PHP BOM的问题

<?php
$basedir = str_replace('/clearBOM.php','',str_replace('\\','/',dirname(__FILE__)));
$auto = 1;
checkdir($basedir);
function checkdir($basedir){
    if ($dh = opendir($basedir)) {
        while (($file = readdir($dh)) !== false) {
            if ($file != '.' && $file != '..'){
                if (!is_dir($basedir.'/'.$file)) {
                    $filename = $basedir.'/'.$file;
                    echo 'filename:'.$basedir.'/'.$file.checkBOM($filename).'<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);
}

?>

使用的方法是将该代码放入文件后保存为php放在网站的根目录，或者你想去哪个目录的BOM就放在哪个目录，然后直接用URL访问这个PHP文件就可以了！