Default values for input in Bash Scripting - Mini Project: Build & Apply

Default values for input in Bash scripting

📖 Scenario: You are writing a simple Bash script that asks the user for their favorite fruit. Sometimes, the user might not enter anything. You want to make sure the script uses a default fruit if the user leaves the input empty.

🎯 Goal: Build a Bash script that asks for user input and uses a default value if the input is empty.

📋 What You'll Learn

Create a variable to store user input

Set a default value if the input is empty

Print the final chosen fruit

💡 Why This Matters

🌍 Real World

Scripts often ask users for input but need to handle cases where the user presses Enter without typing anything. Using default values keeps scripts friendly and reliable.

💼 Career

Knowing how to handle default values in Bash scripts is useful for system administrators and developers who automate tasks and want to make scripts user-friendly.

1

Create a variable to store user input

Write a line to read user input into a variable called fruit using read -p with the prompt "Enter your favorite fruit: ".

Bash Scripting

# Read user input into variable fruit
# Your code here

Need a hint?

Use read -p "prompt" variable to get input from the user.

2

Set a default value if input is empty

Add a line that sets fruit to "apple" if it is empty, using the syntax ${fruit:-apple}.

Bash Scripting

read -p "Enter your favorite fruit: " fruit
# Set fruit to "apple" if empty
# Your code here

Need a hint?

Use variable=${variable:-default} to assign a default value if the variable is empty.

3

Print the final chosen fruit

Write a line to print the message "Your favorite fruit is: " followed by the value of fruit.

Bash Scripting

read -p "Enter your favorite fruit: " fruit
fruit=${fruit:-apple}
# Print the chosen fruit
# Your code here

Need a hint?

Use echo to display text and variables.

4

Run the script and see the output

Run the script and enter nothing when prompted. The output should be exactly Your favorite fruit is: apple.

Bash Scripting

read -p "Enter your favorite fruit: " fruit
fruit=${fruit:-apple}
echo "Your favorite fruit is: $fruit"
# Run the script and check output

Need a hint?

Just press Enter without typing anything when prompted.