git diff is a powerful command in Git that you can use to show changes between commits, commit and working tree, etc. To view changes between the index (also known as the staging area) and a named commit, you can use the
git diff command in a specific way.
Understanding the scenario: The index or the staging area is the place where Git tracks changes which will be included in the next commit. Sometimes, it can be helpful to compare the changes you’ve staged (i.e., added to the index) with those in a specific commit.
Executing the command: You can use the following command to compare the changes between the index and a specific commit:
git diff --cached [commit]
[commit] represents the commit hash, tag, or any other reference that points to the commit you want to compare with.The
--cached option makes
git diff compare your staged changes with the named commit.
Here’s a concrete example: If you want to compare the changes between the index and the commit with the hash
a1b2c3d4, you would use the following command:
git diff --cached a1b2c3d4
Interpreting the output: The output of
git diff is a list of differences between the specified commit and your staged changes. It shows what was added or removed to transition from the commit to your current staged changes. This is shown in a format similar to the unified diff format.
For example, a line starting with a
- indicates that it was present in the commit but is not staged for the next commit. Conversely, a line starting with a
+ indicates that it was not present in the commit but is now staged for the next commit.
Remember to replace
[commit] with the actual commit hash or reference that you want to compare with. If you are unsure of the commit hash, you can use the
git log command to view a history of commits, each with its associated hash.
git diff with the
--cached option allows you to view the changes between the index (staged changes) and a specific commit, which can be useful when preparing your next commit or during code reviews.