What version of Perl are you using? This works for me: 
    #!/usr/bin/perl -w
    use strict;

    my $sortname = shift;
    print join ' ', sort $sortname 1..20;

    sub num { $a <=> $b }
    sub alpha { $a cmp $b }

[download]
Save this as foo.pl, and... 
    % foo.pl num
    1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

    % foo.pl alpha
    1 10 11 12 13 14 15 16 17 18 19 2 20 3 4 5 6 7 8 9

[download]
This is consistent w/ the sort docs: 
    SUBNAME may be a scalar variable name
    (unsubscripted), in which case the value provides
    the name of (or a reference to) the actual subroutine
    to use.  In place of a SUBNAME, you can provide a
    BLOCK as an anonymous, in-line sort
    subroutine.

[download]
However, I do seem to remember running into your situation in the past. I don't know what version of Perl I was using then; probably 5.004 or some such. I'm now using 5.005_03, which could explain it.

If you are using a real database, though, I would suggest that you try using "order by", as it's likely to be faster than anything you can do yourself, particularly if you have your columns indexed.

In reply to RE: Dynamic sort algorithm selection by btrott
in thread Dynamic sort algorithm selection by Sentinel

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.