用于检测并清除掉文件开头的BOM信息

<?php
ini_set('memory_limit', '-1');
/*检测并清除BOM*/
$basedir = dirname(__FILE__); //扫描当前文件路径 可自动设置
$auto = 1;
checkdir($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);
                }
            }
        } //end while
        closedir($dh);
    } //end if($dh
    
} //end function
function checkBOM($filename) {
    global $auto; // www.junphp.com
    $contents = file_get_contents($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, $rest);
            return "<font color=red>BOM found, automatically removed.</font>";
        } else {
            return ("<font color=red>BOM found.</font>");
        }
    } else return ("BOM Not Found.");
} //end function
function rewrite($filename, $data) {
    $filenum = fopen($filename, "w");
    flock($filenum, LOCK_EX);
    fwrite($filenum, $data);
    fclose($filenum);
} //end function