use IO::Socket::INET;
use IO::Select;
use strict;
use warnings;

my @sockets;
my $select = new IO::Select();
my $packet_rcvd;

for ($ARGV[0] .. $ARGV[1]) {
    my $socket = new IO::Socket::INET(Proto => "udp", LocalPort => $_, LocalAddr => "localhost") || die "failed to establish socket for port $_";
	print "udp socket created for port $_\n";
	$select->add($socket);
}
print "all socket created\n";

while (1) {
	my @sockets = $select->can_read(10);
	for my $socket (@sockets) {
        my $peer = $socket->recv($packet_rcvd, 50);
		print "packet $packet_rcvd recvd at port " . $socket->sockport() . "\n";
		$socket->send("abcdefg", 0, $peer);
	}
	print $select->count(), "\n";
}