TTER_EMAIL,
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 <a href="git-commit-tree.html">git-commit-tree(1)</a> after the
filters have run.</p>
</div>
<div class="paragraph">
<p>If any evaluation of &lt;command&gt; returns a non-zero exit status, the whole
operation will be aborted.</p>
</div>
<div class="paragraph">
<p>A <em>map</em> function is available that takes an "or