diff --git a/README.md b/README.md
index fd83a82..b4b19fe 100644
--- a/README.md
+++ b/README.md
@@ -1,5 +1,5 @@
 # Core System
-[![License: GPL v3](https://img.shields.io/badge/License-GPL%20v3-blue.svg)](./LICENSE.txt)
+[![License: GPL v3](https://img.shields.io/badge/License-GPL%20v3-blue.svg)](./LICENSE.txt) [![Codacy Badge](https://api.codacy.com/project/badge/Grade/6e66409513d7451b949afbf0373ba71f)](https://www.codacy.com/manual/KevinFrantz/core-system?utm_source=github.com&utm_medium=referral&utm_content=KevinFrantz/core-system&utm_campaign=Badge_Grade)
 
 This repository contains scripts to set up an working client system, maintain it and to save the data on an USB stick.
 It's adapted to the needs of Kevin Veen-Birkenbach aka. Frantz.
diff --git a/scripts/import-data-from-system.sh b/scripts/import-data-from-system.sh
index bba8e2f..4b4e808 100644
--- a/scripts/import-data-from-system.sh
+++ b/scripts/import-data-from-system.sh
@@ -3,7 +3,7 @@
 # @author Kevin Veen-Birkenbach [aka. Frantz]
 # @param $1 If the first parameter is "reverse" the data will be exported to the system
 DATA_FOLDER=$(readlink -f "$(dirname "$(readlink -f "${0}")")/../data");
-if [ -z $(mount | grep $DATA_FOLDER) ]
+if [ -z "$(mount | grep $DATA_FOLDER)" ]
   then
     echo "The data folder $DATA_FOLDER is locked. You need to unlock it!"
     bash "$(dirname "$(readlink -f "${0}")")/unlock.sh" || exit 1;
@@ -26,9 +26,9 @@ do
       then
         echo "The destination file allready exists!";
         echo "Difference:"
-        diff $destination $source
+        diff "$destination" "$source"
     fi
-    destination_dir=$(dirname $destination)
+    destination_dir=$(dirname "$destination")
     mkdir -p "$destination_dir"
     if [ -f "$source" ]
       then
diff --git a/scripts/lock.sh b/scripts/lock.sh
index 270035b..a3f2001 100644
--- a/scripts/lock.sh
+++ b/scripts/lock.sh
@@ -3,4 +3,4 @@
 # @author Kevin Veen-Birkenbach [aka. Frantz]
 DECRYPTED=$(readlink -f "$(dirname "$(readlink -f "${0}")")/../data");
 echo "Locking directory $DECRYPTED..."
-fusermount -u $DECRYPTED && echo "Data is now encrypted." && echo "Removing directory $DECRYPTED..." && rmdir $DECRYPTED
+fusermount -u "$DECRYPTED" && echo "Data is now encrypted." && echo "Removing directory $DECRYPTED..." && rmdir "$DECRYPTED"
diff --git a/scripts/system-setup.sh b/scripts/system-setup.sh
index eefb68c..31f328b 100644
--- a/scripts/system-setup.sh
+++ b/scripts/system-setup.sh
@@ -22,7 +22,7 @@ fi
 echo "Synchronizing gui tools..."
 sudo pacman --needed -S gnome-shell-extensions
 echo "Install NASA picture of the day GNOME extension..."
-git clone https://github.com/Elinvention/gnome-shell-extension-nasa-apod.git $HOME/.local/share/gnome-shell/extensions/nasa_apod@elinvention.ovh
+git clone https://github.com/Elinvention/gnome-shell-extension-nasa-apod.git "$HOME/.local/share/gnome-shell/extensions/nasa_apod@elinvention.ovh"
 gnome-shell-extension-tool -e nasa_apod@elinvention.ovh
 echo "Synchronizing web tools..."
 sudo pacman --needed -S chromium firefox firefox-ublock-origin firefox-extension-https-everywhere firefox-dark-reader firefox-noscript
@@ -31,6 +31,8 @@ sudo pacman --needed -S gimp
 echo "Synchronizing communication tools..."
 yay pacman --needed -S slack-desktop skypeforlinux-stable-bin
 echo "Synchronizing development tools..."
+echo "Synchronizing code quality tools..."
+sudo pacman --needed -S shellcheck
 echo "Synchronizing visualization tools..."
 sudo pacman --needed -S dia
 echo "Synchronizing IDE's..."
@@ -62,7 +64,7 @@ sudo pacman --needed -S docker
 echo "Synchronizing orchestration tools..."
 sudo pacman --needed -S ansible
 echo "Add current user($USER) to user group docker..."
-sudo usermod -a -G docker $USER
+sudo usermod -a -G docker "$USER"
 echo "Enable docker service..."
 sudo systemctl enable docker --now
 echo "Synchronizing games..."
diff --git a/scripts/unlock.sh b/scripts/unlock.sh
index 7f7d186..028468d 100644
--- a/scripts/unlock.sh
+++ b/scripts/unlock.sh
@@ -5,6 +5,6 @@ ENCRYPTED=$(readlink -f "$(dirname "$(readlink -f "${0}")")/../.encrypted");
 DECRYPTED=$(readlink -f "$(dirname "$(readlink -f "${0}")")/../data");
 echo "Unlocking directory $DECRYPTED..."
 echo "Creating directory $DECRYPTED..."
-mkdir $DECRYPTED
+mkdir "$DECRYPTED"
 echo "Encrypting directory $DECRYPTED to $DECRYPTED..."
-encfs $ENCRYPTED $DECRYPTED && echo "ATTENTION: DATA IS NOW DECRYPTED!"
+encfs "$ENCRYPTED" "$DECRYPTED" && echo "ATTENTION: DATA IS NOW DECRYPTED!"