Why commit

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I am starting to learn Git. I prefer GUIs to the command line. Now I understand, in the GUI, I need to stage files, then commit them and then push , to upload them. But why are push and commit two different things? Why would want to just commit locally, without the following upload to keep files synced? The first reason is you might not be able to push to the remote , because you aren't connected to the internet. The second reason is that sometimes commits aren't ready to be pushed.

For example, I practice TDD. After I commit a failing test which I do , I don't want to push that to the remote, because then my team may pull in a failing test suite.

Another common practice is to squash these commits before pushing them out so it looks like the feature was one single commit. Third reason is that it's a personal project that you don't want to share with anyone , and so there is no remote to push to at all. You don't have to have a remote with a git repo. Fourth reason is you may have multiple remotes in general, distributed semantics get in the way.

So after you commit, how would git know which remote you want to push to? All of them? A certain one? A certain two out of the seven? Pushing must be explicit from git's perspective due to the semantics of git being a distributed VCS.

See poke's answer for more detail. This is off topic to the question, but the command line shells including bash are extremely powerful interfaces once you learn to use them. After you become proficient with these tools, using them is much faster than any GUI you're going to find. This has to do with the fact that you can do powerful actions with keystrokes instead of the mouse, and that it's infinitely customizable to fit your needs. Git is a distributed version control system. As such, there is no single central repository, like with Subversion or even CVS.

So if there was a single command to commit and push, then where would that commit would go? What would be the remote repository? In Git, there is no central repository. There is not even any hierarchy in repositories. For a local repository, any other repository is a remote repository it can interact with. And the local repository is just a possible remote repository for any other repository.

So local and remote are just points of view relative to your current location: The local repository is always the current repository, and every other repository is a remote that you can interact with. When working with Git, your local repository is what you interact with: You commit all your changes locally. So when you have that local repository, which has the full history and all the changes, you need a way to interact with other repositories, in order to allow you to share the history.

The two ways to do that are push and pull or fetch. Since with distributed repositories, every repository is the same, every repository can push or pull from another assuming they have access. In the end, committing and pushing is required to be separate steps because one is interacting with the local repository while the other is a deliberate step to share changes with a remote repository.

In the old days like five years ago--ancient history by today's standards of memory people were sometimes not connected to the internet! And they wanted to continue working! So they just committed as they worked. When connection was achieved, they'd go ahead and push all their commits. In such a case, it is very simple to do the change as the stylesheet changes are part of last commit on your branch.

Here's how we can handle this;. This command will override the commit Add styles for navigation on remote repo with updated commit that we just made in our local repo. One thing to keep in mind while force pushing branches is that if you are working on the same branch with multiple people, force pushing may cause trouble for other users when they try to normally push their changes on a remote branch that has new commits force pushed.

Hence, use this feature wisely. You can learn more about Git force push options here. In this case, it is second commit from the top, so changing it won't be as direct as it was in the first situation.

Let's see how we can handle this:. Whenever a commit is made in a branch, it is identified by a unique SHA1 hash string. Think of it as a unique ID that separates one commit from another. You can view all the commits, along with their SHA1 hashes in a branch by running git log. With this, you would see an output that looks somewhat as follows, where the most recent commits are at the top;. This is where git rebase command comes into play.

Whenever we wish to edit a specific commit with git rebase , we need to first rebase our branch by moving back HEAD to the point right before the commit we wish to edit. In our case, we need to change the commit that reads Page Navigation View. Here, notice the hash of commit which is right before the commit we want to modify; copy the hash and perform the following steps:.

Notice how each commit has a word pick in front of it, and in the contents below, there are all possible keywords we can use. Since we want to edit a commit, we need to change pick df1cdc7 Page Navigation View to edit df1cdc7 Page Navigation View. Save the changes and exit editor. Open the file and perform desired changes as per the review feedback. Since we have staged the changes, it is time to move branch HEAD back to the commit we originally had while also including the new changes we added , run git rebase --continue , this will open your default editor in the terminal and show you the commit message that we edited during rebase; Page Navigation View.

You can change this message if you wish, but we would leave it as it is for now, so save and exit the editor. Git Snapshots are always committed to the local repository. This is fundamentally different from SVN, wherein the working copy is committed to the central repository. This changes the basic development model for Git users. Instead of making a change and committing it directly to the central repo, Git developers have the opportunity to accumulate commits in their local repo.

This has many advantages over SVN-style collaboration: it makes it easier to split up a feature into atomic commits, keep related commits grouped together, and clean up local history before publishing it to the central repository.

While isolation and deferred integration are individually beneficial, it is in a team's best interest to integrate frequently and in small units. For more information regarding best practices for Git team collaboration read how teams structure their Git workflow.

Aside from the practical distinctions between SVN and Git, their underlying implementation also follows entirely divergent design philosophies. For example, a SVN commit consists of a diff compared to the original file added to the repository.

Git, on the other hand, records the entire contents of each file in every commit. Git's snapshot model has a far-reaching impact on virtually every aspect of its version control model, affecting everything from its branching and merging tools to its collaboration work-flows.

Commit the staged snapshot. This will launch a text editor prompting you for a commit message. Commit a snapshot of all changes in the working directory. This only includes modifications to tracked files those that have been added with git add at some point in their history. A shortcut command that immediately creates a commit with a passed commit message.

By default, git commit will open up the locally configured text editor, and prompt for a commit message to be entered. Passing the -m option will forgo the text editor prompt in-favor of an inline message.

A power user shortcut command that combines the -a and -m options. This combination immediately creates a commit of all the staged changes and takes an inline commit message. This option adds another level of functionality to the commit command. Passing this option will modify the last commit. Instead of creating a new commit, staged changes will be added to the previous commit. This command will open up the system's configured text editor and prompt to change the previously specified commit message.

First, you need to stage the file with git add , then you can commit the staged snapshot. This command will add hello. We can examine the result of this action by using the git status command. The green output new file: hello. From the commit is created by executing:. For example:. It is a common practice to use the first line of the commit message as a subject line, similar to an email.

The rest of the log message is considered the body and used to communicate details of the commit change set. Note that many developers also like to use the present tense in their commit messages. This makes them read more like actions on the repository, which makes many of the history-rewriting operations more intuitive.