i just downloaded a basic list of commands for linux.

[usonian]

1. Probably this one:

https://opensource.com/article/22/5/essential-linux-commands

YOU MADE ME LOOK.
Used to see killall only on MacOS.
The two seem to coexist everywhere.
in short kill PID, killall PROCESS_NAME


Printer software is none too smart, and I think they skimp on memory.
You may be clearing the effect of buffer overflow or memory leaks in the printer software.

FWIW, Apple has a lot of extra commands designed to run its hardware.
Not sure how up to date this list is, but it highlights commands unique to Apple:
https://ss64.com/osx/

Diskutil is in linux? Anyway it seems to get most things right.

For extra credit:
Apple changed the default shell somewhere in time. To change to to bash
chsh -s /bin/bash
It will ask for your password.
You can also do it in terminal->Preferences (now called Settings) -> Basic (you can change your shell there)

Things to learn: The find command. It's incredibly useful and tricky to get right.
You can batch rename files with the "ren" command written in perl. (It's not built-in)
I'll explain it separately. Saves days worth of work, but use with care
mv needs to be put into a loop to rename multiple files. That's where your SHELL means a lot. Scripts vary depending on your shell.
I used a lot of perl scripts to do chores independent of shells. Easier to read and program.