Lists disk usage of files in the current folder by file extension

diskusage_by_ext.sh

# Based on answer from Yuval here: https://askubuntu.com/a/1214458/687179
# output pairs in the format: `filename size`.
# I used `nawk` because it's faster.
find . -type f -print0 | xargs -0 stat -f'%N %z' | awk '
  {
    split($1, a, ".");       # first token is filename
    ext = a[length(a)];      # only take the extension part of the filename
    size = $2;               # second token is file size
    total_size[ext] += size; # sum file sizes by extension
  }
  END {
    # print sums
    for (ext in total_size) {
      print ext, total_size[ext];
    }
  }' | sort -rn -k2,2