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pootsbook/isbn.rb

Created July 26, 2012 13:04
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Solutions to ISBN cleaning and validation
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isbn.rb
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@anthonysterling
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https://gist.github.com/3181919

@byrichardpowell
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https://gist.github.com/3181928

@MikeHibbert
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https://gist.github.com/3181935

@jamesmills
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James: https://gist.github.com/3181931

@jamiefdhurst
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Jamie: https://gist.github.com/3181897

@utterlyforked
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#!/usr/bin/env ruby

def is_isbn13_checksum_valid?(isbn13)
  sum = 0
  13.times { |i| sum += i.modulo(2)==0 ? isbn13[i].to_i : isbn13[i].to_i*3 }
  0 == sum.modulo(10)
end

def is_isbn_length_valid?(isbn)
  return isbn.length == 13
end

File.open("isbn.txt", "r").each_line { |s|
  isbn = s.scan(/\d/).join('')
  if is_isbn_length_valid?(isbn) && is_isbn13_checksum_valid?(isbn)
    puts isbn + ' is valid'
  else
    puts isbn + ' is not valid'
  end
}

@samlambert
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Sam: https://gist.github.com/3181910

@creativenucleus
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https://gist.github.com/3181943

@graemetait
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Graeme https://gist.github.com/3181908

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