use strict;
use warnings;
use 5.010;

use Text::Banner;

my @current;
my @letters;
while (<>) {
    chomp;
    push @current, $_;
    if (@current == 8) {
        push @letters, fingerprint(@current);
        @current = ();
    }
}
use Data::Dumper;

sub chunk_transpose {
    my @r;
    for (@_) {
        my @c = split //;
        for my $c (0..$#c) {
            $r[$c] .= $c[$c];
        }
   }
   return @r;
}

sub fingerprint {
    my @a = chunk_transpose(@_);
    my @f;
    while (@a) {
        my $f = '';
        for (1..8) {
            $f .= shift @a;
        }
        if ($f =~ /\S/) {
            $f =~ s/^\s+//;
            $f =~ s/\s+$//;
        } else {
            $f = ' ';
        }
        push @f, $f;
    }
    wantarray ? @f : $f[0];
}

my %table;

my $b = Text::Banner->new;
for (0..126) {
    $b->set(chr);
    $b->fill('#');
    my $f = (fingerprint split /\n/, $b->get)[0];
    $table{$f} = chr if defined $f;
}

no warnings;
say join '', @table{@letters};

##</code><code>##

$ perl banner.pl | perl unbanner.pl 
st anotherl hacke