Change author information for all Git commits

Sometimes we want to update all of our previous Git commits so that they use a specific author name and/or e-mail address. One use case is when previous commits include a mix of e-mail addresses, and one or more of them is private.

We can see our previous commits and commit information using git log.

To update the author information of all of our Git commits, we enter the following command:

git filter-branch -f --env-filter \
"GIT_AUTHOR_NAME='Newname'; GIT_AUTHOR_EMAIL='newemail'; \
GIT_COMMITTER_NAME='committed-name'; GIT_COMMITTER_EMAIL='committed-email';" HEAD

To verify that the author commit information has indeed been updated, we once again type git log.

In future, we can check which e-mail address we are using with this command:

git config --global user.email

The --global flag indicates the user e-mail address used for all repositories. If we only want to see the e-mail address used for the current repository, then we type git config user.email. In both cases, we set our desired e-mail address by typing the command, followed by "our.new.address@email.com".

Now that we’ve updated our author information, we may get an error message when trying to perform a git pull. The message will look something like refusing to merge unrelated histories. This can be resolved with the following commands:

git pull origin main --allow-unrelated-histories
git merge origin origin/main

Sources:

• Change user name and e-mail of previous commits
• Resolve pull issues by allowing unrelated histories