#TWSBashBlazeChallenge - Day 3

Challenge: User Account Management

In this challenge, you will create a bash script that provides options for managing user accounts on the system. The script should allow users to perform various user account-related tasks based on command-line arguments.

###################################################################
# Author: Sasiram Beeke
# Date: 02/08/2023
# Description: User Account Management
# Tip: to execute shell give permision +x scriptname
###################################################################


#!/bin/bash
# check if a username exists
username_exists() {
    if id "$1" &>/dev/null; then
        return 0 # Username exists
    else
        return 1 # Username does not exist
    fi
}

# create a new user account
create_user() {
    read -p "Enter the new username: " new_username
    if username_exists "$new_username"; then
        echo "Error: Username already exists. Please choose a different username."
        exit 1
    fi

    read -s -p "Enter the password for the new user: " new_password
    echo
    read -s -p "Confirm the password: " confirm_password
    echo

    if [ "$new_password" != "$confirm_password" ]; then
        echo "Error: Passwords do not match. User account creation failed."
        exit 1
    fi

    # Create the new user account
    sudo useradd -m "$new_username" &>/dev/null
    echo "$new_username:$new_password" | sudo chpasswd
    echo "User account '$new_username' created successfully."
}

# delete an existing user account
delete_user() {
    read -p "Enter the username to be deleted: " del_username
    if ! username_exists "$del_username"; then
        echo "Error: Username does not exist. Deletion failed."
        exit 1
    fi

    # Delete the user account
    sudo userdel -r "$del_username" &>/dev/null
    echo "User account '$del_username' deleted successfully."
}

# reset the password of an existing user account
reset_password() {
    read -p "Enter the username for password reset: " reset_username
    if ! username_exists "$reset_username"; then
        echo "Error: Username does not exist. Password reset failed."
        exit 1
    fi

    read -s -p "Enter the new password for the user: " new_password
    echo
    read -s -p "Confirm the new password: " confirm_password
    echo

    if [ "$new_password" != "$confirm_password" ]; then
        echo "Error: Passwords do not match. Password reset failed."
        exit 1
    fi

    # Reset the user's password
    echo "$reset_username:$new_password" | sudo chpasswd
    echo "Password for user '$reset_username' reset successfully."
}

# list all user accounts on the system
list_users() {
    echo "List of user accounts:"
    echo "Username      UID"
    echo "-----------------"
#    cut -d: -f1,3 /etc/passwd
while IFS=: read -r username _ uid _; do
        echo "- $username   (UID: $uid)"
    done < /etc/passwd
}

# display usage information and available options
usage() {
    echo "Usage: $0 [options]"
    echo "Options:"
    echo "  -c, --create    Create a new user account"
    echo "  -d, --delete    Delete an existing user account"
    echo "  -r, --reset     Reset the password of an existing user account"
    echo "  -l, --list      List all user accounts on the system"
    echo "  -h, --help      Display this help message"
}

# Main script starts here
# Check if there are any command-line arguments
if [ $# -eq 0 ]; then
    usage
    exit 1
fi
while [[ $# -gt 0 ]]; do
    key="$1"

    case $key in
        -c|--create)
            create_user
            ;;
        -d|--delete)
            delete_user
            ;;
        -r|--reset)
            reset_password
            ;;
        -l|--list)
            list_users
            ;;
        -h|--help)
            usage
            ;;
        *)
            echo "Error: Invalid option. Use -h or --help to see available options."
            exit 1
            ;;
    esac
    shift
done

Assume the script is named user_management.sh. Let's go through different scenarios:

Part 1: Account Creation

1. Implement an option -c or --create that allows the script to create a new user account. The script should prompt the user to enter the new username and password.

2. Ensure that the script checks whether the username is available before creating the account. If the username already exists, display an appropriate message and exit gracefully.

After creating the account, display a success message with the newly created username.

Here, I am creating a username with the same name to validate the script.

Part 2: Password Reset

1. Implement an option -r or --reset that allows the script to reset the password of an existing user account. The script should prompt the user to enter the username and the new password.

2. Ensure that the script checks whether the username exists before attempting to reset the password. If the username does not exist, display an appropriate message and exit gracefully.

3. After resetting the password, display a success message with the username and the updated password.

Part 3: Help and Usage Information

1. Implement an option -h or --help that displays usage information and the available command-line options for the script.

Part 4: List User Accounts

1. Implement an option -l or --list that allows the script to list all user accounts on the system. The script should display the usernames and their corresponding user IDs (UID).

Part 5: Account Deletion

1. Implement an option -d or --delete that allows the script to delete an existing user account. The script should prompt the user to enter the username of the account to be deleted.

2. Ensure that the script checks whether the username exists before attempting to delete the account. If the username does not exist, display an appropriate message and exit gracefully.

3. After successfully deleting the account, display a confirmation message with the deleted username.

I attempted to delete a user that does not exist to validate the script.