Change GTK theme once per minute

theme_looper.rb

#!/usr/bin/ruby

themes_dir = Dir["/usr/share/themes/*"].select do |entry|
	File.directory?(entry) && File.exists?(entry + "/index.theme") && File.exist?(entry + "/gtk-3.0")
end.sort!

theme_names = themes_dir.sort.map { |dir| File.basename(dir) }

theme_names.each do |theme_name|
	sleep 60 # 60 is 1 minute. Change it according to your need.
	puts "Changing theme to #{theme_name}"
	system("gsettings set org.gnome.desktop.interface gtk-theme '#{theme_name}'")
end