Re: [PATCH v3 2/2] Use O_IGNORE_CTTY where appropriate

[Paul Eggert]

On 2023-06-06 02:21, Sergey Bugaev wrote:

> _hurd_port2fd and
> _hurd_intern_fd are both public APIs, documented with
>
> "FLAGS are as for `open'; only O_IGNORE_CTTY and O_CLOEXEC are meaningful"

You could change the documentation so that it now says that flags that 
imply O_IGNORE_CTTY are also meaningful. That should be fine.


> I think it's a good practice to always pass O_IGNORE_CTTY where
> it makes sense to

Does your patch do that, for every 'open'-like call?


> Maybe with GCC there is a chance, considering it's a GNU project?

Sure. I expect even 'git' will do it if you write the patch, as they 
care about performance. Also tar, coreutils, grep, and other "open files 
a lot" apps should benefit.


> > I suppose fopen could add a new 'T' flag, as a GNU extension, that would
> > add O_IGNORE_CTTY to the open flags.
>
> What would be the compatibility implications of this? -- what if POSIX
> later declares that 'T' must mean something else?

I wouldn't worry overmuch about that. We could ask for forgiveness later.

Thinking bigger - why does Hurd mess with this stuff at all? Wouldn't it 
be better if O_IGNORE_CTTY was the default, and a different flag 
(O_PAY_ATTENTION_TO_CTTY, say :-) enables the ctty dance? POSIX would 
allow that behavior, as it does not require the controlling terminal to 
be required if O_NOCTTY is not set.