random_wallpaper.sh

#!/bin/bash

shopt -s nullglob
cd ~/Obrazy/Tapety/

while true; do
	files=()
	for i in *.jpg *.png; do
		[[ -f $i ]] && files+=("$i")
	done
	range=${#files[@]}

    if grep -q "sway" <<< "$XDG_CURRENT_DESKTOP" ; then
        output "*" background "${files[RANDOM % range]}" fill
	else
	    ((range)) && feh --bg-scale "${files[RANDOM % range]}"
	fi

	sleep 15m
done