shell scripting project #1

day02/pam-main.sh

@@ -0,0 +1,199 @@
+#/bin/bash
+# Date: 10/09/2025
+# This is script for user & group management in linux.
+# Usage: pam-main.sh
+# Author: Bhikesh Khute
+RED='\033[0;31m'
+GREEN='\033[0;32m'
+YELLOW='\033[1;33m'
+WHITE='\033[1;37m'
+PURPLE='\033[0;35m' 
+CYAN='\033[0;36m'
+NC='\033[0m'
+echo "------------------------------------------------------"
+echo -e "=======\033[45m Welcome to Login Management System \033[0m======="
+echo "------------------------------------------------------"
+while true; do
+if [[ $EUID -ne 0 ]]; then
+  echo "This script must be run as root (sudo)."; exit 1
+fi
+done
+while true; do
+echo -e "${RED}1. Add user${NC}"
+echo -e "${GREEN}2. Delete user${NC}"
+echo -e "${PURPLE}3. Modify user - Add user to multiple groups${NC}"
+echo -e "${CYAN}4. Modify user - Changing Login Shell${NC}"
+echo -e "${YELLOW}5. Modify user - Disable Login${NC}"
+echo -e "${GREEN}6. Modify user - Enable Login${NC}"
+echo -e "${CYAN}7. Modify user - Add user to sudo group${NC}"
+echo -e "${RED}8. Add group${NC}"
+echo -e "${GREEN}9. Backup directories${NC}"
+echo -e "${PURPLE}10. Exit${NC}"
+read -p "Select the option: " choice
+case $choice in 
+	1) 
+	read -rp "Enter first and last name of the user(Example - Ramesh Sippy): " fullname #Example - Ramesh Sippy
+	username="$(awk '{print tolower($1 $2)}' <<<"$fullname")"
+	if id -u "$username" >/dev/null 2>&1; then
+	  echo "User '$username' already exists."; echo "-----------------------------------------------"; unset username; break
+	fi
+	if useradd -c "$fullname" -m -s /bin/bash "$username" >/dev/null 2>&1; then
+	  randpass="$(openssl rand -base64 14 2>/dev/null || tr -dc 'A-Za-z0-9!@#%+=' </dev/urandom | head -c16)"
+	  printf '%s:%s\n' "$username" "$randpass" | chpasswd
+	  passwd --expire "$username" >/dev/null
+	  echo "$username created. Temporary password: $randpass (will be forced to change on first login)"
+	else
+	  echo "Failed to create user '$username'."
+	fi
+	echo "-----------------------------------------------"
+	unset username
+	unset randpass
+	;;
+        2)
+	awk -F: '$3 >= 1000 {print $1}' /etc/passwd | nl -w1 -s". "
+	read -r -p "Select user NUMBER to be deleted: " choice
+	[[ "$choice" =~ ^[0-9]+$ ]] || { echo "Invalid selection."; continue; }
+	username="$(awk -F: '$3 >= 1000 {print $1}' /etc/passwd | sed -n "${choice}p")"
+	if [[ -z "${username:-}" ]]; then echo "Invalid selection."; else
+	    current="${SUDO_USER:-$USER}"
+	    if [[ "$username" == "$current" ]]; then echo "Refusing to delete the current user '$current'."; else
+	    read -r -p "Type the username '$username' to confirm deletion: " confirm
+	    if [[ "$confirm" == "$username" ]]; then
+	      if userdel -r "$username" >/dev/null 2>&1; then
+	        echo "$username deleted."
+	      else
+	        echo "Failed to delete '$username'."
+	      fi
+	    else
+	      echo "Confirmation mismatch. Aborting."
+	    fi
+	  fi
+	fi
+	echo "-------------------------------------------------"
+	unset username
+	unset choice
+	unset current
+	;;
+	3)
+	echo "------------------Normal Users List------------------"
+	awk -F: '$3 >= 1000 {print $1}' /etc/passwd | nl -w1 -s". " #Filtering only normal users
+	echo "------------------Group List-------------------------"
+        getent group | awk -F: '{print $1}' | nl -w1 -s". "
+	read -p "Select the existing user NUMBER: " choice
+	read -p "Select the group NUMBER to be added: " gchoice
+	username=$(awk -F: '$3 >= 1000 {print $1}' /etc/passwd | sed -n "${choice}p")
+	grpname=$(awk -F: '$3 >= 1000 {print $1}' /etc/group | sed -n "${gchoice}p")
+        if [[ -n "${username:-}" && -n "${grpname:-}" ]]; then
+	  usermod -aG "$grpname" "$username" && echo "$username added to group $grpname"
+	else
+	  echo "Invalid selection."
