【Linux】shell简单模拟实现

#!/bin/bash

# 函数定义，实现加法
function add() {
    local total=$(($1 + $2))
    echo "$total"
}

# 函数定义，实现减法
function subtract() {
    local difference=$(($1 - $2))
    echo "$difference"
}

# 函数定义，实现乘法
function multiply() {
    local product=$(($1 * $2))
    echo "$product"
}

# 函数定义，实现除法
function divide() {
    if [ $2 -ne 0 ]; then
        local quotient=$(($1 / $2))
        echo "$quotient"
    else
        echo "Cannot divide by zero!"
    fi
}

# 读取用户输入
echo "Enter two numbers:"
read num1
read num2

# 读取用户希望执行的操作
echo "Enter the operation you want to perform:"
echo "1. Add"
echo "2. Subtract"
echo "3. Multiply"
echo "4. Divide"
read operation

# 根据用户的选择执行相应的操作
case $operation in
    1)
        add $num1 $num2
        ;;
    2)
        subtract $num1 $num2
        ;;
    3)
        multiply $num1 $num2
        ;;
    4)
        divide $num1 $num2
        ;;
    *)
        echo "Invalid operation!"
        ;;
esac