echoserver

#!/usr/bin/env python

"""
usage: echoserver [HOST [PORT]]

TODO: properly support IPv4 hostnames
"""

import sys
import socket
import SocketServer

class EchoServer(SocketServer.ThreadingMixIn, SocketServer.TCPServer):
    pass

class EchoServerV6(EchoServer):
    address_family = socket.AF_INET6

class EchoRequestHandler(SocketServer.StreamRequestHandler):
    """
    Handle one connection from a client.
    """
    def handle(self):
        print "connection from %s" % self.client_address[0]
        while True:
            line = self.rfile.readline()
            if not line: break
            print "%s wrote: %r" % (self.client_address[0], line.rstrip())
            self.wfile.write(line)
        print "%s disconnected" % self.client_address[0]

def serve(host, port):
    # TODO: we should choose the IPv4 server class if we're given an IPv4
    # hostname/address
    server = EchoServerV6((host, port), EchoRequestHandler)

    if len(server.server_address) == 2:
        print "server listening on %s:%s" % server.server_address
    else:
        print "server listening on [%s]:%s" % server.server_address[0:2]
        if server.socket.getsockopt(socket.IPPROTO_IPV6, socket.IPV6_V6ONLY):
            print '(IPv6 only)'
        else:
            print '(dual stack IPv6 and IPv4)'

    try:
        server.serve_forever()
    except KeyboardInterrupt:
        pass

    print "shutting down; waiting for connenctions to close..."
    server.shutdown()

if __name__ == '__main__':
    host, port = '', 5000
    if len(sys.argv) > 1:
        host = sys.argv[1]
    if len(sys.argv) > 2:
        port = int(sys.argv[2])

    try:
        serve(host, port)
    except KeyboardInterrupt:
        print ''