i3: Randomize wallpaper on login

tree/.config/i3/config

@@ -201,7 +201,7 @@ client.background       #ffffff
 exec --no-startup-id xcompmgr -c -f -n
 
 # wallpaper
-exec --no-startup-id feh --bg-scale ~/.config/wallpapers/3440x1440/planets.jpg
+exec --no-startup-id start-wallpaper
 
 # autostart
 exec --no-startup-id nextcloud

tree/.local/bin/random-file-of

@@ -0,0 +1,3 @@
+#!/bin/sh
+
+fd -d1 . $@ | sort -R | head -n 1

tree/.local/bin/start-wallpaper.tpl

@@ -0,0 +1,11 @@
+#!/bin/sh
+
+{% if hostname == "sputnik" %}
+
+feh --bg-scale $(random-file-of ~/.config/wallpapers/3440x1440)
+
+{% else %}
+echo "Wallpaper not configured for this system"
+exit 1
+{% end %}
+