添加一个新函数创建了一个未定义的变量

我正在为样式指南生成器调整一些PHP来拉入.scss文件并显示它，但在第56行我得到一个通知:未定义变量。

这一行是

$sass = 'sass'.strstr($path, "/");

和整个函数。php是

<?php
  // Display title of each markup samples as a list item
  function listMarkupAsListItems ($type) {
    $files = array();
    $handle=opendir('markup/'.$type);
    while (false !== ($file = readdir($handle))):
        if(stristr($file,'.html')):
            $files[] = $file;
        endif;
    endwhile;
    sort($files);
    foreach ($files as $file):
        $filename = preg_replace("/'.html$/i", "", $file);
        $title = preg_replace("/'-/i", " ", $filename);
        $title = ucwords($title);
        echo '<li><a href="#sg-'.$filename.'">'.$title.'</a></li>';
    endforeach;
  }
  // Display markup view and source
  function showMarkup($type) {
    $files = array();
    $handle=opendir('markup/'.$type);
    while (false !== ($file = readdir($handle))):
        if(stristr($file,'.html')):
            $files[] = $file;
        endif;
    endwhile;
    sort($files);
    foreach ($files as $file):
        $filename = preg_replace("/'.html$/i", "", $file);
        $title = preg_replace("/'-/i", " ", $filename);
        $documentation = 'doc/'.$type.'/'.$file;
        echo '<div class="sg-markup sg-section">';
        echo '<div class="sg-display">';
        echo '<h2 id="sg-'.$filename.'" class="sg-h2">'.$title.'</h2>';
        if (file_exists($documentation)) {
          echo '<div class="sg-doc">';
          include($documentation);
          echo '</div>';
        }
        include('markup/'.$type.'/'.$file);
        echo '</div>';
        echo '<div class="sg-markup-controls"><button type="button" class="sg-btn sg-btn--source">View Source</button> <a class="sg-btn--top" href="#top">Back to Top</a></div>';
        echo '<div class="sg-source sg-animated">';
        echo '<button type="button" class="sg-btn sg-btn--select">Copy Source</button>';
        echo '<pre class="line-numbers"><code class="language-markup">';
        echo htmlspecialchars(file_get_contents('markup/'.$type.'/'.$file));
        echo '</code></pre>';
        echo '</div>';
        echo '</div>';
        $sass = 'sass'.strstr($path, "/");
        $sass = str_replace(".html",".scss",$sass);
        if (file_exists($sass)) {
          echo '<div class="sg-sub-section">';
          echo '<div class="sg-markup-controls">';
          echo '<button type="button" class="sg-btn sg-btn--source">View Sass</button>';
          echo '</div>';
          echo '<div class="sg-source">';
          echo '<button type="button" class="sg-btn sg-btn--select">Copy Sass</button>';
          echo '<pre class="line-numbers"><code class="language-scss">';
          echo file_get_contents($sass);
          echo '</code></pre>';
          echo '</div>';
          echo '</div>';
        }
    endforeach;
  }
?>

我肯定这是一些简单的PHP问题，我错了。如有任何帮助，我将不胜感激。

更新:$sass的代码取自另一个代码片段，看看两个注释(谢谢)，似乎$path变量是问题所在?我想我需要将它定义为我要查找的文件夹路径?