t; bytes -&gt; int -&gt; int -&gt; unit</code></pre><div class="info ">
<div class="info-desc">
<p><code class="code">add_subbytes&nbsp;b&nbsp;s&nbsp;ofs&nbsp;len</code> takes <code class="code">len</code> characters from offset
    <code class="code">ofs</code> in byte sequence <code class="code">s</code> and appends them at the end of buffer <code class="code">b</code>.</p>
</div>
<ul class="info-attributes">
<li><b>Since</b> 4.02</li>
</ul>
</div>

<pre><span id="VALadd_substitute"><span class="keyword">