README.md

Elixir sockets made decent

This library wraps gen_tcp, gen_udp and gen_sctp, ssl and implements websockets and socks.

Installation

In your mix.exs file

defp deps do
  [
    # ...
    {:socket, "~> 0.3"},
    # ...
  ]
end

Then run mix deps.get to install

Examples

defmodule HTTP do
  def get(uri) when is_binary(uri) or is_list(uri) do
    get(URI.parse(uri))
  end

  def get(%URI{host: host, port: port, path: path}) do
    sock = Socket.TCP.connect! host, port, packet: :line
    sock |> Socket.Stream.send! "GET #{path || "/"} HTTP/1.1\r\nHost: #{host}\r\n\r\n"

    [_, code, text] = Regex.run ~r"HTTP/1.1 (.*?) (.*?)\s*$", sock |> Socket.Stream.recv!

    headers = headers([], sock) |> Enum.into(%{})

    sock |> Socket.packet! :raw
    body = sock |> Socket.Stream.recv!(String.to_integer(headers["Content-Length"]))

    { { String.to_integer(code), text }, headers, body }
  end

  defp headers(acc, sock) do
    case sock |> Socket.Stream.recv! do
      "\r\n" ->
        acc

      line ->
        [_, name, value] = Regex.run ~r/^(.*?):\s*(.*?)\s*$/, line

        headers([{ name, value } | acc], sock)
    end
  end
end

Websockets

Client

socket = Socket.Web.connect! "echo.websocket.org"
socket |> Socket.Web.send! { :text, "test" }
socket |> Socket.Web.recv! # => {:text, "test"}

In order to connect to a TLS websocket, use the secure: true option:

socket = Socket.Web.connect! "echo.websocket.org", secure: true

The connect! function also accepts other parameters, most notably the path parameter, which is used when the websocket server endpoint exists on a path below the domain ie. "example.com/websocket":

socket = Socket.Web.connect! "example.com", path: "/websocket"

Note that websocket servers send ping messages. A pong reply from your client tells the server to keep the connection open and to send more data. If your client doesn't send a pong reply then the server will close the connection. Here's an example of how to get get both the data you want and reply to a server's pings:

socket = Socket.Web.connect! "echo.websocket.org"
case socket |> Socket.Web.recv! do
  {:text, data} ->
    # process data
  {:ping, _ } ->
    socket |> Socket.Web.send!({:pong, ""})
end

Server

server = Socket.Web.listen! 80
client = server |> Socket.Web.accept!

# here you can verify if you want to accept the request or not, call
# `Socket.Web.close!` if you don't want to accept it, or else call
# `Socket.Web.accept!`
client |> Socket.Web.accept!

# echo the first message
client |> Socket.Web.send!(client |> Socket.Web.recv!)