Git Tips

If you work with any kind of text files, a version control program is your best friend. And Git is probably the best.

The easiest way to learn git is tutorial. All other git commands you will learn by googling for them when in need.

If you want to share your code in an open source way, Github is nowadays the top choice. They also helped with the tutorial above.

Work on several branches simultaneously

In newer versions of git (2.5+), you can open a branch of your local repository into a separate path without cloning the repo. Stackoverflow knows more.

git worktree add path/to/separate/folder [branch-name]

The only limitation is that you cannot check out the same branch twice. But now you can work on several branches without having to switch between them. And, since they all originate from one repository, you can push them with one command.

Compare all local branches with remote

If you use more than one branch in git, you may want to keep them also backed up in a remote repository. And to keep track of all branches and their relation to the remote ones, there are commands like

git fetch -v
git branch -v

Linux users may be familiar with this flag -v, which stands for verbose, for many programs. Also here, it makes git list all branches and their status compared to remote.

Change the url (path) of origin

With

git remote -v

you can check what the current url (path) to your remotes are. Now to change (update) the url just use

git remote set-url origin https://new.git.repo.url

Make branch track remote branch

If you create a new branch locally and want to push it to origin, use

git push -u origin branch-name

to push it and set the local branch to track its remote copy.

If you forgot to do this, you can use

git branch -u origin/branch-name

to start tracking after a push.

Manage several remotes

Checking out remote branches

Having several remotes as backup may be a good idea. Let’s say you want to check out a new (remote) branch. If you have several remotes, then doing

git fetch
git checkout branchname

doesn’t work. You need to do

git checkout -b branchname remote-name/branchname

according to stackoverflow.

Push to several remotes

Now that we have several remotes, we want to keep them up to date. But pushing each one separately is too much work! Stackoverflow suggests to create a new remote and add extra push urls:

git remote add all git://repo1.url
git remote set-url --add --push all git://repo2.url

Unfortunately the last command overwrites the original url for pushing; so we have to add it back with

git remote set-url --add --push all git://repo1.url

Now, we can use the remote all as the new remote repository that our branches track. Push{nbsp}all pushes to all repositories, but pull only fetches the first repository.

Recover lost files (discard changes)

The more I use git the more I love it! One of the nicest features of git is that you can undo changes – including deletion of files. I wanted to remove some files and accidentally typed: rm{nbsp}something{nbsp}\*, whereas I wanted rm{nbsp}something*. But of course bash didn’t know that and merrily deleted everything in my directory (except a folder).

But as always, git saves the day. With

git checkout -- /path/to/file

you can discard any changes on this file. Including deletion.

If you want to do this for every file in the current directory, type:

git checkout -- .

The dot is important.

Copy (checkout) files from other branches

Sometimes you want to http://nicolasgallagher.com/git-checkout-specific-files-from-another-branch/[fetch some files] from another branch. But you don’t want to check out the whole branch; just copy some files from it.

Git can do this already:

git checkout other_branch -- path/to/files/

Just use -- with git checkout and it just fetches those files while staying in the current branch. Sweet!

Combine (squash) commits

If you want to combine the last few commits into one, you can use

git reset --soft HEAD~3

to go back to the third commit before HEAD. With the --soft option, you keep all files and changes from current working directory.

Now you can commit those changes with one commit!

Extract Subtrees

If your project becomes large or if you are like me and have a git repository for many things, you may want to extract a part of it and keep the commits.

Git gives you a history of a certain file with

git log -- special.file

But git can also extract the history of a sub-folder into a separate branch:

git-subtree split --prefix=path/to/subfolder --branch=new-branch

But this works only with sub-folders. So my tips are

• keep separate stuff in separate folders
• split up large commits that change separate parts