题目这操作题有没有大神帮我解答一下啊

# 打印一个环境安装的脚本
menu(){
    cat <<END
        1) CREATE
        2) DELETE
        3) RENAME
        4) COPY
        5) exit
        please input the num you want
END
}
# 执行打印菜单
menu

# 读入一个执行的编号
time=$(date '+%Y-%m-%d')
while (true)
do
read num
[ "$num" = "1" ] &&{
    
    echo "CREATE" 
    mkdir $time
   
}

[ "$num" = "2" ] && {

    echo "DELETE"
    rm -rf $time
   
}

[ "$num" = "3" ] && {

    echo "RENAME"
    mv $time xuehao
   
}

[ "$num" = "4" ] && {

    echo "COPY"
    touch $time
    cp $time xuehao
   
}

[ "$num" = "5" ]&& {

    echo "退出"
    exit 0
}
done