modify feh-wallpaper-changer to kill previous instance

home/common/optional/desktop/cinnamon/autostart.nix

@@ -10,7 +10,7 @@
       Hidden=false
       Name[en_GB]=feh-wallpaper-changer
       Comment[en_GB]=Periodically changes the wallpaper using feh
-      X-GNOME-Autostart-Delay=0
+      X-GNOME-Autostart-Delay=5
     '';
   };
 }

home/common/optional/desktop/common/x11/scripts/feh-wallpaper-changer.nix

@@ -2,6 +2,15 @@
 {
   home.packages = with pkgs; [
     (writeShellScriptBin "feh-wallpaper-changer" ''
+
+      # Kill previous instance if exists
+      script_name=''${BASH_SOURCE[0]}
+      for pid in $(pidof -x $script_name); do
+          if [ $pid != $$ ]; then
+              kill -9 $pid
+          fi 
+      done
+
       wallpaper_dir="$HOME/.local/share/bg/"
       if [ ! -d "$wallpaper_dir" ]; then
         echo "No wallpapers in $wallpaper_dir, cloning from remote"