Simple gnome 3 wallpaper switcher

Gnome 3 uses dconf rather than gconf, so gconf-based wallpaper switchers won't work. Luckily, the actual change is only that one line if you do it right.

I created a script that uses a cache of wallpapers. First, here's the script that searches your wallpapers directory for actual images (to filter out stupid Thumbs.db and things like that) and adds them to a file.

#!/bin/bash
find "$HOME/wallpapers" -type f \
  -exec sh -c 'file "$1" | grep -q "image"' '{}' '{}' \; \
  -a -fprint wallpapers-cache-new \
\
&& mv wallpapers-cache-new wallpapers-cache

That outputs a file called wallpapers-cache, and the wallpaper switcher itself uses that:

#!/bin/bash

WALLPAPERS="$HOME/wallpapers-cache"
export DISPLAY=:0

r=`rl -c1 $WALLPAPERS`

gsettings set org.gnome.desktop.background picture-uri "file://$r"

rl comes from the randomize-lines package in Debian-based OSes.

Add the latter to crontab to change your desktop as often as you'd like. Voilà!