Repositories and Commits
Create a Repository
To get started with a local git repository, the programmer must first create one. So far, we made all the repositories for you and you were able to clone the code to your local machine.
To create a git repository, the programmer navigates to their project directory and uses the command
git init, like so:
Students-Computer:~ student$ mkdir homework Students-Computer:~ student$ cd homework Students-Computer:homework student$ git init Initialized empty Git repository in /Users/student/homework/.git/
Now the programmer is ready to code away!
After a while, the programmer has made a lot of changes and saved their code files many times over. So when do they make a commit to their repository? Here’s a good rule of thumb:
Any time a significant change in functionality is made, perform a commit.
If the programmer has created the Git repository and is ready to commit, they can do so by following the commit process that you have seen before. Let’s review it now.
The procedure for making a commit to a Git repository includes four stages.
git statusgives the programmer information about files that have been changed.
git addallows the programmers to add specific or all changed files to a commit.
git commit -m MESSAGEcreates the new commit with the files that the programmer added, with a message describing the changes included in the commit. Here,
MESSAGEshould be a descriptive message within double-quotes.
git logdisplays a log of every commit in the repository.
If the steps above are followed correctly, the programmer will find their latest commit at the top of the log.
Here is how the process looks in the terminal:
Students-Computer:homework student$ git status On branch main Initial commit Untracked files: (use "git add <file>..." to include in what will be committed) learning-git.js nothing added to commit but untracked files present (use "git add" to track) Students-Computer:homework student$ git add . Students-Computer:homework student$ git commit -m "My first commit" [master (root-commit) 2c1e0af] My first commit 1 file changed, 1 insertion(+) create mode 100644 learning-git.js Students-Computer:homework student$ git log commit 2c1e0af9467217d76c7e3c48bcf9389ceaa4714b Author: Student <[email protected]> Date: Wed Apr 24 14:44:59 2019 -0500 My first commit
To break down what happens in a commit even further:
git status, the output shows two categories: modified tracked files and modified untracked files.
Modified tracked means that the file exists in the Git repository already, but it is different than the version in the repository.
Modified untracked means that it is a new file that is not currently in the repository.
git add adds files to the commit, but it does not commit those files.
git add ., all the modified files were added to the commit.
If a programmer only wants to add one modified file, they can do so.
git commit actually commits the files that were added to the repository.
-m "My first commit", a comment was added to the commit.
This is helpful for looking through the log and seeing detailed comments of the changes made in each commit.
It’s important to include a descriptive commit message. Such messages are visible in your local Git log, as well as in the commit history on GitHub. A good commit message allows you and your fellow developers to easily identify the changes made in a given commit.
git log shows the author of the commit, the date made, the comment, and a 40-character hash.
This hash or value is a key for Git to refer to the version.
Programmers use these hashes to reference specific commits, or snapshots, in the repository’s history.
Check Your Understanding
What git command is NOT a part of the commit process?