I wrote an application that uses Net::Telnet to login to a remote server. On servers that don't expect to receive a particular term type, the application runs fine. However, on servers that expect a VT102 terminal type, the application errors out.

The logs for Putty tell me that the troublemaking server expects my application to send back a Terminal Type: 

Event Log: server:    SB TTYPE SEND
Event Log: client:    SB TTYPE IS XTERM

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According to the docs, Net::Telnet the option_send method to answer a Telnet option negotiation request "is not yet implemented". Luckily I found Net::Telnet::Options, which appears to be designed to manage such requests.

use Net::Telnet;
use Net::Telnet::Options;

# Create Telnet Object
my $t = new Net::Telnet(Dump_log   => 't_dump.txt', 
                        Output_log => 't_input.txt', 
                        Input_log  => 't_output.txt',
                        Errmode    => 'return',
                        Timeout    => '10',  
                        );

# Create Telnet Options Object
my $nto = Net::Telnet::Options->new();

# Accept and deal with incoming TERM TYPE option requests
$nto->acceptDoOption('TTYPE', {'SB' => \&ttype_sb_callback } );

sub ttype_sb_callback
{
   my ($cmd, $subcmd, $data, $pos) = @_;
   my $socket = "23";

   $nto->sendOpt($socket, 'SB', 24, 'IS', 'VT102');
   return ;
}

$t->open($host);
$t->waitfor('/login:/');
$t->print("$username");

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Right after the initial login, the error occurs since the TERM TYPE handshake is not able to be made between my application and the server application:

($prematch, $match) = $t->waitfor(Match => "/Welcome/");
unless (defined $match) {
  print $t->errmsg;
}

[download]

The error message is: pattern match read eof

Net::Telnet::Options looks very promising but it looks like I'm not integrating it into my code correctly. What might I have to change to get the application to see my TERM TYPE response?

In reply to Managing TERM TYPE Option Requests with Net::Telnet by initself

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