cmd: add internal/browser package

cmd/cover, cmd/trace, and cmd/pprof all open browsers.
'go bug' will soon also open a browser.
It is time to unify the browser-handling code.

Change-Id: Iee6b443e21e938aeaaac366a1aefb1afbc7d9b2c
Reviewed-on: https://go-review.googlesource.com/29160
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

1 files changed, 41 insertions, 0 deletions

diff --git a/src/cmd/internal/browser/browser.go b/src/cmd/internal/browser/browser.go
new file mode 100644
index 0000000000..11e65c2feb
--- /dev/null
+++ b/src/cmd/internal/browser/browser.go
@@ -0,0 +1,41 @@
+// Copyright 2016 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package browser provides utilities for interacting with users' browsers.
+package browser
+
+import (
+	"os"
+	"os/exec"
+	"runtime"
+)
+
+// Commands returns a list of possible commands to use to open a url.
+func Commands() [][]string {
+	var cmds [][]string
+	if exe := os.Getenv("BROWSER"); exe != "" {
+		cmds = append(cmds, []string{exe})
+	}
+	switch runtime.GOOS {
+	case "darwin":
+		cmds = append(cmds, []string{"/usr/bin/open"})
+	case "windows":
+		cmds = append(cmds, []string{"cmd", "/c", "start"})
+	default:
+		cmds = append(cmds, []string{"xdg-open"})
+	}
+	cmds = append(cmds, []string{"chrome"}, []string{"google-chrome"}, []string{"firefox"})
+	return cmds
+}
+
+// Open tries to open url in a browser and reports whether it succeeded.
+func Open(url string) bool {
+	for _, args := range Commands() {
+		cmd := exec.Command(args[0], append(args[1:], url)...)
+		if cmd.Start() == nil {
+			return true
+		}
+	}
+	return false
+}