First of all, we need to understand how the author name and email are set by the git version control.
1. Set the author name and email globally
With the help of the following commands, we can set the committer’s name and email globally.
$ git config --global user.name "John Doe"
$ git config --global user.email "john@doe.org"
2. Set the author name and email for each repository
We can set these details at repository level by omitting the –global flag.
git config user.name "John Doe"
git config user.email "john@doe.org"
Change the author while committing the code
We can use the flag –author=”Name ” with the git commit command. For example,
git commit -m "New feature added" --author="John Doe "
Change author of the last commit
It’s relatively easy to change the author of the last commit. Simply run the following command in the terminal, and you’re done!
git commit --amend --author="author_name " --no-edit
Don’t forget to include email address in “<>“
Change the author of the past commits (not the latest)
This will be a little more challenging. Keep in mind that when we update the past commits , we actually rewrite the history of the git branch. We are going to use the rebase command, which can help you update almost everything in the past commits.
First of all, we will identify the last “valid commit”.
We want to modify the author of the last two commits, so we will use the commit hash 574b2bcfad6f7d347bc9a08953f037a1d8b79967 with the rebase command.
git rebase -i 574b2bcfad6f7d347bc9a08953f037a1d8b79967
Git will now open the default editor with the similar details as shown below.
Now we will mark the commits we want to modify by replacing the word “pick” with “edit”.
Git will walk us through each commit, and we can update the author details.
Stopped at 3800a1cf1... make login responsive
You can amend the commit now, with
git commit --amend
Once you are satisfied with your changes, run
git rebase --continue
Now use below commands to update the author and continue rebase till the last commit
git commit --amend --author="author_name " --no-edit
git rebase --continue
Once done, if we again run the git log command, we will get the below output.
commit 5e679a69f5aed75d75a0a838167789d3d19431e5 (HEAD -> feature1)
Author: John Doe
Date: Sun Feb 26 23:46:13 2023 +0530
New feature added
commit 6293a1uk38fa37e827cc0f4355m77lck65aav965
Author: John Doe
Date: Sun Feb 26 23:39:06 2023 +0530
make login responsive
commit 574b2bcfad6f7d347bc9a08953f037a1d8b79967
Author: John Doe
Date: Sun Feb 26 11:13:40 2023 +0530
make dashboard screen
commit a0a838167789d3d194315e679a69f5aed75d75bb
Author: John Doe
Date: Sun Feb 26 10:38:57 2023 +0530
added border to images
commit 0a7634029ff6968a48781207acd61d74f45c35c6 (master)
Author: John Doe
Date: Sun Feb 26 10:26:45 2023 +0530
First commit
The important point is that the commit hashes of the last two commits have changed. If the branch is present remotely, we must force push it in order to push these changes to the git remote repository.
Using the git filter-branch
If we want to update the commits in bulk for the entire branch, we can use the following script:
#!/bin/bash
export FILTER_BRANCH_SQUELCH_WARNING=1 # This will suppress the warning shown by git
git filter-branch -f --env-filter '
if test "$GIT_AUTHOR_EMAIL" = "richard.roe@gmail.com"
then
GIT_AUTHOR_NAME="John Doe"
GIT_AUTHOR_EMAIL=john.doe@gmail.com
fi
if test "$GIT_COMMITTER_EMAIL" = "richard.roe@gmail.com"
then
GIT_COMMITTER_NAME="John Doe"
GIT_COMMITTER_EMAIL=john.doe@gmail.com
fi
' HEAD
The script mentioned above will change the author of every commit that meets the condition.
What is the difference between a committer and an author?
The author is the person who originally wrote the code, and the committer is the person who committed the code on behalf of the original author. For instance, if a project maintainer receives a patch and applies it, the author of the patch still receives credit for the work.
The git-filter-branch is such a powerful command that it can easily corrupt repositories or leave you with a mess worse than you began with. Avoid using it with the public or shared repositories.
Thanks for reading, I hope this is helpful.
