Bash one-liners I keep looking up

A personal cheat sheet. Nothing clever, just things I search for every few months.

Largest directories

du -h --max-depth=1 . | sort -h | tail

What is listening on a port

ss -tlnp | grep :8080

Rename files to lowercase

for f in *; do mv -n -- "$f" "${f,,}"; done

Find files changed in the last day

find . -type f -mtime -1

Repeat a command until it succeeds

until ping -c1 -W1 example.com; do sleep 2; done