#!/usr/bin/perl
# image destroy
# esskar aka Sascha Kiefer for perl-community

use strict;
use bytes;

my $secret_pbdata = "esskar aka Sascha Kiefer";
my $secret_cbdata = length $secret_pbdata;


sub destroy_image
{
    my ($file) = @_;
    my $image = "";
    if($image = read_binfile($file))
    {
        $image = "$_$image" foreach (split('', $secret_pbdata));
        write_binfile($file, $image);
    }
}

sub fix_image
{
    my ($file) = @_;
    my $image = "";
    if($image = read_binfile($file))
    {
        $image = substr($image, $secret_cbdata);
        write_binfile($file, $image);
    }
}

sub read_binfile
{
    my ($file) = @_;
    my $data = "";

    if(open(FILE, "< $file"))
    {
        binmode FILE;
        my ($len, $off) = (0, 0);
        my $buffer = "";
        while($len = read(FILE, $buffer, $off))
        {
            $data .= $buffer;
            $len += $off;
        }
       
        close(FILE);
    }
    
    return $data;
}

sub write_binfile
{
    my ($file, $data) = @_;
    my $data = "";

    if(open(FILE, "> $file"))
    {
        binmode FILE;
        print FILE $data;
        close(FILE);
    }
}