Simple script for detecting unreferenced images in an Xcode directory structure

xc-unused-images.rb

#!/usr/bin/env ruby

#delete flag
should_delete = false
if ARGV.length >= 1
    ARGV.each do |arg|
      if arg.downcase.eql?('--delete')
        should_delete = true
        puts "--delete detected; will delete unreferenced image files.\n"
      end
  end
end
  

# get all the file names we are interested in
source_filenames = Dir['**/*.m']
source_filenames.concat( Dir['**/*.xib'] )
source_filenames.concat( Dir['**/*.plist'] )

png_filenames = Dir['**/*.png']

image_references = Hash.new
png_filenames.each { |filename| image_references[File.basename(filename.downcase)] = 0 }

# add our 'Known Good' images
image_references['default.png'] = 1
image_references['default-landscape.png']

['default-portraitupsidedown.png',
 'default-landscapeleft.png', 
 'Default-LandscapeRight.png',
 'Default-Portrait.png',
 'Default-Landscape.png',
 'Default.png'].each do |filename|
   image_references[filename.downcase] = 1
end

# find all references to images in souces
source_filenames.each do |filename|
  begin
    file = File.open("#{filename}", "r")
    contents = file.read.downcase
    png_filenames.each do |image_filename|
      base_image_filename = File.basename(image_filename).downcase
      if contents.index(base_image_filename) != nil
        image_references[base_image_filename] += 1 if image_references.has_key?(base_image_filename)
        
        # check for the 2x version as well
        retina_base_image_filename = "#{File.basename(base_image_filename,File.extname(base_image_filename))}@2x#{File.extname(base_image_filename)}"
        image_references[retina_base_image_filename] += 1 if image_references.has_key?(retina_base_image_filename)
      end
    end
    file.close
  rescue Exception => ex
    puts "Error opening #{filename} - #{ex}\n"
  end
end

# show results
unused_image_count = 0
image_references.each  do |filename,refcount| 
  if refcount == 0 
    puts "#{filename}\n" 
    unused_image_count += 1
  end
end

puts "  #{unused_image_count} unreferenced images out of #{png_filenames.count}.\n"

if should_delete
  delete_count = 0
  png_filenames.each do |image_filename|
    begin
      base_image_filename = File.basename(image_filename).downcase
      if image_references[base_image_filename] == 0
        File.delete( image_filename )
        delete_count += 1
      end
    rescue
      puts "Failed to delete #{image_filename}\n"
    end
  end
  puts "\n deleted #{delete_count} unreferenced image files.\n"
end