Subject: Re: ptyfs fully working now...
To: None <tech-kern@netbsd.org>
From: Christos Zoulas <christos@zoulas.com>
List: tech-kern
Date: 11/11/2004 20:41:00
In article <20041111202546.GA2234@jodi.nimenees.com>,
Eric Haszlakiewicz <erh@jodi.nimenees.com> wrote:
>On Thu, Nov 11, 2004 at 05:41:29PM +0000, Rui Paulo wrote:
>> On Thu, 11 Nov 2004 13:49:38 GMT
>> christos@zoulas.com (Christos Zoulas) wrote:
>> 
>> > I don't understand the question. I just removed all the pty's and rebooted
>> > with ptyfs mounted. I don't think that you can disable one specifically.
>> 
>> Using the old scheme, I can disable a pty like this:
>> ttyp1   none    network off
>> 
>> Or am I reading ttys(5) erroneously ?
>
>	As I read it, that will do nothing.  Or, perhaps if not nothing, it will
>cause the pty allocation to fail on that pty and skip to the next one.
>I'm having trouble thinking of a case where you would want to do something
>like that.
>	So, for pty's the /etc/ttys file:
> - doesn't specify a program to run
> - doesn't specify a terminal emulation to use
> - (probably) doesn't have any noticable effect when disabling a pty

It does not disable a pty.

>Am I missing something or is there no point to having the ptys in there
>even without ptyfs?

Up to yesterday's commit you wanted to have the pty's there if you
were using utmp entries for them. This is because ttyslot(3) would
return 0, if the entries were not there. This has now been changed
for both regular and ptyfs ptys. The rationale is that you don't
want to have a ttys file that is 1000 lines long to cover all the
ptys. So you don't need to have /etc/ttys entries for ptys if you
are running with a kernel and libc newer than yesterday. So it is
better to remove any pty entries from /etc/ttys even if you are
not using ptyfs.  Read the updated manual page for ttyslot(3) for
an explanation.

christos