README.md

isbn

Version 2.0

Introduction

This library provides methods to manipulate isbns. As of version 2.0 there has been a near complete rewrite of this library but this time there are tests. A few methods have been removed. Here is what remains:

Prerequisites

It depends on the LibJpeg and Gocr libraries. Recommended Homebrew.

brew install libjpeg
brew install gocr

Installing ISBN

Installing via Bundler

Add to your Gemfile:

gem 'isbn'

Then run:

bundle install

Installing via RubyGems

Run:

gem install isbn

Using ISBN

• ISBN.ten will return a 10 digit isbn if you give it a 10 or 13 digit isbn

  • it will raise a No10DigitISBNAvailable error if given an isbn starting with 979 because 979 isbns do NOT have a 10 digit counterpart.

• ISBN.thirteen will return a 13 digit isbn if you give it 10 or thirteen digit isbn

• ISBN.as_used will convert an isbn into the used book version for that isbn

  • for isbns starting with 978 it returns an isbn starting with 290
  • for isbns starting with 979 it returns an isbn starting with 291

• ISBN.as_new will convert an isbn into the new book version for that isbn

  • for isbns starting with 290 it returns an isbn starting with 978
  • for isbns starting with 291 it returns an isbn starting with 979

• ISBN.valid? will compare the check digit of the passed in isbn with that of one it computes

• ISBN.from_image accept a jpeg of an isbn and OCR it into an isbn.

  • it depends on the LibJpeg and Gocr libraries. I recommend Homebrew.

• ISBN.from_string fetches isbn from string