Category: Git(Hub) Tip of the Day 2017

How to merge from a remote tracking branch into your local branch in command line – 124

Today’s tip is the continuation from Tip 118 – how to download and merge from a remote branch into Visual Studio, but using the command line.

Let’s suppose you have a local branch that’s tracking the remote branch (see yesterday’s tip). And let’s say someone has made an update to that remote branch (e.g. they made a commit `newfile.md` via the GitHub UI to the branch). Now you want to get those changes into your local branch.

First, we’ll put this week’s earlier tip to good use by doing a `git fetch` just to get those changes onto your computer.

Now you want to merge those changes into your local branch.

First, make sure you’ve checked out the desired branch to receive the merge.

Second, do the merge from the remote tracking branch (since it has the data)

$ git merge origin/<branch-name>

git merge origin/I-am-a-new-branch

And now if you do a `dir` or `ls` you’ll see the changes. In my example, the newfile.md is now shown in the local branch.

newfile.md shown in local branch

How to checkout a remote branch for the first time via the command line – 123

In Tip 116 you saw you to create a local copy of a remote branch in VS. In today’s tip, you’ll learn how to do this from the command line.

First, let’s verify our current list of branches.

git branch -a showing only 1 local branch 

Next, you can use the following git command (provided you only have one remote)

$ git checkout I-am-a-new-branch

It seems that you don’t have to specify the `origin/` part. Git knows to look for corresponding tracking branches.

And you’ll have your local branch.

creating a new local branch from a remote tracking branch

As I’ve mentioned time and time again, I hate shortcuts when learning things for first time. This SO answer tells me there’s a more complete way.

$ git checkout -b <branch-name> origin/<branch-name>

I gave this a try with my gh-pages branch and sure enough it worked!

git checkout -b gh-pages origin/gh-pages

How to fetch down updates from a Git remote repository – 122

In Tip 117 you saw how to fetch down updates from a Git remote in Visual Studio. Note: I said “fetch down” instead of “pull down” because tip 117 only fetches the data. The result is the data for the remote tracking branches is updated, but not applied to your local branch. Hence the “incoming commits” terminology in Visual Studio.

Today you’ll see how to rinse and repeat for the command line.

First, let’s verify the currently listed branches our local remote is aware of.

$ git branch -a

git branch -a showing 3 remote tracking branches

Second, let’s add a new branch to the remote on GitHub.

I-am-a-new-branch (less than a minute ago)

Third, let’s sanity check that no magic sync’ing has happened behind the scenes.

$ git branch -a

And you’ll see the same number of remote tracking branches. (yes, I took a second screenshot. I’m too lazy to think about optimization 🙂 TBH I have to verify what I’m writing here!

git branch -a still showing 3 remote tracking branches

Fourth, run the git command to fetch

$ git fetch origin

I know you can do just `git fetch` but I don’t like learning shortcuts first.

git fetch origin creates a new tracking branch

I’m not sure if the branch on the left is the remote tracking branch or if it is the one on the right. My guess is the one on the left hand side represents the branch from GitHub and the one on the right represents the remote tracking branch.

Nonetheless, you now have a new remote tracking branch as shown below.

remotes/origin/I-am-a-new-branch

How to use a double verbose to print the name of the upstream branch on command line – 121

Ah Git. It is the gift that keeps on giving if you’re into studying developer tool usability.

Suppose you wanted to get the last commit ID and message while listing all your branches. The `–verbose` or `-v` for short will provide you with that information, e.g.

$ git branch –verbose -a

git branch --verbose -a

Yay! But while I was scanning the documentation, I came across this usability gem*

If given twice, print the name of the upstream branch, as well. (see also git remote show <remote> ).

Yep, if you do a

$ git branch -vv -a

you’ll get even more information! Note the blue text depicting the upstream branch.

git branch --v -a

*Specifying the –verbose option twice reminds me of old school text-adventure games where you’d have to look twice in the same location to find a second item. If you thought to do that, you’ll get a bonus or something. Now I might have to search the Git documentation for the common commands to see what other options exist where you have to specify a parameter twice!

 P.S. I can’t find in Visual Studio where to see the upstream branch. You can see all remote branches in the history view, but that’s not quite the same. Perhaps since  in Team Explorer (as far as I can tell) 1. you can’t rename a branch checked out from a remote tracking branch and 2. can’t checkout more than one remote tracking branch, it’s assumed that the upstream branch has the same name as your local branch. That’s my guess.