Tail -f but with PHP in a browser

gistfile1.phtml

<?php
error_reporting(E_ALL);

$file = '/var/log/fpm/fpm-php.log';

echo '<h5>'.$file.'</h5>';

$offset = filesize($file) - 80240;
if( $offset < 0 )
    $offset = 0;

$file_content = file_get_contents($file, null, null, $offset) or die('Kunde inte öppna filen');
$file_content = htmlentities($file_content);
echo str_replace(PHP_EOL, '<br>', $file_content);

?>
<script>

window.onload = function() {
  window.scrollTo(0, document.height);
  var stopReload = false;
  
  window.addEventListener('scroll', function() {
    stopReload = true;
    if ((window.innerHeight + window.scrollY) >= document.body.offsetHeight) {
    	reloadSoon();
    }  
  }, false);

  document.onmouseup = function() {
    if( window.getSelection().type != "None" )
	stopReload = true; 
  };

  var reloadSoon = function() {
    stopReload = false;
    setTimeout(function() {
      if( !stopReload ) 
        document.location.reload();
    }, 1000);
  };

  reloadSoon();
};

</script>