diffdirdelta.sh

#!/bin/bash

# "diff" two different directories, outputting the filesize difference between them.
#
# $ diffdir foo bar
# baz.js: 52b 56p - -4b


# ensure we are only dealing with two directories
if [[ "$#" -ne 2  || !( -d "$1" && -d "$2") ]]; then
  echo "need to pass two valid directories";
  exit 1
fi

FILES_TO_DIFF=$(/usr/bin/diff -qr "$1" "$2" | awk '{print $2}')

for file in $FILES_TO_DIFF; do
  filename=$(basename $file);
  file1="$1"/"$filename"
  file2="$2"/"$filename"
  file1size=$(du -k "$file1" | cut -f1)
  file2size=$(du -k "$file2" | cut -f1)
  echo $filename  $file1size  $file2size - $(expr $file1size - $file2size)
done;

du outputs in blocks, but stat -f "%z" does the trick (outputs in bytes)