Linux编程：使用if语句、select语句 、case三种语句，输入one时，显示“Today is Monday”输入two时，显示“Today is Tuesday”输入three时

今天下雨啦，心情是无聊且郁闷啊！
来写写今天Linux老师布置的作业吧~~~

题目如下：

其实，这道题怎么说呢？
看起来很简单，做起来也很简单。。。。。。
思路：
题目要求用if，select,case三种方法，
那我就先用select语句判断要用的方法，
然后用case语句选择对应的方法的功能。

废话不多说，上代码。
代码如下：

#!/bin/sh
echo "Please enter the method you want to use(1,2,3):"
#先用select语句判断要用的方法
select i in "if" "select" "case"
do
        echo "you chose the ($i) way:"
        break
done
#用case语句选择对应的方法的功能
case $i in
		#if方法
        "if")echo "The method of if:"
        echo "please enter the number(one,two,three):"
        #用while循环来嵌套，即使输入错了也会提示重新输入。
        while [ 0 ]
        do
                read num
                if [ $num = "one" ];then
                        echo "Today is Monday"
                        break
                elif [ $num = "two" ];then
                        echo "Today is Tuesday"
                        break
                elif [ $num = "three" ];then
                        echo "Today is Wednesday"
                        break
                else
                        echo -e "enter error! please enter again:\c"
                fi
        done;;

		#select方法
        "select")echo "Please enter the method you want to use(1,2,3):"
                select num in "Monday" "Tuesday" "Wednesday"
                do
                        echo "Today is $num"
                        break
                done;;

		#case方法
        "case")echo "The method of case:"
                echo "please enter the number(one,two,three):"
                read num
                case $num in
                        "one")echo "Today is Monday";;
                        "two")echo "Today is Tuesday";;
                        "three")echo "Today is Wednesday";;
                        *)echo "enter error!"
                        esac;;

        *)echo "enter error!"
esac

贴一下其中的运行截图：

在这里提醒一下兄弟们，
变量引用要加$$,判断条件要加空格如：错误：[$num=“one”]
正确：[空格$num空格=空格"one"空格]
!!!
憨憨的我踩过的坑！兄弟们，我帮你们填平了，可别踩了！
就这样，我要走了，beybey，宝。