User account management script in Bash Scripting - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to add a new user named 'john'.

Bash Scripting

sudo useradd [1]

Drag options to blanks, or click blank then click option'

A-m john

Bjohn

C-d /home/john

D-s /bin/bash

Attempts:

3 left

💡 Hint

Common Mistakes

Forgetting to create the home directory with '-m'.

Using only the username without options.

The '-m' option creates the user's home directory when adding the user 'john'.

2fill in blank

medium

Complete the code to delete a user named 'alice' and remove her home directory.

Bash Scripting

sudo userdel [1]

Drag options to blanks, or click blank then click option'

A-d alice

Balice

C-f alice

D-r alice

Attempts:

3 left

💡 Hint

Common Mistakes

Deleting the user without removing the home directory.

Using incorrect options like '-d' which is not valid here.

The '-r' option removes the user's home directory and mail spool when deleting the user.

3fill in blank

hard

Fix the error in the script that locks the user account 'bob'.

Bash Scripting

sudo passwd [1] bob

Drag options to blanks, or click blank then click option'

A-l

B-u

C-d

D-e

Attempts:

3 left

💡 Hint

Common Mistakes

Using '-u' which unlocks the account instead.

Using '-d' which deletes the password.

The '-l' option locks the user account by disabling the password.

4fill in blank

hard

Fill both blanks to create a user 'carol' with home directory and bash shell.

Bash Scripting

sudo useradd [1] [2] carol

Drag options to blanks, or click blank then click option'

A-m

B-s /bin/bash

C/bin/bash

D-d

Attempts:

3 left

💡 Hint

Common Mistakes

Using '-d' instead of '-m' for home directory.

Not specifying the shell option.

Use '-m' to create the home directory and '-s' to specify the shell.

5fill in blank

hard

Fill all three blanks to create a user 'dave' with home directory, bash shell, and add to group 'developers'.

Bash Scripting

sudo useradd [1] [2] [3] dave

Drag options to blanks, or click blank then click option'

A-m

B-s /bin/bash

C-G developers

D/bin/bash

Attempts:

3 left

💡 Hint

Common Mistakes

Forgetting to add the user to the 'developers' group.

Using the shell path as an option instead of a value.

Use '-m' for home directory, '-s' to set shell, and '-G' to add to groups.

Practice

1. What is the main purpose of a bash script that manages user accounts with commands like useradd and userdel?

easy

A. To change the system hostname

B. To automate adding, deleting, and listing users on the system

C. To update software packages automatically

D. To monitor network traffic

Solution

1. Step 1: Understand the commands used

   The commands useradd and userdel are specifically for managing user accounts on Linux systems.

2. Step 2: Identify the script's goal

   Since the script uses these commands, its main purpose is to automate user account management tasks like adding, deleting, and listing users.

3. Final Answer:

   To automate adding, deleting, and listing users on the system -> Option B

4. Quick Check:

   User management commands = automate user tasks [OK]

Hint: Look for user management commands like useradd/userdel [OK]

Common Mistakes:

• Confusing user management with system updates
• Thinking it changes network settings
• Assuming it modifies system hostname

2. Which of the following is the correct syntax to add a new user named alice in a bash script?

easy

A. createuser alice

B. adduser alice

C. newuser alice

D. useradd alice

Solution

1. Step 1: Recall the standard command for adding users

   The standard Linux command to add a user is useradd.

2. Step 2: Match the command with the username

   Using useradd alice correctly adds a user named alice.

3. Final Answer:

   useradd alice -> Option D

4. Quick Check:

   Standard add user command = useradd [OK]

Hint: Remember: useradd is the standard command to add users [OK]

Common Mistakes:

• Using adduser which may not be available on all systems
• Typing createuser or newuser which are invalid commands
• Confusing commands with other system utilities

3. What will be the output of this bash snippet if the script is run with root privileges?

if id "bob" &>/dev/null; then
  echo "User exists"
else
  echo "User does not exist"
fi

medium

A. User does not exist

B. User exists

C. Syntax error

D. Permission denied

Solution

1. Step 1: Understand the id command usage

   The command id "bob" checks if user bob exists. If bob does not exist, it returns an error.

2. Step 2: Analyze the if condition and output

   The script redirects errors to /dev/null, so if bob does not exist, the else branch runs, printing "User does not exist".

3. Final Answer:

   User does not exist -> Option A

4. Quick Check:

   id command fails = else branch runs [OK]

Hint: id command success means user exists; else means no user [OK]

Common Mistakes:

• Assuming output shows error messages
• Thinking permission issues cause output
• Confusing command syntax with errors

4. Identify the error in this script snippet that tries to delete a user named charlie:

userdel charlie
if [ $? -eq 0 ]; then
  echo "User deleted"
else
  echo "Failed to delete user"
fi

medium

A. Missing sudo or root privileges to run userdel

B. Incorrect syntax for if statement

C. userdel command should be userremove

D. No error, script works fine

Solution

1. Step 1: Check command permissions

   The userdel command requires root privileges. Running it without sudo or as root will fail.

2. Step 2: Verify script syntax and commands

   The if statement syntax and command are correct, but permission issues cause failure.

3. Final Answer:

   Missing sudo or root privileges to run userdel -> Option A

4. Quick Check:

   userdel needs root = permission error if missing [OK]

Hint: Remember: userdel needs root or sudo to succeed [OK]

Common Mistakes:

• Thinking userdel syntax is wrong
• Using wrong command name like userremove
• Ignoring permission requirements

5. You want to write a bash script that adds multiple users from a list in a file users.txt. Which script snippet correctly reads each username and adds the user, skipping empty lines?

hard

A. read users.txt | while read user; do
useradd $user
done

B. for user in $(cat users.txt); do
useradd $user
done

C. while read user; do
[ -z "$user" ] && continue
useradd "$user"
done < users.txt

D. cat users.txt | while useradd; do
echo $user
done

Solution

1. Step 1: Understand reading lines safely

   Using while read user reads each line safely, including spaces, and allows skipping empty lines.

2. Step 2: Check skipping empty lines and adding users

   The condition [ -z "$user" ] && continue skips empty lines. Then useradd "$user" adds the user correctly.

3. Final Answer:

   while read user; do [ -z "$user" ] && continue useradd "$user" done < users.txt -> Option C

4. Quick Check:

   Safe line read + skip empty + add user = while read user; do [ -z "$user" ] && continue useradd "$user" done < users.txt [OK]

Hint: Use while read and check empty lines to avoid errors [OK]

Common Mistakes:

• Using for loop with word splitting causing errors
• Incorrect pipe usage with cat and while
• Not skipping empty lines causing useradd errors