the repo was on the first slide.
EDIT BY LET's CODE FOR ERROR MESSAGE
Came to know the actual issue now .
I was using nod v0.10 and it is buggy in getting the streams so I was getting the error. Downgraded to v0.8 and same code is working perfect .