.zelda

~/src/youtube/vids

download.rb

#!/usr/bin/env ruby

# Output directory is in .zelda
# Refactoring could include code to look for ~/.zelda, etc.
configFile = File.new ".zelda"
outputDir  = File.expand_path configFile.readline.strip
configFile.close

# Check configuration.
raise "Episodes list not found at episodes.txt"         if !File.exists?    "episodes.txt"
raise "Invalid output directory - #{outputDir}"         if !File.directory? outputDir
raise "Cannot write to output directory - #{outputDir}" if !File.writable?  outputDir

# Print our output directory.
puts "Output directory is: #{outputDir}"

# Read each line of the episodes list via a block.
# Block ensures file is closed even if exceptions escape.
File.foreach "episodes.txt" do |line|
  options = line.strip.split ","
  # Verify the options split into an array of 3 elements.
  # Skip to the next line if it didn't.
  if options.size != 3
    puts "Invalid options line: \"#{line.strip}\""
    next
  end
  # Define our variables.
  episode          = options[0]
  part             = options[1]
  url              = options[2]
  episodeOutputDir = "#{outputDir}/ep#{episode}"
  episodeFile      = "#{episodeOutputDir}/part#{part}.mp4"
  # DO WORK! (If we need to)
  Dir.mkdir episodeOutputDir unless File.directory? episodeOutputDir
  system "youtube-dl -o #{episodeFile} \"#{url}\"" unless File.exists? episodeFile
end

# Notes on xxxx if yyyy vs xxxx unless yyyy
# I like to use xxxx if yyyy if yyyy is an exceptional case, and usually xxxx wouldn't be executed
#   e.g. "Only do X if Y condition exists" - like the exceptions at the top of the file
# I like to use xxxx unless yyyy if xxxx is the usual action, and not doing it is exceptional
#   e.g. "Do X, except don't do it if Y condition exists" - like the last couple lines of code

episodes.txt

1,2
2,3,http://www.youtube.com/watch?v=q6g2jyBdpc0&feature=related
3,1,http://www.youtube.com/watch?v=bDHAUrqhokA