#! /usr/local/bin/perl -w

use strict;

my $data = [qw| z x y 2 1 3 |];

print 'no sort:' , @$data ,"\n";
print 'sort:   ' , (sort _sort_a_tron @$data) , "\n";

sub _sort_a_tron {  
  
  no warnings; 
  return ( $a <=> $b or $a cmp $b );   
  
} 

# output #
# no sort:zxy213
# sort:   xyz123