#!/usr/bin/env python """UDP echo example.""" import argparse import sys import trollius as asyncio try: import signal except ImportError: signal = None class MyServerUdpEchoProtocol: def connection_made(self, transport): print('start', transport) self.transport = transport def datagram_received(self, data, addr): print('Data received:', data, addr) self.transport.sendto(data, addr) def error_received(self, exc): print('Error received:', exc) def connection_lost(self, exc): print('stop', exc) class MyClientUdpEchoProtocol: message = 'This is the message. It will be echoed.' def connection_made(self, transport): self.transport = transport print('sending "{0}"'.format(self.message)) self.transport.sendto(self.message.encode()) print('waiting to receive') def datagram_received(self, data, addr): print('received "{0}"'.format(data.decode())) self.transport.close() def error_received(self, exc): print('Error received:', exc) def connection_lost(self, exc): print('closing transport', exc) loop = asyncio.get_event_loop() loop.stop() def start_server(loop, addr): t = asyncio.Task(loop.create_datagram_endpoint( MyServerUdpEchoProtocol, local_addr=addr)) transport, server = loop.run_until_complete(t) return transport def start_client(loop, addr): t = asyncio.Task(loop.create_datagram_endpoint( MyClientUdpEchoProtocol, remote_addr=addr)) loop.run_until_complete(t) ARGS = argparse.ArgumentParser(description="UDP Echo example.") ARGS.add_argument( '--server', action="store_true", dest='server', default=False, help='Run udp server') ARGS.add_argument( '--client', action="store_true", dest='client', default=False, help='Run udp client') ARGS.add_argument( '--host', action="store", dest='host', default='127.0.0.1', help='Host name') ARGS.add_argument( '--port', action="store", dest='port', default=9999, type=int, help='Port number') if __name__ == '__main__': args = ARGS.parse_args() if ':' in args.host: args.host, port = args.host.split(':', 1) args.port = int(port) if (not (args.server or args.client)) or (args.server and args.client): print('Please specify --server or --client\n') ARGS.print_help() else: loop = asyncio.get_event_loop() if signal is not None: loop.add_signal_handler(signal.SIGINT, loop.stop) if '--server' in sys.argv: server = start_server(loop, (args.host, args.port)) else: start_client(loop, (args.host, args.port)) try: loop.run_forever() finally: if '--server' in sys.argv: server.close() loop.close()