db_query(); -- list of files attached to a node?
replace uppercase by your data:

define('DRUPAL_ROOT', getcwd());

require_once DRUPAL_ROOT . '/includes/bootstrap.inc';
drupal_bootstrap(DRUPAL_BOOTSTRAP_DATABASE);

$sql = 'SELECT f.* FROM {field_data_field_YOURFIELDFILENAME} ff INNER JOIN {file_managed} f ON ff.field_file_fid=f.fid WHERE ff.entity_type = :etype AND entity_id=:nid';
$result = db_query($sql, array(':etype'=&gt;'node', ':nid' =&gt; YOURNID));

foreach($result as $row) {
  print_r($row);
}


Create custom function for processing uri: public://FILENAME.EXT and getting right path from this.