ue will be zero.
If it is executable, the hook will be executed and the exit
status of the hook is returned.
On execution, .stdout_to_stderr and .no_stdin will be set.
(See below.)</p>
</dd>
</dl>
</div>
</li>
</ol>
</div>
</div>
</div>
<div class="sect1">
<h2 id="_data_structures">Data structures</h2>
<div class="sectionbody">
<div class="ulist">
<ul>
<li>
<p><code>struct child_process</code></p>
</li>
</ul>
</div>
<div class="paragraph">
<p>This describes the arguments, redirections, and environment of a
