Git CLI Commands

You may never use the Git CLI (Command Line Interface). None the less it is important to understand what the commands are. Most, if not all, Git GUIs use these commands to perform the git tasks that the GUI offers. Knowing the basics of the CLI will make using Git GUI like VSCode easier.

git clone

The git clone command is used to create a local repository. This command needs to be run in a command prompt or terminal from the folder that is to be the parent folder of the local repository.

This command is used everytime to create a new local repository. It is used only once per local repository. Without this command working with git would be impossible.

>git clone <remote-repository-URL> <folder-name>

Example: >git clone https://github.com/Star-City-Robotics/SwerveDrive-2024.git SwerveDrive

Where:

<remote-repository-URL> is the link to the remote repository. This URL can be obtained from the GitHub page for that repository. It is available in the green button on the main page for the source code, above the source code directory tree. Copy and paste the HTTPS version of the repository URL.
<folder-name> is the name of the folder or directory that will be created in your current working directory. This argument is optional. If it is not present, the last part of the URL without the .git will be used as the folder name. In the above example, the default foler name is SwerveDrive-2024.

git status

The git status is probably the most commonly used git command.
It provides the status of your local repository. It will list which files have been added or modified, which files have been marked for committing, and other useful information.

>git status

git add

The git add command is used to mark a modified file or a new file so that it can be committed to the local repository. Some GUI applications hide this command and performs it in the background when a commit is run.

>git add <list of files to be committed>

example: >git add README.md doc/Doxyfile

A directory or folder cannot be added directly to a repository. Adding and committing a file in the directory or folder will automatically create the directory or folder in the repository.

git commit

The git commit command is how changes are stored in the local repository. In some SCM applications, a commit is called a checkin. In terms of SCM, the two keywords mean the same thing. With git, we use the term commit because it matches the git command to move changed code into the local repository.

The commit process takes more than running the command. As the git commit command runs, an editor pops up. You enter a descriptive and useful comment that explains what changes were made and why. Make sure that these comments are meaningful to the other developers on the team.

A comment of “fixed bug” is meaningless. It does not describe what was done or why. A comment like “fixed bug ### that caused the motors to stop at random times.” is meaningful.

>git commit

Note: Only files marked for being commited by the git add command will be actually be put into the local repository.

Selecting Commit Editor

The default editor that is used for the commit is set when Git is installed.
This may not necessarily be the editor you want to use. The default editor can be set at a later time by running the following command:

>git config –global core.editor <editor-command>

The <editor-command> is usually just the editor name. It can contain options for the editor. The editor used as the default editor must be a text1 editor that is installed on the computer that the local repository is on.

git push

Once changes to the source code has been verified, tested, and are working, these changes can be moved to the remote repository on GitHub to make them available for the rest of the programming team. This is done using the git push command.

Sometimes, the push command will fail if there are conflicts with the changes. For example, if two programmers change the same section of code. The first programming to push those changes to the remote repository will be successful. When the second programmer attempts to push their changes to the remote repository, git will not know how to add these changes. In this case, the second programmer will need to resolve the merge issues manually. The code that conflicts will be highlighted in the local repository by having both sets of code enclosed in “============”, “>>>>>>>>>>>>>>>”, and “<<<<<<<<<<” lines.
Once the merger issues have been resolved, the new code can be committed to the local repository and then pushed to the remote repository.

>git push

Authentication

Some times the git push will fail because the user is not or no longer recognized as a valid programmer for the remote repository. When this happens, you need to reauthenticate yourself using the GitHub CLI command gh auth login from a command prompt window or a terminal on your laptop and the GitHub mobile app on your phone. The gh command will tell you what to do: log into your GitHub Account on a browser and the browser will ask you to enter a code number into the GitHub app on your phone.

>gh auth login

Note: gh is GitHub CLI, Command Line Interface.

3.5 git pull

As other developers push changed code to the remote repository, your local repository becomes out of sync. To restore your local repository so that you are using the latest version of the code, you need to fetch those changes. The git pull command is how you make your local repository up to date.

If you have a file that is modified, git will try to merge the changes from the remote repository into your modified file. If it cannot, you end up with merge issues. Just like merge issues resulting from a git push, you need to manually resolve those changes locally. The difference between a pull and a push merge issue, you do not push your resolved merge issues until you are ready for your next git push.

>git pull

git branch

The git branch command is used to see what branches are available and to create a new branch. By defaults, the git branch command lists what branches are available to the local repository. To see what branches exist in the remote repository, use the option --all.

To create a new branch, place the new repository name at the end of the command. Before creating a new branch, make sure that the local repository.

The branch that the local repository is switched to will have an * before it in the list.

List the branches that this local repository is aware of:
>git branch

List all the branches in the remote repository:
>git branch --all

Create a new branch:
>git branch <branch-name>

git checkout

The git checkout command is used to switch which branch the local repository is being worked on. When a new local repository is cloned, it is references the main branch. In order to work in another branch, the local repository needs to be switched to that branch.

If the branch does not exist, it must either be created with the git branch command before calling the git checkout command, or the two commands can be combined by using the -b option with the checkout command.