Unveiling the Art of Sync: Mastering Fetching and Pulling in Git

How Cloning Works

• After cloning there will be two branch references:

  1. A regular branch reference that I can move around myself.(the default branch of the Github repo)

  2. origin/master. This is a "Remote Tracking Branch". It's a reference to the state of the master branch on the remote. I can't move this myself. It's like a bookmark pointing to the last known commit on the master branch on origin remote.

     

Remote Tracking Branches

• "At the time you last communicated with this remote repository, here is where x branch was pointing"

• They follow this pattern <remote>/<branch>.

  • origin/master references the state of the master branch on the remote repo named origin.

  • upstream/logoRedesign references the state of the logoRedesign branch on the remote named upstream (a common remote name)

• Run git branch -r to view the remote branches our local repository knows about.

• After committing, the master branch will move but the remote tracking branch will remain unchanged

• When you run git status, it will show that the master branch is ahead of ‘origin/master’ by 1 commit. To sync the remote branch with the local branch, run git push

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

  

• To go back to the original cloned state, run git checkout origin/master

Remote Branches

• Once you've cloned a repository, we have all the data and Git history for the project at that moment in time. However, that does not mean it's all in our workspace!

• The GitHub repo has a branch called puppies, but when I run git branch I don't see it on my machine! All I see is the master branch. So what's going on?

• Run git branch -r to view the remote branches our local repository knows about.

• By default, my master branch is already tracking origin/master but there are no branches to track other remote branches. I want my own local branch called puppies, and I want it to be connected to origin/puppies, just like my local master branch is connected to origin/master.

• Run git switch <remote-branch-name> to create a new local branch from the remote branch of the same name and connect it to the remote branch. For example, git switch puppies makes me a local puppies branch AND sets it up to track the remote branch origin/puppies.

  

Git Fetch

• Suppose that while you are working on the Local repository, the GitHub Rep has changed. How would you get those changes?

  

• Fetching allows us to download changes from a remote repository, BUT those changes will not be automatically integrated into our working files.

• It lets you see what others have been working on, without having to merge those changes into your local repo.

• Think of it as "Please go and get the latest information from Github, but don't screw up my working directory."

• The git fetch <remote> command fetches branches and history from a specific remote repository. It only updates remote-tracking branches. For example, git fetch origin would fetch all changes from the origin remote repository.

• We can also fetch a specific branch from a remote using git fetch <remote> <branch>. For example, git fetch origin master would retrieve the latest information from the master branch on the origin remote repository.

    git fetch <remote>
    # If not specified, <remote> defaults to origin
  

  

• I now have those changes on my machine, but if I want to see them I have to checkout origin/master. My master branch is untouched!

Git Pull

• git pull is another command we can use to retrieve changes from a remote repository. Unlike fetch, pull actually updates our HEAD branch with whatever changes are retrieved from the remote.

• "go and download data from Github AND immediately update my local repo with those changes"

  

• To pull, we specify the particular remote and branch we want to pull using git pull <remote> <branch>. Just like with git merge, it matters WHERE we run this command from. Whatever branch we run it from is where the changes will be merged into.

• git pull origin master would fetch the latest information from the origin's master branch and merge those changes into our current branch.

• If we run git pull without specifying a particular remote or branch to pull from, git assumes the following:

  • remote will default to origin

  • branch will default to whatever tracking connection is configured for your current branch which is already set up.

• For example, if I am on my local master branch, then git pull would pull from origin/master automatically.

• Pulls can result in conflicts hence we should always pull first, then merge conflicts and then push.