View source for Introduction to Linux in HPC/Linux Directory Structure

[[Category:Tutorials|Linux Directory Structure]]<nowiki />
{{DISPLAYTITLE:Linux Directory Structure}}<nowiki />
{{Syllabus Introduction to Linux}}<nowiki />
__TOC__

This part of the tutorial introduces the directory structure on a Linux system and shows how to navigate in it. It explains how a path looks like in Linux, which standard directory structure is shared by most systems and how to navigate from one directory to another.

=== Video === <!--T:5-->

<youtube width="600" height="340" right>rV7Hwi__zZo</youtube>

([[Media:HPC.NRW_Introduction_to_Linux_in_HPC_03_Linux_Directory_Structure.pdf|Slides as pdf]])

=== Quiz === <!--T:5-->  

{{hidden begin 
|title = 1. Which one is the top directory in Linux?
}}
<quiz display=simple>
{
|type="()"}
+  <code>/</code>
|| Explanation: The tree structure for directory is used in Linux system. Therefore the top directory in Linux is /. The /home directory may be an upper level directory for all non-root users. The last option C:\ represents the C drive on Windows.
-  <code>/home</code>
|| 
-  <code>C:\</code>
||  That's Windows
</quiz>
{{hidden end}}


{{hidden begin 
|title = 2. The command <code>cd</code> without arguments: if you start in <code>/var/log/</code> and run <code>cd</code> with no arguments, what do you expect will happen?
}}
<quiz display=simple>
{
|type="()"}
- Nothing it stays in <code>/var/log/</code>
||
+ It goes to your home directory
|| Explanation: It goes to your home directory. <code>cd</code> without arguments is a shortcut to take you home. As long as your home directory exists, you can always go home
- It goes to the filesystem root
||  
- The shell stops having a working directory
|| 
- It’s an error
||
- The shell prompt turns into a shark and eats you
||
</quiz>
{{hidden end}}


{{hidden begin 
|title = 3. Which of these oversimplifications describes the directory structure in a Linux system best?
}}
<quiz display=simple>
{
|type="()"}
- Everything is a directory
|| 
+ Everything is a file
|| Explanation: In Linux, directories are files with a directory flag. There are even more "special" files, like <code>/dev/null/</code>, <code>/proc/cpuinfo/</code> or links.
- Directories are files and files are directories
|| Explanation:  Directories are files, but files are not directories
- All of the above
||
</quiz>
{{hidden end}}


{{Warning|mode=warn|text= '''no undo and make sure what you want to do (page 48)'''}}

=== Exercises in Terminal=== <!--T:5--> 

 4. Go to a specific subfolder of a folder (example: <code>cd Documents/courses/</code>) and get back to the home directory using <code>cd</code> command. List 3 different ways to do it using one command. Check after every action your path with <code>pwd</code> command.
   {| role="presentation" class="wikitable mw-collapsible mw-collapsed"
    | <strong>Answer:</strong>
    |-
    | 
       <code>cd</code>
       <code>cd ~</code>
       <code>cd $HOME</code>
        the last option $HOME is an environment variable. You will learn about environment variables later.
    |}
       
 5. Go to the directory <code>/tmp</code> and jump between <code>/tmp</code> and your home directory back and forth. Check after every action your path with <code>pwd</code> command.
   {| role="presentation" class="wikitable mw-collapsible mw-collapsed"
    | <strong>Answer:</strong>
    |-
    | 
        <code>cd /tmp</code>
        <code>cd -</code>
        <code>cd -</code> with <code>cd -</code> you change back to the previous working directory, pass the dash <code>-</code> character as an argument to the <code>cd</code> command.
    |}


{{hidden begin 
|title = Bonus question: How do you copy and paste in the Linux terminal?
}}
<quiz display=simple>
{
|type="()"}
- Ctrl-C & Ctrl-V
|| That's Windows
- <code>yy</code> & <code>pp</code>
|| That's vim
+ Middle Mouse
|| Alternative Solution: Ctrl-Shift-C & Ctrl-Shift-V
-You can't, that's a Windows feature.
||
</quiz>
{{hidden end}}


{{Tutorial Navigation
| previous = [[Introduction_to_Linux_in_HPC/The_Command_Line | The Command Line ]]
| main = [[Introduction_to_Linux_in_HPC | Overview ]]
| next = [[Introduction_to_Linux_in_HPC/Files | Files ]]
}}