Exercise Monday

Goal: In this lesson, we'll create a one-page website that says "hello" to the world. In the process, we'll learn about Git, a tool for tracking changes to our code. The steps we follow in this lesson will reflect the daily workflow we'll use when coding all of our projects throughout our time at Epicodus. You can also use the cheat sheet as a reference for starting your projects during this section — but using Git for your projects will soon become second nature.

Configuring Your Git Name and Email


On Personal Machines

In order to save code using the Git version control system, Git needs to have our name and email. On our personal machines, we can do this just once with a global configuration in the terminal:

$ git config --global user.name "Padma Patil"
$ git config --global user.email [email protected]

A global configuration sets a configuration everywhere on a machine — not just in one directory or file. When we create a configuration for just one project directory on a machine, it's called a local configuration.

On Campus on Shared Computers

However, even on the shared computers on campus at Epicodus, we won't use local Git configurations. Instead, at the beginning of each class session one student in a pair will set up global Git credentials. The instructions on how to do this are the same as above. Note that these global Git credentials will be wiped when students shut down the computers at the end of every work day.

Later on, the same student who set up the global Git credentials will use other Git commands to save the local project on their remote GitHub account. Then, the other student(s) in the pair will copy that project, saving it to their own remote GitHub account. We'll go over this workflow in detail when we are ready for this step.

Getting Authorship on Shared Projects — On Campus or Remote

We pair program at Epicodus, which means there are always multiple authors for one project. To give credit to all the authors on a project, we use Git's built-in tool called commit trailers. We'll learn about commit trailers later on when we start making commits. However, we're not ready for this step — we're still working on setting up our first project!

Starting a New Project


Whenever we start a new project, we create a new project directory.

At Epicodus, we generally create new projects on the Desktop directory. However, you may want to create a new directory on your personal machine for storing projects as well.

If we open the terminal and enter ls, we'll see a list of the files and directories that in our home directory. Chances are, you won't want to store your newly-created projects in the home directory.

Creating a Project Directory


Instead, we'll want to navigate to the Desktop directory for easy access. Let's change directories from our home directory into our Desktop using the cd command:

$ cd Desktop

You can create a new project here, or, if you prefer, create a new directory where your projects will be stored and then $ cd into that directory.

Next, we'll create a project directory called hello-world:

$ mkdir hello-world

Remember, mkdir is short for make directory.

We can run the ls command to see that hello-world has been added to the list of directories on our Desktop (or wherever you've chosen to create your new directory).

Next, we'll move into the hello-world directory:

$ cd hello-world

To confirm that we're in the correct directory, we can check our location with a pwd:

$ pwd

Initializing Git


Before we start writing any code, we'll create a Git directory within our project directory that will track everything we add, modify and delete within this directory.

We do this by initializing a new Git repository:

$ git init
Initialized empty Git repository in /Users/staff/Desktop/hello-world/.git/

If we run ls, though, we won't see the new directory. Why not?

Well, if you take a look at the terminal's response to our $ git init command, you'll see that the following file was initialized:

Initialized empty Git repository in /Users/staff/Desktop/hello-world/.git/

Note that the exact path, the list of all the directories we'd need to navigate through to get to hello-world, will be different on your personal machine.

Next, note the name of the file that was created inside hello-world:

.git

Whenever a file has a period in front of the name, it will be hidden. That means they won't appear when we run the ls command. They also won't show up if we navigate to the directory using the point-and-click interface in the GUI (graphical user interface) of our computer.

If we want to see hidden files in the terminal, we need to add a modifier to our ls command:

$ ls -a
.git

The -a stands for all, so $ ls -a means list all files, even hidden ones. Modifiers added to terminal commands are also known as flags. There are many flags we can use to modify terminal commands.

To see all files on a Windows machine, run the following command:

> ls -force

We'll see that the .git directory has been created in our hello-world directory. Let's cd into this directory and take a quick peek at its contents.

$ cd .git
$ ls
HEAD        description info        refs
config      hooks       objects

These are all the files Git uses to track our project and we don't need to worry about any of them. In fact, we should never modify the .git folder because Git will take care of all tracking automatically. In general, it's common for files and directories that shouldn't be modified to be hidden — that ensures we don't accidentally modify them.

As we add, update and delete files, Git will be in the background, automatically making notes of every change in our project directory.

Let's return to the top level of our project directory by changing directories and moving up one level:

$ cd ..

Now, we are ready to add a new file to our project. This will be the HTML page that will say "Hello" to the world.

Terminology


  • Initialize: In Git, we can initialize a new, empty repository to track changes to the project directory by running git init. We should always run this command in the top level of the project directory.

  • Global: A configuration option that refers to every directory in every location of the device.

  • Hidden files: These are files on your machine that are not listed with an ls terminal command. Instead, you can see them with the ls -a terminal command. The .git directory is hidden by default.

Daily Git Workflow


This workflow is only for students pair programming in person at Epicodus.

Set up name and email

On Personal Computers

Git needs your name and email to be able to connect local work on our machines to a remote GitHub account. To set up your Git credentials on your personal computer, you can do this just once by setting up global credentials that will be applied to all projects.

$ git config --global user.name "Padma Patil"
$ git config --global user.email [email protected]

On Shared Computers On Campus at Epicodus

On shared computers on campus at Epicodus, at the beginning of each class session one student in a pair will set up global Git credentials. The instructions on how to do this are the same as above. Note that these global Git credentials will be wiped when students shut down the computers at the end of every work day.

Later on, the same student who set up the global Git credentials will use other Git commands to save the local project on their remote GitHub account. Then, the other student(s) in the pair will copy that project, saving it to their own remote GitHub account. We'll go over this workflow in detail when we are ready for this step.

Sharing Authorship on Shared Projects

Later on we will learn how to use a commit trailer when creating commits to share authorship among multiple people.

Create a new project directory with Git repository

In terminal:

$ cd Desktop
$ mkdir hello-world
$ cd hello-world
$ git init

Git Commands


  • git init: Initializes new local Git repository.

  • git config --global user.name ___: Globally configures Git profile for entire device (use only on your personal machine).

Lesson 7 of 66
Last updated December 1, 2022