source: config-package-dev/encode @ 7a1d9a7

#!/usr/bin/perl
# Encode name of a file in a Debian package name.
#
# The purpose of this encoding is to cause Debian configuration
# packages (potentially from different sites) that divert the same
# configuration file to conflict with each other.  Thus, it is
# important that all sites using this Debian configuration package
# system use this encoding.
#
# This encoding is intended to be human-readable, so that users can
# determine the cause of conflicts between different configuration
# packages.

use strict;
use warnings;
 
$ARGV[0] =~ s,^/,,;
foreach (split('', $ARGV[0])) {
    if (m/[a-z0-9.-]/) {
        print "$_";
    } elsif (m/[A-Z]/) {
        print "+".lc($_)."+";
    } elsif ($_ eq '/') {
        print "++";
    } elsif ($_ eq '_') {
        print "+-+";
    } else{
        print "+x".hex(ord($_))."+";
    }
}