Linux Commands

Permission denied again? Read rwx in seconds, pick the right chmod number and change file owners on Ubuntu 26.04 without breaking anything.

Find out what is eating your disk, then partition, format and mount a new drive on Ubuntu 26.04 without guessing device names.

Turn on the Ubuntu firewall without locking yourself out. Allow SSH first, open only the ports you need, then manage rules by number.

A service will not start? Learn the systemctl and journalctl commands that show what failed on Ubuntu 26.04 and how to fix it fast.

Install, update and clean up software on Ubuntu 26.04 the right way: apt for archive packages, snap for Store apps, and when to use which.

Learn grep on Ubuntu 26.04 and 26.10 with expanded examples, Key Takeaways and a free multi-format cheat sheet.

Learn tar on Ubuntu 26.04 and 26.10 with gzip, xz and exclude examples, plus a free multi-format cheat sheet.

Fifteen advanced Ubuntu commands for 26.04 and 26.10: tar, rsync, tmux, find, ss and journalctl, with a free cheat sheet.

Fifteen Ubuntu security commands for 26.04 and 26.10 covering sudo, ssh, ufw, nftables, iptables and scanners, with a free cheat sheet.

Learn wget on Ubuntu 26.04 and 26.10 for resumes, rate limits and batch downloads, with a free cheat sheet.