# List directory contents by size, for items that are larger than 1M.
#
# $1 directory, optional, defaults to $PWD
# $2 traversal depth, optional, defaults to 1, requires numeric value
# $3 sort order, optional, defaults to ascending unless r is specified

list_by_size () {
  dir=${1:-"$PWD"}
  depth=${2:-1}
  sort=${3:-""}

  if [[ -d "${dir}" && $depth -gt 0 && (-z "${sort}"
    || "${sort}" = "r") ]]; then
    du -d$depth "$dir" \
      | sort -k1 -n"$sort" \
      |	awk '{M = 1024; G = 1024^2; if ($1 >= G) {print $1/G"G\t"$2}
          else if ($1 >= M) {print $1/M"M\t"$2}}' \
      | column -t;
  else
    echo "list_by_size usage: list_files_by_size dirname depth" >&2;
  fi
}