lass="code"><span class="constructor">Sys_error</span></code> when the system
    calls they invoke fail.<br>

<pre><span id="TYPEin_channel"><span class="keyword">type</span> <code class="type"></code>in_channel</span> </pre>
<div class="info ">
The type of input channel.<br>
</div>


<pre><span id="TYPEout_channel"><span class="keyword">type</span> <code class="type"></code>out_channel</span> </pre>
<div class="info ">
The type of output channel.<br>
</div>


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