#!/bin/sh
function _diffab(){
x=0
for i in `cat $1`;do
for j in `cat $2`;do
if [ $i == $j ];then
x=1
break;
fi
done
if [ $x -ne 1 ];then
echo $i
fi
x=0
done
}
if [ "$1" == "" ] || [ "$2" == "" ];then echo "use like this: $0 filea fileb" else { _diffab $1 $2 _diffab $2 $1 } fi