UNIX for Beginners Questions & Answers

array1=( "macOS Mojave" "iTunes" )
cd /Volumes
array2=( * )

macOS Mojave
iTunes
Mac me

 DIFF=`echo "${array1[@]}" "${array2[@]}" | tr ' ' '\n' | sort | uniq -u`

for x in "${DIFF[@]}"
        do
                echo -e "$x"
        done

Mac
me

Mac me

echo "${array1[@]}" "${array2[@]}" | tr ' ' '\n' | sort | uniq -u

printf "%s\n" "${array1[@]}" "${array2[@]}" | sort | uniq -u

IFS=$'\n'
echo "${array1[*]}"$'\n'"${array2[*]}" | sort | uniq -u
Mac me

length=${#DIFF[@]}
for (( i=0; i<${length}; i++ ));
do
echo ${DIFF[i]}
done

DIFF[0] Mac me 
Windows
DIFF[0] Mac me Windows

DIFF[0] Mac me
DIFF[1] Windows

arr1=( "macOS Mojave" "iTunes" )
cd /Volumes
arr2=( * )

IFS=$'\n'
DIFF=`echo "${arr1[*]}"$'\n'"${arr2[*]}" | sort | uniq -u`
VOLCOUNT=`printf "%s\n" "${arr1[@]}" "${arr2[@]}" | sort | uniq -u | wc -l`
if [ "$VOLCOUNT" -gt "$COUNT" ]; then
        for x in "${DIFF[@]}"
        do
                echo -e "To: ${TO}\nSubject: Alert: ${SUBJECT}$x \n\n$SIGN" | $MAIL -a gmail ${TO}
        done
else
        >/dev/null 2>&1
fi
unset $IFS
exit 0