/etc/passwd and /etc/shadow in Linux CLI - Mini Project: Build & Apply

Exploring /etc/passwd and /etc/shadow Files

📖 Scenario: You are a system administrator learning how to read user account information on a Linux system. The /etc/passwd file stores basic user info, and the /etc/shadow file stores secure password data.Understanding these files helps you manage users and security on your system.

🎯 Goal: Build simple commands to read and extract information from /etc/passwd and /etc/shadow files.

📋 What You'll Learn

Use cat to display file contents

Use cut to extract specific fields

Use grep to find lines matching a username

Understand the structure of /etc/passwd and /etc/shadow

💡 Why This Matters

🌍 Real World

System administrators often need to read and understand user account files to manage users and security on Linux systems.

💼 Career

Knowing how to read /etc/passwd and /etc/shadow is essential for Linux system administration and security auditing roles.

1

Display the contents of /etc/passwd

Use the command cat /etc/passwd to display the full contents of the /etc/passwd file.

Linux CLI

# Type the command to display /etc/passwd contents
# Your code here

Need a hint?

The cat command shows the whole file content.

2

Extract the usernames from /etc/passwd

Use the command cut -d ':' -f 1 /etc/passwd to extract only the usernames (the first field) from the /etc/passwd file.

Linux CLI

cat /etc/passwd
# Use cut to extract usernames from /etc/passwd
# Your code here

Need a hint?

The cut command splits lines by ':' and selects the first part.

3

Find the line for the user root in /etc/shadow

Use the command grep '^root:' /etc/shadow to find the line starting with root: in the /etc/shadow file.

Linux CLI

cat /etc/passwd
cut -d ':' -f 1 /etc/passwd
# Use grep to find the root user line in /etc/shadow
# Your code here

Need a hint?

The grep command searches for lines starting with 'root:' in the file.

4

Display the username and encrypted password field from /etc/shadow

Use the command cut -d ':' -f 1,2 /etc/shadow to display only the username and encrypted password fields from the /etc/shadow file.

Linux CLI

cat /etc/passwd
cut -d ':' -f 1 /etc/passwd
grep '^root:' /etc/shadow
# Use cut to show username and password fields from /etc/shadow
# Your code here

Need a hint?

Use cut with fields 1 and 2 separated by a comma to get username and password.