echo " a.read a file"
echo " b.create a file"
echo " c.add on existing file"
echo " d. exit"
"; do
echo "Enter a,b,c or d: \c"
read answer
echo
case "$answer" in
a)

read answer
cat $answer
;;
b)

read answer
echo
cat> $answer
;;
c)

read answer
echo
cat>> $answer
;;
d)
break
;;
*)

continue
;;
esac
done
echo "Done"