a quick file indexer for ruby

quick-indexer.rb

# a quick file indexer for ruby
def checksum(file_loc)
    sum = 0
    File.open(file_loc){|f|f.each_byte{|b|sum^=b}}
    sum
end
$index = []
def enter dir
    (Dir.entries(dir) - %w(. ..)).each do |ent|
        if File.directory? File.join(File.expand_path(dir), ent)
            enter File.join(File.expand_path(dir), ent)
            next
        end
        $index << {
            'name'       => File.join(File.expand_path(dir), ent),
            'checksum'   => checksum(File.join(File.expand_path(dir), ent))
        }
    end
end
enter ARGV.shift
require 'yaml'
print YAML.dump($index)