generate_screenshot_html.rb

#!/usr/bin/env ruby
require 'erb'

source_dir = ARGV[0]
files = Dir.entries(source_dir).map do |fname|
  fname =~ /\.png$/ ? fname : nil
end.compact.sort

image_template = '<a href="<%= fname %>"><img src="<%= fname %>" width="300"/></a>'
renderer = ERB.new(image_template)
files.each do |fname|
  puts renderer.result(binding)
end