my $exp = new Expect;
$exp = Expect->spawn('sudo sh /usr/local/scripts/pre_backup.sh')
        or die "Cannot spawn pre-backup: $!\n\n";
if ($exp->expect(undef, 'Password')) {
        $exp->send("$password\cM");
}

##</code><code>##

if ($exp->expect(undef, 'any key to continue')) {
        $exp->send("\cM");
}