Thanks to the excellent video Kata in Bash from Andrea Francia, where he creates from scratch a mini testing framework for Bash, today I learned some things:

Do you know:

👉 how to split multiple inputs in a string, space separated, with a one-liner?

#!/bin/bash

read -ra numbers <<< "1 2"
echo "$((numbers[0]+numbers[1]))"

# returns 2

or comma separated

#!/bin/bash

IFS=, read -ra numbers <<< "1,2"
echo "$((numbers[0]+numbers[1]))"

# returns 2

👉 how to create a temporary file which will be automatically destroyed?

This is useful for those commands which require files as inputs, for example diff

> diff <(echo "something") <(echo "something_else")
1c1
< something
---
> something_else

It relies on Process Substitution

👉 that True and False are commands?

true always succeeds, false always fails

> true
> echo $?
0

> false
> echo $?
1