Playing around with line-based socket protocols

ruby-sockets/line-protocol/client.rb

@@ -0,0 +1,37 @@
+require 'date'
+require 'time'
+require 'socket'
+
+DATEFMT = '%Y%m%d%H%M%S'
+
+def recordify(msg)
+  code = '%-31s' % 'DERP'
+  num = '%-12d' % (rand.to_s.tr('.', '0')[0,5]).to_i
+  timestamp = Time.now.strftime(DATEFMT)
+  len = '%-6d' % msg.length
+  "#{code}#{num}#{len}#{timestamp}#{msg.gsub(/\r/, '\r').gsub(/\n/, '\n')}\r\n"
+end
+
+def main
+  print "What to say?: "
+  msg = gets
+  TCPSocket.open('127.0.0.1', 15778) do |sock|
+    sock.send(recordify(msg), 0)
+    response = sock.recv(66)
+    sock.close
+
+    puts "raw response --> #{response.inspect}"
+    code = response[0..30].to_s.strip
+    num = response[31..42].to_s.strip
+    raw_timestamp = response[49..62].to_s.strip
+    timestamp = DateTime.strptime(raw_timestamp, DATEFMT)
+
+    puts "code: '#{code}'"
+    puts "num: '#{num}'"
+    puts "timestamp: '#{timestamp}'"
+  end
+end
+
+if __FILE__ == $0
+  main
+end

ruby-sockets/line-protocol/server.rb

@@ -0,0 +1,45 @@
+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..30].to_s.strip
+    num = request[31..42].to_s.strip
+    len = request[43..48].to_s.strip
+    puts "raw date --> '#{request[49..62]}'"
+    timestamp = DateTime.strptime(request[49..62].strip, DATEFMT)
+    msg = request[63..(63 + len.to_i)].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