A friend asked for a quick script to help him sort a top-50 list of games. Here’s what I threw together:

#!/usr/bin/env ruby

# rank.rb - Rank a list of items, two at a time.

# Copyright (c) 2010 Jay McGavren
#
# Permission is hereby granted, free of charge, to any person obtaining
# a copy of this software and associated documentation files (the
# "Software"), to deal in the Software without restriction, including
# without limitation the rights to use, copy, modify, merge, publish,
# distribute, sublicense, and/or sell copies of the Software, and to
# permit persons to whom the Software is furnished to do so, subject to
# the following conditions:
#
# The above copyright notice and this permission notice shall be
# included in all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
# LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
# OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
# WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.


require 'fileutils'
require 'curses'

file_name = ARGV[0] or fail "Usage: #{__FILE__} filename.txt"

def random_index(list)
  rand(list.length)
end

def write_store(name, entries)
  File.open(name, 'w+') do |file|
    file.puts(entries)
  end
end

def read_store(name)
  entries = []
  File.open(name) do |file|
    entries = file.readlines
  end
  entries
end

entries = read_store(file_name)

Curses.noecho
Curses.init_screen
Curses.stdscr.keypad(true)

loop do
  # Pick 2 random items.
  indices = [0, 0]
  while (indices[0] == indices[1]) do
    indices = [random_index(entries), random_index(entries)]
  end
  indices.sort!
  # Present them.
  Curses.setpos(0, 0)
  Curses.addstr(<<-EOD)
    Which is better?
    1. #{entries[indices[0]]}
    2. #{entries[indices[1]]}
    3. Exit
  EOD
  begin
    result = nil
    until ([?1, ?2, ?3].include?(result)) do
      result = Curses.getch
    end
    case result
    # Higher one chosen?
    when ?1
      # Do nothing.
    # Otherwise:
    when ?2
      # Swap them.
      entries[indices[0]], entries[indices[1]] = entries[indices[1]], entries[indices[0]]
    # Exit chosen?
    when ?3
      # Exit loop.
      break
    else
      fail "wtf?"
    end
  end
  write_store("#{file_name}.bak", entries)
end

# Save.
FileUtils.mv("#{file_name}.bak", file_name)

Curses.close_screen

It picks two entries at random, and swaps their positions if you choose the later one as your favorite. Lather, rinse, repeat. Like a bubble sort without adjacent items.

Curses? Well, it was the quickest way to get Ruby to respond to a single keypress. And since you’re going to be making a lot of entries, I didn’t want you to have to hit Enter after every one.

So here you see my list of artists with 5-star songs, originally in alphabetical order, but with my favorites starting to bubble to the top:

• 10,000 Maniacs
• Enigma
• Boom Boom Satellites
• Alpha
• Amon Tobin
• Aphex Twin
• Barenaked Ladies
• Arovane
• Audioslave
• Boards of Canada
• Massive Attack
• Red Snapper
• Tipper
• Beach Flea
• Cake
• Ben Folds Five
• Counting Crows
• Propellerheads
• Billy Joel
• The Smashing Pumpkins
• Lemon Jelly
• Fatboy Slim
• Boards Of Canada
• Shpongle
• Bola
• Coldplay
• Weekend Players
• Boulderdash
• Buckethead
• Crunch
• Ulrich Schnauss
• Basement Jaxx
• µ-Ziq
• Dol-lop
• Chicane
• Depeche Mode
• Clint Mansell
• Train
• Boom Bip
• Bent
• Creed
• Beck
• Cujo
• DJ Cam
• Röyksopp
• Daft Punk
• Red Hot Chili Peppers
• Death Cab for Cutie
• Plaid
• Deftones
• Delarosa & Asora
• Christian Kleine
• Caviar
• Third Eye Blind
• Duncan Sheik
• E.S. Posthumus
• Eat Static
• The Crystal Method
• 3 Doors Down
• Blind Melon
• Fluke
• Hive
• BT
• Loden
• Goldie
• Groove Armada
• Hexstatic
• R.E.M.
• Hybrid
• Bush
• Sugar Ray
• Jay McGavren
• Single Cell Orchestra
• Kenji Kawai
• LFO
• Saru
• Sarah McLachlan
• Arkarna
• Prefuse 73
• James Bong
• Lusine ICL
• Banco de Gaia
• Mighty Dub Cats
• Mike & Rich
• The Cranberries
• Natalie Merchant
• Orbital
• P.M. Dawn
• Clue to Kalo
• Pearl Jam
• Photek
• Deep Forest
• Polygon Window
• Portishead
• Loess
• Prince
• Proem
• Billie Myers
• Freaky Chakra
• Dave Matthews Band
• Global Communication
• Roni Size & Reprazent
• DJ Krush
• Moby
• Blessid Union of Souls
• Londonbeat
• Savath & Savalas
• Seal
• The Chemical Brothers
• Shantel
• Genesis
• Jimpster
• Elton John
• The Wiseguys
• Living Colour
• Stone Temple Pilots
• Janet Jackson
• Talvin Singh
• Blackwatch & Greed
• Squarepusher
• Soundgarden
• The Dust Brothers
• The Postal Service
• The Prodigy
• Seb & Lo-tec
• Spring Heel Jack
• Dot Allison
• Isao Tomita
• Patchwork
• Bôa
• A Man Called Adam
• wunsch/demmin
• Chicago

Been meaning to write something like this for a while, and my friend’s request was just the final nudge. Hopefully this will help others looking for something similar.