du.php - PHP Disk Usage script

I’m starting to copy my scripts from https://justynshull.com/oldsite/phpscripts.html but figured I’d start with this one so I can get the syntax hilighting/formatting down with wordpress.

 <?php
  // $a = shell_exec('df -h');
  //echo getenv('DOCUMENT_ROOT');
  chdir(getenv('DOCUMENT_ROOT'));
  chdir('..');
  echo shell_exec('pwd');
  $a = shell_exec('du -hx *');
  //$a = shell_exec('ls -l');
  echo '<h2>Disk space</h2>h2>< pre>';
  echo $a;
  echo '< /pre>';
?>