#!/usr/bin/env bash
echo "Select Your Options (Seperated by spaces): 1 2 3"
read selection
#exit(1) unless every component of $selection is one of 1, 2, or 3
set -f #to supress glob expansion
for input in $selection; do
case "$input" in 1);; 2);; 3);; *) exit 1;; esac
done
for input in $selection; do
case "$input" in
1 ) echo "you selection option 1"
;;
2 ) echo "you selection option 2"
;;
3 ) echo "you selection option 3"
;;
esac
done