#!/usr/bin/perl -w
use POSIX;              
use IO::Socket;         
use IO::Select;         
use strict;

    my (
        $listen_socket, # socket to listen on
        $socket_errmsg  # error msg if socket not created
        );

    $listen_socket = IO::Socket::INET->new( LocalAddr =>'a.b.c.d',
                                            LocalPort => 7172,
                                            Proto => 'udp',
                                            Listen => 5,
                                            Reuse => 1 )
               or $socket_errmsg =
                       "Can't make server listen socket : $@\n";

    if( !$listen_socket )
    {
        print $socket_errmsg."\n";
    }