set -e for exit on error in Bash Scripting - Mini Project: Build & Apply

Using set -e to Exit on Error in Bash Scripts

📖 Scenario: You are writing a simple bash script to run a few commands in order. You want the script to stop immediately if any command fails, so you don't continue with wrong results.

🎯 Goal: Learn how to use set -e in a bash script to make it exit on the first error.

📋 What You'll Learn

Create a bash script with three commands

Add set -e to make the script exit on error

Test the script to see it stops when a command fails

Print a message after the commands to confirm script behavior

💡 Why This Matters

🌍 Real World

In real scripts, <code>set -e</code> helps catch errors early and prevents running commands that depend on previous successful steps.

💼 Career

Many jobs require writing reliable bash scripts for automation. Knowing how to use <code>set -e</code> is essential for safe scripting.

1

Create a bash script with three commands

Create a bash script with these three commands exactly: echo "Start script", ls /nonexistentfolder, and echo "End script".

Bash Scripting

# Write the three commands below
# Your code here

Need a hint?

Use echo to print messages and ls to list a folder that does not exist.

2

Add set -e to exit on error

Add the line set -e at the very top of the script to make it exit immediately if any command fails.

Bash Scripting

# Add set -e at the top

# Your code here

Need a hint?

set -e must be the first line in the script.

3

Add a success message after commands

Add a new line at the end of the script that prints echo "Script completed successfully".

Bash Scripting

set -e
echo "Start script"
ls /nonexistentfolder
echo "End script"
# Add success message below
# Your code here

Need a hint?

This message will only print if no command fails before it.

4

Run the script and observe output

Run the script and observe that it prints Start script, then stops with an error because ls /nonexistentfolder fails. It should NOT print End script or Script completed successfully. Use bash yourscript.sh to run.

Bash Scripting

# Run the script in your terminal
# Your code here

Need a hint?

The script stops after the error. You will see the error message from ls.