iban-tools
iban-tools is a Ruby library for manipulating and validating IBAN account numbers. You can read more about IBAN on Wikipedia
INSTALLATION
gem install iban-tools
The gem should be compatible with MRI 1.8 and 1.9.
USAGE
require 'iban-tools'
IBANTools::IBAN.valid?("GB82 WEST 1234 5698 7654 32")
=> true
Advanced usage, gives more detailed error messages
IBANTools::IBAN.new("XQ75 BADCODE 666").validation_errors
=> [:unknown_country_code, :bad_check_digits]
Pretty print, canonicalize, and extract fields from an IBAN code
iban = IBANTools::IBAN.new(" ro49 aaaa 1B31007593840000")
iban.code
=> "RO49AAAA1B31007593840000"
iban.country_code
=> "RO"
iban.prettify
=> "RO49 AAAA 1B31 0075 9384 0000"
Credit
Iulianu wrote iban-tools. (AlphaSights) is now maintaining the gem.