Simple comparator script for UNIX-like systems. i.e. works on FreeBSD and Mac.

comparator.sh

#!/bin/bash

#Parses 1st and 2nd argument as directory paths and compares MD5 sums recursively
#Usage: ./comparator.sh /mount/directory /other_mount/directory

find "$1" -type f | while read filename; do

name="${filename#$1*}"
sum1="$(md5 -q "$1$name")"
sum2="$(md5 -q "$2$name")"

if [ "${sum1% *}" = "${sum2% *}" ]; then
  echo "ok: $1$name"
else
  echo "error: $1$name"
fi

done