mkuser.sh: validate input and wire up user removal

Check username format and existence before adding or deleting, fix the
Arch default group list, remove the debug pause, and make menu option 2
call Remove_user.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

mkuser.sh

@@ -8,6 +8,16 @@ Create_user(){
 	echo -n "Username: "
 	read -r uname
 
+	if [[ ! "${uname}" =~ ^[a-z_][a-z0-9_-]*[$]?$ ]]; then
+		echo "Error: Invalid username format (use lowercase letters, numbers, hyphens, underscores)"
+		return 1
+	fi
+
+	if id "${uname}" >/dev/null 2>&1; then
+		echo "Error: User '${uname}' already exists"
+		return 1
+	fi
+
 	echo "Additional Groups: "
 	echo
 	echo "[1] - Arch Linux Defaults"
@@ -16,18 +26,19 @@ Create_user(){
 	read -r dgroups
 
 	if [ "${dgroups}" = "1" ];then
-		addgroups="power, wheel, optical network, video, audio, storage"
+		addgroups="power,wheel,optical,network,video,audio,storage"
 	elif [ "${dgroups}" = "2" ];then
 		addgroups="disk,wheel,storage,audio,video,optical,lp,network,dbus,xbuilder"
 	elif [ "${dgroups}" = "3" ];then
 		echo -n "Enter desired groups (comma separated): "
 		read -r custgroups
 		addgroups="${custgroups}"
+	else
+		addgroups=""
 	fi
-	echo "${addgroups}"
-	read -r -n 1 -p "wait"
+
 	useradd -m -g users -G "${addgroups}" -s /bin/bash "${uname}"
-        passwd "${uname}"
+	passwd "${uname}"
 	echo
 
 	if [ -d /home/"${uname}" ];then
@@ -42,11 +53,22 @@ Remove_user(){
 	echo -n "Username to delete: "
 	read -r duser
 
-	userdel ${duser}
-	if [ -d /home/${duser} ];then
-		rm -R /home/${duser}
+	if [[ ! "${duser}" =~ ^[a-z_][a-z0-9_-]*[$]?$ ]]; then
+		echo "Error: Invalid username format"
+		return 1
+	fi
+
+	if ! id "${duser}" >/dev/null 2>&1; then
+		echo "Error: User '${duser}' does not exist"
+		return 1
+	fi
+
+	userdel "${duser}"
+	if [ ! -d /home/"${duser}" ];then
+		echo "User ${duser} deleted"
 	else
-		echo "User deletion failed"
+		rm -R /home/"${duser}"
+		echo "User ${duser} deleted"
 	fi
 }
 main(){
@@ -64,10 +86,13 @@ main(){
 
 		if [ "${choice}" = "1" ];then
 			Create_user
+		elif [ "${choice}" = "2" ];then
+			Remove_user
 		else
-			echo "no"
+			echo "Invalid option"
 		fi
-done
+		read -r -n 1 -p "Press any key to continue..."
+	done
 }
 
 case "$1" in