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# Shell intro

<iframe src="https://drive.google.com/file/d/1OnRrPlBRjwK22Suh9Ig-r_ZVk4Be0dRj/preview" width="250" height="320" allow="autoplay"></iframe> <iframe src="https://drive.google.com/file/d/13SiT88-g7C1zAiTecCfTlzRHG5zgSarg/preview" width="250" height="320" allow="autoplay"></iframe>

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## Brief History

* Since the early 1970s, the **UNIX** operating system was first created. During this time it has branched out into different versions: Ultrix, AIX, Xenix, SunOS, and **Linux** (Linus Torvalds, 1991).
<img src="https://cdn.freebiesupply.com/images/large/2x/linux-logo-png-transparent.png" alt="Richard Stallman" height="320" width="200"/> <img src="https://files.tecnoblog.net/wp-content/uploads/2018/09/linus-torvalds-dedo-meio-700x394.jpg" alt="Linus Torvalds" height="320" width="480"/>

* The original **Bourne shell** (Steven Bourne) distributed with V7 Unix in 1979 (`/bin/sh`);
* The Free Software Foundation inside the GNU (GNU's Not Unix) project <img src="https://upload.wikimedia.org/wikipedia/commons/8/83/The_GNU_logo.png" alt="gnu" height="40" width="40"/>, **Richard Stallman**) developed a clone of the Bourne shell, written from scratch, named ***Bash*** the Bourne-Again SHell (punning tribute);
<img src="https://upload.wikimedia.org/wikipedia/commons/7/7b/Richard_Stallman_-_F%C3%AAte_de_l%27Humanit%C3%A9_2014_-_010.jpg" alt="Richard Stallman" height="320"/>

## What Is a Shell? <img src="https://cdn11.bigcommerce.com/s-36f60/images/stencil/1280x1280/products/1374/17221/irish-scallop-shell__57163.1608493750.jpg?c=2" alt="shell" height="50" width="50"/>

> translate the user's command lines into operating system instructions

<iframe src="https://drive.google.com/file/d/1nDTSKicMjxILk9la31VAQ-aqH0Xk9_mw/preview" width="250" height="320"></iframe>

sort -n phonelist > phonelist.sorted

## Playground

https://labs.play-with-docker.com/

<iframe src="https://drive.google.com/file/d/1mML1Qcg1UVzTp1bPo9OsKfwQoQesaO2b/preview" width="240" height="310" frameborder="0"></iframe>

## Commands, Arguments, and Options

echo "Hello World!"

* neofetch (`apk add neofetch` Alpine Linux | `apt install neofetch` Debian-based)
* date
* cal
* ls, cd, pwd, mkdir...