multiaddr conversion tool

multiaddr.go

+package main
+
+import (
+	"encoding/hex"
+	"flag"
+	"fmt"
+	"os"
+
+	ma "github.com/jbenet/go-multiaddr"
+)
+
+var usage = `multiaddr conversion
+usage: multiaddr [fmt] <>`
+
+var formats = []string{"string", "bytes", "hex", "raw"}
+var format string
+
+func init() {
+	flag.Usage = func() {
+		fmt.Fprintf(os.Stderr, "usage: %s <multiaddr>\n\nFlags:\n", os.Args[0])
+		flag.PrintDefaults()
+	}
+
+	usage := fmt.Sprintf("output format, one of: %v", formats)
+	flag.StringVar(&format, "format", "string", usage)
+	flag.StringVar(&format, "f", "string", usage+" (shorthand)")
+}
+
+func main() {
+	flag.Parse()
+	args := flag.Args()
+	if len(args) != 1 {
+		die("error: can only take one argument")
+	}
+
+	m, err := ma.NewMultiaddr(args[0])
+	if err != nil {
+		die(err)
+	}
+
+	fmt.Println(outfmt(m))
+}
+
+func outfmt(m ma.Multiaddr) string {
+	switch format {
+	case "string":
+		return m.String()
+	case "bytes":
+		return fmt.Sprintf("%v", m.Bytes())
+	case "raw":
+		return string(m.Bytes())
+	case "hex":
+		return "0x" + hex.EncodeToString(m.Bytes())
+	}
+
+	die("error: invalid format", format)
+	return ""
+}
+
+func die(v ...interface{}) {
+	fmt.Fprint(os.Stderr, v...)
+	fmt.Fprint(os.Stderr, "\n")
+	flag.Usage()
+	os.Exit(-1)
+}