working prototype

client.rb

@@ -0,0 +1,36 @@
+#!/usr/bin/env ruby
+
+require 'socket'
+require 'io/console'
+
+HOST = 'localhost'
+PORT = 6789
+VERSION = 0.01
+
+socket = TCPSocket.new(HOST, PORT)
+
+puts "PORT: #{PORT}"
+puts "HOST: #{HOST}"
+
+#reader = Thread.new do
+Thread.new do
+  loop do
+    msg = socket.gets
+    exit 0 unless msg
+    ver, msg = msg.split('|',2)
+    next unless ver.to_f <= VERSION
+    next unless msg != nil
+    # In message version 0.01 and lower,
+    # all messages are in an assumed format...
+    row,col,chars = msg.split('|',3)
+    print "\x1b[#{row};#{col}H#{chars}\x1b[A"
+  end
+end
+
+while (char = STDIN.noecho(&:getch))
+  exit unless char != "\x03" # ^C
+  exit unless char != "\x04" # ^D
+  next unless char.ord >= 0x20 # Non printing
+  next unless char.ord != 0x7F # DEL (Non print)
+  socket.puts "#{VERSION}|#{char}"
+end

server.rb

@@ -0,0 +1,79 @@
+#!/usr/bin/env ruby
+
+require 'socket'
+
+PORT = 6789
+ROWS = 24
+COLS = 40
+VERSION = 0.01
+
+server = TCPServer.new(PORT)
+sockets = [server]
+
+puts "PORT: #{PORT}"
+puts 'Listening...'
+
+buffer = ' '*ROWS*COLS
+cont = 0
+
+def new_buf_cont_out(buf, count, newtext)
+  buf = buf.dup
+  out = ''
+  nti = 0 # New Text Index
+  while nti < newtext.length
+    out << "#{VERSION}|"
+    out << ((count/COLS)+1).to_s + '|'
+    out << ((count%COLS)+1).to_s + '|'
+    loop do
+      out << newtext[nti]
+      buf[count] = newtext[nti]
+      count += 1
+      nti += 1
+      break if nti >= newtext.length
+      break if count%COLS == 0
+    end
+    count = 0 if count >= (ROWS*COLS)
+    out << "\n"
+  end
+  return [buf, count, out]
+end
+
+loop do
+  ready, = IO.select(sockets)
+  newtext = ''
+
+  ready.each do |sck|
+    if sck == server
+      client = server.accept
+      sockets << client
+      puts "Connection: #{client.peeraddr}"
+      client.puts new_buf_cont_out(buffer,0,buffer)[2]
+      client.puts new_buf_cont_out(buffer,cont-1,'')[2]
+      next
+    end
+    begin
+
+      msg = sck.gets
+      unless msg
+        puts "Disconnect: #{sck.peeraddr}"
+        sck.close
+        sockets.delete(sck)
+        next
+      end
+      ver, msg = msg.chomp.split('|',2)
+      next unless ver.to_f <= VERSION
+      next unless msg != nil
+      newtext << msg
+    rescue Errno::ECONNRESET, Errno::EPIPE
+      puts "Disconnect (err): #{sck.peeraddr}"
+      sck.close
+      sockets.delete(sck)
+    end
+    buffer, cont, out = new_buf_cont_out(buffer,cont,newtext)
+    clients = sockets - [server]
+    clients.each { |c| c.puts out }
+    #if out != ''
+    #  puts "#{cont}: (#{(cont/COLS)+1},#{(cont%COLS)+1})"
+    #end
+  end
+end