https://code.google.com/archive/p/css-redundancy-checker/

wget https://storage.googleapis.com/google-code-archive-source/v2/code.google.com/css-redundancy-checker/source-archive.zip
unzip source-archive.zip
gem install hpricot 
ruby css-redundancy-checker.rb [cssfile] [directory of html files OR .txt file listing urls to use]
		

# vim url.txt
http://www.netkiller.cn/zh-cn/
http://www.netkiller.cn/index.html
http://www.netkiller.cn/zh-tw/index.html

ruby css-redundancy-checker.rb your.css url.txt