task3 solution added

Challenges/Day_3/user_management.sh

@@ -0,0 +1,125 @@
+#!/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
+