# ------------------------------------------------------------------
# loaded modules
# ------------------------------------------------------------------
use strict;
use warnings;
use Digest::MD5;
use Cwd;
use File::Find;
use threads;
use threads::shared;
#
#
# ------------------------------------------------------------------
# start threads 
# ------------------------------------------------------------------
my $StopDotPrintFlag : shared;
sub DotPrintThread 
   {
    my ($Interval, @Trash) = @_;
    use IO::Handle;
    autoflush STDOUT 1;
    my $IntervalCount=0; 
    while ($StopDotPrintFlag != 2) 
         { 
          if ($StopDotPrintFlag == 1) 
            { 
              print STDOUT ".";
            }
          $IntervalCount++;
          sleep $Interval;
         }
          return $IntervalCount;
   }
#
#
# ------------------------------------------------------------------
# start programm
# ------------------------------------------------------------------
my $dir = getcwd;
my @files;
find(\&get_dir,$dir);

  $StopDotPrintFlag = 0;
  my $Interval = 1;
  my $DotPrintThread = threads->new(\&DotPrintThread, $Interval);
  $StopDotPrintFlag = 1;

for my $file(@files)
   {
    my $md5 = Digest::MD5->new;
    open FILE, $file;
    binmode(FILE);
    while(<FILE>) { $md5->add($_); }
    my $digest = $md5->hexdigest;
    close FILE;
    
    open(my $fh, ">>md5_check.txt") or die $!;
    print $fh "\nDigest is $digest for $file\n";
    close $fh;
   }
  
$StopDotPrintFlag = 2;
my $NumberOfPrintedDots=$DotPrintThread->join;
print "\napplied time was ".$NumberOfPrintedDots*$Interval." seconds\n";

sub get_dir
 {
  push(@files,$File::Find::name) if(-f $File::Find::name);
  }