After you have forked a repository and cloned it to GitHub for Mac you can view the repository on GitHub.com and add some buddies as collaborators so that they could also work on your fork… but, first, let's make some changes ourselves!

GitHub for Mac includes a handy shortcut so that you can quickly view your repositories in the Finder:

  1. Find the repository in the list within the sidebar.
  2. Control-click the repository.
  3. In the contextual menu, select Open in Finder.

Show in Finder

Make a change

If you cloned the Spoon-Knife repository, you'll notice that there are a few simple project files in it: A README text file, an HTML page, and a CSS file. Open README.md in your favorite text editor, change the text to whatever you like, and then save it.

Now that you've made changes to your local copy, let's use GitHub for Mac to commit this change.

What is a commit?

Think of a commit as a snapshot of your project – code, files, everything — at a particular point in time.

View your change

Switch back to GitHub for Mac and click Spoon-Knife in the Repositories list. This will show the Changes view, where you can see that README.md now has been highlighted as modified. On the right, you can see a diff showing which lines were changed.

Changes View

What is a diff?

A diff is a simple, visual comparison between two files. It illustrates the difference between the latest version of a file and the previous version of the same file. Both GitHub.com and GitHub for Mac display diffs with a red highlight on lines where text has been removed, and a green highlight where text has been added.

Commit your change locally

To commit these changes, type a commit summary (and, optionally, an extended description, if you want to provide more details of the changes you made) and click Commit.

At this point you'll notice that there are no longer any files to commit—instead, there’s now one unsynced commit, which you can view by clicking on the “Unsynced” header. This means that your changes have been committed with Git locally but not yet synced to your remote repository on GitHub.com.

Unsynced commits

Making partial commits

If you click on the line numbers in the gutter, you can choose to make a partial commit. Only the lines highlighted in blue will be committed. The rest of your changes will remain intact, so that you can make additional modifications and commits.

GitHub for Mac showing partial line commits

Sync your changes with GitHub

To send those changes to your remote repository, all you have to do is click the Sync button in the upper-right of the window.

Sync will also pull in any changes made by others, so that you’re left with the latest version of all the files.

Celebrate

Congratulations! You've made some changes to a repository and committed them with Git. Now let's take a look at viewing the history of commits in a project.