+	fi
+	echo "-------------------------------------------------"
+	unset grpname
+	unset username
+	unset choice
+	unset gchoice
+	;;
+        4)
+	echo "------------------Normal Users List------------------"
+	awk -F: '$3 >= 1000 {print $1}' /etc/passwd | nl -w1 -s". " #Filtering only normal users
+	read -p "Select the existing username: " choice
+	username=$(awk -F: '$3 >= 1000 {print $1}' /etc/passwd | sed -n "${choice}p")
+	curr_shell=$(getent passwd "$username" | cut -d: -f7)
+	if [ "$curr_shell" = "/bin/sh" ]; then
+		    chsh -s /bin/bash "$username"
+		    echo "$username's shell is successfully changed to bash"
+		    echo "-------------------------------------------------"
+	elif [ "$curr_shell" = "/bin/bash" ]; then
+		    chsh -s /bin/sh "$username"
+		    echo "$username's shell is successfully changed to sh"
+		    echo "-----------------------------------------------"
+	fi
+	unset username
+	unset curr_shell
+	unset choice
+	;;
+        5)
+	echo "------------------Normal Users List------------------"
+	awk -F: '$3 >= 1000 {print $1}' /etc/passwd | nl -w1 -s". " #Filtering only normal users
+	read -p "Select the existing username: " choice
+	username=$(awk -F: '$3 >= 1000 {print $1}' /etc/passwd | sed -n "${choice}p")
+	if getent passwd "$username" > /dev/null; then
+		nologin_path="$(command -v nologin || echo /sbin/nologin)"
+		echo "Changing $username shell to $nologin_path"
+		usermod -s "$nologin_path" "$username"
+		echo "$username's login disabled."
+		echo "-------------------------------"
+	else
+		echo "User $username not found!"
+	fi
+	unset username
+	unset choice
+	unset nologin_path
+	;;
+        6)
+        echo "------------------Normal Users List------------------"
+        awk -F: '$3 >= 1000 {print $1}' /etc/passwd | nl -w1 -s". " #Filtering only normal users
+        read -rp "Select the existing user: " choice
+	[[ "$choice" =~ ^[0-9]+$ ]] || { echo "Invalid selection."; continue; }
+	username="$(awk -F: '$3 >= 1000 {print $1}' /etc/passwd | sed -n "${choice}p")"
+	if [[ -n "${username}" ]] && getent passwd "$username" > /dev/null; then
+		echo "Changing $username shell to /bin/bash"
+		usermod -s /bin/bash "$username"
+		echo "---------------------------------------------------"
+        else
+                echo "User $username not found!"
+	fi
+	unset username
+	unset choice
+        ;;
+        7)
+	echo "------------------Normal Users List------------------"
+	awk -F: '$3 >= 1000 {print $1}' /etc/passwd | nl -w1 -s". " #Filtering only normal users
+	read -p "Enter the existing username: " choice
+	username=$(awk -F: '$3 >= 1000 {print $1}' /etc/passwd | sed -n "${choice}p")
+	admin_group="$(getent group sudo >/dev/null 2>&1 && echo sudo || echo wheel)"
+	usermod -aG "$admin_group" "$username"
+	echo "$username added to $admin_group group."
+	echo "----------------------------------------------------------------------"
+	unset username
+	unset choice
+	unset admin_group
+	;;
+        8)
+	read -r -p "Enter the group name to be added: " grpname
+	if getent group "$grpname" >/dev/null 2>&1; then
+	  echo "Group '$grpname' already exists."
+	elif groupadd "$grpname" >/dev/null 2>&1; then
+	  echo "--------------------$grpname added.------------------"
+	else
+	  echo "Failed to add group '$grpname'."
+	fi
+	;;
+        9)
+	mkdir -p /opt/dir_backups
+	awk -F: '$3 >= 1000 {print $1}' /etc/passwd | nl -w1 -s". "
+	read -r -p "Select the user NUMBER to associate with the backup: " choice
+	username="$(awk -F: '$3 >= 1000 {print $1}' /etc/passwd | sed -n "${choice}p")"
+	read -r -p "Specify the absolute path of the directory to be backed up: " dirback
+	if [[ -d "$dirback" ]]; then
+	  ts="$(date +%F_%H-%M-%S)"
+	  tar -czf "/opt/dir_backups/${username}_$ts.tar.gz" -C "$dirback" . >/dev/null 2>&1 && \
+	    echo "Backup completed successfully" || echo "Backup failed"
+	else
+	  echo "Directory '$dirback' not found."
+	fi
+	echo "-----------------------------"
+	unset username
+	unset dirback
+	unset choice
+	unset ts
+	;;	
+        10)
+	break;
+	;;
+        *)
+	echo "Invalid option. Try again."
+	;;
+esac
+done