#!/usr/bin/perl

use strict;
use warnings;

use Tie::File;
tie my @tied_array, 'Tie::File', 'tiefile'  or die "Could not tie to tiefile: $!";

push(@tied_array, $_) for (1..3);

print "\@tied_array has " . scalar @tied_array . " elements before sorting\n";
@tied_array = sort {uc($a) cmp uc($b)} @tied_array;
print "\@tied_array has " . scalar @tied_array . " elements after sorting\n";
untie @tied_array;