How to upload or commit to Github project as different author? [duplicate]

I have made a series of commits in Git and I realise now that I forgot to set my user name and user email properties correctly (new machine). I have not yet pushed these commits to my repository, so how can I correct these commits before I do so (only the 3 latest commits on the master branch)?

I have been looking at git reset and git commit -C <id> --reset-author, but I don't think I'm on the right track.

Warning: now deprecated in favor of filter-repo.

Rebase/amend seems inefficient, when you have the power of filter-branch at your fingertips:

git filter-branch --env-filter 'if [ "$GIT_AUTHOR_EMAIL" = "incorrect@email" ]; then
     GIT_AUTHOR_EMAIL=correct@email;
     GIT_AUTHOR_NAME="Correct Name";
     GIT_COMMITTER_EMAIL=$GIT_AUTHOR_EMAIL;
     GIT_COMMITTER_NAME="$GIT_AUTHOR_NAME"; fi' -- --all

(split across lines for clarity, but not necessary)

Be sure to inspect the result when you're done, to make sure that you didn't change anything you didn't mean to!

The interactive rebase approach is pretty nice when used in conjunction with exec. You can run any shell command against a specific commit or all commits in the rebase.

First set your git author settings

git config --global user.name "John Doe"
git config --global user.email [email protected]

Then to reset the author for all commits after the given SHA

git rebase -i YOUR_SHA -x "git commit --amend --reset-author -CHEAD"

This will pop up your editor to confirm the changes. All you need to do here is save and quit and it will go through each commit and run the command specified in the -x flag.

Per @Dave's comment below, you can also change the author while maintaining the original timestamps with:

git rebase -i YOUR_SHA -x "git commit --amend --author 'New Name <[email protected]>' -CHEAD"