Attempt to udev better

udev/handle-trackman-marble

@@ -1,14 +1,17 @@
 #!/usr/bin/env bash
 set -o errexit
+set -o pipefail
 
 main() {
-  export RUNNING_AS="${RUNNING_AS:-me}"
-  export RUNNING_AS_ID="$(id -u "${RUNNING_AS}")"
-  export XINPUT_EXE="${XINPUT_EXE:=xinput}"
+  export RUNNING_AS="${RUNNING_AS:-dan}"
+  RUNNING_AS_ID="$(id -u "${RUNNING_AS}")"
+  export RUNNING_AS_ID
 
-  export XAUTHORITY="/home/${RUNNING_AS}/.Xauthority"
+  export XINPUT_EXE="${XINPUT_EXE:=xinput}"
+  export XAUTHORITY="/run/user/${RUNNING_AS_ID}/gdm/Xauthority"
   export DBUS_SESSION_BUS_ADDRESS="unix:path=/run/user/${RUNNING_AS_ID}/bus"
-  export DISPLAY=:0
+  : "${DISPLAY:=0}"
+  export DISPLAY
   export HOME="/home/${RUNNING_AS}"
 
 
@@ -25,8 +28,14 @@ main() {
     __get_prop_id "${device_id}" 'Scroll Method Enabled'
   )"
 
+  local scrollbutton
+  scrollbutton="$(
+    __get_prop_id "${device_id}" 'Button Scrolling Button'
+  )"
+
   __run_xinput_as set-prop "${device_id}" "${natscroll_enabled}" 1
   __run_xinput_as set-prop "${device_id}" "${scrollmeth_enabled}" 0 0 1
+  __run_xinput_as set-prop "${device_id}" "${scrollbutton}" 8
 }
 
 __get_device_id() {