Re: [Expectperl-discuss] Nested telnet sessions using Expect.pm module

[Andrew C. <an...@xt...>]

I hope this comes out O.K. My crappy mailler won't let me set the word
wrap.

On Wed, 2003-10-08 at 17:30, Austin Schutz wrote:
> 	Yeah, that's what you do. You don't need to do interact to accomplish
> this. Also, you can use the '-i' flag to expect() to wait for input from both
> the device and the user.
> 	Well, that's how I would do it anyway.
> 
> 
> 	Austin

Following that advice and shamelessly stealing from various examples,
I've basically got that working. The guts are:

## Router interface etc configured.
## Logon to the device.
$net_telnet->print("telnet $ipaddress /vrf $VRF");

## Create a handle to STDIN
my $stdin = Expect->exp_init( \*STDIN );
$stdin->stty(qw(raw -echo));
$stdin->log_stdout(0);

## Create a handle for the telnet session
my $device = Expect->exp_init( \*$net_telnet );

$device->log_stdout(1);
$device->log_file($expect_log);

$stdin->set_group($device);

## If we see the router prompt we're not on the
## remote device anymore. Exit the expect loop.
expect(
    undef,
    '-i', [$device],
    [qr'ROUTER#$'],

    '-i', [$stdin],
    [ qr'\n', sub { exp_continue; }
    ],
    );

## Reset teminal or carriage returns get screwed up.
$stdin->stty(qw(sane));

print "\nCleaning up config.\n";
bless $net_telnet, 'Net::Telnet';

##Remove interface and exit.

This all seems to be working great. The main problem I had was being
able to see what I was typing without the input line being echoed after
I pressed enter. After trying a huge combination of terminal settings I
read about $exp->set_group and that fixed everything. The beauty of this
setup is by adding more regexs you could parse/filter the input.

For anyone who's wondering, I always use a Net::Telnet object instead of
a raw IO socket on TCP 23 because I got caught out a while back by hosts
expecting telnet options you can't do with raw IO.

Having struggled through this I'm "interested" now, so I'd appreciate
any comments or suggestions on how to do this better. Thanks for
everyones help.

Cheers,


Andrew



Anyone who isn't confused really doesn't understand the situation.
-Edward R. Murrow. 1908-1965.