Add readline support for interactive mode in go tool pprof

go-tool-pprof-readline-support.diff

diff --git a/src/cmd/pprof/internal/plugin/plugin.go b/src/cmd/pprof/internal/plugin/plugin.go
index a22ec5f..4d545de 100644
--- a/src/cmd/pprof/internal/plugin/plugin.go
+++ b/src/cmd/pprof/internal/plugin/plugin.go
@@ -6,7 +6,6 @@
 package plugin

 import (
-       "bufio"
        "fmt"
        "os"
        "regexp"
@@ -14,6 +13,8 @@ import (
        "time"

        "cmd/pprof/internal/profile"
+
+       "github.com/chzyer/readline"
 )

 // A FlagSet creates and parses command-line flags.
@@ -166,16 +167,19 @@ type UI interface {
 // prints messages to standard output,
 // prints errors to standard error, and doesn't use auto-completion.
 func StandardUI() UI {
-       return &stdUI{r: bufio.NewReader(os.Stdin)}
+       r, err := readline.New("(pprof+r) ")
+       if err != nil {
+               panic(err)
+       }
+       return &stdUI{r: r}
 }

 type stdUI struct {
-       r *bufio.Reader
+       r *readline.Instance
 }

 func (ui *stdUI) ReadLine() (string, error) {
-       os.Stdout.WriteString("(pprof) ")
-       return ui.r.ReadString('\n')
+       return ui.r.Readline()
 }

 func (ui *stdUI) Print(args ...interface{}) {