Basic use of Awk.
Some features of Bash.
Getting Bluetooth audio working on Debian Jessie.
Linux user configuration files, and what they do.
Setting up home folder encryption on Debian.
Tools for finding things out on Linux.
Networking on Linux.
The Nix package manager — reliable, immutable packaging.
Solutions to problems I've had while using the NixOS Linux distribution, built on top of the Nix package manager.
Getting from an unpartitioned disk to a mounted file system in Linux.
Using QEMU to run an emulator on Linux, with some specific notes on emulating a Raspberry Pi.
Process redirection and substitution in bash.
How to use rsync to setup backups.
Scheduling regular tasks in Linux.
Ways to find files and text in Linux.
What are terminal emulators? How do you get xterm to behave itself? What are virtual terminals? Terminal multiplexing.
Some features of zsh, and useful keybindings.