dumb client/server socket

client.rb

require 'socket'

class Client
  private
  attr_reader :host, :port

  public
  def initialize(host, port)
    @host, @port = host, port
  end

  def set(key, value)
    request("SET #{key} #{value}")
  end

  def get(key)
    request("GET #{key}")
  end

  private
  def request(message)
    client = TCPSocket.new(host, port)
    client.write(message)
    client.close_write
    client.read
  end
end

client = Client.new("localhost", "4481")
p client.set("name", "brian")
p client.get("name")

server.rb

require 'socket'

class Server
  def initialize(port)
    @server = TCPServer.new(port)
    @storage = {}
  end

  def start
    Socket.accept_loop(@server) do |connection|
      handle(connection)
      connection.close
    end
  end

  private
  def handle(connection)
    request = connection.read
    connection.write(process(request))
  end

  def process(request)
    command, key, value = request.split

    case command.upcase
    when 'GET'
      @storage[key]
    when 'SET'
      @storage[key] = value
    end
  end
end

server = Server.new(4481)
server.start