#!/usr/bin/perl

use strict;
use warnings;

use IO::Socket::INET;
use IO::Select;

my $sel = IO::Select->new;
my $port   = getservbyname 'bootps', 'udp';
my $socket = IO::Socket::INET -> new (LocalPort  => $port,
                                     Broadcast  =>  1,
                                     Proto      => 'udp')
            or die "Failed to bind to socket: $@";

$sel->add($socket);
my $n = 10;
my $mess;    
while (1) { 
   my @r = $sel->can_read($n);
   unless (@r) { print "Nothing after $n seconds\n"; next; }
   $socket -> recv ($mess, 1024);
   print "Saw a bootp request.\n";
}

__END__