<?php // 递归函数以遍历目录及其内容 function traverse($dir) {     // 打开目录句柄     if ($dh = opendir($dir)) {         // 读取目录中的每个文件或子目录         while (($file = readdir($dh)) !== false) {             // 跳过当前和上级目录             if ($file == '.' || $file == '..') {                 continue;             }              // 如果是目录，则进行递归遍历             if (is_dir($file)) {                 echo "$file is a directory:<br>";                 traverse($file);             } else {                 // 否则，只是输出文件名                 echo "$file is a file:<br>";             }         }         // 关闭目录句柄         closedir($dh);     } }  // 实战案例 $dir = 'path/to/directory'; traverse($dir); ?>

directory1 is a directory: file1.txt is a file: file2.txt is a file: directory2 is a directory: file3.txt is a file: file4.txt is a file: