mcast.py 文件源码

def receiver(group):
    # Look up multicast group address in name server and find out IP version
    addrinfo = socket.getaddrinfo(group, None)[0]

    # Create a socket
    s = socket.socket(addrinfo[0], socket.SOCK_DGRAM)

    # Allow multiple copies of this program on one machine
    # (not strictly needed)
    s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)

    # Bind it to the port
    s.bind(('', MYPORT))

    group_bin = socket.inet_pton(addrinfo[0], addrinfo[4][0])
    # Join group
    if addrinfo[0] == socket.AF_INET: # IPv4
        mreq = group_bin + struct.pack('=I', socket.INADDR_ANY)
        s.setsockopt(socket.IPPROTO_IP, socket.IP_ADD_MEMBERSHIP, mreq)
    else:
        mreq = group_bin + struct.pack('@I', 0)
        s.setsockopt(socket.IPPROTO_IPV6, socket.IPV6_JOIN_GROUP, mreq)

    # Loop, printing any data we receive
    while True:
        data, sender = s.recvfrom(1500)
        while data[-1:] == '\0': data = data[:-1] # Strip trailing \0's
        print (str(sender) + '  ' + repr(data))