Push & pull

Show off some of what you learned in earlier levels. First, the change goes to the staging area.

Then commit it:

Your new fourth commit is at the front of the chain, on main, here in your local repository.

The remote, the copy you made in Level 5, has no idea this commit exists. It only knows about the three pages that existed when you cloned it.

That is the gap you are about to close. Your book has four pages; the family copy has three.

Before you push for the first time there is one tiny extra step. You must tell Git that your local main branch should sync up with the remote's copy of main. The remote's copy of a branch is known as the upstream branch, or the remote branch. Once linked, Git knows where your pages go.

git push sends every new page on your branch to the linked scrapbook named origin. --set-upstream links your local main with the remote's main, and it is only needed the first time. From now on, plain git push knows where to go.

On the graph a new label appears: origin/main. That is Git's note of where the remote's main was the last time you talked to it. Woohoo, you successfully pushed your fourth commit. Your friends and family can now see the fourth page in the official copy. Now stop dilly-dallying.

Meanwhile, Your Friend has cloned the family copy too, and has stuck a fifth page onto it: a new file, friend.py. The shared scrapbook is now one page ahead of yours.

You need a way to retrieve that page from the shared copy into your own. In Git speak, that is called pulling changes into your repository, and git pull is the command for it.

Bring the page over:

Yup. Your main branch now contains a fifth commit, and you did not make it. You made the first four yourself; the fifth was made by Your Friend. Hover it and you will see their name on the stamp, and that they created a new file called friend.py.

Git's true purpose is enabling exactly this kind of collaboration and tracking by multiple developers.

Under the hood, git pull does two things: it fetches the remote's new pages, then merges them into your branch. You can do the first half on its own with git fetch, which downloads new pages and updates the origin/main label without touching your own branch. Handy when you want to look before you leap.

There is also a flag you will hear about: git push --force tells the remote to accept your branch no matter what it currently holds. On a branch someone else pushed to first, that erases their pages. It has its uses, and everyday work is not one of them.