Configuration file reading in Bash Scripting - Mini Project: Build & Apply

Configuration file reading

📖 Scenario: You are managing a simple script that needs to read settings from a configuration file to decide how it behaves.Imagine you have a config file that stores user preferences like username and theme color.

🎯 Goal: Build a bash script that reads a configuration file and extracts specific settings into variables.This will help automate tasks based on user preferences stored in the config file.

📋 What You'll Learn

Create a configuration file named settings.conf with exact key-value pairs.

Write a bash script that reads the configuration file line by line.

Extract the values of username and theme from the config file.

Print the extracted values in a friendly message.

💡 Why This Matters

🌍 Real World

Many scripts and programs use configuration files to store user preferences or settings. Reading these files allows automation scripts to adapt their behavior without changing code.

💼 Career

Understanding how to read config files is essential for system administrators, DevOps engineers, and anyone writing automation scripts to manage software or servers.

1

Create the configuration file

Create a file named settings.conf with these exact lines:
username=alice
theme=dark

Bash Scripting

# Create the file settings.conf with the required lines
# Your code here

Need a hint?

Use echo commands with redirection to create the file and add lines.

2

Prepare variables to hold config values

In your bash script, create two empty variables called username and theme to hold the config values.

Bash Scripting

echo "username=alice" > settings.conf
echo "theme=dark" >> settings.conf

# Create empty variables username and theme
# Your code here

Need a hint?

Assign empty strings to username and theme variables.

3

Read the configuration file and extract values

Use a while loop with read to read settings.conf line by line.
Inside the loop, use case to check if the line starts with username= or theme=.
Extract the value after the equal sign and assign it to the corresponding variable.

Bash Scripting

echo "username=alice" > settings.conf
echo "theme=dark" >> settings.conf

username=""
theme=""

# Read settings.conf line by line and extract username and theme
# Your code here

Need a hint?

Use parameter expansion ${line#username=} to get the value after the equal sign.

4

Print the extracted configuration values

Print the message: User: alice, Theme: dark using the variables username and theme with echo and an f-string style format.

Bash Scripting

echo "username=alice" > settings.conf
echo "theme=dark" >> settings.conf

username=""
theme=""

while IFS= read -r line; do
  case "$line" in
    username=*) username="${line#username=}" ;; 
    theme=*) theme="${line#theme=}" ;; 
  esac
done < settings.conf

# Print the message with username and theme
# Your code here

Need a hint?

Use printf with %s placeholders to insert variables.