use strict;
use warnings;
use Tie::CharArray;
use Compress::Zlib;

++$|;

my $filename = $ARGV[0] || die "usage: need a filename";
if ( ! -f "$filename" ) {
    print STDERR "couldn't open: $filename\n";
    exit(-1);
}

open IN, $filename or die $!;
binmode IN;
read IN, my $stringdata, 1e8;

tie my @data, 'Tie::CharArray', $stringdata;

my $piecenum=0;

my $progress = progress(length $stringdata);
my $piecedata;
for (0..length($stringdata)-1) {
    $progress->($_);
    shift(@data);
    $data[0] = "\x78";
    $data[1] = "\x9c";
    ( $piecedata = uncompress($stringdata)) || next;
    print "\nFound piece at $_\n";
    open OUT, sprintf('>piece_%03d.txt', $piecenum++) or die $!; binmo
+de OUT;
    print OUT $piecedata ^ chr(0xAA) x length $piecedata;
}

sub progress {
    my $max = $_[0];
    my $last = 0;
    return sub { print $last = int(100*$_[0]/$max), "%... " if $last !
+= int(100*$_[0]/$max) };
}
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