expectperl-discuss

[Expectperl-discuss] stty settings

[<ex...@ih...>]

I'm not completely confident that I understand how 

$obj->slave->stty() syntax works.

Can I do this: obj->slave->stty(qw('rows 45' 'columns 80');

I'm having trouble running some scripts.  They work fine interactively
but when I run them through a command server they fail and I think
it may have something to do with window sizes.

My expect runs a bourne shell script if I run my perl script
by hand it executes the sh script fine responding with the right
answer when needed via expect.  I have a command server (perl)
that accepts commands from remote hosts and runs them as a specified
user.  The same expect that worked when run on the command line
fails when run through the command server.  It's not clear to
me what is happening but I'm guessing that it's window sizes
and that the sh script responds differently depending on the
window size and that causes a different response/answer pair
then what I get when I run manually.

Is this all horribly vague? Or does it ring a bell for anyone?

Re: [Expectperl-discuss] stty settings

[Roland G. <Ro...@Gi...>]

> I'm not completely confident that I understand how 
> 
> $obj->slave->stty() syntax works.
> 
> Can I do this: obj->slave->stty(qw('rows 45' 'columns 80');

No, IO::Stty isn't a complete stty replacement (though there are 
efforts in that direction).

From the Expect FAQs:

  I'm spawning a telnet/ssh session and then let the user
  interact with it.  But screen-oriented applications on the
  other side don't work properly.

    You have to set the terminal screen size for that.  Luckily,
    IO::Pty already has a method for that, so modify your code
    to look like this:

      my $exp = new Expect;
      $exp->slave->clone_winsize_from(\*STDIN);
      $exp->spawn("telnet somehost);

    Also, some applications need the TERM shell variable set so
    they know how to move the cursor across the screen.  When
    logging in, the remote shell sends a query (Ctrl-Z I think)
    and expects the terminal to answer with a string, e.g.
    'xterm'.  If you really want to go that way (be aware,
    madness lies at its end), you can handle that and send back
    the value in $ENV{TERM}.  This is only a hand-waving
    explanation, please figure out the details by yourself.

  I set the terminal size as explained above, but if I resize
  the window, the application does not notice this.

    You have to catch the signal WINCH ("window size changed"),
    change the terminal size and propagate the signal to the
    spawned application:

      my $exp = new Expect;
      $exp->slave->clone_winsize_from(\*STDIN);
      $exp->spawn("ssh somehost);
      $SIG{WINCH} = \&winch;
      sub winch {
        $exp->slave->clone_winsize_from(\*STDIN);
        kill WINCH => $exp->pid if $exp->pid;
        $SIG{WINCH} = \&winch;
      }

      $exp->interact();

Hope this helps,

Roland
--
Ro...@Gi...