Bash Unit 1

Connecting to the cluster

First steps

The command ssh lets you connect to the cluster. You will need VPN active to be able to connect if you are not using the university LAN or “eduroam” WLAN (when you are working from home).

ssh [username]@corso.came.sbg.ac.at
# For example:
ssh nfortelny@corso.came.sbg.ac.at
Tip

You will see a number of different commands over the next days. The key commands are listed at the bottom of this page.

Next you will change your password. Make sure to remember this password, which you will you throughout this course.

passwd

Now we are connected to the cluster. In the following we will explore this file system. Details will be explored in the next lecture of this course. For now, just execute the commands and see if you can make sense of the results.

The cluster has a file system like any computer. Currently you are in your home directory. The current “path” is shown by the following command:

pwd

You can list the content of your home directory using

ls
ls -l
Tip

Do not confuse the lowercase letter l (as used in ls -l) with the number 1 (“one”).

You can clear the terminal by typing

clear

Now, use the up- and down-arrows on your keyboard to look through the history of commands.

Now create a directory:

mkdir day1

List content of the directory again:

ls
ls -l                   # This shows you the home directory (and the day1 directory that is within the home directory)
ls -l day1/     # This shows you the content of the day1 directory
Tip

Note: folder and directory mean the same thing. We will use directory from now on.

What does mkdir do? Bring up the manual (press q to exit the manual).

man mkdir

Now create some files. There are many ways to create a file.

# Create an empty file in directory "day1"
touch day1/this_file_is_empty.txt

# Write the text "abcdefgh" in a file.
echo "abcdefgh"  > day1/letters.txt

List files again.

ls
ls -l
ls -l day1/

Take a look at the file content.

head day1/*

Treasure Game

Next, we will play a little treasure game, where you have to navigate through directories to find a treasure. You will need three commands to play this game:

  • list files and folders in your directory ls
  • change between directories cd
  • look at the content of a file cat

Now you are ready to start. First, download the game:

cd ~/
git clone https://github.com/tayssirgh/mozmoz-treasure.git
cd mozmoz-treasure

Next, run the game:

chmod +x ./.welcome.sh
./.welcome.sh

You start your journey by entering the folder the-woodland-gate, and looking at the grimoire:

cd the-woodland-gate
cat grimoire