Simple HTTP header parser

header_parser.ex

defmodule HeaderReader do
  def read(conn) do
    {:ok,headers} = Agent.start_link(fn -> %{} end)
    init_line = :gen_tcp.recv(conn, 0)
    do_read(headers, conn, :gen_tcp.recv(conn, 0))
  end

  defp do_read(headers, conn, {:ok, "\r\n"}) do
    IO.inspect Agent.get headers, fn state -> state end
    :gen_tcp.close conn
  end

  defp do_read(headers, conn, {:ok, line}) do
    [name, value] = line |> String.trim() |> String.split(": ", parts: 2)
    Agent.update(headers, fn state -> Map.put(state, name, value) end)
    IO.inspect line
    do_read(headers, conn, :gen_tcp.recv(conn, 0))
  end
end


{:ok, conn} = :gen_tcp.connect('178.172.160.2', 80, [:binary, packet: :line, active: false])
:gen_tcp.send(conn, "GET / HTTP/1.0\n\n")
HeaderReader.read(conn)