Inspecting a repository

The git status command is a relatively straightforward command. It simply shows you what's been going on with git add and git commit. Status messages also include relevant instructions for staging/unstaging files. Sample output showing the three main categories of a git status call is included below:

Untracked files typically fall into two categories. They're either files that have just been added to the project and haven't been committed yet, or they're compiled binaries like .pyc, .obj, .exe, etc. While it's definitely beneficial to include the former in the git status output, the latter can make it hard to see what’s actually going on in your repository.

For this reason, Git lets you completely ignore files by placing paths in a special file called .gitignore. Any files that you'd like to ignore should be included on a separate line, and the * symbol can be used as a wildcard. For example, adding the following to a .gitignore file in your project root will prevent compiled Python modules from appearing in git status:

The first status output will show the file as unstaged. The git add action will be reflected in the second git status, and the final status output will tell you that there is nothing to commit—the working directory matches the most recent commit. Some Git commands (e.g., git merge) require the working directory to be clean so that you don't accidentally overwrite changes.

Log output can be customized in several ways, from simply filtering commits to displaying them in a completely user-defined format. Some of the most common configurations of git log are presented below.

Display the entire commit history using the default formatting. If the output takes up more than one screen, you can use Space to scroll and q to exit.

Limit the number of commits by . For example, git log -n 3 will display only 3 commits.

Condense each commit to a single line. This is useful for getting a high-level overview of the project history.

Along with the ordinary git log information, include which files were altered and the relative number of lines that were added or deleted from each of them.

Display the patch representing each commit. This shows the full diff of each commit, which is the most detailed view you can have of your project history.

Search for commits by a particular author. The ＜pattern＞ argument can be a plain string or a regular expression.

Search for commits with a commit message that matches ＜pattern＞, which can be a plain string or a regular expression.

Show only commits that occur between < since > and < until >. Both arguments can be either a commit ID, a branch name, HEAD, or any other kind of revision reference.

Only display commits that include the specified file. This is an easy way to see the history of a particular file.

A few useful options to consider. The --graph flag that will draw a text based graph of the commits on the left hand side of the commit messages. --decorate adds the names of branches or tags of the commits that are shown. --oneline shows the commit information on a single line making it easier to browse through commits at-a-glance.

5. Check the status of the file.

Most of this is pretty straightforward; however, the first line warrants some explanation. The 40-character string after commit is an SHA-1 checksum of the commit’s contents. This serves two purposes. First, it ensures the integrity of the commit—if it was ever corrupted, the commit would generate a different checksum. Second, it serves as a unique ID for the commit.

This ID can be used in commands like git log .. to refer to specific commits. For instance, git log 3157e..5ab91 will display everything between the commits with ID's 3157e and 5ab91. Aside from checksums, branch names (discussed in the Branch Module) and the HEAD keyword are other common methods for referring to individual commits. HEAD always refers to the current commit, be it a branch or a specific commit.

The ~ character is useful for making relative references to the parent of a commit. For example, 3157e~1 refers to the commit before 3157e, and HEAD~3 is the great-grandparent of the current commit.

The Usage section provides many examples of git log, but keep in mind that several options can be combined into a single command:

This will display a full diff of all the changes John Smith has made to the file hello.py.

The .. syntax is a very useful tool for comparing branches. The next example displays a brief overview of all the commits that are in some-feature that are not in main.