As we are doing a small project about Pinterest, we have to download some data, including images and "re-pin" relations, from www.pinterest.com. At the beginning, I suppose this project is purely a computer vision project, which only needs taking care of the algorithms and the implementation. But I am worry, Pinterest has not opened its API yet, which means I may need to implement a simple web spider to traverse the web page and extract the data we need out. It is a complicate thing... After few hours of investigation, I found this "answer" from StackOverflow, which is very useful and inspiring.
It's a pain to read the HTTP/1.1 standard document. But all the little details got added to it because somebody really needs that little detail and now uses it.
The original link is attached here.