rsync source with destination every time any change occurs in source

zwatch.sh

#!/bin/sh
set -eu
trap "echo 'usage: $0 <pier> <base> [desk]' >&2" EXIT
pier=$1
base=$2
if [ 3 -eq $# ]; then
  desk=$3
else
  desk=base
fi
trap - EXIT
set -x
rsync -avL --delete $base/ $pier/$desk/
fswatch -o $base | xargs -n1 -I{} sh -c "rsync -avL --delete $base/ $pier/$desk/; date"