php:什么.和...表示在dir-> read()的输出中

Question

<?php

$d = dir('css');
echo "Handle: " . $d->handle . "<br>";
echo "Path: " . $d->path . "<br>";

while (($file = $d->read()) !== false){
  echo "filename: " . $file . "<br>";
}
$d->close();
?>

结果:

Handle: Resource id #4
Path: css
filename: .
filename: ..
filename: css
filename: img
filename: index.html
filename: js
filename: lightbox

题:

在结果中,做什么.和..意味着什么？

Answer 1

.是当前目录,..是一个向上.大多数代码示例都要if-statement跳过em.

以下是PHP文档中的示例:

http://php.net/manual/en/function.readdir.php#example-2318

即使在文档上,它也只是忽略了代码.