What is a magnet url

A magnet is a URI scheme that identifies files by their hash, normally used in peer to peer file sharing networks (like Bittorrent). Basically, a magnet link identifies a torrent you want to download, and tells the torrent client how to download it. They make it very easy to share files over the internet, and use a combination of DHT and trackers to tell your torrent client where other peers who can share the file with you are.

Why is magnet_url

While working on a side project, I realized that I had the misfortune of trying to get the component parts of a magnet-url and then do further processing of them. I quickly wrote some Regex for it, but then I realized that this would be really useful for other projects that are dealing with torrents in Rust. By making it modifiable, too, it would allow for the creation of custom magnet links, which would also be useful for torrent based projects.

Why use magnet_url

magnet_url has the goal of, as you may have guessed, parsing the parts of magnets. It does this using some relatively simple regexes. The crate is designed to be very simple and efficient, with a lot of flexibility. It's also designed to be relatively easy to handle errors, and modification of its source is greatly encouraged through documentation and its license.

How to use this crate

Parsing a magnet is very simple:

use magnet_url::Magnet;
let magneturl = Magnet::new("magnet:?xt=urn:btih:08ada5a7a6183aae1e09d831df6748d566095a10&dn=Sintel&tr=udp%3A%2F%2Fexplodie.org%3A6969&tr=udp%3A%2F%2Ftracker.coppersurfer.tk%3A6969&tr=udp%3A%2F%2Ftracker.empire-js.us%3A1337&tr=udp%3A%2F%2Ftracker.leechers-paradise.org%3A6969&tr=udp%3A%2F%2Ftracker.opentrackr.org%3A1337&tr=wss%3A%2F%2Ftracker.btorrent.xyz&tr=wss%3A%2F%2Ftracker.fastcast.nz&tr=wss%3A%2F%2Ftracker.openwebtorrent.com&ws=https%3A%2F%2Fwebtorrent.io%2Ftorrents%2F&xs=https%3A%2F%2Fwebtorrent.io%2Ftorrents%2Fsintel.torrent");

This returns the Magnet struct, which is made up of the fields listed below this section. To access one of these fields is also very simple:

use magnet_url::Magnet;
let magneturl = Magnet::new("magnet:?xt=urn:btih:08ada5a7a6183aae1e09d831df6748d566095a10&dn=Sintel&tr=udp%3A%2F%2Fexplodie.org%3A6969&tr=udp%3A%2F%2Ftracker.coppersurfer.tk%3A6969&tr=udp%3A%2F%2Ftracker.empire-js.us%3A1337&tr=udp%3A%2F%2Ftracker.leechers-paradise.org%3A6969&tr=udp%3A%2F%2Ftracker.opentrackr.org%3A1337&tr=wss%3A%2F%2Ftracker.btorrent.xyz&tr=wss%3A%2F%2Ftracker.fastcast.nz&tr=wss%3A%2F%2Ftracker.openwebtorrent.com&ws=https%3A%2F%2Fwebtorrent.io%2Ftorrents%2F&xs=https%3A%2F%2Fwebtorrent.io%2Ftorrents%2Fsintel.torrent");
println!("{:?}", magneturl.dn);

If you'd like to modify parts of the magnet_url to customize it, that can be done as well!

use magnet_url::Magnet;
let mut magneturl = Magnet::new("magnet:?xt=urn:btih:08ada5a7a6183aae1e09d831df6748d566095a10&dn=Sintel&tr=udp%3A%2F%2Fexplodie.org%3A6969&tr=udp%3A%2F%2Ftracker.coppersurfer.tk%3A6969&tr=udp%3A%2F%2Ftracker.empire-js.us%3A1337&tr=udp%3A%2F%2Ftracker.leechers-paradise.org%3A6969&tr=udp%3A%2F%2Ftracker.opentrackr.org%3A1337&tr=wss%3A%2F%2Ftracker.btorrent.xyz&tr=wss%3A%2F%2Ftracker.fastcast.nz&tr=wss%3A%2F%2Ftracker.openwebtorrent.com&ws=https%3A%2F%2Fwebtorrent.io%2Ftorrents%2F&xs=https%3A%2F%2Fwebtorrent.io%2Ftorrents%2Fsintel.torrent");
println!("{:?}", magneturl.dn);
magneturl.dn = String::from("hello_world");
println!("{:?}", magneturl.dn);

In fact, you can construct your own magnet url as well, as long as you fill in all the parameters!

use magnet_url::Magnet;
//Note, this magnet won't actually download, sorry :/
Magnet {
    dn: "hello_world".to_string(),
    hash_type: "sha1".to_string(),
    xt: "2aae6c35c94fcfb415dbe95f408b9ce91ee846ed".to_string(),
    xl: 1234567890,
    tr:
        {
            let mut tr_vec = Vec::new();
            tr_vec.push("https://example.com/".to_string());
            tr_vec
        },
    kt: "cool+stuff".to_string(),
    ws: String::new(),
    acceptable_source: String::new(),
    mt: String::new(),
    xs: String::new(),
};

From a Magnet struct, you can generate a magnet string again

use magnet_url::Magnet;
//Note, this magnet won't actually download, sorry :/
let magnet_struct = Magnet {
    dn: "hello_world".to_string(),
    hash_type: "sha1".to_string(),
    xt: "2aae6c35c94fcfb415dbe95f408b9ce91ee846ed".to_string(),
    xl: 1234567890,
    tr: vec!["https://example.com/".to_string()],
    kt: "cool+stuff".to_string(),
    ws: String::new(),
    acceptable_source: String::new(),
    mt: String::new(),
    xs: String::new(),
};

let magnet_string = magnet_struct.to_string();
println!("{}", magnet_string);

Invalid magnet url's will result in a panic! (This will be changed to an error in v2.0.0

use magnet_url::Magnet;
#[should_panic]
let _magnet_link = Magnet::new("https://example.com");