use strict;
use warnings;
use Cwd;
use Benchmark;

my $dir = 'c:/windows';

my ( @a1, @a2 );

timethese 1, {
    glob => sub {
        my $cwd = getcwd;
        chdir $dir;

        @a1 =  glob '*/*';

        chdir $cwd;
    },
    read => sub {
        my $cwd = getcwd;
        chdir $dir;

        opendir my $h, '.' or die;
        my @a = grep { $_ ne '.' and $_ ne '..' and -d $_ } readdir $h;
        for my $d ( @a ) {
            opendir my $hh, $d or next;
            push @a2, map "$d/$_", 
                      grep { $_ ne '.' and $_ ne '..' } 
                      readdir $hh;
        }

        chdir $cwd;
    }
};

use Test::More;
is $#a1, $#a2, 'array lengths are equal'
or do {
    use Test::Differences;
    eq_or_diff [ sort @a1 ], [ sort @a2 ], 'look deeper', 
        { context => 0 };;
};
done_testing;