Rubyx - Array natural number sorting

gistfile1.rb

##################################################
# Add natural number sorting to arrays
##################################################
class Array

  # Method which sort an array composed of strings with embedded numbers by
  # the 'natural' representation of numbers inside a string.
  def natcmp

    reg_number = /\d+/

    # We call the sort method of the Array class.
    self.sort do |str1, str2|

      # We try to find an embedded number
      a = str1.match(reg_number)
      b = str2.match(reg_number)

      # If there is no number
      if [a,b].include? nil
        str1 <=> str2
      else
        while true
          begin
            # We compare strings before the number. If there
            # are equal, we will have to compare the numbers
            if (comp = a.pre_match <=> b.pre_match) == 0
              # If the numbers are equal
              comp = (a[0] == b[0]) ? comp = a[0] + a.post_match <=> b[0] + b.post_match :
                                      comp = a[0].to_i <=> b[0].to_i
            end

            str1, str2 = a.post_match, b.post_match
            a = str1.match(reg_number)
            b = str2.match(reg_number)
          rescue
            break
          end
        end
        comp
      end
    end
  end

  # Same as 'natcmp' but replace in place.
  def natcmp!
    self.replace(natcmp)
  end

end

...
# Sort the array, inplace using natural number sorting
files.natcmp!