php批量检测并去除BOM头的代码

开发中会遇到BOM头, 导致程序无法执行. 浏览器返回接口如下图:

去除BOM头解决方法:
<?php
ini_set('memory_limit','1024M'); 
function checkdir($basedir) { 
if ($dh = opendir ( $basedir )) { 
while ( ($file = readdir ( $dh )) !== false ) { 
if ($file != '.' && $file != '..') { 
if (! is_dir ( $basedir . "/" . $file )) { // 如果是文件 
echo "filename: $basedir/$file " . checkBOM ( "$basedir/$file" ) . " <br>"; 
 } else { 
$dirname = $basedir . "/" .$file; // 如果是目录 
 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 ( $charset [3] ) == 191) { // BOM 的前三个字符的ASCII 码分别为 239 187 191 
if ($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 ); 
} 

$auto=1;
$dir='D:/web/';//项目文件路径
checkDir($dir);
?>