Unit 7: Sharing

What GitHub actually is

GitHub is not git. It is a computer on the internet that holds another copy of your repository.

That copy is called a remote. Yours is nearly always nicknamed origin. Sending commits there is a backup, and it is how other people get your work.

Introducing them

git remote add origin <address> teaches your repo where the online copy lives. It does not send anything yet — it is writing down an address.

Terminal

$ git remote add origin https://github.com/you/notes.git
$ git remote -v
origin	https://github.com/you/notes.git (fetch)
origin	https://github.com/you/notes.git (push)

Pushing

git push -u origin main sends your commits up. The -u is only needed the first time: it remembers the pairing, so afterwards plain git push is enough.

Notice git now says whether you are ahead of the online copy.

Terminal

$ git push -u origin main
To https://github.com/you/notes.git
 * [new branch]      main -> main
branch 'main' set up to track 'origin/main'.
$ git status
On branch main
Your branch is up to date with 'origin/main'.

nothing to commit, working tree clean

origin/main is a memory

Your repo keeps a branch called origin/main. It is your memory of where the online copy was last time you looked — not a live reading.

That is why git status can say "up to date" when it is not. It is telling you the truth about what it knows.

Terminal

$ git status
On branch main
Your branch is ahead of 'origin/main' by 1 commit.
  (use "git push" to publish your local commits)

nothing to commit, working tree clean

Getting a whole project

git clone <address> downloads a repository — all of it, every commit and branch ever made — and sets origin up for you.

After cloning you have a complete, working copy. Everything you have learned works offline on it.

Terminal

$ git clone https://github.com/sam/recipes.git recipes
Cloning into 'recipes'...
done.
$ cd recipes
$ ls
cake.txt
$ git log --oneline
cae6ffc (HEAD -> main, origin/main, origin/HEAD) Add the cake recipe

Two ways to look

git fetch asks the server what is new and updates your origin/main memory. It does not touch your files. Perfectly safe.

git pull does the same thing and then merges the new commits into your branch. It is fetch plus merge.

Terminal

$ git fetch
From https://github.com/team/notes
   8d532b5..64bf0fc  main       -> origin/main
$ git status
On branch main
Your branch is behind 'origin/main' by 1 commit, and can be fast-forwarded.
  (use "git pull" to update your local branch)

nothing to commit, working tree clean

Actually getting the work

Now git pull brings the commits into your branch, and the new file appears on your disk. Because you had made no commits of your own, it is a plain fast-forward.

Terminal

$ git pull
From https://github.com/team/notes
   8d532b5..64bf0fc  main       -> origin/main
Updating 8d532b5..64bf0fc
Fast-forward
 sam.txt | 1 +
 1 file changed, 1 insertion(+)
 create mode 100644 sam.txt
$ ls
notes.txt
sam.txt