t; int -&gt; int -&gt; int</code></pre><div class="info ">
<code class="code">input ic buf pos len</code> reads up to <code class="code">len</code> characters from
   the given channel <code class="code">ic</code>, storing them in byte sequence <code class="code">buf</code>, starting at
   character number <code class="code">pos</code>.
   It returns the actual number of characters read, between 0 and
   <code class="code">len</code> (inclusive).
   A return value of 0 means that the end of file was reached