User account management script in Bash Scripting - Practice Problems & Coding Challenges

Challenge - 5 Problems

💻 Command Output

intermediate

What is the output of this user creation script snippet?

Consider this bash script snippet that attempts to add a user and set a password. What will be the output if the user 'alice' already exists on the system?

Bash Scripting

if id "alice" &>/dev/null; then
  echo "User alice already exists"
else
  sudo useradd alice
  echo "alice:password123" | sudo chpasswd
  echo "User alice created"
fi

A User alice created

B Error: useradd command not found

C User alice already exists

D Password set for alice

💡 Hint

The script checks if the user exists before creating.

The script uses 'id alice' to check if the user exists. If yes, it prints 'User alice already exists' and skips creation.

📝 Syntax

intermediate

Identify the syntax error in this user deletion script

Which option correctly fixes the syntax error in this bash script that deletes a user and their home directory? Original snippet: sudo userdel -r $username if [ $? -eq 0 ] echo "User deleted" else echo "Failed to delete user" fi

Bash Scripting

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

A Add 'then' after the if condition: if [ $? -eq 0 ]; then

B Replace 'fi' with 'end'

C Remove the else block entirely

D Add a semicolon after echo statements

💡 Hint

Bash if statements require 'then' after the condition.

The 'if' statement must have 'then' after the condition to be valid syntax.

🔧 Debug

advanced

Why does this script fail to add multiple users from a file?

This script reads usernames from a file and tries to add them. Why does it fail to add any users? Script: while read user; do sudo useradd $user echo "Added $user" done < users.txt

Bash Scripting

while read user; do
  sudo useradd "$user"
  echo "Added $user"
done < users.txt

A The script lacks quotes around $user causing word splitting

B The script does not handle empty lines or spaces in usernames

C The input redirection syntax is incorrect

D The read command trims trailing spaces causing empty usernames

💡 Hint

Variables with spaces need quotes in bash commands.

Without quotes, usernames with spaces split into multiple arguments causing useradd to fail.

🚀 Application

advanced

What is the value of the variable 'count' after running this script?

This script counts how many users in the system have a home directory under /home. What is the value of 'count' after execution? Script: count=0 for user in $(cut -d: -f1 /etc/passwd); do home_dir=$(getent passwd "$user" | cut -d: -f6) if [[ $home_dir == /home/* ]]; then ((count++)) fi done echo $count

Bash Scripting

count=0
for user in $(cut -d: -f1 /etc/passwd); do
  home_dir=$(getent passwd "$user" | cut -d: -f6)
  if [[ $home_dir == /home/* ]]; then
    ((count++))
  fi
done
echo $count

A The total number of users in /etc/passwd

B Zero, because the script has a syntax error

C The number of users without home directories

D The number of users with home directories under /home

💡 Hint

The script filters users by home directory path prefix.

The script increments count only for users whose home directory starts with /home.

🧠 Conceptual

expert

Which option best describes the purpose of the 'usermod' command in user management scripts?

In bash scripts managing users, what is the primary purpose of the 'usermod' command?

A To create a new user account with default settings

B To modify existing user account properties like username, home directory, or shell

C To delete a user account and remove its files

D To list all current user accounts on the system

💡 Hint

Think about changing user details without deleting or creating.

The 'usermod' command changes properties of existing users, such as username or shell.