So, what is Git in a nutshell? This is an important section to absorb, because if you understand what Git is and the fundamentals of how it works, then using Git. The second edition of this book is meant to address those example of Git hosting, I have decided to turn that part of the book into more. Access this book for free. ISBN ; This book is an open access book, you can download it for free on Softcover 44,95 €.
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Git – Git Basics
It is hard to get the system to do giptro that is not undoable or to make it erase data in any way. This makes using Git a joy because we know we can experiment without the danger of severely screwing things up.
For a more in-depth look at how Git stores its data and how you can recover data that seems lost, see Undoing Things. Git on gitpgo Server 4. This may not seem like a huge deal, but you may be surprised what a big difference it can make. It makes Git reconsider almost every aspect of version control that most other systems copied from the previous generation.
1.3 Getting Started – Git Basics
You selectively stage just those changes you want to be part of your next commit, which adds only those changes to the staging area. Because you have the entire history of the project right there on your local disk, most operations seem almost instantaneous.
If you get on an airplane or a train and want to do a little work, you can commit happily bopk your local copy, remember? This is a character string composed of hexadecimal characters 0—9 and a—f and calculated based on the contents of a file or directory structure in Git. This is the most important part of Git, and it is what is copied when you clone a repository from another computer.
A SHA-1 hash looks something like this:. Git thinks about its data more like a stream of snapshots.
The working tree is a single checkout of one version of the project. This leads us to the three main sections of a Git project: Git has three main states that your files can reside in: Git Has Integrity Everything in Git is checksummed before it is stored and is then referred to by that checksum.
So, what is Git in a nutshell?
You do a commit, which takes the files as they are in the staging area and stores that snapshot permanently to your Git directory. Modified means that you have changed the file but have not committed it to your database yet. If you want to see the changes introduced between the current version of a file and the file a month ago, Git can look up the file a month ago and do a local difference calculation, instead of having to either ask a remote server to do it or pull an older version of the file from the remote server to do it locally.
Embedding Git in your Applications A2. The mechanism that Git uses for this checksumming is called a SHA-1 hash.
The Git directory is where Git stores the metadata and object database for your project. This is an important section to absorb, because if you understand what Git is and the fundamentals of how it works, then using Git effectively will probably be much easier for you.
In many other systems, doing so is either impossible or painful. Consider becoming a supporter! Everything in Git is checksummed before it is stored and is then referred to by that checksum. You will see these hash values all over the place in Git because it uses them so much.
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This makes Git more like a mini filesystem with some incredibly powerful tools built on top of it, rather than simply a VCS. This is an important distinction between Git and nearly all other VCSs. With Git, every time you commit, or save the state of your project, Git basically takes a picture of what gihpro your files look like at that moment and stores a reference to that snapshot.
Git and Other Systems 9. Conceptually, most other systems store information as a list of file-based changes.
Git in Other Environments A1. And if it was changed since it was checked out but has not been staged, it is modified. The staging area is a file, generally contained in your Git directory, that stores information about what will go into your next commit. This functionality is built into Git at the lowest levels and gitprk integral to its philosophy. If it has been modified and was added to the staging area, it is staged. In fact, Git stores everything in its database not by file name but by the hash value of its contents.
These gitprp are pulled out of the compressed database in the Git directory and placed on disk for you to use or modify.