A script I wrote to convert files from IMG_XXXX.jpg to YYYY-MM-DD HH.MM.SS.jpg format, with proper duplicate file

rename_photos.rb

require 'exifr'

files = Dir['*.jpg']
puts "Renaming #{files.count} files..."
new_file_names = Hash.new { |h,k| h[k] = [] }

files.each do |file|
  exif = EXIFR::JPEG.new(file)
  dt = exif.date_time_original
  new_file_name = "#{dt.strftime('%Y-%m-%d %H.%M.%S')}"
  if exif.subsec_time_digitized
    new_file_name += ".#{exif.subsec_time_digitized}"
  end
  new_file_names[new_file_name] << file
end

new_file_names.each do |new_name, old_names|
  if old_names.count > 1
    old_names.each.with_index(1) do |name, i|
      File.rename(name, "#{new_name} (#{i}).jpg")
    end
  else
    File.rename(old_names[0], "#{new_name}.jpg")
  end
end

new_files = Dir['*.jpg']
puts "We now have #{new_files.count} files."