Fantastic list. I just want add one to this sublist. I use these often:

9. Find files tips

find . -maxdepth 1 -type f -printf '%f\n'

-printf '%f\n': This is a function to print in a formatted manner, typically used in C or other languages. %f means here print the filename only, without directory or slashes. And add a newline off course, but you could also print it by space enclosed between quotes: "%f" I prefer this over executing separate echo process.

-type f: This will limit the output depending on the filetype you define. Here f means files only. This can have multiple types too, in example directories or executables.

-maxdepth 1: Do not search subdirectories, only look in current directory like ls does. You could specify more depth too. And there is even -mindepth 2 in example, if you want to skip some top level directories and only search somewhere deep. This makes sense if you have organized structure of directories in example.

Most people will run a post 2.6 kernel, so prlimit will be available as an interesting alternative to ulimit.

Looks like the site is down or blocked in my country.

Could anyone please be so nice and copy paste those commands here?

Nice.

The most interesting command for the Linux shell is known as Barmin patch.