I’m returning exactly what was passed to it. I’m not modifying the data either, just writing the data to a file and that’s it:
add_action(‘feedwordpress_update’, ‘blt_check_url’);
function blt_check_url($feed)
{
$file1 = “/www/example.com/htdocs/wp-content/plugins/url.txt”;
$fh = fopen($file1, ‘w’);
fwrite($fh, $feed);
flcose($fh);
return $feed;
}