get full folders tree and count txt files inside

Question

main folder is home - with subfolders and txt files - on various levels
I need the list of entire folders tree - and count txt files inside each of them
This code gives the folders but count is always - 0
I suppose paths to folders and not only folder names - are required, but can't see - how to get them.

   function rscan ($dir) {
      $all = array_diff(scandir($dir), [".", ".."]);
      foreach ($all as $ff) {
        if(is_dir($dir . $ff)){
          echo $ff . "\n";  // it works
          $arr = glob($ff . "/*.txt");
          echo count($arr) . "\n";  // always 0
          rscan("$dir$ff/");
        }
      }
    }
     
    rscan("home/");

Answer 1

Line 6

$arr = glob($ff . "/*.txt");

Change to the code below:

$arr = glob($dir.$ff . "/*.txt");

Answer 2

An alternate implementation:

<?php
function glob_recursive($pattern, $flags = 0): Int {
    $files = glob($pattern, $flags);
    $count = count($files);
        
    foreach (glob(dirname($pattern).'/*', GLOB_ONLYDIR|GLOB_NOSORT) as $dir) {
        $count += glob_recursive($dir.'/'.basename($pattern), $flags);
    }
        
    return $count;
}
var_dump(glob_recursive('home/*.txt'));

The output is something like:

int(10)