Have you tried it with

__DATA__
28 31
199 201
[download]

? To get it to really work, I had to add a loop:

sub elide {
    my ($start,$end) = @_;

    if ($end < $start)                 { ($start, $end) = ($end, $star
+t) }
    elsif ($start == $end)             { return $start }
    if (length($end) > length($start)) { return "$start-$end" }
    else {
        my $pow = 1;
        $pow *= 10 while int($end/$pow) > int($start/$pow);
        $end %= $pow;
    } 
    return "$start-$end";
}
[download]