#!/usr/bin/perl

use strict; # https://perlmonks.org/?node_id=11161465
use warnings;
use IO::Socket::Multicast;

my $s = IO::Socket::Multicast->new(LocalPort => 9999) or die $@;
$s->mcast_add('239.1.1.1', 'tybalt') or die "group $!";

while(1)
  {
  $s->recv(my $data, 1024);
  print $data;
  }