Goals: Introduction to the Linux File System, its structure and how to navigate around it, as well as creating, moving and copying files and folders.

What the file system is, and a typical organization / hierarchy.
Some high-level comparison to that of Windows.
Absolute vs relative paths.
Commands: pwd, cd, ls, mv, cp, mkdir, rmdir, rm
History: history
File Ownership and Permissions.

Within this and following sections, we have tried to make the descriptions and examples generic.
If you are following along as part of a scheduled training or bootcamp, where you see <project-name> replace this with the project name being used for the workshop (which changes) and <username> with your username.
Also, the hostname that you might see might change depending on the cluster you’re using.
If you are training independently, please use your own project folder, but contact arcc-help@uwyo.edu if you would like a copy of the files and directories used in our examples.

1 Some high-level comparison to that of Windows
2 Linux OS General Structure
3 Linux Hierarchical Structure: Example
4 Absolute Path: /home/arcc-t05/
5 Relative Path: workshop/projects/p01/etc/
6 Ex: Starting at / (root), what is the absolute path to the bits folder?
7 Ex: Starting in the home folder what is the relative path to the Jan folder?
8 Commands:
9 ls: List information about the FILEs (cwd by default)
10 mkdir: Create the DIRECTORY(ies), if they do not already exist
11 mv: Rename SOURCE to DEST, or move SOURCE(s) to DIRECTORY
12 cp: Copy SOURCE to DEST, or multiple SOURCE(s) to DIRECTORY
13 rmdir: Remove the DIRECTORY(ies), if they are empty
14 rm: Remove (unlink) the FILE(s)
15 rm: WARNING
16 history
17 Exercises: Navigation
18 File Ownership and Permissions
19 Permission Denied
20 Exercises: Permissions

Some high-level comparison to that of Windows

	Windows	Linux
Structure	Uses (data) drives C:, D:, E:…	Uses a tree hierarchy starting at “`/`” Known as the root directory.
	`<drive>\<folder01>\<folder02>`	`/<folder01>/<folder02>`
Syntax	Uses the back slash: “\”	Uses the forward slash: “/”
Home folder	`C:\Users\<username>`	`/home/<username>`
Application Install	`C:\Program Files\`	`/usr/`
Folder and Filenames	Case insensitive: FoLdEr = FOLDER	Case sensitive: FoLdEr ≠ FOLDER
		Wherever you are within the hierarchy is known as your current working directory (cwd)

Linux OS General Structure

Linux Hierarchical Structure: Example

Absolute Path: /home/arcc-t05/

Path starts with a “/”

Absolute Path: /home/arcc-t05/workshop/projects/p01/etc/

Relative Path: workshop/projects/p01/etc/

Path does not start with a “/”

Relative Path: p01/etc/

Ex: Starting at / (root), what is the absolute path to the bits folder?

Answer:

/usr/include/bits/

Ex: Starting in the home folder what is the relative path to the Jan folder?

Answer:

arcc-t05/workshop/data/2023/Jan/

Commands:

Commands are used to perform certain operating system tasks through the Command Line Interface, as directed by the interpreter (as opposed to a Graphical Interface Interpreter we would usually use).

The next couple of parts list and briefly summarize the commands we will be covering within this section:

pwd, cd, ls, mkdir, mv, cp, rmdir and rm.

We will then follow up with examples on how to use them.

<command --help>

Command	Description
pwd	`pwd: pwd [-LP] Print the name of the current working directory.`
cd	`cd: cd [-L\|[-P [-e]] [-@]] [dir] Change the shell working directory.`
ls	`Usage: ls [OPTION]... [FILE]... List information about the FILEs (the current directory by default)`
mkdir
mv

Commands: <command --help>

Command	Description
cp
rmdir
rm

pwd: Print the name of the current working directory

cd: Change the shell working directory

cd: Change working directory (cont)

Answer:

Did we define an an absolute or relative path?

When we print out the working directory, we are presented with a '/' in front of opt, however when we changed directories to opt, our cd command did not have a '/'. Therefore, we defined the relative path to the opt directory.

cd: Change the shell working directory

Answer:

Relative path, since we specified the full path, starting with root: /

ls: List information about the FILEs (cwd by default)

mkdir: Create the DIRECTORY(ies), if they do not already exist

mv: Rename SOURCE to DEST, or move SOURCE(s) to DIRECTORY

cp: Copy SOURCE to DEST, or multiple SOURCE(s) to DIRECTORY

cp: folders

rmdir: Remove the DIRECTORY(ies), if they are empty

rm: Remove (unlink) the FILE(s)

rm: folders and file(s)

rm: WARNING

From the command-line there is NO trash bin!

Using rm/rmdir is FINAL!

history

Exercises: Navigation

Answers

Use: cd or cd ~ as a shortcut to return to your home folder instead of using a cd /home/$USER or cd /home/<insert_your_username>/
cd stands for: change directory

File Ownership and Permissions

User: This is the owner of the file/folder. By default, the person who created it becomes its owner.
- <username> is the owner
Group: A group is a collection of users. The primary purpose of the group is to define a set of privileges for a given resource that can be shared among the users within the group.
- <project-name> is the group.
- In general, for a workshop, all attending users / the arcc-txx users (if being used) have been setup to be within this group.
Other: This is any other user who has access to the file/folder. This person has neither created the file, nor do they belong to a user group.

Permission Denied

If we change directories, and go to /project/<project-name>/intro_to_linux, what permissions do the contents of this directory have?

Exercises: Permissions

Answers

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Using the Terminal

Workshop Home

Intro to Linux CLI: The File System

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Summary