git-change-author

#!/bin/bash
##########################################################################
# git-change-author: Git Bulk Commit Author Rewriter                     #
#                                                                        #
#   Easily change the name and email of any of the commits in            #
#   a git repository.                                                    #
#                                                                        #
#      ./git-change-author "Your Name" "email@address" <SHA1>            #
#                                                                        #
# Part of HopeSeekr's BashScripts Collection                             #
# https://github.com/hopeseekr/BashScripts/                              #
#                                                                        #
# Copyright © 2012-2021 Theodore R. Smith <theodore@phpexperts.pro>      #
# GPG Fingerprint: 4BF8 2613 1C34 87AC D28F  2AD8 EB24 A91D D612 5690    #
#                                                                        #
# License: Creative Commons Attribution v4.0 International               #
#                                                                        #
##########################################################################

if [[ -z "$1" || "$1" == "--help" || -z "$2" ]]; then
    echo '   Usage: git-change-author "Your Name" "email@address" [SHA1]'
    exit 1
fi

AUTHOR="$1"
EMAIL="$2"
START_HASH="${3:---root}"

echo "On the next screen, you need to change 'pick' to 'edit' for every commit which you wish to alter."
echo ""
echo -n "Press ENTER to continue..."
read


git rebase --rebase-merges -i ${START_HASH}

while [ "$?" -eq 0 ]; do
    git -c user.name="${AUTHOR}" -c user.email="${EMAIL}" commit --amend --no-edit --author "${AUTHOR} <${EMAIL}>"
    git rebase --continue
done

# Reset the git commit times so that GitHub, et. al., will show the original date and not now.
git rebase --rebase-merges --committer-date-is-author-date "${START_HASH}"

echo ""
echo ""
echo "Don't forget to run \`git push -f\`... preferably on a test branch first!"