What you may need here is a "Schwartzian Transform", so that you can sort based on a transformed key, where the transform is to expand any group of digits into a wider, fixed-sized group. In this way, "K-2-D-1A" gets a sort key of "K-002-D-001A", and "K-2-D-10A" gets a sort key of "K-002-D-010A". Since all sequences of numbers are now equally wide, you'll get the sort order you desire. But since the Schwartzian Transform holds on to unmodified data, you'll have the untransformed keys to display.

Here's an (untested) starting point: 

  my @data = qw(K-2-D-1A K-2-D-2A K-2-D-10A);

  my @sorted =
    map { $_->[0] }
    sort { $a->[1] cmp $b->[1] }
    map { [$_, normalize_digits($_) ] }
    @data;

  sub normalize_digits {
    my ($key) = @_;
    $key =~ s/(\d+)/sprintf("%03d", $1)/eg;
    return $key;    # thanks, ikegami
  }

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This builds a composite data structure with the original key and a "normalized" key, sorts the structure based on the normalized key, and then discards the normalized key.

Update: Or, better yet, don't reinvent the wheel, and use Sort::Naturally (which I'd somehow overlooked).

In reply to Re: Sorting question by dws
in thread Sorting question by perl_seeker

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