include all hashes in algorithms list

alternative to #54

opts/opts.go

@@ -9,6 +9,7 @@ import (
 	"fmt"
 	"io"
 	"io/ioutil"
+	"sort"
 	"strings"
 
 	mh "github.com/multiformats/go-multihash"
@@ -34,8 +35,15 @@ var FlagValues = struct {
 	Encodings  []string
 	Algorithms []string
 }{
-	Encodings:  []string{"raw", "hex", "base58", "base64"},
-	Algorithms: []string{"sha1", "sha2-256", "sha2-512", "sha3"},
+	Encodings: []string{"raw", "hex", "base58", "base64"},
+	Algorithms: func() []string {
+		names := make([]string, 0, len(mh.Names))
+		for n := range mh.Names {
+			names = append(names, n)
+		}
+		sort.Strings(names)
+		return names
+	}(),
 }
 
 // SetupFlags adds multihash related options to given flagset.