Git for beginners: The definitive practical guide

Answer 1

How do you create a new project/repository?

A git repository is simply a directory containing a special .git directory.

This is different from "centralised" version-control systems (like subversion), where a "repository" is hosted on a remote server, which you checkout into a "working copy" directory. With git, your working copy is the repository.

Simply run git init in the directory which contains the files you wish to track.

For example,

cd ~/code/project001/
git init

This creates a .git (hidden) folder in the current directory.

To make a new project, run git init with an additional argument (the name of the directory to be created):

git init project002

(This is equivalent to: mkdir project002 && cd project002 && git init)

To check if the current current path is within a git repository, simply run git status - if it's not a repository, it will report "fatal: Not a git repository"

You could also list the .git directory, and check it contains files/directories similar to the following:

$ ls .git
HEAD         config       hooks/       objects/
branches/    description  info/        refs/

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If for whatever reason you wish to "de-git" a repository (you wish to stop using git to track that project). Simply remove the .git directory at the base level of the repository.

cd ~/code/project001/
rm -rf .git/

Caution: This will destroy all revision history, all your tags, everything git has done. It will not touch the "current" files (the files you can currently see), but previous changes, deleted files and so on will be unrecoverable!

Answer 2

Git Reset

Say you make a pull, merge it into your code, and decide you don't like it. Use git-log, or tig, and find the hash of wherever you want to go back to (probably your last commit before the pull/merge) copy the hash, and do:

# Revert to a previous commit by hash:
git-reset --hard <hash>

Instead of the hash, you can use HEAD^ as a shortcut for the previous commit.

# Revert to previous commit:
git-reset --hard HEAD^

Answer 3

How to track remote branches

Assuming there is a remote repository that you cloned your local repository from and also assuming that there is a branch named 'some_branch' on that remote repository, here is how to track it locally:

# list remote branches
git branch -r

# start tracking one remote branch
git branch --track some_branch origin/some_branch

# change to the branch locally
git checkout some_branch

# make changes and commit them locally
....

# push your changes to the remote repository:
git push

Answer 4

Workflow example with GIT.

Git is extremely flexible and adapts good to any workflow, but not enforcing a particular workflow might have the negative effect of making it hard to understand what you can do with git beyond the linear "backup" workflow, and how useful branching can be for example.

This blog post explains nicely a very simple but effective workflow that is really easy to setup using git.

quoting from the blog post: We consider origin/master to be the main branch where the source code of HEAD always reflects a production-ready state:

The workflow has become popular enough to have made a project that implements this workflow: git-flow

Nice illustration of a simple workflow, where you make all your changes in develop, and only push to master when the code is in a production state:

Now let's say you want to work on a new feature, or on refactoring a module. You could create a new branch, what we could call a "feature" branch, something that will take some time and might break some code. Once your feature is "stable enough" and want to move it "closer" to production, you merge your feature branch into develop. When all the bugs are sorted out after the merge and your code passes all tests rock solid, you push your changes into master.

During all this process, you find a terrible security bug, that has to be fixed right away. You could have a branch called hotfixes, that make changes that are pushed quicker back into production than the normal "develop" branch.

Here you have an illustration of how this feature/hotfix/develop/production workflow might look like (well explained in the blog post, and I repeat, the blog post explains the whole process in a lot more detail and a lot better than I do.

Answer 5

The Pro Git free book is definitely my favorite, especially for beginners.

Answer 6

I've also found Git Internals to be very useful. It is written by Scott Chacon (author of Pro Git, and maintainer of the Git Community Book). What I like about Git Internals is it focuses on the concepts first and then the commands, and being that it is ~100 small pages it is quickly digestible.