command to compare two directories in linux recursively

[user@host tmp]$ cat compare.sh

#!/bin/bash

prefix1='/tmp/directory1/messaging' # First directory without trailing /

prefix2='/tmp/directory2/messaging' # Second directory without trailing /

find -L $prefix1 -type f | while read filename; do

name="${filename#$prefix1*}"

sum1="$(md5sum -b $prefix1$name)"

sum2="$(md5sum -b "$prefix2$name")"

if [ "${sum1% *}" = "${sum2% *}" ]; then

echo "ok: $prefix1$name" >> /dev/null

#echo ""

else

echo "not ok: $prefix1$name"

diff $prefix1$name $prefix2$name

fi

done