Overview

This repository contains files for configuring your CS50 development environment on the Thayer Computing systems. Specifically, it contains the following:

• README.md - a file with these instructions, in 'Markdown' format.
• dotfiles - a directory with 'dot' files for your home directory; see dotfiles/README.md.
• shared - a symbolic link to a shared directory of CS50 content provided by the instructor.

Preparing your laptop

You cannot connect to Thayer's Linux servers unless you are connected to the Dartmouth campus network; if you are off campus, connect your laptop to Dartmouth's VPN.

Preparing for Linux development

1. Open a Terminal window:

   • on MacOS, launch Terminal from the Utilities folder (inside the Applications folder)
   • on Windows, launch Windows Command Prompt

2. In that Terminal window, you will see a prompt, likely ending in $. After that prompt, type the following command but substitute your Dartmouth NetID:

   ssh d12345x@plank.thayer.dartmouth.edu

   (The ssh command means 'secure shell', which opens a secure connection to server named plank.thayer.dartmouth.edu and launches the bash shell program under user id d12345x.)

   If it reports "connection refused" or (after a long wait) "connection timed out", double-check that you are connected to Dartmouth's network or VPN.

   If it asks you Are you sure you want to continue connecting (yes/no/[fingerprint])?, say yes.

   It will ask for your password; use your NetID password. It will pause briefly, warn you about your usage of disk space on the Thayer File System (ThayerFS), and then give you a command prompt; it will look something like this:

   $ ssh d12345x@plank.thayer.dartmouth.edu
   d12345x@plank.thayer.dartmouth.edu's password:
   << You are currently using 47.39M of your 5.00G home directory quota. >>
   d12345x@plank:~$

   In the above example, $ is the shell prompt on your laptop; if you are tempted to copy-paste the ssh command, don't copy that prompt!

3. You are now at the command line: the computer prints a prompt (d12345x@plank:~$) and waits for you to type a command. The prompt indicates you are user d12345x, logged into server named plank, and your current working directory is ~, which is shorthand for your home directory. All of your files will live in your home directory (like a folder) or in subdirectories (like subfolders). Below, we do not show the prompt, just the commands you should type.

4. At the prompt, type the command copy_skel to install the standard Thayer-issue bash configuration files:

   copy_skel

   This program installs (or overwrites) the files .bashrc and .profile in your home directory. Important: if you have used Thayer's Linux systems before, and have customized your copy of these configuration files, type n when the script asks to overwrite them; if you type y you will lose your customizations and begin with fresh Thayer-supplied default configuration.

5. Set up your GitHub account and provide GitHub a 'key' so your account on plank can access GitHub; follow these instructions, and then return here.

6. Clone this repository into your home directory:

   git clone git@github.com:cs50spring2021/cs50-dev.git

   The result is a subdirectory named cs50-dev in which you should do all your development for this course.

7. The repository contains some necessary extensions to the bash configuration files; update your bash configuration to invoke them when you next log in:

   echo source ~/cs50-dev/dotfiles/bashrc.cs50 >> ~/.bashrc
   echo source ~/cs50-dev/dotfiles/profile.cs50 >> ~/.profile

   These echo commands append a line to the bottom of each file. Within those files, the source command tells bash to read commands from the named file.

8. Copy our recommended files into your home directory:

   cp -i cs50-dev/dotfiles/emacs .emacs
   cp -i cs50-dev/dotfiles/vimrc .vimrc
   cp -i cs50-dev/dotfiles/gitconfig .gitconfig

   Important: if you already had a Linux account on Thayer systems, and already had one or more of those dot files, cp will ask if you want to overwrite them; type y if you want to use our recommended file, and type n otherwise. You may want to compare our files to yours, and edit in our suggestions as you see fit.

9. (OPTIONAL) To pick a preferred editor, edit ~/cs50-dev/dotfiles/profile.cs50 to uncomment one line defining EDITOR. You can postpone this step until you've decided on your favorite editor.

   Read about editors.

10. Finally, log out of plank (use the exit command to exit bash), and log back in using the ssh command from above.

    exit

Developing your code

Do all your work in the c50-dev folder. Thus, after login, use the cd command to change your current directory (aka working directory) to the cs50-dev subdirectory:

d12345x@plank:~$ cd cs50-dev
d12345x@plank:cs50-dev$ 

Note how the prompt changed to reflect the new directory. From there, create or clone new git repositories for your coursework.

More information

Much more information about the systems we use in CS50, including links to many other resources, can be found on the systems page of the course website.