change the author of a commit in git?

删除项目里的大文件

git filter-branch --index-filter \ 
        'find -name ''*.mp3'' -or -name ''*.ogg'' | xargs -d''\n'' rm -f'

#Suppose you want to remove a file (containing confidential information or copyright violation) from all commits:

git filter-branch --tree-filter 'rm filename' HEAD

git filter-branch --commit-filter '
        if [ "$GIT_COMMITTER_NAME" = "<Old Name>" ];
        then
                GIT_COMMITTER_NAME="<New Name>";
                GIT_AUTHOR_NAME="<New Name>";
                GIT_COMMITTER_EMAIL="<New Email>";
                GIT_AUTHOR_EMAIL="<New Email>";
                git commit-tree "$@";
        else
                git commit-tree "$@";
        fi' HEAD

 export GIT_AUTHOR_DATE="Fri Jan 2 21:38:53 2009 -0800"
         export GIT_COMMITTER_DATE="Sat May 19 01:01:01 2007 -0700"

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


git filter-branch -f --env-filter "
    GIT_AUTHOR_NAME='Newname'
    GIT_AUTHOR_EMAIL='newemail'
    GIT_COMMITTER_NAME='Newname'
    GIT_COMMITTER_EMAIL='newemail'
  " HEAD