Ruby script to recursively download a given directory from your dropbox.

dropbox_dump.rb

require 'dropbox_sdk'  # gem install dropbox-sdk
require 'fileutils'
require 'thread'

# Example: downloads entire dropbox
#  DropboxDump.new('your_access_token', '/download/destination').download("/")
class DropboxDump
  attr_accessor :client, :dest, :work_q, :worker_count

  def initialize(access_token, dest, max_workers = 3)
    @client = DropboxClient.new(access_token)
    @dest = dest
    @work_q = Queue.new
    # Dropbox has a request limit on their API so if you do too many workers it might go over the limit and start failing.
    @worker_count = max_workers
  end

  def download(path)
    download_directory(path)

    workers = (0...worker_count).map do  
      Thread.new do
        begin
          while file = work_q.pop(true)
            if file
              download_file(file)
            end
          end
        rescue ThreadError
          # if queue is empty, it raises an error, but we don't really care
        rescue => e
          puts "Error: #{e}"
        end
      end
    end
    workers.map(&:join); "ok"
  end

  def download_directory(path)
    # Dropbox isn't case sensitive, so we are just downcasing all the file paths so we don't run into problems.
    path = path.downcase

    folder_path = "#{dest}#{path}"
    # Create the full directory path if it is not already there
    FileUtils.mkdir_p(folder_path)
    puts folder_path

    # Loop through each file for the given path
    files = client.metadata(path)['contents']
    files.each do |file|
      if file["is_dir"]
        download_directory(file['path'].downcase)
      else
        work_q.push(file)
      end
    end
  end

  def download_file(file)
    # See comment above about downcasing
    file_path = file['path'].downcase
    local_path = "#{dest}#{file_path}"

    if file["is_dir"]
      download_directory(file_path)
    else
      # download file
      if File.file?(local_path)
        puts "  -> File Exists: #{local_path}"
      else
        begin
          contents, metadata = client.get_file_and_metadata(file_path)
          open(local_path, 'w') {|f| f.puts contents }
          puts "  -> Saved: #{local_path}"
        rescue => e
          puts "ERROR saving #{local_path}"
          puts "metadata: #{file}"
          puts "error:"
          puts e
        end
      end
    end
  end
end