HTTP is the protocol that powers the modern internet. It is behind every web page, every link click, every graphic loaded, and every form submitted. In this chapter, we saw that HTTP is a text-based protocol that runs over a TCP connection. We learned the HTTP formats for both client requests and server responses.
In this chapter, we also implemented a simple HTTP client in C. This client had a few non-trivial tasks – parsing a URL, formatting a GET request HTTP header, waiting for a response, and parsing the received data out of the HTTP response. In particular, we looked at handling two different methods of parsing out the HTTP body. The first, and easiest, method was Content-Length, where the entire body length is explicitly specified. The second method was chunked encoding, where the body is sent as separate chunks, which our program had to delineate between.
We also briefly looked at the POST requests and the content formats associated with them.
In the next chapter, Chapter 7...