#!/usr/bin/perl 

use strict;
use warnings;
use Expect;

my $cmd1 = "show version | no-more ";
 
my $access_protocol   = 'telnet';
my $router            = '172.16.2.1';
my $expect_log_file   = 'expect-log-file.txt';
my $timeout           = 15;
my $username          = 'username1';
my $password          = 'asdfasdfasdf';

#Uncomment to hide stdout:
#$Expect::Log_Stdout = 0;

my $exp = Expect->spawn("$access_protocol $router") or die "Can't connect to $router: $!\n";

$exp->expect  ($timeout,
  ['(yes/no)',sub{my $fh = shift; $fh->send("yes\n"); exp_continue;}],
  ['(sername: )|(ogin: )$',sub{my $fh = shift; $fh->send("$username\n"); exp_continue;}],
  ['(assword:)$',sub{my $fh = shift; $fh->send("$password\n"); exp_continue;}],             
  ['timeout',sub{&login_error();}],
  '-re', '> $', #wait for router prompt, then exit expect
																													);
$exp->log_file($expect_log_file);                                                                        
$exp->expect  ($timeout,
  ['',sub{my $fh = shift; $fh->send("$cmd1 \n");}]
																													);    

$exp->expect  ($timeout,
  ['More',sub{my $fh = shift; $fh->send(" "); exp_continue}],
  '-re', '[#>:]$', #wait for router prompt, then exit expect,
																													);
$exp->expect  ($timeout,
  ['',sub{my $fh = shift; $fh->send("exit \n");}]
																													);
                                                                                                                    
sub login_error {
  print "Unable to login to router $router.  Try to login manually with SSH. \n";
  exit;
}