# The Command Line

# [Lecture] A NOTE ON SOLUTIONS!

Colt 在教學過程中所用到的代碼都可以在下面連結中取得：

# [Lecture] Introduction to the Command Line

在這邊 Colt 介紹了 命令行（command line） 的重要性。在這邊更直白地說，即使是我們所能見到的 圖形使用者介面（GUI, Graphical User Interface） 也是將很多命令行封裝寫在他的背後，很多可以透過圖形化介面完成的，百分之九十九都可以透過命令行完成，反之則否。

關於更多命令行的介紹與使用方式，可以參考：

除此之外，在命令行中可以透過 man 查看命令的說明文件：

$ man ls

# [Lecture] `cd` and `ls`

cd：變更當前的目錄位置，即 改變目錄（change directory）
ls：列出當前目錄下的所有檔案和目錄，即 列出檔案塊（list segment）

# [Lecture] `touch` and `mkdir`

touch：用於更改文件訪問和修改時間，也被用於創建新文件。
mkdir：創建目錄，即 建立目錄（make directory）

# [Lecture] Removing Files and Folders

rm：用於刪除文件系統中的文件、目錄、設備文件、符號連結…等，源自 刪除（remove） 的縮寫。
加上 -rf 參數用以刪除文件夾。

# [Lecture] Command Line Exercise

# Demand

Make a new folder named "Animals"
Inside of "Animals" add 2 directories: "AwesomeAnimals" and "SketchyAnimals"
Inside of "AwesomeAnimals" add the following files: "Capybara.js", "ArcticFox.html" and "TreeFrog.txt"
Inside of "SketchyAnimals" add the following files: "BrownRecluse.html" and "BulletAnt.js"
Also inside of "SketchyAnimals" create a "Snakes" directory. Snakes are extra sketchy.
Inside the "Snakes" directory create the following files: "Cobra.css" and "ReticulatedPython.py"
You have a change of heart and decide that Bullet Ants are no longer sketchy. Remove the "BulletAnt.js" file.
All animal life goes extinct. Delete the entire "Animals" directory
BONUS: See if you can do this without ever changing directories(without using cd)

# Solution

# Make a new folder named `"Animals"`
$ mkdir Animals

# Inside of `"Animals"` add 2 directories: `"AwesomeAnimals"` and `"SketchyAnimals"`
$ mkdir Animals/AwesomeAnimals
$ mkdir Animals/SketchyAnimals

# Inside of `"AwesomeAnimals"` add the following files: `"Capybara.js"`, `"ArcticFox.html"` and `"TreeFrog.txt"`
$ touch Animals/AwesomeAnimals/Capybara.js
$ touch Animals/AwesomeAnimals/ArcticFox.html
$ touch Animals/AwesomeAnimals/TreeFrog.txt

# Inside of `"SketchyAnimals"` add the following files: `"BrownRecluse.html"` and `"BulletAnt.js"`
$ touch Animals/SketchyAnimals/BrownRecluse.html
$ touch Animals/SketchyAnimals/BulletAnt.js

# Also inside of `"SketchyAnimals"` create a `"Snakes"` directory. Snakes are extra sketchy.
$ mkdir Animals/SketchyAnimals/Snakes

# Inside the `"Snakes"` directory create the following files: `"Cobra.css"` and `"ReticulatedPython.py"`
$ touch Animals/SketchyAnimals/Snakes/Cobra.css
$ touch Animals/SketchyAnimals/Snakes/ReticulatedPython.py

# You have a change of heart and decide that Bullet Ants are no longer sketchy. Remove the `"BulletAnt.js"` file.
$ rm Animals/SketchyAnimals/BulletAnt.js

# All animal life goes extinct.  Delete the entire `"Animals"` directory
$ rm -rf Animals

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