detection whether is an e-shop written in Magento

I'm trying to create a script which would do a simple thing. The input is a list of URLs and output is a list of those eshops which are written in Magento.

I've read that there is no way to realize whether is the eshop in Magento or something else but I've also read that there is a lot of signs that could tell you that this web page is using Magento almost 100% sure.

So I've found this page: magento detector which can tell you whether is it a Magento or not so I'm trying to use their information.

They say for example this:

Magento has its user interface files in a directory called /skin/. For the frontend (not the admin ui) the files are located in /skin/frontend. So if this directory exists in the page source then it is very likely that the store runs on Magento.

For example for this eshop: starkk told the detector that it is a magento and the one of condition it meets is the condition I've mentioned above.

How could I check whether the directory exists? I took a look on: http://ift.tt/1SHgVVO using browser but the page raises error.

And additional question: Do you know another and better way how to detect Magento?

via Chebli Mohamed