PHP function to clear multi-level directories

PHP custom function clears the contents of a directory and subdirectories. The code is simple and concise. Friends in need can refer to it.

The complete code is as follows.

<?php
//清空多层目录
function del_dir($dir){
{
if (!$dir) { return ; }
$cacheDir = $dir;
$dh = opendir($cacheDir);
while ( $file = readdir($dh) ) {

if (($file == '.') || ($file == '..')) { continue; }
if (file_exists( $cacheDir .'/'.$file)) {
  if(is_dir( $cacheDir .'/'.$file)){
     del_dir($cacheDir .'/'.$file);
  }elseif (!unlink($cacheDir .'/'. $file)) {
//删除完操作
}
}
}
}
}
?>