PERL and TELNET 3

[unixrookie]

I need to write a script to telnet into a router and issue a few commands any ideas. I know there is a telnet module but i'm not to familiar with it's workings? I'm new to perl so i thank you in advance for your help

 

[raider2001]

The module you want is Net-Telnet. I have used it and it works fine on Windows and Unix systems. The module comes with a few examples that can get you started. I've included the first program that I wrote using Net-Telnet.

use Net::Telnet ();

$host = 'xxxx';
$username = "yyyy";
$password = "zzzz";
$t = new Net::Telnet;
$t->open($host);
$t->waitfor('/login:/');
$t->print($username);
$t->waitfor('/Password:/');
$t->print($password);
$t->waitfor('/]#/');
$t->print('uptime');
$t->getline;
($up) = $t->getline;
print "uptime for $host is $up\n";
$t->waitfor('/]#/');
close($t);

 

[unixrookie]

Once again the experts have not let me down. Thanks for the help.

 

[unixrookie]

Ok folks now is when I become the bug. Is there a way for me to see the script as it happenes or send it to a logfile. So I can see the responses from the hosts the script telnets to? This would allow me to troubleshoot errors I'm getting with timeouts against prompt matches. Thanks

 

[hmerrill]

I've never used Net::Telnet before, but here's a snippet from "perldoc Net::Telnet" having to do with options to new:

$obj = Net::Telnet->new([Binmode => $mode,]
[Cmd_remove_mode => $mode,]
[Dump_Log => $filename,]
[Errmode => $errmode,]
[Fhopen => $filehandle,]
[Host => $host,]
[Input_log => $file,]
[Input_record_separator => $char,]
[Option_log => $file,]
[Output_log => $file,]
[Output_record_separator => $char,]
[Port => $port,]
[Prompt => $matchop,]
[Telnetmode => $mode,]
[Timeout => $secs,]);

Looks like you can set argument "DumpLog" to capture output from the remote host.

HTH.
Hardy Merrill
Mission Critical Linux, Inc.

http://www.missioncriticallinux.com

 

[unixrookie]

hmerrill and raider2001,
Again Thanks for the time you both have provided excellent information you'll be happy to know I have completed the script and all is working well. Couldn't have done it without you. This forum rocks!!

 

[unixrookie]

Sorry! I spoke to soon. My log files don't seem to be capturing any I/O. Any suggestions? The files get created but are always empty regardless of whether or not the script runs clean. Raider2001 I used the $t->getline; statement so the script kicks back the status of my transfer but unless i'm infront of the screen I wouldn't see that. My hopes are that I can be lazy and cron the script to run overnight and check the logfile in the morning, LOL maybe even have it e-mailed to me LOL.

 

[raider2001]

How are you invoking the logging? I just tried the following and it works fine.

my $t = new Net::Telnet(
                        Dump_log   => 'dump.log',
                        Input_log    => 'input.log',
                        Output_log  => 'output.log',
                        );

FYI, the following link has some helpful information on Net-Telnet.

http://tlc.perlarchive.com/articles/perl/ls0001.shtml

 

[unixrookie]

I tried it your way and I get the same result blank files the only difference is your way they are .log files. Can I view those through a text editor or do I need something special. Also the file sizes are 0kb so even if there is info I cant view in notepad the file size should still be bigger than 0kb correct.

Befor your last post I was invoking like this on merrill's suggestion. the script is creating the file it's just not filling it. i tried different variations on the filename extensions.

$filename = "dump";
$file = "outlog";
$obj = Net::Telnet->new (Dump_Log => $filename,);
$obj = Net::Telnet->new (Output_log => $file);

 

[raider2001]

I tried the following script running on a Windows and a linux system. On both systems, it created the 3 log files. All 3 files are text files. Try running this script (change the host, username, password, and prompt).

use Net::Telnet;
my $host = "XXX";
my $user = "YYY";
my $password = "ZZZ";
my $prompt = "]#";
my (@data, $line);
my $t = new Net::Telnet(
                        Timeout     => '5',
                        Prompt      => "/$prompt/",
                        Dump_log    => 'dump.log',
                        Input_log   => 'input.log',
                        Output_log  => 'output.log',
                        );
$t->Net::Telnet::open($host);
$t->login(
          Name     => $user,
          Password => $password,
         );
@data = $t->cmd(String => 'uptime');
foreach $line (@data) {
     print "$line\n";
}
$t->close();