expectperl-discuss

[Expectperl-discuss] problem with opening non-default pty on Solaris

[<kw...@nw...>]

All,

I'm new to this group.  May be the problem I encounter is
a simple and well known one.  Any help is appreciated.

Solaris is configured with 48 pairs of pseudo-terminal by
default (/dev/ptyp0 to /dev/ptyrf).  But on some of the
machines I work with, they have been configured to provide
over 120 pseudo-terminals, and the first 70 or so pairs are
claimed by some daemon processes.

When my perl-expect script is run, it fails because it (or
IO:Pty) attempts to open the first 48 pairs and finds that
none of them are openable - in other words, it does not
realize that there are more non-default pty's available
in the system.

************************************************************
*                                                          *
*  My question is, therefore: Is there a tunable parameter *
*  that we can use to inform Expect or Pty to recognize    *
*  the other non-default pty's?                            *
*                                                          *
************************************************************

Help is appreciated very much.

Ideally, Expect or Pty should automatically look up some
config file (or even just look into /dev to see how many
pty?? terminals have been set up) to figure that out by
itself.

mk kwong

Re: [Expectperl-discuss] problem with opening non-default pty on Solaris

[Roland G. <RGi...@cp...>]

> Solaris is configured with 48 pairs of pseudo-terminal by
> default (/dev/ptyp0 to /dev/ptyrf).  But on some of the
> machines I work with, they have been configured to provide
> over 120 pseudo-terminals, and the first 70 or so pairs are
> claimed by some daemon processes.

Interesting. Which version of Solaris? Normally, Solaris 
provides /dev/ptmx to allocate a new pty/tty pair, and IO-Tty uses it 
before it tries the BSD-style ptys...

> When my perl-expect script is run, it fails because it (or
> IO:Pty) attempts to open the first 48 pairs and finds that
> none of them are openable - in other words, it does not
> realize that there are more non-default pty's available
> in the system.

Are you sure? The latest version of IO-Tty tries all possible character 
combinations, so if a free pty exists, IO-Tty should find it.

You could add

  $IO::Tty::Debug = 1;

to your script, then IO-Tty will print out low-level information about 
what method of pty allocation it is trying.

Hope this helps,

Roland
-- 
RGi...@cp...