SWI-Prolog -- udp_broadcast

Documentation
- Reference manual
- Packages
  - SWI-Prolog C-library
    - library(udp_broadcast): A UDP broadcast proxy
      - Caveats
        
        udp_broadcast_close/1
        
        udp_broadcast_initialize/2
        
        udp_peer_add/2
        
        udp_peer_del/2
        
        udp_peer/2
        
        udp_term_string_hook/3
        
        udp_unicast_join_hook/3

Availability::- use_module(library(udp_broadcast)).(can be autoloaded)

[semidet]udp_broadcast_initialize(+IPAddress, +Options)

Initialized UDP broadcast bridge. IPAddress is the IP address on the network we want to broadcast on. IP addresses are terms ip(A,B,C,D) or an atom or string of the format A.B.C.D. Options processed:

scope(+ScopeName)

Name of the scope. Default is subnet.

subnet_mask(+SubNet)

Subnet to broadcast on. This uses the same syntax as IPAddress. Default classifies the network as class A, B or C depending on the the first octet and applies the default mask.

port(+Port)

Public port to use. Default is 20005.

method(+Method)

Method to send a message to multiple peers. One of

broadcast: Use UDP broadcast messages to the LAN. This is the default
multicast: Use UDP multicast messages. This can be used on WAN networks, provided the intermediate routers understand multicast.
unicast: Send the messages individually to all registered peers.

For compatibility reasons Options may be the subnet mask.

Examples

Using a multicast UDP network

Although the broadcast networks are the default. multicast networks have the advantage that you do not need to know your IP address and, with router support, they can be used on a WAN. Therefore simplest way to initialise the network to make two or more processes communicate on a LAN is using a multicast network:

?- udp_broadcast_initialize(ip(239,0,0,2), [method(multicast)]).
?- listen(write(X), writeln(X)).
?- broadcast(udp(subnet, write(hello))).
hello

See also: - IPv4 Multicast Address Space Registry. The range 239.0.0.0 - 239.255.255.255 is reserved as Organization-Local Scope.