Just a running list of commands I forget constantly. Mostly Linux stuff, occasionally other junk. No commentary, no fluff—just copy/paste when your brain blanks.

Run a quick python server:

python3 -m http.server

Find and sort files in a dirname based on their modification times

find dirname -type f -print0 | xargs -0 stat --format '%Y :%y %n' | sort -nr | cut -d: -f2- | head

Exchange SSH keys with a server

ssh-copy-id remote_user@host

Directory Operations

# Get directory size
du -sh /path/to/directory

# Sort files and directories by size
du -sh -- * | sort -rh

# Just sort directories by size
du -sh -- */ | sort -rh

# Just the top 10 of either
du -sh -- */ | sort -rh | head -n 10

Compress a file or directory

tar -czf new-file.tar.gz oldfile oldirectory

Extract a compressed tar.gz

tar -xzf filename.tar.gz

Create backup with exclusions

tar -cvpf /backups/fullbackup.tar --directory=/ --exclude=proc --exclude=sys --exclude=dev/pts --exclude=foo --exclude=mnt .

Allow PPA metadata changes when updating Ubuntu

# Ensure Ubuntu is >= 18.04 LTS, or apt version is >= 1.6
sudo apt-get update --allow-releaseinfo-change

yt-dlp

Use cookies (from file)

yt-dlp --cookies cookies.txt --user-agent "agent string" downloadurl

Default Best Video + Audio

yt-dlp -f "bv*+ba/b" "URL"

Force a Specific Format

yt-dlp -f "bv*+ba/b" -S "ext:mp4:m4a" --recode mp4 "URL"