How to recursively list files in a directory and its subdirectories in PHP?

You can use the RecursiveIteratorIterator class in PHP to recursively list files in a directory and its subdirectories. Here's an example:

function listFiles($directory) {
   $iterator = new RecursiveIteratorIterator(
      new RecursiveDirectoryIterator($directory, RecursiveDirectoryIterator::SKIP_DOTS),
      RecursiveIteratorIterator::SELF_FIRST,
      RecursiveIteratorIterator::CATCH_GET_CHILD
   );

   foreach ($iterator as $file) {
      if ($file->isDir()) {
         echo 'Directory: ' . $file->getPathname() . PHP_EOL;
      } else {
         echo 'File: ' . $file->getPathname() . PHP_EOL;
      }
   }
}

You can use the listFiles function by passing the directory path as an argument:

$directory = '/path/to/directory';
listFiles($directory);

The above code will recursively list all the files and directories in the given directory, including subdirectories. The isDir method is used to check if the current item is a directory or a file.