Switch from kingpin to cobra

This enables easier use of sub-commands for flexibility

cmd/helpers.go

@@ -0,0 +1,19 @@
+package cmd
+
+import (
+	"fmt"
+	"os"
+
+	"github.com/spf13/cobra"
+)
+
+func usage_er(cmd *cobra.Command, msg interface{}) {
+	cmd.Usage()
+	fmt.Println("")
+	er(msg)
+}
+
+func er(msg interface{}) {
+	fmt.Println("ERROR:", msg)
+	os.Exit(1)
+}

cmd/leak.go

@@ -0,0 +1,66 @@
+package cmd
+
+import (
+	"fmt"
+
+	"github.com/jimeh/rbheapleak/leak"
+	"github.com/spf13/cobra"
+)
+
+var leakOpts = struct {
+	Format  string
+	Verbose bool
+}{}
+
+// leakCmd represents the leak command
+var leakCmd = &cobra.Command{
+	Use:   "leak [flags] <dump-A> <dump-B> <dump-C>",
+	Short: "Find objects which are likely leaked memory.",
+	Long: `Find objects which are likely leaked memory.
+
+Compares the objects in three different dumps (A, B, C), to identify which
+objects are present in both B and C, and not present in A.`,
+
+	// Args: cobra.ExactArgs(3),
+	Run: func(cmd *cobra.Command, args []string) {
+		if len(args) != 3 {
+			usage_er(cmd, fmt.Sprintf("requires 3 args, received %d", len(args)))
+		}
+
+		finder := leak.NewFinder(args[0], args[1], args[2])
+		finder.Verbose = leakOpts.Verbose
+
+		err := finder.Process()
+		if err != nil {
+			er(err)
+		}
+
+		switch leakOpts.Format {
+		case "hex":
+			finder.PrintLeakedAddresses()
+		case "full":
+			finder.PrintLeakedObjects()
+		default:
+			usage_er(
+				cmd,
+				fmt.Sprintf("\"%s\" is not a valid format", leakOpts.Format),
+			)
+		}
+	},
+}
+
+func init() {
+	rootCmd.AddCommand(leakCmd)
+
+	leakCmd.PersistentFlags().StringVarP(
+		&leakOpts.Format,
+		"format", "f", "hex",
+		"Output format: \"hex\" / \"full\"",
+	)
+
+	leakCmd.PersistentFlags().BoolVarP(
+		&leakOpts.Verbose,
+		"verbose", "v", false,
+		"print verbose information",
+	)
+}

cmd/root.go

@@ -0,0 +1,62 @@
+package cmd
+
+import (
+	"bytes"
+	"fmt"
+	"os"
+	"runtime"
+	"strings"
+
+	"github.com/spf13/cobra"
+)
+
+// BuildInfo represents info collected as build-time.
+type BuildInfo struct {
+	Version string
+	Commit  string
+	Date    string
+}
+
+var rootCmd = &cobra.Command{
+	Use:           "rbheapleak",
+	Short:         "rbheapleak analyzes ObjectSpace dumps from Ruby processes.",
+	SilenceUsage:  true,
+	SilenceErrors: true,
+}
+
+func versionString(info *BuildInfo) string {
+	var buffer bytes.Buffer
+	var meta []string
+
+	buffer.WriteString(info.Version)
+
+	if info.Commit != "unknown" {
+		meta = append(meta, info.Commit)
+	}
+
+	meta = append(meta, runtime.Version())
+
+	if info.Date != "unknown" {
+		meta = append(meta, info.Date)
+	}
+
+	if len(meta) > 0 {
+		buffer.WriteString(fmt.Sprintf(" (%s)", strings.Join(meta, ", ")))
+	}
+
+	return buffer.String()
+}
+
+func Execute(info *BuildInfo) {
+	rootCmd.Version = versionString(info)
+	rootCmd.SetVersionTemplate("{{.Use}} {{.Version}}\n")
+
+	if err := rootCmd.Execute(); err != nil {
+		fmt.Println(err)
+		os.Exit(1)
+	}
+}
+
+func init() {
+	rootCmd.Flags().BoolP("version", "v", false, "Show version.")
+}