use strict;

my @data = (
['-r--r--r--','1','yourname','8318','2000-01-01','ant.txt'],
['-r--r--r--','1','yourname','11986','1992-12-30','tiger.txt'],
['-r--r--r--','1','yourname','72698','2004-03-03','duck.txt'],
['-r--r--r--','1','yourname','46852','1788-01-26','goose.txt']
);

print( "Which column to sort on?" );
my $column = ( <STDIN> =~ m/^\d+$/ );
exit( 1 ) if ( ! defined($column) );

my @sorted = sort { $a->[$column] cmp
                    $b->[$column] } @data;

print( join( "\n", map { join( ",", @{$_} )
                         } @sorted ) );