#! /usr/bin/perl -w

# Copyright (c) 1998 Greg Bacon.  All Rights Reserved.
# This program is free software.  You may distribute it or modify
# it (perhaps both) under the terms of the Artistic License that
# comes with the Perl Kit.

use strict;
use integer;

foreach my $file (@ARGV) {
    unless (open FILE, $file) {
        warn "$0: failed open $file: $!\n";
        next;
    }

    my $key = int rand 256;

    my $out = <<EOTop;
#! /usr/bin/perl

my \$prog = '';

{
    my \$key  = $key;
    local \$/;

    \$prog = pack "c*",
             map { \$_ ^= \$key }
             unpack "c*", <DATA>;
}

eval \$prog;
__END__
EOTop

    while (<FILE>) {
        $out .= pack "c*",
                map { $_ ^= $key }
                unpack "c*", $_;
    }
    close FILE;

    unless (open FILE, ">$file") {
        warn "$0: failed open >$file: $!\n";
        next;
    }

    print FILE $out;
    close FILE;;
}