Unit Sorting

unit_sort.rb

#!/usr/bin/env ruby                                                                              

puts "Usage: #{$0} [input-file]..." if ARGV.empty?

matches = []

ARGV.each do |path|
  begin
    File.foreach(path) do |line|
      match = /^#?(\d+)([^ ]*) - (.*)/.match(line)
      if match
        matches << match
      elsif not line.strip.empty?
        STDERR.puts "Unknown line format: #{line.dump}"
      end
    end
  rescue Errno::ENOENT
    STDERR.puts "Couldn't open file: #{path.dump}"
  end
end

matches.sort_by!{ |match| [match[1].to_i, match[2]] }

matches.each{ |match| puts match[0] }