use strict;
use Digest::MD5;

my (%files);
my $md5 = Digest::MD5->new;
foreach my $dir ( @ARGV ) {
    next unless (-d $dir);

    foreach my $f (<$dir/*>) {
        next if (-d $f);
        open(FILE, $f) or die qq{Can't open $f: $!\n};
            binmode(FILE);
            $md5->addfile(*FILE);
        close(FILE);
        push(@{$files{$md5->hexdigest}}, $f);
        $md5->reset;
    }
}

print qq{The following entries appear to be duplicates, };
print qq{and warrant closer examination:\n};

foreach my $k ( keys %files ) {
    if ( scalar @{$files{$k}} > 1 ) {
        print qq{\t}, q{Checksum: }, $k, qq{\n};
        print qq{\t\t}, join( qq{\n\t\t}, @{$files{$k}} ), qq{\n};
    }
}