box-o-sand/ruby-sockets/line-protocol/server.rb

require 'date'
require 'time'
require 'eventmachine'

DATEFMT = '%Y%m%d%H%M%S'

def generic_response
  code = '%-31s' % 'SNARF'
  num = '%-12d' % (rand.to_s.tr('.', '0')[0,5]).to_i
  filler = (' ' * 7)
  timestamp = Time.now.strftime(DATEFMT)
  "#{code}#{num}#{filler}#{timestamp}\r\n"
end

module LineProtocolServer
  def post_init
    puts "# BEGIN CONN #{Time.now}"
  end

  def receive_data(request)
    code = request[0,31].to_s.strip
    num = request[31,12].to_s.strip
    len = request[43,6].to_s.strip
    puts "raw date --> '#{request[49,14]}'"
    timestamp = DateTime.strptime(request[49,14].strip, DATEFMT)
    msg = request[63,len.to_i+1].strip

    puts "code: '#{code}'"
    puts "num: '#{num}'"
    puts "len: '#{len}'"
    puts "timestamp: '#{timestamp}'"
    puts "msg: '#{msg}'"

    send_data(generic_response)
  end

  def unbind
    puts "# END CONN #{Time.now}"
  end
end

EventMachine.run do
  EventMachine.start_server('0.0.0.0', 15778, LineProtocolServer)
  puts 'Listening on 0.0.0.0:15778'
end