Add a link to torrent file for magnet only websites

Magnet2Torrent.user.js

// ==UserScript==
// @name        Magnet2Torrent
// @namespace   loadletter
// @match       *://btdigg.org/search*
// @match       *://btindex.org/*
// @version     2
// @grant       none
// ==/UserScript==
Array.forEach(document.getElementsByTagName('a'), change_links);
function change_links(a) 
{
	if(!a.href.startsWith('magnet'))
		return;
	var mag = /magnet:\?xt=urn:btih:([A-Fa-f0-9]{40})/.exec(a.href);
	a.href = 'http://torrage.com/torrent/' + String(mag[mag.length - 1]).toUpperCase() + '.torrent';
}