HTTP/0.9 in Go

This repository contains a small HTTP/0.9 client and server written in Go. It follows the original HTTP implementation described by the W3C.

The code is an educational example. HTTP/0.9 does not have the features expected from a modern HTTP client or server.

What it implements

The client opens a TCP connection to a host and port.
A request contains GET, one space, and a document address.
The client ends generated requests with CRLF. The server also accepts LF without CR.
The server ignores words after the document address.
Responses contain raw HTML without a status line or headers.
Closing the connection marks the end of a response.
Errors are returned as human-readable HTML.
Client-aborted transfers are not recorded as server errors.
The server does not keep request state after disconnecting.

Run the server from its directory because it loads the HTML files using relative paths:

cd server
go run .

The server listens on port 80 and exposes / and /index.html.

Open another terminal and enter the client directory:

cd client

Pass the document address as the third argument:

go run . localhost 80 /index.html

You can also pipe a raw request into the client, like nc:

echo "GET /index.html" | go run . localhost 80

In pipe mode, the client forwards stdin without changing it. The server returns the HTML document and closes the connection.