while loop in Bash Scripting - Mini Project: Build & Apply

Counting Down with a While Loop in Bash

📖 Scenario: You are creating a simple countdown timer script in Bash. This script will count down from a starting number to zero, showing each number on the screen.

🎯 Goal: Build a Bash script that uses a while loop to count down from a given number to zero, printing each number.

📋 What You'll Learn

Create a variable called count with the starting number 5

Create a variable called limit with the value 0

Use a while loop that runs as long as count is greater than or equal to limit

Inside the loop, print the current value of count

Decrease count by 1 in each loop iteration

💡 Why This Matters

🌍 Real World

Counting down or up is common in scripts that wait for a certain time or repeat tasks a fixed number of times.

💼 Career

Understanding loops and variables in Bash is essential for automating tasks in system administration and DevOps roles.

1

Set up the starting number

Create a variable called count and set it to 5.

Bash Scripting

# Create a variable called count and set it to 5
# Your code here

Need a hint?

Use count=5 to create the variable.

2

Set the limit for the countdown

Create a variable called limit and set it to 0.

Bash Scripting

count=5
# Create a variable called limit and set it to 0
# Your code here

Need a hint?

Use limit=0 to create the variable.

3

Write the while loop to count down

Write a while loop that runs while count is greater than or equal to limit. Inside the loop, print the value of count and then decrease count by 1.

Bash Scripting

count=5
limit=0
# Write a while loop that runs while count >= limit
# Inside the loop, print count and decrease count by 1
# Your code here

Need a hint?

Use while [ "$count" -ge "$limit" ] to start the loop. Use echo "$count" to print. Use count=$((count - 1)) to decrease.

4

Run the script and show the countdown

Run the script to print the countdown from 5 to 0.

Bash Scripting

count=5
limit=0
while [ "$count" -ge "$limit" ]
do
  echo "$count"
  count=$((count - 1))
done

# Run the script to show the countdown
# Your code here

Need a hint?

Run the script in your terminal. It should print numbers from 5 down to 0, one per line.