Update newer files from one dir to another dir

copy-trans.rb

#!/usr/bin/env ruby19

# Read a directory tree and convert newer sources
# on the fly.

require 'pathname'

EXTENSIONS=%w{.jpg .JPG}


abort 'Need two arguments' unless ARGV.size >= 2

from = Pathname.new(ARGV.shift)
to = Pathname.new(ARGV.shift)

abort 'Need source directory' unless from.directory?

from.find do |source|
  if EXTENSIONS.include? source.extname
    target = to + source.relative_path_from(from)

    if !target.exist? || target.mtime < source.mtime
      target.parent.mkpath
      puts "Updating #{source} -> #{target}"
      system 'touch', target.to_s
    end
  end
end