Re: bash sets O_NONBLOCK on pts

[Stephane Chazelas]

2019-10-03 13:58:40 -0400, Chet Ramey:
> On 10/2/19 11:38 AM, Stephane Chazelas wrote:
> 
> > BTW, what's the point of the check_dev_tty() function? It seems
> > it just attempts to open the tty (the controlling one or the one
> > open on stdin), closes it, but doesn't return anything about the
> > success of failure in doing so.
> 
> It's to make up for an old bug that's probably gone everywhere. Back
> in the day, there were systems and services that would start interactive
> shells without a controlling terminal. Opening and closing /dev/tty
> forced the controlling terminal to be allocated.
[...]

Thanks.

I suspected it may be something like that. Though I thought,
without actually double-checking it, that the rest of the code
would end up opening the terminal device (without O_NOCTTY) anyway.

It may be worth adding a comment to document that purpose of the
function, and maybe rename it to something like
control_tty_if_not_already_controlled or something that more
accurately describes its intent.

-- 
Stephane