Step 1: Install UglifyJS
npm install -g uglify-js
Step 2: Write some Bash script code to find and minify all js files in a folder
1for file in path/to/js/folder/*.js; do 2 uglifyjs "$file" --stats -c -m -o "$file" 3 echo minified: "$file" 4done
Step 3: Run script
Save script in Step 2 to a file called 'minify-js.sh' and run it using Terminal:
1sudo chmod +x minify-js.sh 2./minify-js.sh
Modify this code a litte and you can use it with cleancss or other minifier.
This code help me much in deploying my webiste (a static site built with Jekyll). Hope it help someone else.