A regular expression to match a BitTorrent Magnet Link.
/^magnet:\?xt=urn:btih:[0-9a-fA-F]{40,}.*$/
What is BitTorrent Magnet Link:
BitTorrent Magnet Link is a URI scheme that defines the format of magnet links.
BitTorrent Magnet Link Examples:
- magnet:?xt=urn:btih:40A89A6F4FB1498A98087109D012A9A851FBE0FC