df (disk free space) in Linux CLI - Mini Project: Build & Apply

Check Disk Free Space with df Command

📖 Scenario: You are managing a Linux server and want to check how much disk space is free on your system. This helps you avoid running out of space and keep your server running smoothly.

🎯 Goal: Learn to use the df command to display disk free space information and filter the output to see only the root filesystem usage.

📋 What You'll Learn

Use the df command to show disk space usage

Use a variable to store the filesystem name /

Use grep to filter the output for the root filesystem

Print the filtered disk space information

💡 Why This Matters

🌍 Real World

System administrators often need to monitor disk space to prevent servers from running out of space, which can cause crashes or data loss.

💼 Career

Knowing how to use basic Linux commands like <code>df</code> and scripting with variables and conditionals is essential for roles in system administration, DevOps, and IT support.

1

Create a variable for the root filesystem

Create a variable called root_fs and set it to the string "/" to represent the root filesystem.

Linux CLI

# Create a variable called root_fs and set it to "/"
# Your code here

Need a hint?

Use root_fs="/" to store the root filesystem path.

2

Run the df command and filter for root filesystem

Use the df -h command piped to grep with the variable root_fs to filter the output and show only the disk space info for the root filesystem. Store this output in a variable called root_usage.

Linux CLI

root_fs="/"
# Use df -h and grep with root_fs, store output in root_usage
# Your code here

Need a hint?

Use root_usage=$(df -h | grep " $root_fs$") to get the filtered disk space info.

3

Print the root filesystem disk usage

Print the content of the variable root_usage to display the disk free space information for the root filesystem.

Linux CLI

root_fs="/"
root_usage=$(df -h | grep " $root_fs$")
# Print the root_usage variable
# Your code here

Need a hint?

Use echo "$root_usage" to print the disk usage info.

4

Add a check to show a message if root filesystem info is missing

Add an if statement to check if root_usage is empty. If it is empty, print "Root filesystem info not found.". Otherwise, print the root_usage variable.

Linux CLI

root_fs="/"
root_usage=$(df -h | grep " $root_fs$")

# Add if statement to check if root_usage is empty
# Your code here

Need a hint?

Use if [ -z "$root_usage" ] to check if the variable is empty.