Let's say you have a JavaScript application that has 3 files:

ui.js
script.js
analytics.js

And you need to create bundle.js.

Use cat – the universal Unix bundler. It's always available on all systems, doesn't require an installation or upgrades, and it works at the speed of a hard drive.

cat ui.js script.js analytics.js > bundle.js

Or even better, just write your entire application in a single script.js file like I do. See you next time!