The default sort order is lexical. If you want a numeric sort, you need to specify a sort routine using the <=> operator (see perlop). See sort for more information.

Since your filenames have both numeric and alpha components, you will probably need to split the pieces apart before doing the comparison. The Schwartzian Transform is good for this kind of thing.

Here is one approach. Extend the sort routine as needed if you want to specify a secondary/etc sort order in the event two filenames start with the same numeric component. 

use strict;
use warnings;

my @files = qw(
                9.10.force.0.5.1LGY.pdb
                29.30.force.0.5.1LGY.pdb
                30.31.force.0.5.1LGY.pdb
                31.32.force.0.5.1LGY.pdb
                100.101.force.0.5.1LGY.pdb
                101.102.force.0.5.1LGY.pdb
               );

my @sorted =
    map { $_->[0] }
    sort { $a->[1] <=> $b->[1] }
    map { [ $_, split( /\./, $_ ) ] }
    @files;

print "$_\n" for @sorted;

[download]

Love those pdb files. :-) Lipase, huh? Interesting stuff.

In reply to Re: sorting an array of file names by bobf
in thread sorting an array of file names by hotel

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.