A little utility I wrote for myself to pick a random wallpaper.
First, it finds where your current wallpaper exists. Then it looks for other images1 in that same directory and picks one at random. Then it sets that as your new wallpaper.
You'll need to have Rust installed.
$ git clone https://github.com/MCluck90/random-wallpaper-rs.git
$ cd random-wallpaper-rs
$ cargo run --release
1: Images are defined as files which end with one of the following extensions: .bmp, .gif, .jpg, .jpeg, .png. It does not check if these are valid files.