Converts a sequence of nucleotides (in char format) in an ASCII text

dna_text.rb

#!/usr/bin/env ruby
# Don't forget to do: chmod +x ./dna_text.rb
print 'INPUT sequence: '

sequence = gets.strip.scan(/\w/)

binary = sequence.map do |n|
  case n
  when 'A' then '00'
  when 'C' then '01'
  when 'G' then '10'
  else '11'
  end
end.join('')

text = Array(binary).pack('B*')
puts "OUTPUT text: #{text}"