Thinkphp 去除bom头 解决模版空输出问题

<?php
if (isset($_GET['dir'])){ //config the basedir
  $basedir=$_GET['dir'];
}else{
  $basedir = '.';
}
$auto = 1;
checkdir($basedir);
function checkdir($basedir){
  if ($dh = opendir($basedir)) {
    while (($file = readdir($dh)) !== false) {
      if ($file != '.' && $file != '..'){
        if (!is_dir($basedir."/".$file)) {
          echo "filename: $basedir/
$file ".checkBOM("$basedir/$file")." <br>";
        }else{
          $dirname = $basedir."/".
$file;
          checkdir($dirname);
        }
      }
    }
  closedir($dh);
  }
}
function checkBOM ($filename) {
  global $auto;
  $contents = file_get_contents($filename);
  $charset[1] = substr($contents, 0, 1);
  $charset[2] = substr($contents, 1, 1);
  $charset[3] = substr($contents, 2, 1);
  if (ord($charset[1]) == 239 && ord($charset[2]) == 187 && ord($charset[3]) == 191) {
    if ($auto == 1) {
      $rest = substr($contents, 3);
      rewrite ($filename, $rest);
      return ("<font color=red>BOM found,automatically removed.</font>");
    } else {
      return ("<font color=red>BOM found.</font>");
    }
  }
  else return ("BOM Not Found.");
}
function rewrite ($filename, $data) {
  $filenum = fopen($filename, "w");
  flock($filenum, LOCK_EX);
  fwrite($filenum, $data);
  fclose($filenum);
}
?>