socket:udp_receive/4

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

[det]udp_receive(+Socket, -Data, -From, +Options)

Wait for and return the next datagram. The Data is returned as a Prolog term depending on Options. From is a term of the format Ip:Port indicating the sender of the message. Here, Ip is either an ip4 or ip6 structure. Socket can be waited for using wait_for_input/3. Defined Options:

as(+Type): Defines the type for Data. Possible values are atom, codes, string (default) or term (parse as Prolog term).
encoding(+Encoding): Specify the encoding used to interpret the message. It is one of octet. iso_latin_1, text or utf8.
max_message_size(+Size): Specify the maximum number of bytes to read from a UDP datagram. Size must be within the range 0-65535. If unspecified, a maximum of 4096 bytes will be read.

For example:

receive(Port) :-
    udp_socket(Socket),
    tcp_bind(Socket, Port),
    repeat,
        udp_receive(Socket, Data, From, [as(atom)]),
        format('Got ~q from ~q~n', [Data, From]),
        fail.