Turn any application that uses STDOUT into a WebSocket server. Inspired by https://github.com/joewalnes/websocketd but written in ruby. $ ./websocket.rb start 'iostat -w 1 disk0'

websocket.rb

#!/usr/bin/env ruby
require 'em-websocket'
require 'thor'

module Handler
  def initialize(args)
    @ws = args
  end

  def receive_data(data)
    @buf ||= ''
    @buf << data

    while line = @buf.slice!(/(.+)\r?\n/) do
      @ws.send(line)
    end
  end
end

class WebSocket < Thor
  desc "start COMMAND", "starts the websocket server"
  option :host, default: "0.0.0.0"
  option :port, default: 8080
  option :debug, default: false, type: :boolean
  def start(command)
    EventMachine::WebSocket.start(host: options[:host], port: options[:port], debug: options[:debug]) do |ws|
      ws.onopen  { EM.popen(command, Handler, ws) }
      ws.onclose { puts "WebSocket closed" }
      ws.onerror { |e| puts "Error: #{e.message}" }
    end
  end
end

WebSocket.start(ARGV)