#!/usr/bin/perl

use warnings;
use strict;

my $length = 5;
my $password = "passw";
my @chars = ('a' .. 'z', 'A' .. 'Z', 0-9, '!', '@', '#', '$', '%', '^', '&', '*', ' ');

my %tried;
my $tries = 0;

my $starttime = time();

while(1)
{
  my @temp_chars;
  for (1 .. $length)
  {
     my @character = shuffle(@chars);
     my $char = $character[0]; 
     push(@temp_chars, $char); 
  }

  my $guess = join("", @temp_chars);
 
  if (exists $tried{$guess})
  {
     print "\tSkipping $guess - already attempted\n\n";
  }
  $tries++;
  $tried{$guess} = "1";


  if ($guess eq $password)
  {
     my $endtime = time();
     my $time_took = $endtime - $starttime;
     print "We found your password. It is $guess!\n";
     print "It took $time_took seconds and $tries tries";
     exit;
  }
  else
  {
     print "Guessing: $guess\t\tTry # $tries\n\n";
  }  

}


sub shuffle {
    return @_ if !@_ || ref $_ [0] eq 'ARRAY' && !@{$_ [0]};
    my $array = @_ == 1 && ref $_ [0] eq 'ARRAY' ? shift : [@_];
    for (my $i = @$array; -- $i;) {
        my $r = int rand ($i + 1);
       ($array -> [$i], $array -> [$r]) = ($array -> [$r], $array -> [$i]);
    }
    wantarray ? @$array : $array;
}