Yes.
Oh, you want to know how?
while true; do
echo "Letter:"
read a
if [ $a = "a" ]
then
echo "LOL"
elif [ $a = "b" ]
then
echo "ROFL"
fi
done
Of course, you probably want some way to get out of that infinite loop. The command to run in that case is break
. I would write the whole thing like this:
while read -p Letter: a; do
case "$a" in
a) echo LOL;;
b) echo ROFL;;
q) break;;
esac
done
which lets you exit the loop either by entering 'q' or generating end-of-file (control-D).