Tag Archives: Localhost

Diving into Node.js – Very First App

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What do I have till now?

After Node.js is istalled, described in my previous post, I can simply run this command:

stoimenpopov:~# node server.js

and this will start the server with the code within server.js. But what’s the code of server.js?

Following the instructions of Node’s homepage and most of the tutorials I’ve found, I can simply copy/paste the code from the first lines of Node’s page:

var http = require('http');
http.createServer(function (req, res) {
  res.writeHead(200, {'Content-Type': 'text/plain'});
  res.end('Hello World\n');
}).listen(8124, "127.0.0.1");
console.log('Server running at http://127.0.0.1:8124/');

There are several things I find interesting in this code, making it different from JavaScript as we know it. First of all what is

var http = require(‘http’)

and why I need it? What is the purpouse of 8124 and 127.0.0.1?

Node is built in modules and to use one of them you must first include it with require. Just like the example above with require(‘http’). In the same manner you can include every module of Node.

What are the Node’s modules are pretty well described in the API page. Well I’d like to say that the API page is quite insufficient. That is very bad, cause most of the code you’ll need developing a node.js applicatoin isn’t described/explained there. Continue reading Diving into Node.js – Very First App →

PHP Functions: realpath()

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Watch Out – Hard Code

Perhaps every developer knows that hard coded paths are no good! The code’s good to be flexible and extensible, but what the way to achieve that? In a typically developed application you’re completely sure the way the folders are nested will be permanent and no change will occur, and that’s maybe true, but however don’t be completely sure.

An Example

Let’s take a typical example. You’ve to access a uploaded file with PHP. By default the files are uploaded in the /tmp folder with PHP given name. That’s why immediately after the upload (the form submit) you’ve to process the _POST and the _FILES arrays and perhaps move the uploaded file somewhere else.

However you’d like to access this file wherever the application is – on the production servers or on the development server or even on the localhost!

I ran into that kind of problem/task. The thing I’d like to achieve was a bit different. I constructed the path with the dirname() function, but there were still ‘/../../’ chunks in it. So the solution is the realpath() function that removes those chunks and converts the path into one “calculated” real path to the file.

Let me show you an example:

// get the uploaded file path
$scriptPath = dirname(__FILE__);
 
// get the realpath to avoid the /../ part of the path
// with dirname they remain in the path
$uploadFolderPath = realpath($scriptPath . '/../../folder_name/');

If you were using dirname() you’d get something like that:

/folder1/folder2/folder3/../../folder2/file.txt

Now with realpath() the result is:

/folder1/folder2/file.txt

That’s more clear and even both are working correctly I’d prefer the second one!