Git Rundown

The Importance of Version Control

What is git?

Git is a distributed version control system.

Distributed:

Files are stored on multiple machines (i.e. your local machine and github.com)
Many people can work on one project simultaneously

Version control:

previous versions of the project can be saved and retrieved

Benefits of Distributed Systems

Your code is safely saved in case your computer explodes.

Benefits of Version Control

You can easily merge two different versions of the same project from two different people
If you break code, you can always go back to a previous version of the project

Commits

A commit represents the state of your project at the time the commit was made.

Git stores commit by keeping track of changes from one commit to the next.

Visualizing Commits

Because commits are made sequentially and they build off of each other, commits can be visualized as a sequence from one to the next.

Branches

Branches facilitate collaboration.
Side branches will not affect the whole project until they are merged.
Branch often (i.e. for every new feature).

Created a new branch (iss53) to fix issue #53.

Make a commit (C3) while on branch iss53.

An urgent bug was found. Postpone work on issue #53 to do a hotfix.

Merge the hotfix branch with master to put the bug fix into production.

Continue working on issue #53.
Make a new commit (C5) on the iss53 branch

Now we want to merge in the fix for issue #53 into master so that it will appear in production.

The branch iss53 is now merged with master! iss53 can now be deleted.

Git Commands

Configure git on your computer

git config --global user.name "Sam Smith"
git config --global user.email sam@example.com

Create a new git repository in the current directory

git init

Checkout a repository from a remote server

git clone username@host:/path/to/repository

Adding to Commit

Add tracked and untracked file(s) to a commit

git add <filename>
git add * (adds all files/folders in the current directory)
git add :/ (adds all files/folders in the repository)

Remove file(s) from a commit (make them untracked)

git rm <filename>

Committing

Add changes in tracked file(s) to the commit

git commit -a

Add a message to the commit

git commit -m “fixed the bug after days of banging my head against the wall--I will be taking the rest of the day off to visit the hospital”

git commit -am “two-in-one”

Pushing

Push to a remote server

git push
git push <remote> <branch>
git push origin master

Find out what’s going on in your local repo

git status

Branching

Create a new branch

git branch <branch name>

Switch to a branch

git checkout <branch name>

Merge a branch (merge a foreign branch to the local branch you are in)

git merge <foreign branch>