#!/bin/bash

cp /dev/null diff.txt

so=$( awk '{ print $2 }' $1 )
sn=$( awk '{ print $2 }' $2 )

for i in $so 
do
 ds=$i
  for j in $sn
  do
   if [ "$j" == "$i" ]
    then
     ds="exist"
      break  
    fi 
  done 
    if [ "$ds" != "exist" ]
    then
     echo $ds >> diff.txt
   fi
done