#!/bin/sh -e
# Flatten folder hierarchy
# Args: depth
find -mindepth 2 -maxdepth ${depth:-2} -depth -type d "$@" | while read folder; do
	newname="$(echo "$folder" | sed 's|^./||;s|/|_|g')"
	mv -v "$folder" "$newname"
	parent="$(dirname "$folder")"
	test "$(basename "$folder")" = "$(basename "$parent")" &&
		rm -d "$parent" &&
		mv -v "$newname" "$parent"
done
find -maxdepth ${depth:-2} -empty -type d -delete