From 8162153c3c84c62286f1328ea0b7962b07e51b73 Mon Sep 17 00:00:00 2001
From: Laurent Modolo <laurent@modolo.fr>
Date: Mon, 28 Sep 2020 14:56:58 +0200
Subject: [PATCH] add start of 4

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+---
+title: Unix file system
+---
+
+# Unix file system
+
+[![cc_by_sa](/Users/laurent/Documents/formations/2020_08_UNIX/img/cc_by_sa.png)](http://creativecommons.org/licenses/by-sa/4.0/)
+
+Objective: Understand how files are organized in Unix
+
+> On a UNIX system, everything is a file ; if something is not a file, it is a process.
+>
+> Machtelt Garrels
+
+The followings are files:
+
+- a text file
+- an executable file
+- a folder
+- a keyboard
+- a disk
+- an usb key
+- ...
+
+This mean that your keyboard is represented as a file within the OS.
+
+This file system is organized as a tree. As you have seen every folder has a parent folder exept the `/` folder whose parent is itself.
+
+Every file can be accessed by an **absolute path** starting at the root. Your user home folder can be accessed with the path `/home/etudiant/`. Go to your user home folder.
+
+We can also access file with a **relative path**, using the special folder "**..**". From your home folder, go to the *ubuntu*  user home folder without passing by the root (we will see use of the "**.**" folder later).
+
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