php批量清理文件BOM头

递归检查指定目录下的所有文件，检测并清除UTF-8 BOM头（Byte Order Mark）;用法：将代码保存为clearBOM.php在浏览器直接访问。

<?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);
}
?>