Git Pull

git pull updates your current local working branch, and all of the remote tracking branches. It’s a good idea to run git pull regularly on the branches you are working on locally.

Without git pull, (or the effect of it,) your local branch wouldn’t have any of the updates that are present on the remote.

What Does git pull Do?

git pull

git pull is one of the 4 remote operations within Git. Without running git pull, your local repository will never be updated with changes from the remote. git pull should be used every day you interact with a repository with a remote, at the minimum. That’s why git pull is one of the most used Git commands.

git pull and git fetch

git pull, a combination of git fetch + git merge, updates some parts of your local repository with changes from the remote repository. To understand what is and isn’t affected by git pull, you need to first understand the concept of remote tracking branches. When you clone a repository, you clone one working branch, master, and all of the remote tracking branches. git fetch updates the remote tracking branches. git merge will update your current branch with any new commits on the remote tracking branch.

git pull is the most common way to update your repository.

However, you may want to use git fetch instead. One reason to do this may be that you expect conflicts. Conflicts can occur in this way if you have new local commits, and new commits on the remote. Just like a merge conflict that would happen between two different branches, these two different lines of history could contain changes to the same parts of the same file. If you first operate git fetch, the merge won’t be initiated, and you won’t be prompted to solve the conflict. This gives you the flexibility to resolve the conflict later without the need of network connectivity.

Another reason you may want to run git fetch is to update to all remote tracking branches before losing network connectivity. If you run git fetch, and then later try to run git pull without any network connectivity, the git fetch portion of the git pull operation will fail.

If you do use git fetch instead of git pull, make sure you remember to git merge. Merging the remote tracking branch into your own branch ensures you will be working with any updates or changes.

How to Use git pull

Common usages and options for git pull

You can see all of the many options with git pull in git-scm’s documentation.

Examples of git pull

Working on a Branch

If you’re already working on a branch, it is a good idea to run git pull before starting work and introducing new commits. Even if you take a small break from development, there’s a chance that one of your collaborators has made changes to your branch. This change could even come from updating your branch with new changes from master.

It is always a good idea to run git status - especially before git pull. Changes that are not committed can be overwritten during a git pull. Or, they can block the git merge portion of the git pull from executing. If you have files that are changed, but not committed, and the changes on the remote also change those same parts of the same file, Git must make a choice. Since they are not committed changes, there is no possibility for a merge conflict. Git will either overwrite the changes in your working or staging directories, or the merge will not complete, and you will not be able to include any of the updates from the remote.

If this happens, use git status to identify what changes are causing the problem. Either delete or commit those changes, then git pull or git merge again.

Keep master up to date

Keeping the master branch up to date is generally a good idea.

For example, let’s say you have cloned a repository. After you clone, someone merges a branch into master. Then, you’d like to create a new branch to do some work. If you create your branch off of master before operating git pull, your branch will not have the most recent changes. You could accidentally introduce a conflict, or duplicate changes. By running git pull before you create a branch, you can be sure that you will be working with the most recent information.

Undo A git pull

To effectively “undo” a git pull, you cannot undo the git fetch - but you can undo the git merge that changed your local working branch.

To do this, you will need to git reset to the commit you made before you merged. You can find this commit by searching the git reflog. The reflog is a log of every place that HEAD has pointed - every place that you have ever been checked out to. This reflog is only kept for 30 to 90 days, depending on the commit, and is only stored locally. (The reflog is a great reason not to delete a repository if you think you’ve made a mistake!)

Run git reflog and search for the commit that you would like to return to. Then, run git reset --hard <SHA> to reset HEAD and your current branch to the SHA of the commit from before the merge.

Force git pull to Overwrite Local Files

If you have made commits locally that you regret, you may want your local branch to match the remote branch without saving any of your work. This can be done using git reset. First, make sure you have the most recent copy of that remote tracking branch by fetching.

git fetch <remote> <branch> ex: git fetch origin master

Then, use git reset --hard to move the HEAD pointer and the current branch pointer to the most recent commit as it exists on that remote tracking branch.

git reset --hard <remote>/<branch> ex: git reset --hard origin/master

_Note: You can find the remotes with git remote -v, and see all available remote tracking branches with git branch --all.

git pull with Rebase

If there have been new commits on both your local branch and the remote branch, a merge commit will be created when you git pull. This recursive merge is the default merge style when there are two splits in history being brought together. But, you may want history on a branch to be only one line.

You can update your local working branch with commits from the remote, but rewrite history so any local commits occur after all new commits coming from the remote, avoiding a merge commit. This is done with git pull --rebase.

Using git pull --rebase does not affect the integrity of the changes or the commits, but it does affect how history looks in the commit parent/child relationship.