orcid_checksum_check.rb

# encoding: utf-8
class String
  def is_orcid?
    /(\d{4}-){3}\d{3}[0-9X]{1}$/.match?(self)
  end

  def valid_orcid?
    parts = self.scan(/[0-9X]/)
    mod = parts[0..14].map(&:to_i)
                      .inject { |sum, n| (sum + n)*2 }
                      .modulo(11)
    result = (12 - mod) % 11
    parts.last == ((result == 10) ? "X" : result.to_s)
  end
end

puts "https://orcid.org/0000-0002-4519-8167".is_orcid?
puts "https://orcid.org/0000-0002-4519-8165".valid_orcid?
puts "https://orcid.org/0000-0002-6662-847X".valid_orcid?