shell脚本结合函数实现简单计算器功能

#!/bin/bash
function tool_menu()
{
echo "****************************************************"
echo "* *"
echo "* calculation tools *"
echo "* *"
echo "****************************************************"
}
function menu_choice()
{
echo "A: Add two num."
echo "B: Minus two num."
echo "C: Multiply two num."
echo "D：Divide two num."
echo "Q: Close this function."
echo "Please input your chiose:"
}
function add_num()
{

echo "add."
# echo "please input your number"
# read a
# echo "please input your number"
# read b
let c=$a+$b
echo "$a+$b is:$c"
}
function minus_num()
{

echo "minus."
# echo "please input your number"
# read a
# echo "please input your number"
# read b
let c=$a-$b
echo "$a-$b is:$c"
}
function multiply_num()
{
echo "multiply."
# echo "please input your number"
# read a
# echo "please input your number"
# read b
let c=$a*$b
echo "$a*$b is:$c"

}

function divide_num()
{

echo "divide."
# echo "please input your number"
# read a
# echo "please input your number"
# read b
let c=$a/$b
echo "$a/$b is:$c"

}
function main()
{
clear
tool_menu
while :
do
menu_choice
read menu_choice
read a
read b
case $menu_choice in
A|a) add_num $a $b;;
B|b) minus_num ;;
C|c) multiply_num ;;
D|d) divide_num ;;
Q|q) break;;
*) "error";;
#read a
#read b
#add_num $a $b
esac
# minus_num $a $b
# multiply_num $a $b
# devide_num $a $b
done
}
main
exit 0
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