Re: [Axiom-developer] Hypertex and pty

[Waldek Hebisch]

I wrote:
> Vanuxem Grégory wrote:
> > Le jeudi 26 octobre 2006 ? 02:36 +0200, Waldek Hebisch a écrit :
> > > I wanted to try hypertex in silver on Gentoo Linux.  It turned out
> > > that I can not start sman, becouse 'ptyopen' was failing.  Atfter
> > > a little investigation I found out that the machine (which otherwise
> > > uses bleeding edge new software) has only old legacy pty's -- the
> > > new '/dev/ptmx' and '/dev/pts' were not enabled.  All other
> > > software worked fine, trying '/dev/ptmx' first and then silently
> > > falling back to legacy pty's -- only Axiom assumed that Linux
> > > must have working '/dev/ptmx'.
> > > 
> > > While I consider this machine as misconfigured, the problem may
> > > appear in real use.  If we want Axiom to "just work" it should
> > > also try new method first and then fall back to legacy pty's.
> > > 
> > 
> > See http://wiki.axiom-developer.org/189GraphicsDoesNotWorkOnDebian
> > 
> 
> I see, I am not the first with this problem.  Concerning the patch:
> while technically it seem to work (I tested a slight variation of it),
> it has many problems:
> 
> 1) the patch duplicates code (my variation avoids duplication)
> 2) on Linux there is 'openpty' library function which is smart
>    enough to try first '/dev/ptmx' and if needed fall back to
>    legacy pty's. 'openpty' also handles extra issues (like 
>    changing access rights to legacy pty's) -- we probably should
>    use it.
> 3) in general 'openpty.c.pamphlet' is messy and the patch from
>    wiki only adds to this mess
> 

Using BSD method on Linux is no go (I wonder if BSD method still
works on BSD) -- first time it worked, but second time I got
completly anresponsive Axiom (but hypertex worked).  More precisely,
clef run out of pty's and did not start up, so nobody would forward
input to AXIOMsys.  How it happened that machine run out of pty's
(the machine had "full" set of 256 pty's) -- it turned out to be
a permission problem.  Namely, only a handful of slave tty* node
were writable by user starting Axiom -- anybody using pty's is
supposed to use a setuid helper which adjusts permissions as
needed.

openpty call works, but there is a Makefile/configure problem:
openpty is in libutil, so we need to link in additional library.
For tests I added it from command line using 'make LDF=-lutil',
but for serious use we need a configure test.

Gaby, is LDF the right variable to set or do we need extra one?

-- 
                              Waldek Hebisch
address@hidden