Change commit author in Git

If you’ve ever had a reason to change the author name and/or email of one or more commits in a Git repository then fear not, it can be done. It, quite obviously, involves rewriting the history of your repository, and involves running a BASH script that utilizes the git-filter-branch utility included in the Git installer.

The script(s)

Both of these scripts should be executed in a BASH enabled terminal prompt, with git installed and in the root folder of the repository to change.

Updating specific commits

Use this script if you have multiple committers in your repository, and you only want to change the author of specific commits

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#!/bin/sh


git filter-branch --env-filter '

OLD_EMAIL="[email protected]"
CORRECT_NAME="Your New Name"
CORRECT_EMAIL="[email protected]"

if [ "$GIT_COMMITTER_EMAIL" = "$OLD_EMAIL" ]
then
    export GIT_COMMITTER_NAME="$CORRECT_NAME"
    export GIT_COMMITTER_EMAIL="$CORRECT_EMAIL"
    export GIT_AUTHOR_NAME="$CORRECT_NAME"
    export GIT_AUTHOR_EMAIL="$CORRECT_EMAIL"
fi
if [ "$GIT_AUTHOR_EMAIL" = "$OLD_EMAIL" ]
then
    export GIT_COMMITTER_NAME="$CORRECT_NAME"
    export GIT_COMMITTER_EMAIL="$CORRECT_EMAIL"
    export GIT_AUTHOR_NAME="$CORRECT_NAME"
    export GIT_AUTHOR_EMAIL="$CORRECT_EMAIL"
fi
' --tag-name-filter cat -- --branches --tags

Updating all commits

Use this script if you only have a single committers in your repository, or if you for some reason want to change the author of all commits regardless of who committed originally.

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#!/bin/sh


git filter-branch --env-filter '

OLD_EMAIL="[email protected]"
CORRECT_NAME="Your New Namr"
CORRECT_EMAIL="[email protected]"

export GIT_COMMITTER_NAME="$CORRECT_NAME"
export GIT_COMMITTER_EMAIL="$CORRECT_EMAIL"
export GIT_AUTHOR_NAME="$CORRECT_NAME"
export GIT_AUTHOR_EMAIL="$CORRECT_EMAIL"
' --tag-name-filter cat -- --branches --tags

After running one of the above scripts, and inspecting the history of the repository to make sure it’s rewritten correctly, run the below command.

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git push --force --tags origin 'refs/heads/*'

And finally delete the temporary clone, to make sure nothing gets messed up down the road.

And that’s it, you’re done. I hope it all makes sense, and you find it useful. Feel free to comment if I can improve the post, or you’re unsure about something.