http://wiki.perl-community.de/bin/edit/Spielwiese/EineL%F6sung?topicparent=Spielwiese.WebStart

use strict;
use Digest::MD5;
use File::Find;
use threads;
use threads::shared;
#
#
# ------------------------------------------------------------------
# get time
# ------------------------------------------------------------------
my @time        = localtime();
my $time_string = sprintf "%02d.%02d.%02d",
              $time[5]+1900, $time[4]+1, $time[3],
              $time[2], $time[1], $time[0];
#
#
# ------------------------------------------------------------------
# threads component
# ------------------------------------------------------------------
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;
   }
#
#
# ------------------------------------------------------------------
# file details
# ------------------------------------------------------------------
my $directory = '.';
my $result_file = "md5_check_$time_string\.txt";
unlink ("$result_file");
#
my @files;
find(\&get_dir,$directory);
#
print "\n\tMD5_CHECK.PL powered by R.Hehlert\n";
#
#
# ------------------------------------------------------------------
# start threads
# ------------------------------------------------------------------
$StopDotPrintFlag = 0;
my $Interval = 1;
print "\n\tStarting 0% [";
my $DotPrintThread = threads->new(\&DotPrintThread, $Interval);
$StopDotPrintFlag = 1;
#
#
# ------------------------------------------------------------------
# start main programm
# ------------------------------------------------------------------
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 $fh, ">>$result_file") or die $!;
           print $fh "Digest is $digest for $file\n";
           close $fh;
         }
#
#
# ------------------------------------------------------------------
# stop threads
# ------------------------------------------------------------------
$StopDotPrintFlag = 2;
my $NumberOfPrintedDots=$DotPrintThread->join;
print "\t] 100% applied time was ".$NumberOfPrintedDots*$Interval." seconds\n";
print "\n\tPls. read $result_file for results\n";
#
#
# ------------------------------------------------------------------
# get all files from all directorys
# ------------------------------------------------------------------
sub get_dir
   {
    push (@files,$File::Find::name);
   }
#   
#END

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

   push (@files,$File::Find::name) if(-f $File::Find::name);