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

use strict;

sub  forward {$a cmp $b} # removed prototype
sub backward {$b cmp $a} # removed prototype

my @sorter = qw/forward backward/;

my @list = qw(kholsky stencil dnubietna barkhausen
    manganese fairing fleische flake schlozhauer gascoigne);

my $offset = shift || 0;

my $subname= $sorter[$offset];
print "$_\n" for sort $subname @list;