os/exec: add Cmd.Waitmsg, fix a misleading comment

Fixes #2948

R=golang-dev, r
CC=golang-dev
https://golang.org/cl/5655048

diff --git a/src/pkg/os/exec/exec.go b/src/pkg/os/exec/exec.go
index a00fdad497faa94a336242014ad6d29a9f51e22b..fe254672169c66e890e20979009f11a724733e83 100644 (file)
--- a/src/pkg/os/exec/exec.go
+++ b/src/pkg/os/exec/exec.go
@@ -68,7 +68,7 @@ type Cmd struct {
        // new process. It does not include standard input, standard output, or
        // standard error. If non-nil, entry i becomes file descriptor 3+i.
        //
-       // BUG: on OS X 10.6, child processes may sometimes inherit extra fds.
+       // BUG: on OS X 10.6, child processes may sometimes inherit unwanted fds.
        // http://golang.org/issue/2603
        ExtraFiles []*os.File
 
@@ -79,6 +79,10 @@ type Cmd struct {
        // Process is the underlying process, once started.
        Process *os.Process
 
+       // Waitmsg contains information about an exited process,
+       // available after a call to Wait or Run.
+       Waitmsg *os.Waitmsg
+
        err             error // last error (from LookPath, stdin, stdout, stderr)
        finished        bool  // when Wait was called
        childFiles      []*os.File
@@ -288,6 +292,7 @@ func (c *Cmd) Wait() error {
        }
        c.finished = true
        msg, err := c.Process.Wait(0)
+       c.Waitmsg = msg
 
        var copyError error
        for _ = range c.goroutine {