updated install script

scripts/installers/ubuntu-20.04-install.sh

@@ -29,7 +29,7 @@ function install_os_tools() {
 function add_arm_user() {
     echo -e "${RED}Adding arm user${NC}"
     # create arm group if it doesn't already exist
-    if ! [ $(getent group arm) ]; then
+    if ! [[ "$(getent group arm)" ]]; then
         sudo groupadd arm
     else
         echo -e "${RED}arm group already exists, skipping...${NC}"
@@ -103,12 +103,12 @@ function clone_arm() {
     fi
 
     git clone --recurse-submodules https://github.com/shitwolfymakes/automatic-ripping-machine.git arm
-    
+
     cd arm
     git submodule update --init --recursive
     git submodule update --recursive --remote
     cd ..
-    
+
     sudo chown -R arm:arm /opt/arm
     sudo find /opt/arm/scripts/ -type f -iname "*.sh" -exec chmod +x {} \;
 }
@@ -175,8 +175,8 @@ function setup_autoplay() {
         else
             echo -e "\n${dev}  /mnt${dev}  udf,iso9660  users,noauto,exec,utf8  0  0 \n" | sudo tee -a /etc/fstab
         fi
-        sudo mkdir -p /mnt$dev
-        sudo chown arm:arm /mnt$dev
+        sudo mkdir -p "/mnt$dev"
+        sudo chown arm:arm "/mnt$dev"
     done
 }
 
@@ -206,12 +206,12 @@ function install_armui_service() {
 
 function launch_setup() {
     echo -e "${RED}Launching ArmUI first-time setup${NC}"
-    site_addr=`sudo netstat -tlpn | awk '{ print $4 }' | grep .*:8080`
-    if [ -z $site_addr ]; then
+    site_addr=$(sudo netstat -tlpn | awk '{ print $4 }' | grep ".*:8080")
+    if [[ -z "$site_addr" ]]; then
         echo -e "${RED}ERROR: ArmUI site is not running. Run \"sudo systemctl status armui\" to find out why${NC}"
     else
         echo -e "${RED}ArmUI site is running on http://$site_addr. Launching setup...${NC}"
-        sudo -u arm nohup xdg-open http://$site_addr/setup > /dev/null 2>&1 &
+        sudo -u arm nohup xdg-open "http://$site_addr/setup" > /dev/null 2>&1 &
     fi
 }