finally changing the wallpaper, mostly in testing however

files/wallpaper.sh

@@ -0,0 +1,11 @@
+#!/bin/bash
+
+dbus-send --session --dest=org.kde.plasmashell --type=method_call /PlasmaShell org.kde.PlasmaShell.evaluateScript string:
+var Desktops = desktops();                                                                                                                       
+for (i=0;i<Desktops.length;i++) {
+        d = Desktops[i];
+        d.wallpaperPlugin = "org.kde.image";
+        d.currentConfigGroup = Array("Wallpaper",
+                                    "org.kde.image",
+                                    "General");
+        d.writeConfig("Image", "file:///PATH/TO/IMAGE.png");