Useful commands
Command Name	Description
env	Print all environment variables for the current user
file	Print out the type of the file
perf perf top perf record	Show and record lots of Linux performance data (not on MacOS or OpenBSD) JE Zine
less	Pager for text files JE comic Try & while in the pager to filter lines, ! to anti-filter lines
expand/unexpand	Convert from tabs to spaces (expand) or spaces to tabs (unexpand -a).
dmidecode	Print out BIOS information (including most of the devices connected)
hwinfo	Print out hardware info
lshw	List hardware
inxi	Show a compressed view of the system hardware (often used for IRC sharing)
fwupdmgr	Firmware update manager (to run BIOS updates)
nvtop	Monitor for GPU consumption
rlwrap	Add history/Ctrl support for repls that don't have them (i.e. Python)
watch	Re-run a command every 2 seconds
cal	A little CLI calendar
pv	Give you stats on data going through a pipe
ts	Put a timestamp in front of every line
ncdu	Figure out what's using your disk space.
diff	Find out the difference between 2 files. Add -U 8 for context.
comm	Find out the lines that 2 already-sorted files have in common
column	Format the output into columns
xsel/xclip MacOS: pbcopy/pbpaste	Copy + paste into system clipboard.
dnspeep	Inspect DNS requests (repo)
git	Distributed version control (JE subcommands
mitmproxy	Man-in-the-middle network proxy, for sniffing traffic. JE comic
ss -tunapl	Show open sockets (JE comic)
ngrep	Listen to network traffic (simplified tcpdump, JE comic
Mouse
Issue	How to fix
Mouse locks up	From root command line: 1. modprobe -r psmouse 2. modprobe psmouse

Many thanks to Julia Evans, Nixcraft, and others for the inspiration.