GNOME: Switch wallpaper each login
Load random wallpaper on each login
$ cat ~/.config/autostart/wallpaper.desktop
[Desktop Entry]
Name=Wallpaper
GenericName=Set wallpaper on GNOME startup
Comment=Set wallpaper on GNOME startup
Exec=/home/ajg/bin/gnome-wallpaper.sh
Terminal=false
Type=Application
X-GNOME-Autostart-enabled=true
$ cat ~/bin/gnome-wallpaper.sh
#!/usr/bin/env bash
WALLPAPER="$(~/bin/wallpaper.sh)"
gsettings set org.gnome.desktop.background picture-uri "file://$WALLPAPER"
gsettings set org.gnome.desktop.background picture-uri-dark "file://$WALLPAPER"
$ cat ~/bin/wallpaper.sh
#!/bin/bash
find ~/Pictures/Wallpapers/ -type f \
\( -iname '*.jpg' -o -iname "*.png" \) \
| shuf -n 1