100,000 of whys!

1. 如何通过终端安装Docker?
   打开终端，输入命令行# brew cask install docker，Homebrew工具更新完毕后会自行从https://download.docker.com上拉取Docker安装包,然后稍微等待一下。

    Updating Homebrew...
    ==> Auto-updated Homebrew!
    Updated 1 tap (homebrew/core).
    ...
    ==> Tapping homebrew/cask
    Cloning into '/usr/local/Homebrew/Library/Taps/homebrew/homebrew-cask'...
    remote: Enumerating objects: 3643, done.
    remote: Counting objects: 100% (3643/3643), done.
    remote: Compressing objects: 100% (3633/3633), done.
    remote: Total 3643 (delta 24), reused 614 (delta 8), pack-reused 0
    Receiving objects: 100% (3643/3643), 1.21 MiB | 317.00 KiB/s, done.
    Resolving deltas: 100% (24/24), done.
    Tapped 1 command and 3533 casks (3,648 files, 3.9MB).
    ==> Satisfying dependencies
    ==> Downloading https://download.docker.com/mac/stable/37877/Docker.dmg################################ 100.0%
    ==> Verifying SHA-256 checksum for Cask 'docker'.
    ==> Installing Cask docker
    ==> Moving App 'Docker.app' to '/Applications/Docker.app'.
      docker was successfully installed!

Congratulations！！

2. Linux 下如何使用命令echo打印出有颜色的内容？
   -->文字颜色：

# syntax: echo -e "\033[1;颜色码+m some_text \033[0m"
echo -e "\033[1;31mThis is red text\033[0m"
This is red text

\033[:告诉终端后面是设置颜色的参数
\033[1;31m：将颜色设置为红色
\033[0m：将颜色恢复初始设置
文字颜色码：
0：恢复初始设置；30：黑；31：红色；32：绿色；33：黄色；34：蓝色；35：洋红；36：青色；37：白色
-->背景颜色：

echo -e "\033[1;42mGreed Background\033[0m"

Greed Background颜色码：
0：恢复初始设置；40：黑；41：红色；42：绿色；43：黄色；44：蓝色；45：洋红；46：青色；47：白色
-->文字闪动：

echo -e "\033[37;31;5mMySQL Server Stop...\033[39;49;0m"

红色数字处还有其他数字参数：0 关闭所有属性、1 设置高亮度（加粗）、4 下划线、5 闪烁、7 反显、8 消隐

3. Loading......