Luhn

Adds methods to Fixnum and String to generate and validate Luhn checksums.

Installation

Add this line to your application's Gemfile:

gem 'luhn', :git => 'git://github.com/moeffju/luhn.git'

And then execute:

$ bundle

If you're not using bundler, you will have to build the gem from source.

Usage

Fixnum:

4100410382.luhn?  #=> true
410041038.luhn    #=> 2
410041038.luhn!   #=> 4100410382

4100410648.luhn?  #=> true
410041064.luhn    #=> 8
410041064.luhn!   #=> 4100410648

And for Strings:

'4 10041064 8'.luhn?  #=> true
'4 10041064'.luhn     #=> "8"
'4 10041064'.luhn!    #=> "4 100410648"

Contributing

  1. Fork it
  2. Create your feature branch (git checkout -b my-new-feature)
  3. Commit your changes (git commit -am 'Added some feature')
  4. Push to the branch (git push origin my-new-feature)
  5. Create new Pull Request