gistfile1.txt

#!/usr/bin/env ruby
require "pp"

DICTIONARY_PATH = "/usr/share/dict/words"

if ARGV.empty?
  puts "Usage: ruby t9-lookup.rb 12345 [max_length]"
  exit 1
end

# Build the dictionary
dictionary = {}
File.open(DICTIONARY_PATH, "r") do |file|
  file.each do |line|
    word = line.strip
    t9 = word.tr("a-z", "22233344455566677778889999")
    dictionary[t9] ||= []
    dictionary[t9] << word
  end
end

# Lookup t9 and print matching words
t9 = ARGV[0]

if max_length = ARGV[1]
  matching_t9s = dictionary.keys.select { |k| k.start_with?(t9) && k.size <= max_length.to_i }
  matching_words = matching_t9s.map { |t9| dictionary[t9] }.flatten.sort_by { |t9| -t9.size }
  pp matching_words
else
  pp dictionary[t9]
end

exit 0