CSCI 338: Fall 2023

Software Engineering

CSCI 338: Fall 2023

Resources > Git & GitHub

Useful Online Resources

Git Cheatsheet

Basic Commands

git clone Copies a remote repository (e.g., one hosted on a GitHub server) onto your local machine (within your current directory).
git status Tells you which of the files in your current directory are different from the latest commit in the repo.
git add Stages the specified files to be committed
git log Shows you the commit history
git commit Saves a snapshot of your staged files at the moment the commit is issued. Each commit represents the state of your code at a particular moment in time.
git push Uploads your commits to a remote repo
git pull Downloads changes from a remote repo to your local repo

Branch Commands

git checkout -b my-new-branch Creates a new branch
git branch Tells you which branch you’re on
git checkout main Switches you from your current branch to the main branch
git checkout my-new-branch Switches you from your current branch to the my-new-branch branch
git branch -d my-new-branch Deletes my-new-branch from your local repo
git merge my-new-branch Merges changes from my-new-branch into the current branch.
git rebase my-new-branch Rebases changes from my-new-branch into the current branch.

FAQs

Q: How do I get the latest changes from the class repo while still working on my local branch?

Assumptions:

A: Great question! Here are the steps

Step 1: Get to a stopping point on your my-feature branch

When you’re at a stopping point, stage and commit your changes to the my-feature branch:

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git status      # check if there's anything you need to commit
git add .       # stage all of your changes 
git commit -m "Meaningful commit message"   # commit them

Step 2: Checkout your main branch and pull the latest changes down from GitHub

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git checkout main   # switch your active branch to main
git branch          # verify that you're on main (should have an asterik next to it)
git pull            # download all the new main changes

Step 3: Go back to your my-feature branch and rebase

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git checkout my-feature     # switch your active branch to my-feature
git branch                  # verify that you're on my-feature (should have an asterik next to it)
git rebase main             # incorporate the latest changes from main into your my-feature branch

# Note: you may have to manually resolve conflicts in your code editor. If that's the case, when you're done, type:
git rebase --continue       # continue rebasing

Step 4: When your my-feature branch is ready, push it to GitHub

One caveat: if you’ve rebased my-feature from main on your local machine but you’ve already created a remote my-feature branch on GitHub, you will need to use the force flag to upload your new changes to GitHub:

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git push            # try this first (you may not need the force flag)
git push --force    # if you get an error, use the force flag

Why do you need the force flag? If the lineage of your local my-feature branch differs from the remote version of the branch (because of the rebase), then GitHub will refuse the push. But you can just override the branch protection default and push anyway by using --force (as this is expected behavior).