refactor: improved ux of multibase command

core/commands/multibase.go

@@ -2,6 +2,7 @@ package commands
 
 import (
 	"bytes"
+	"fmt"
 	"io/ioutil"
 	"strings"
 
@@ -17,6 +18,7 @@ var MbaseCmd = &cmds.Command{
 	Subcommands: map[string]*cmds.Command{
 		"encode": mbaseEncodeCmd,
 		"decode": mbaseDecodeCmd,
+		"list":   basesCmd,
 	},
 	Extra: CreateCmdExtras(SetDoesNotUseRepo(true)),
 }
@@ -27,7 +29,21 @@ const (
 
 var mbaseEncodeCmd = &cmds.Command{
 	Helptext: cmds.HelpText{
-		Tagline: "Encode file or stdin into multibase string",
+		Tagline: "Encode data into multibase string",
+		LongDescription: `
+This command expects a file name or data provided via stdin.
+
+By default it will use URL-safe base64url encoding,
+but one can customize used base with -b:
+
+  > echo hello | ipfs multibase encode -b base16 > output_file
+  > cat output_file
+  f68656c6c6f0a
+
+  > echo hello > input_file
+  > ipfs multibase encode -b base16 input_file
+  f68656c6c6f0a
+  `,
 	},
 	Arguments: []cmds.Argument{
 		cmds.FileArg("file", true, false, "data to encode").EnableStdin(),
@@ -47,11 +63,11 @@ var mbaseEncodeCmd = &cmds.Command{
 		files := req.Files.Entries()
 		file, err := cmdenv.GetFileArg(files)
 		if err != nil {
-			return err
+			return fmt.Errorf("failed to access file: %w", err)
 		}
 		buf, err := ioutil.ReadAll(file)
 		if err != nil {
-			return err
+			return fmt.Errorf("failed to read file contents: %w", err)
 		}
 		encoded := encoder.Encode(buf)
 		reader := strings.NewReader(encoded)
@@ -61,7 +77,20 @@ var mbaseEncodeCmd = &cmds.Command{
 
 var mbaseDecodeCmd = &cmds.Command{
 	Helptext: cmds.HelpText{
-		Tagline: "Decode multibase string to stdout",
+		Tagline: "Decode multibase string",
+		LongDescription: `
+This command expects multibase inside of a file or via stdin:
+
+  > echo -n hello | ipfs multibase encode -b base16 > file
+  > cat file
+  f68656c6c6f
+
+  > ipfs multibase decode file
+  hello
+
+  > cat file | ipfs multibase decode
+  hello
+`,
 	},
 	Arguments: []cmds.Argument{
 		cmds.FileArg("encoded_file", true, false, "encoded data to decode").EnableStdin(),
@@ -73,15 +102,15 @@ var mbaseDecodeCmd = &cmds.Command{
 		files := req.Files.Entries()
 		file, err := cmdenv.GetFileArg(files)
 		if err != nil {
-			return err
+			return fmt.Errorf("failed to access file: %w", err)
 		}
 		encoded_data, err := ioutil.ReadAll(file)
 		if err != nil {
-			return err
+			return fmt.Errorf("failed to read file contents: %w", err)
 		}
 		_, data, err := mbase.Decode(string(encoded_data))
 		if err != nil {
-			return err
+			return fmt.Errorf("failed to decode multibase: %w", err)
 		}
 		reader := bytes.NewReader(data)
 		return resp.Emit(reader)