Initial Setup


If at any point you get stuck during this initial setup or throughout the semester, please don’t hesitate to email the course staff at 15-131-staff at cs dot cmu dot edu.

Set Up SSH

SSH is a program that lets you log in to a server and run commands on it. At CMU, you’ll use SSH extensively in most of your CS classes. SSH is also a very important tool for working in industry and knowing how to use it will be essential throughout your career. (Even in academia, SSH is a very important tool.)

Throughout the rest of the semester we’ll teach you about how to use it and why you want to, but for now we’ll just focus on getting it set up so that you can start using it right away.

The exact instructions on how to set up SSH vary based on what operating system you’re using, so choose the relevant section and proceed from there.

Congratulations! Your OS has a built-in terminal (, so you don’t need to download anything. You might consider looking at one of the other terminals for OS X like iTerm2 if you want cooler features like better color support, easier theming, vertical splits, advanced tmux integration, and more.

You have lots of choices for a terminal. Your distro almost certainly has one already, but if you don’t like the default one you can download another. Some popular terminals are

  • Terminator
  • Konsole
  • Gnome Terminal
  • xterm
  • rxvt-unicode

If you’re already somewhat familiar with Linux, we strongly recommend that you follow the Linux initial setup instructions. We’re going to be teaching you more about Linux throughout this course, so you’ll end up being proficient with it by the end of the semester.

If you’re running a recent version of Windows 10, then you can activate a terminal built-in to the OS. To find out if your copy of Windows 10 is recent enough, open the Start Menu, type in winver, and press enter. In the window that appears, look at the number that comes after “OS Build”.

If that number is 14316 or greater, you should follow these instructions to activate the built-in terminal:

  • Open the Start Menu, type in “Turn Windows features on or off”, and press enter.
  • Scroll down to “Windows Subsystem for Linux”, check its box, and press OK. Allow your computer to restart.
  • After boot, open the start menu and type in “Bash on Ubuntu on Windows”, which launches the terminal app. Follow the first-time setup instructions to finish.

If that number is lower than 14316 (or if you’re running a version of Windows other than Windows 10), your copy of Windows does not include this terminal. In that case, we recommend that you use MobaXterm for SSH. Download and install it from that site.

MobaXterm installs a more minimal terminal than the other supported platforms, so copy and paste the following command into your terminal and then press enter before continuing with setup. This command will install the nano program, which is a simple text editor. You may need to confirm the installation by pressing y and then enter if prompted. You should verify that you see an image similar to this before running the command.

apt-cyg install nano

Once you’ve chosen a terminal for your operating system, you can set up an optional shortcut to save some typing.

NOTE: We need to make these changes before running any SSH command, or before launching any SSH session. On OS X and Linux, this means make sure you do these instructions immediately after opening a new terminal window or tab. On MobaXterm, you should verify that you see an image similar to this.

We’re going to edit the ssh config file. Use the following command to do that (you don’t need to understand this command yet–we’ll cover it later in the semester). Copy and paste the command into your terminal and hit enter.

mkdir ~/.ssh && touch ~/.ssh/config && chmod 600 ~/.ssh/config && nano ~/.ssh/config

Add the following (replacing ANDREWID with your Andrew ID) to this file, save the file, and exit nano. (Some notes: The ^ character is used to represent the “control” key, so ^O means “hold control and press the O key”, and nano uses “WriteOut” to mean “save”. Nano will ask you to confirm the filename you want to save. Just hit enter to confirm it.)

Host andrew
GSSAPIAuthentication yes
GSSAPIDelegateCredentials yes

You should now verify that SSH works with your chosen terminal. You will always be asked for a password when SSH’ing in–it’s the same password you use to log onto WebISO.


If you did the optional setup above to set up the shortcut, you can alternatively run

ssh andrew

(Note: it’s literally ‘andrew’, not your Andrew ID).

A Note About Terminals

I’m using the word “terminal” here for consistency with the way people use the word commonly. To be technically correct, I should call it a “terminal emulator,” but this phrasing could lead to confusion so I’m using the slightly less correct phrasing instead.

Get the GPI Configuration

The default settings for the command line and other programs you’re likely to use during the semester are rather minimal, so we’ve written some configuration files that will give you nicer defaults. Of course, if you want to change these settings to better fit your preferences you can do so.

SSH in to andrew.

First, we’ll get a few basic files. Copy the following commands into your terminal, hitting enter after each one.

curl > ~/.bash_login
curl > ~/.bashrc
curl > ~/.bashrc_gpi

curl > ~/.vimrc
git clone ~/.vim/bundle/Vundle.vim
vim +PluginInstall +qall

Side note: these will overwrite any existing files you might have. If you have your own bashrc or vimrc, read the Advanced Usage instructions.

Then, disconnect from Andrew (remember, ^D) and log in again. When you’ve logged in, if you see something like username@unixN:~$ instead of what the prompt used to be, you’re done! If you see a file path, then everything went correctly! (If it looks like nothing changed, something went wrong. Try logging out and back in, and if that doesn’t fix it, make a post on Piazza or email us.)

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