#! /usr/bin/perl
use warnings;
use strict;
use threads;
use threads::shared;

use File::Find ();
use File::Compare ();

use vars qw(@RootDirs %Files);

@RootDirs = ('H:\test\');

print STDERR "Reading Files and sorting them...\n";
my $filesCount = 0;
File::Find::find(sub {
    if (-f $_) {
    push (@{ $Files{-s _} }, $File::Find::name);
    if ($filesCount and $filesCount % 5000 == 0) {
        print STDERR "$filesCount files read\n";
    } # if
    $filesCount++;
    } # if
}, @RootDirs);
print STDERR "$filesCount files read and sorted\n\n";

my $compareCount : shared = 0;
my $doubleCount : shared = 0;
my $finished : shared = 0;

print STDERR "Comparing files...\n";
my $thread = threads->create(\&CompareFiles);
while ($finished == 0) {
    sleep(5);
    printf STDERR "%2d%%\t$compareCount/$filesCount => $doubleCount\n", $compareCount*100/$filesCount;
} # while

$thread->join();
# ------------------------------------------------------------
sub CompareFiles {

    foreach (keys %Files) {
    my @items = @{ $Files{$_} };
    my $count = $#items;
    $compareCount += $count+1;

    next if $count == 0;
    for my $i (0..$#items-1) {
        for my $j ($i+1..$#items) {
        my $cmp = File::Compare::compare($items[$i], $items[$j]);
        if ($cmp == 0) {
            $doubleCount++;
            print "$doubleCount\tA:\t$items[$i]\n";
            print "$doubleCount\tB:\t$items[$j]\n\n";
        } # if
        } # for
    } # for
    } # foreach

    print STDERR "Compared: $compareCount files: 2*$doubleCount Duplicates\n";

    $finished = 1;
} # CompareFiles
# ------------------------------------------------------------