Examining the HTTP response structure

Back in Chapter 3, Routing and Intaking HTTP Requests, we looked at the structure of the HTTP request. When a web server is ready to send back a response, the format is very similar to what we have already seen. The HTTP response will look something like this:

HTTP 1.1 200 OK
Content-Length: 13
Connection: keep-alive
Content-Type: text/plain; charset=utf-8
Hello, world.

What we see is the following:

• The first line contains the HTTP protocol used, a status code, and a status description.
• Response headers are in the key: value format and are separated by a line break.
• There is a blank row.
• There is a response body.

We are not looking at this here because we need to know to build a web application. After all, building these response objects to a valid HTTP specification is precisely one of the reasons that we use web frameworks. Without them, building these blobs would be tedious and error-prone. Instead, it is helpful...