similar to watch, but with diffs and timestamps (and no cli args)

wdiff.sh

#!/bin/bash

INTERVAL=1

afile="$(mktemp)"
bfile="$(mktemp)"

function show_diff() {
  a="$1"
  b="$2"
  diff="$(git diff --no-index --color "$b" "$a" | tail -n +5)"
  if [[ "$diff" != '' ]]; then
    date
    echo "$diff"
  fi
}

"$@" | tee "$bfile"
echo

while true; do
  sleep 1
  "$@" > "$afile"
  show_diff "$afile" "$bfile"
  sleep 1
  "$@" > "$bfile"
  show_diff "$bfile" "$afile"
done

rm "$afile" "$bfile"