Prior to that, the $GIT_COMMIT environment variable will be set to contain
the id of the commit being rewritten. Also, GIT_AUTHOR_NAME,
GIT_AUTHOR_EMAIL, GIT_AUTHOR_DATE, GIT_COMMITTER_NAME, GIT_COMMITTER_EMAIL,
-and GIT_COMMITTER_DATE are set according to the current commit. The values
-of these variables after the filters have run, are used for the new commit.
+and GIT_COMMITTER_DATE are taken from the current commit and exported to
+the environment, in order to affect the author and committer identities of
+the replacement commit created by linkgit:git-commit-tree[1] after the
+filters have run.
+
If any evaluation of <command> returns a non-zero exit status, the whole
operation will be aborted.
' HEAD~10..HEAD
--------------------------------------------------------
+The `--env-filter` option can be used to modify committer and/or author
+identity. For example, if you found out that your commits have the wrong
+identity due to a misconfigured user.email, you can make a correction,
+before publishing the project, like this:
+
+--------------------------------------------------------
+git filter-branch --env-filter '
+ if test "$GIT_AUTHOR_EMAIL" = "root@localhost"
+ then
+ GIT_AUTHOR_EMAIL=john@example.com
+ export GIT_AUTHOR_EMAIL
+ fi
+ if test "$GIT_COMMITTER_EMAIL" = "root@localhost"
+ then
+ GIT_COMMITTER_EMAIL=john@example.com
+ export GIT_COMMITTER_EMAIL
+ fi
+' -- --all
+--------------------------------------------------------
+
To restrict rewriting to only part of the history, specify a revision
range in addition to the new branch name. The new branch name will
point to the top-most revision that a 'git rev-list' of this range