Bash For Loops

What it does: Repeats a block for a sequence of values. The countdown shows numeric iteration and timing with sleep.

What is a for loop? A for loop lets you repeat a block of commands a fixed number of times, or iterate over a list of values.

Why use it? It’s useful for automation—looping through files, numbers, or arguments.

Example: Countdown from 20 to 0

#!/bin/bash
for i in {20..0}
do
  echo "Countdown: $i"
  sleep 1
done