How can I see who made a particular change in Git?

Git, an open-source distributed version control system, provides powerful tools for tracking changes in your code. If you want to find out who made a specific change in your code, there are multiple ways to do so:

1. Git Blame

The git blame command shows line-by-line detail for a specific file including the commit that last modified the line, the author, and when it was modified. The syntax of the git blame command is:

git blame <file-name>

This will print each line of the file prepended with the identifier of the commit that last modified the line.

2. Git Log

The git log command, when used with the -p (patch) option, shows the differences introduced at each commit. This way, you can see who made a particular change. To search for a specific change, use git log in conjunction with grep. Here is the command:

git log -p | grep <change>

This will give you the commit ID, the author, and the date of change.

3. Git Bisect

git bisect is a binary search tool within Git that helps you find the commit that introduced a bug. To use git bisect, you need a good commit (where the bug isn’t present) and a bad commit (where the bug is present). git bisect will keep narrowing down the range until it finds the exact commit where the bug was introduced.

First, start the bisecting process:

git bisect start

Then, specify a bad commit:

git bisect bad <bad-commit>

And a good commit:

git bisect good <good-commit>

Git will then check out a commit in the middle of that range. Test that commit to see if it’s good or bad. Once you’ve determined if the commit is good or bad, tell Git:

git bisect good

or

git bisect bad

Repeat this process until Git finds the exact commit that introduced the bug.

4. Git Show

Once you have the commit ID (from the git blame or git log command), you can use the git show command to see the changes made in that commit, including the author and the date of the change. The syntax of the git show command is:

git show <commit-id>

This will give you the detailed information about the commit including the diff (the actual changes), the author, and the commit message.

By using these Git commands, you can effectively track changes in your code, identify who made a particular change, and also find out when it was done. This helps a lot in collaborative projects and debugging processes.