Re: [9fans] native (mostly) go for plan9

[erik quanstrom <quanstro@quanstro.net>]

> OK, now, the current problem with syscall/exec_plan9.go is that it is
> a little too eager to close FDs. It's doing the close by hand because
> it's not possible on Plan 9 to take an fd and set to to close-on-exec
> -- that's only done on  open on Plan 9 (on unix the code does an
> fcntl). But if an FD is used twice for a child -- as it is with
> combined stdout/stderr -- then the close closes the fd before it can
> be dup'ed a second time. Bad.
>
> I did the lazy thing and commented out the erroneous close for now.
> The easy fix is to track the fds to be closed in a map and then close
> them all later. That's next. Another possibility is to allow '#d/*ctl'
> to be writeable and implement a
> closeonexec
> control message for fds. But maybe that's  just too much. It is
> certainly easy to do, but is that kind of feature something we want to
> add?

just a silly idea, perhaps dup takes an additional argument

	int dup(int old, int new, int flags);

if old and new are the same, flags are applied as if they were given on open.
e.g.
	dupf(fd, fd, OCEXEC);
(by the way, i would put in a word for OCFORK.)

- erik