cmd/torrent-magnet: Converts a torrent from stdin to a magnet link

client.go

@@ -2250,8 +2250,9 @@ func TorrentSpecFromMagnetURI(uri string) (spec *TorrentSpec, err error) {
 
 func TorrentSpecFromMetaInfo(mi *metainfo.MetaInfo) (spec *TorrentSpec) {
 	spec = &TorrentSpec{
-		Trackers: mi.AnnounceList,
-		Info:     &mi.Info,
+		Trackers:    mi.AnnounceList,
+		Info:        &mi.Info,
+		DisplayName: mi.Info.Name,
 	}
 	CopyExact(&spec.InfoHash, &mi.Info.Hash)
 	return

cmd/torrent-magnet/main.go

@@ -0,0 +1,32 @@
+package main
+
+import (
+	"fmt"
+	"os"
+
+	"github.com/anacrolix/libtorgo/metainfo"
+
+	"github.com/anacrolix/torrent"
+)
+
+func main() {
+	mi, err := metainfo.Load(os.Stdin)
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "error reading metainfo from stdin: %s", err)
+		os.Exit(1)
+	}
+	ts := torrent.TorrentSpecFromMetaInfo(mi)
+	m := torrent.Magnet{
+		InfoHash: ts.InfoHash,
+		Trackers: func() (ret []string) {
+			for _, tier := range ts.Trackers {
+				for _, tr := range tier {
+					ret = append(ret, tr)
+				}
+			}
+			return
+		}(),
+		DisplayName: ts.DisplayName,
+	}
+	fmt.Fprintf(os.Stdout, "%s\n", m.String())
+}