#!/bin/bash
s=0
while true
do
echo "...................+"
echo "...................-"
echo "...................*"
echo ".................../"
echo "...................q"
echo "Please type your word:(e.g.1 + 2)"
read a b c
case $b in
+)
let s=a+c
echo " $a + $c =" $s;;
-)
let s=a-c
echo " $a - $c =" $s;;
\*)
let s=a*c
echo " $a * $c =" $s;;
\/)
let s=a/c
echo " $a / $c =" $s;;
esac
case $a in
q) break ;;
esac
done