Overview

In this class, we will learn about computer systems in part by using the C programming language and exploring its relationship to the Intel x86-64 machine language and assembly language. To ensure that we all have a consistent computing environment, you should plan to do your work on the CS department’s Linux server mantis.mathcs.carleton.edu. This short lab will help you get started working on mantis by connecting from another computer. (Note: For some assignments, you’ll be able to use your own laptop without the extra step of connecting to mantis, but the only supported computing environment for actually running your code in this course will be mantis.)

Step 1: Connect to fern

(If you are used to using VSCode to connect to servers, sorry, you can’t anymore because VSCode ultimately crashes the server due to a bug.) (If you get stuck, there are screenshots in this guide.)

Go to https://fern.mathcs.carleton.edu/jupyter/hub/login and log in with your Carleton credentials

fern shares a filesystem with all the other servers and so you’ll possibly see things from previous classes and anything you do on fern will also show up on mantis.

Step 2: Set up your working space on the file system

  • Open a Terminal by clicking the icon with a $ sign and a black box.

  • Set up a long-term working directory named cs208: In that terminal, create a folder named cs208, where you will do your work for the term:

      mkdir cs208

    If you type the command ls in the terminal after that (and then hit enter/return), you’ll see the new folder listed. You can also look at the file explorer, and the folder should show up there, too.

Step 3: Log in to mantis

In the Terminal, type

ssh YOUR_USER_NAME@mantis.mathcs.carleton.edu

And then your password. This is where you would be able to run your files for this class after you edit them on fern.

A typical work session

You’re all set up now, and you won’t need to repeat most of the previous steps anymore. This section describes a typical session with VS Code and mantis.

  1. Restart, but with the cs208 working directory: The next time you log in to fern, the folder will already be there and so you can open it and interact with the files inside as usual.

  2. Start a new program: Go to File->New Python File. Type a hello-world program (e.g., hello.py with a single print statement). Save the file.

NOTE: You should get into the habit of saving frequently, as it may not autosave for you.

  1. Test your program: Connect to mantis via ssh and in the mantis terminal, type a suitable command (e.g., python3 hello.py) to run your program.

  2. Pause to reflect: Ponder the following questions and submit answers to them on Moodle for an engagement credit:

  • Where is your hello.py file stored?

  • Will your file still be on mantis after you close the browser window?

  • Is there a copy on your computer after you close the browser window?

  1. Download a file from mantis: Copy a file from mantis to your local computer (e.g., so you can submit homework via Moodle in your web browser). To do so, in the fern file explorer, right-click on the file you want to download and select Download from the right-click menu. There doesn’t seem to be a drag-and-drop option for this.

  2. Upload a file to mantis: Open the folder containing your file (e.g., new_hello.c) on your local machine. This will be a Windows Explorer, macOS Finder, or Linux folder display. Drag the icon of your file into the files panel on fern.

Next steps

Now that you’re able to connect to mantis, you’re almost ready to work on the first assignment! Take a look at Assignment 1 - Bits & Bytes to get an idea of what you need to do, and then upload a few samples, compile, and run them on mantis.

After you’ve tried some samples, you can get started with Assignment 1. Follow the instructions on the assignment page for getting the code and testing it out.

If you can’t connect to fern

mantis might get overwhelmed with connections during the term. If that happens, don’t get stuck. You don’t need fern to work on mantis!

Getting a Terminal

If you are on Mac, open the Terminal app separate from VSCode (it’s just called Terminal). If you are on Windows, you can use several things, including Command Prompt or Windows Terminal.

SSH

You can connect just the same way, type in:

ssh YOUR_CARLETON_USER_NAME@mantis.mathcs.carleton.edu

And then your password (don’t worry that it looks like you aren’t typing, just keep typing and hit enter).

Running files

You now run everything just like you would through fern’s Terminal, yey!

Editing files

The tricky part is editing files. You can either explore using Emacs or Vi or you can download to your local computer, make changes, and then upload back to mantis.

  • To download a file, you use scp: 
    scp your_username@mantis.mathcs.carleton.edu:/Accounts/YOUR_USER_NAME/cs208/YOUR_FILE WHERE_YOU_WANT_IT_TO_GO
  • To send a file, just reverse the commands: 
    scp LOCAL_FILE_TO_SEND your_username@mantis.mathcs.carleton.edu:/Accounts/YOUR_USER_NAME/cs208/YOUR_FILE