private static string PeriodicUpdate(string path) {
return $@"<pre></pre><script>
var pre = document.querySelector('pre');
function update(){{
var x = new XMLHttpRequest();
x.onreadystatechange = function() {{
if (this.readyState == XMLHttpRequest.DONE) pre.textContent = this.responseText }}
x.open('GET', '{path}', true);
x.send(null);
}}
update();
setInterval(update, 50);
</script>";
}