Crystal Echo Server

echo_server.cr

require "socket"

def handle_connection(socket, client_id)
  puts "#{client_id}: client connected"
  loop do
    message = socket.gets
    if message
      puts "#{client_id}: received #{message}"
      socket << message + "\n"
    else
      puts "#{client_id}: client left"
      break
    end
  end
end

server = TCPServer.new(1234)
next_client_id = 0
loop do
  if socket = server.accept?
    client_id = next_client_id
    next_client_id += 1
    spawn handle_connection(socket, client_id)
  else
    break
  end
end