Hi,
It seems BSD style ptys are on the way out, and most systems will soon
have just Unix98 style ptys. This makes me want to move something to
Unix98 ptys, but I'm not sure of the appropriate way. The issue is that
things like HylaFAX expect to work with well known, persistent, names
for modem ports. A 100% soft modem in user space can easily provide that
with BSD ptys. With Unix98 ptys it is not so obvious what to do. Most
commercial soft modems don't have this issue, as they are part kernel
space/part user space designs. Obviously creating a link to a
dynamically generated pty with a well known name, and various other
things could be done. However, I assume other people have had to do
similar persistent pty things, and there is a well defined common
practice for it. Can anyone tell me what it is? :-\
Regards,
Steve
Hi!
> It seems BSD style ptys are on the way out, and most systems will soon
> have just Unix98 style ptys. This makes me want to move something to
> Unix98 ptys, but I'm not sure of the appropriate way. The issue is that
> things like HylaFAX expect to work with well known, persistent, names
> for modem ports. A 100% soft modem in user space can easily provide that
> with BSD ptys. With Unix98 ptys it is not so obvious what to
> do. Most
Do you actually have user-space softmodem implementation? Is it
open-source? I guess it would be very interesting for remaining modem
users :-).
Pavel
--
When do you have heart between your knees?
Followup to: <[email protected]>
By author: Steve Underwood <[email protected]>
In newsgroup: linux.dev.kernel
>
> Hi,
>
> It seems BSD style ptys are on the way out, and most systems will soon
> have just Unix98 style ptys. This makes me want to move something to
> Unix98 ptys, but I'm not sure of the appropriate way. The issue is that
> things like HylaFAX expect to work with well known, persistent, names
> for modem ports. A 100% soft modem in user space can easily provide that
> with BSD ptys. With Unix98 ptys it is not so obvious what to do. Most
> commercial soft modems don't have this issue, as they are part kernel
> space/part user space designs. Obviously creating a link to a
> dynamically generated pty with a well known name, and various other
> things could be done. However, I assume other people have had to do
> similar persistent pty things, and there is a well defined common
> practice for it. Can anyone tell me what it is? :-\
>
Two options: either continue to use BSD ptys (the kinds of stuff you
describe above is actually the one case where BSD ptys is a better
choice than Unix98 ptys) *or* create symlinks -- or if that doesn't
work for you, device nodes -- dynamically.
I.e. have a program which opens /dev/ptmx, gets a slave pty with a
specific ptsname(), then does a symlink() into a suitable directory.
The symlink is your persistent name.
-hpa