gistfile1.php

 function ign_filter_downloads() //callback routine called by file_download
 {
	global $id, $file_error, $ign_user, $pretext, $s;

	if(empty($id)) {
		//no $id means we need to reparse the URL...
		extract($pretext);
		if($prefs['permlink_mode']=='messy') {
			$id = gps('id'); //get $id from GET
		} else { //we need to parse the uri
			extract(chopurl($_SERVER['REQUEST_URI']));
			$id = $u2; //should probably test for failure here...
		}
	}

	//let's check to see if this file has permissions set and get the category
	$file = safe_row('permissions, category', 'txp_file', "id='$id'");
	$parent = (!empty($file['category'])) ? safe_field('parent','txp_category', "name='{$file['category']}'") : '';
	if(!empty($file['permissions'])) // permissions set, carry on
	{ 
		if(empty($ign_user) || !ign_checkPrivs($file['permissions'])) //if any check fails, give 'em the boot
			$file_error = '403';
	} else if($parent == 'clients'){ 	// let's fire off a quick category comparison for client-specific setups...
		if(empty($ign_user) || $file['category'] !== $ign_user)
			$file_error = '403';
	}

	//return to let file_download do its thing...
	return;

 }