KISS Linux Background Update and Display

bud

#!/bin/sh -f
#
# POSIX sh background setter

img() {
    [ -d "$1" ] && {
        set +f
        set -f -- "$1/"*
        shift "$(shuf -i "1-$#" -n 1)"
    }

    [ -f "${img:=$1}" ] || exit 1

    printf '%s\n' "$img"
}

main() {
#    mkdir -p "${cache_dir:=${XDG_CACHE_HOME:=${HOME}/.cache}/bud}"

    img "$1"

    display \
        -page 3200x \
        -sample 3200x \
        -window root \
        "$img" &
}

main "$1"