$last = -1;

    opendir(D, "DIRNAME") or die $!;
    foreach (readdir(D))
    {
        ($num) = $_ =~ /(\d+)/; next unless $num;
        if ($num > $last) { $pick = $_; $last = $num; }
    }
    closedir(D);

    # Now operate on $pick

##</code><code>##

    $last = -1;

    opendir(D, "DIRNAME") or die $!;
    foreach (readdir(D))
    {
        $num = (stat $_)[9];
        if ($num > $last) { $pick = $_; $last = $num; }
    }
    closedir(D);

    # Now operate on $pick