Manipulate committer/author for historic git commits

commit_authors.sh

# set author/committer for ALL commits in the history

git filter-branch --env-filter '
  export GIT_AUTHOR_NAME=new_name
  export GIT_AUTHOR_EMAIL=new@foo.bar
  export GIT_COMMITTER_NAME=new_name
  export GIT_COMMITTER_EMAIL=new@foo.bar'

# change author/committer for all commits from a particular individual

git filter-branch --env-filter '
  if [ $GIT_AUTHOR_NAME = old_name ]
     then
        export GIT_AUTHOR_NAME=new_name
        export GIT_AUTHOR_EMAIL=new@foo.bar
        export GIT_COMMITTER_NAME=new_name
        export GIT_COMMITTER_EMAIL=new@foo.bar
  fi' -f

# change author/committer for a particular commit

git filter-branch --env-filter '
  if [ $GIT_COMMIT = <commit-id> ]
     then
        export GIT_AUTHOR_NAME=new_name
        export GIT_AUTHOR_EMAIL=new@foo.bar
        export GIT_COMMITTER_NAME=new_name
        export GIT_COMMITTER_EMAIL=new@foo.bar
  fi' -f