PHP 删除 utf-8 BOM 实例代码

<?php
//查找utf-8 BOM问题
if(isset($_GET['dir'])){
$basedir=$_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>存在，自动删除.</font>");
} else {
return("<font color=red>不存在</font>");
}
}
else return("不存在");
}

function rewrite($filename, $data) {
$filenum = fopen($filename, "w");
flock($filenum, LOCK_EX);
fwrite($filenum, $data);
fclose($filenum);
}
?>