This ruby script finds unused image assets in a website project.

img_coverage.rb

#!/usr/bin/env ruby

require 'fileutils'

files = Dir['**/*.{htm,html,shtml,php,css,js}']
images = Dir['**/*.{jpg,png,gif,bmp}']

puts "#{images.size} images found & #{files.size} files found to search against"

content = ""

files.each do |filename|
  content << File.read(filename)
end

images.each do |filename|
  basename = File.basename filename
  dirname = File.dirname filename
  image_not_used = content !~ /\b#{basename}\b/

  if image_not_used
    FileUtils.mkdir_p "../unused/#{dirname}"
    FileUtils.mv filename, "../unused/#{filename}"
    puts "Image '#{filename}' moved to '../unused' folder"
  end
end