With fd: https://github.com/sharkdp/fd https://github.com/sharkdp/fd fd [filter options] -X cat E.g. to combine all .js files into combined.js: fd -e

With fd: https://github.com/sharkdp/fd https://github.com/sharkdp/fd fd [filter options] -X cat E.g. to combine all .js files into combined.js: fd -e js -X cat > combined.js