#!/usr/bin/perl

# Usage to do byteshift of 13
#   To decode: encode_config.pl -s -13 <amail.cfg >amail.cfg.txt
#   To encode: encode_config.pl -s  13 <amail.cfg.txt >amail.cfg



use strict;
use Getopt::Std;

use vars qw/$opt_s/;

getopts("s:");
if(!defined $opt_s) {
  die "Missing shift\n";
}

my $buffer;
while(1) {
  binmode(STDIN, ":raw");
  my $n=sysread STDIN, $buffer, 1;
  if($n == 0) {
    last;
  }
  my $byte = unpack("c", $buffer);
  $byte += 512 + $opt_s;
  $buffer = pack("c", $byte);
  binmode(STDOUT, ":raw");
  syswrite STDOUT, $buffer, 1;
}