Goscrape: Go library to scrape torrents on any UDP tracker

This library partially implementBEP-0015 and returns the number ofseeders,leechersandcompleteddownloads for a given infohash list.

Usage:

go get -u github.com/etix/goscrape

Example:

// Create a new instance of the library and specify the torrent tracker to use.
s,err:=goscrape.New("udp://tracker.kali.org:6969/announce")
iferr!=nil{
log.Fatal("Error:",err)
}

// A list of infohash to scrape, at most 74 infohash can be scraped at once.
// Be sure to provide infohash that are 40 hexadecimal characters long only.
infohash:=[][]byte{
[]byte("176e2a9696092482d4acdef445b53ffcebb56960"),
[]byte("e80cb87fbd938f3b1e47db64c10c3ab04ad49987"),
[]byte("04098e49061bedb3f2d8f90204bf239019d198d9"),
}

// Connect to the tracker and scrape the list of infohash in only two UDP round trips.
res,err:=s.Scrape(infohash...)
iferr!=nil{
log.Fatal("Error:",err)
}

// Loop over the results and print them.
// Result are guaranteed to be in the same order they were requested.
for_,r:=rangeres{
fmt.Println("Infohash:\t",string(r.Infohash))
fmt.Println("Seeders:\t",r.Seeders)
fmt.Println("Leechers:\t",r.Leechers)
fmt.Println("Completed:\t",r.Completed)
fmt.Println("")
}

Result:

Infohash: 176e2a9696092482d4acdef445b53ffcebb56960
Seeders: 3053
Leechers: 248
Completed: 44171

Infohash: e80cb87fbd938f3b1e47db64c10c3ab04ad49987
Seeders: 376
Leechers: 20
Completed: 4161

Infohash: 04098e49061bedb3f2d8f90204bf239019d198d9
Seeders: 100
Leechers: 6
Completed: 703