le timer library</span>
<span class="comment"> * used in this example. The actual implementation of the functions</span>
<span class="comment"> * can be found at the end of this file.</span>
<span class="comment"> */</span>
<span class="keyword">struct </span>timer { <span class="keywordtype">int</span> start, interval; };
<span class="keyword">static</span> <span class="keywordtype">int</span>  timer_expired(<span class="keyword">struct</span> timer *t);
<span class="keyword">static</span> <span clas