去掉utf8 bom

<?php

if ( isset($_GET['dir'] )){

//设置文件目录

$basedir=$_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);

}

?>