php写一个函数,实现扫描并打印出自定目录下(含子目录)所有jpg文件名

<?php$dir = "E:/照片//";//打印文件夹中所有jpg文件function printJpg($dir,$deep = ""){ $dirSource = dir($dir); while($d = $dirSource->read()){  if($d == "." || $d == ".."){   continue;  }  if(filetype($dir.$d) == "dir"){   printJpg($dir.$d."/",$deep."--");  }  if(mime_content_type($dir.$d) == "image/jpeg"){   echo $deep.$d."<br/>";  } }}printJpg($dir);