The 'git fetch' Command

Fetching from remote#

First, you will look at fetching from the remote.

The command git fetch gets the latest changes from the remote repository and copies them into the local repository, updating the local copies of any branches that have been changed.

Crucially, these changes are not mixed with your local branches but are kept in a separate place. So if you have a master branch on the remote Git repository and a master branch on your local Git repository, then your local one will not be affected.

First, make a change to the origin’s repository:

1   cd ..
2   cd git_origin
3   echo 'fetchable change' >> file1
4   git commit -am fetchable

Then go to the cloned repository and fetch the changes on the master branch, which is on the origin remote (git_origin). Type the following two commands in the terminal provided above.

5   cd ../git_cloned
6   git fetch origin master

You did not fetch all the changes from the remote but specified that you wanted the changes on the remote master branch brought down by adding the branch to the command.

The above output means that the origin’s master has been brought into this repository’s references. This branch is now referred to locally as: origin/master.

This has not affected the local master branch at all. Check out this:

7   git log

You can see this repository’s view of all the branches it is aware of by running this:

8   git branch --all

Here, you see the local master branch that is followed by the remotes/origin/HEAD pointer (remember: HEAD is a pointer to a location in the repository), which is linked to remotes/origin/master.

Digging deeper#

If you want to dig into the internals at this point, you can peek at the .git folder again:

9   ls .git/refs/

It has heads, which contains references to the local branch:

10  cat .git/refs/heads/master

And similarly for remote branches:

11  cat .git/refs/remotes/origin/master

So you’ve git fetched the remote branch and now you have a copy of it locally.

Applying remote changes to local#

To apply the remote master’s changes to the local one, merge it just as you would for any other reference:

12  git merge origin/master
13  git log

The key point to take from all this is that pulling involves two actions: fetching (which just brings over the changes from a remote repository and caches it locally for reference) and merging (which actually messes with your local repository).

Personal preference#

In general, I prefer fetching and merging rather than using git pull. If you do git fetch and git merge separately, keep reminding yourself of what’s going on with respect to remotes in your Git repository. Once you’ve internalized that workflow, start using git pull as a convenience. If you use git pull too early, there is a danger of seeing it as magical or at least, not feeling entirely sure about what’s going on.