Access Control Lists (ACLs) in Operating Systems - Mini Project: Build & Apply

Understanding Access Control Lists (ACLs)

📖 Scenario: You are managing a small office network where different employees need different levels of access to shared folders on a server. To keep things organized and secure, you want to set up Access Control Lists (ACLs) that specify who can read, write, or execute files.

🎯 Goal: Build a simple representation of Access Control Lists (ACLs) using a dictionary to map users to their permissions on a shared folder.

📋 What You'll Learn

Create a dictionary named acl with specific users and their permissions.

Add a variable named default_permission to set a fallback permission.

Use a loop to create a list of users who have write permission.

Add a final entry to the ACL for a new user with read-only permission.

💡 Why This Matters

🌍 Real World

ACLs are used in operating systems and network servers to control who can access files and resources, ensuring security and proper access management.

💼 Career

Understanding ACLs is important for system administrators, network engineers, and IT security professionals who manage user permissions and protect data.

1

Create the initial ACL dictionary

Create a dictionary called acl with these exact entries: 'alice': 'read', 'bob': 'write', 'charlie': 'execute'.

Operating Systems

# Create the ACL dictionary with specified users and permissions
# Your code here

Need a hint?

Use curly braces to create a dictionary and separate each user-permission pair with commas.

2

Add a default permission variable

Add a variable called default_permission and set it to the string 'read'.

Operating Systems

acl = {'alice': 'read', 'bob': 'write', 'charlie': 'execute'}
# Add the default_permission variable below
# Your code here

Need a hint?

Just assign the string 'read' to the variable named default_permission.

3

Find users with write permission

Create a list called write_users that contains the names of users from acl who have the permission 'write'. Use a for loop with variables user and permission to iterate over acl.items().

Operating Systems

acl = {'alice': 'read', 'bob': 'write', 'charlie': 'execute'}
default_permission = 'read'
# Create the write_users list below
# Your code here

Need a hint?

Start with an empty list, then add users whose permission is 'write' inside the loop.

4

Add a new user with read permission

Add a new entry to the acl dictionary for user 'diana' with permission 'read'.

Operating Systems

acl = {'alice': 'read', 'bob': 'write', 'charlie': 'execute'}
default_permission = 'read'
write_users = []
for user, permission in acl.items():
    if permission == 'write':
        write_users.append(user)
# Add 'diana' with 'read' permission to acl
# Your code here

Need a hint?

Use square brackets with the new user name as the key and assign the permission 'read'.