#! /bin/bash

tmp=$(mktemp)
tmp2=$(mktemp)
tmp3=$(mktemp)

cat /mnt/pack > $tmp
cat /mnt/pack2 > $tmp2

if [ $(cat $tmp2 | wc -l) -gt $(cat $tmp | wc -l) ];then
    cat $tmp2 > $tmp3
    cat $tmp > $tmp2
    cat $tmp3 > $tmp
fi

for ((i=1; i<=$(cat $tmp | wc -l) ; i++))
do 
    if grep -Fxq "$(awk -v n=$i 'NR==n' $tmp)" $tmp2; then 
        :
    else
        echo "$(awk -v n=$i 'NR==n' $tmp)"
    fi
done

rm $tmp
rm $tmp2
rm $tmp3