set -x for trace mode in Bash Scripting - Mini Project: Build & Apply

Using set -x for Trace Mode in Bash Scripts

📖 Scenario: You are writing a simple bash script to calculate the total price of items bought. You want to see each command as it runs to understand how the script works.

🎯 Goal: Learn how to use set -x to enable trace mode in a bash script and see the commands being executed.

📋 What You'll Learn

Create a variable with item prices

Enable trace mode using set -x

Calculate the total price using a loop

Print the total price with trace output visible

💡 Why This Matters

🌍 Real World

Trace mode helps developers debug bash scripts by showing each command executed. This is useful when scripts get complex or don't work as expected.

💼 Career

Knowing how to use <code>set -x</code> is important for system administrators, DevOps engineers, and anyone writing or maintaining shell scripts in professional environments.

1

Create a list of item prices

Create a bash array called prices with these exact values: 10, 20, 30.

Bash Scripting

# Create a bash array called prices with values 10, 20, 30
# Your code here

Need a hint?

Use parentheses to create an array in bash, like array=(value1 value2).

2

Enable trace mode with set -x

Add the command set -x below the prices array to enable trace mode.

Bash Scripting

prices=(10 20 30)
# Enable trace mode
# Your code here

Need a hint?

Just write set -x on a new line to turn on command tracing.

3

Calculate the total price using a loop

Create a variable total set to 0. Then use a for loop with variable price to iterate over ${prices[@]} and add each price to total.

Bash Scripting

prices=(10 20 30)
set -x

# Initialize total to 0
# Use for loop to add each price to total
# Your code here

Need a hint?

Use total=0 to start. Loop with for price in "${prices[@]}". Add with total=$((total + price)).

4

Print the total price with trace output

Add a echo command to print Total price: followed by the value of total.

Bash Scripting

prices=(10 20 30)
set -x

total=0
for price in "${prices[@]}"; do
    total=$((total + price))
done

# Print the total price
# Your code here

Need a hint?

Use echo "Total price: $total" to show the result.