Using perl to connect to remote hosts via telnet

amir   

Posted at 6:22am on Thursday, March 8th, 2007

too good

Xose   

Posted at 3:39am on Friday, March 23rd, 2007

good

Anonymous   

Posted at 4:54am on Thursday, March 29th, 2007

easily understandable + short = Very GOOD introduction

don   

Posted at 3:22pm on Wednesday, April 4th, 2007

good and easy to start a telnet in perl

Chris   

Posted at 3:33am on Friday, April 6th, 2007

Hello...

i have aquestion related to this Script. You connect to a host. Do you disconnect also? No, or?
thx

Ninomninom   

Posted at 4:07pm on Tuesday, April 17th, 2007

thanks for this document i was looking for an explantion for waitfor and i saw this site and it is explaining ver well. Thanks

Gimi   

Posted at 1:53pm on Wednesday, April 18th, 2007

Runing yous scrips i have this error
pattern match timed-out at

Ajay   

Posted at 11:57pm on Monday, April 23rd, 2007

can i connect to remote windows 2000 machine using NET::TELNET, as i'm not able to connect , actaully it is returing Junk, But same script is running perfectly fine on Windows XP machine ???????????//

aliaz   

Posted at 12:08pm on Friday, April 27th, 2007

I can't connect to windows 2000 server also
there 3 prompte
USERCODE:
PASSWORD
DOMAIN:
my code send me time out saying that the pattern /domain[: ]*/ can't be match

sirc   

Posted at 6:18pm on Sunday, May 27th, 2007

how can i handle the connection error.. if the machine im connecting to is down? how can i catch the error?

Tom   

Posted at 1:32pm on Tuesday, July 10th, 2007

Hi.
I have tried this code but I have recieved an error when I'm executing the script: "pattern match timed-out at line 38".

Line 38 is $telnet->waitfor('/$ $/i');
Someone can helping me solving this ?

djs   

Posted at 4:33pm on Monday, July 16th, 2007

you are not matching a prompt. it looks like you forgot to escape out your $, try this:

$telnet->waitfor('/$ $/i');

ob1   

Posted at 2:01pm on Wednesday, July 18th, 2007

do we need to send an initial carriage return if connecting to a terminal server? it seems to need this before a login prompt is displayed.

ob1   

Posted at 3:53pm on Wednesday, July 18th, 2007

never mind my previous post. print and waitfor combo worked great. thanks for a clear and concise article.

trying to run shell scripts   

Posted at 8:24am on Thursday, July 19th, 2007

Hi I was having problem running shell scripts
So the only way I got it to work was by estimating the time it takes to run so if it ran for 10 sec
I put a sleep 12 and then it worked. I sthere a way to do this without putting sleep commands, I thought the wait for would handle this.

nicky   

Posted at 11:25pm on Tuesday, August 7th, 2007

hi cool artical
can i ask some question?
what does $telnet->waitfor('/$ $/i'); do?
i dont really understand wat '/$ $/i' means u see

also isnt possible to write the result of the
$telnet->print('who');
into a notepad in my c drive? if so how would the code be like?

hb   

Posted at 7:44am on Wednesday, August 8th, 2007

Thank you for help! perldoc Net::Telnet was not so clear for me before.


In my script I have writen :



(translated to your example )

@output = $telnet->waitfor('/$ $/i'); print @output;

compare with :
$output = $telnet->waitfor('/$ $/i'); print $output;

RR   

Posted at 2:48pm on Wednesday, August 8th, 2007

I am having problem in connecting to the server
'timed-out waiting for command prompt at C:perl temptelnet.pl line 10'

although i am giving the same username and paasword that i am using manually.

Can someone help me out here

manoj   

Posted at 5:59am on Thursday, August 9th, 2007

I am facing problem.
i am executing command "cat test.txt" on remote machine through this module.this file contain number of lines & each line having numbers of fields, each of them seperated by tab.

when i get the output of that command & i try to split each line using tab as seperator.it does not work (split does not find tab in the line).

can some one haelo me. its urgent

Aparna   

Posted at 12:06am on Friday, August 17th, 2007

really good and made telnet easy thru perl

thaha   

Posted at 4:57am on Wednesday, August 29th, 2007

thanks a lot to provide such a nice intro to the telnet thru perl.

downloadsoftware.com@gmail.com   

Posted at 3:05am on Friday, September 7th, 2007

port 23 connection failed

bdizzel   

Posted at 1:13pm on Tuesday, September 18th, 2007

i was curious on what /$ $/i means any ideas?

Mark   

Posted at 11:45pm on Tuesday, September 18th, 2007

bdizzel ....

You mean waitfor('/$ $/i');?

I guess that this is waiting for the prompt "$ " (dollar, space). Note that the first dollar is escaped so it is interpreted as a character. The last dollar indicates end of line.

bdizzel   

Posted at 11:03am on Thursday, September 20th, 2007

thank you mark, i also have another question, when i used the command print $telnet->cmd('who'); , the very last line of the print is my prompt i recieve after i log in- bash2-:03$ ... i was wondering if there is a way to get that out of there, i was thinking about using chop or chomp but no success there... any help is appreciated thank you in advanced

McNally   

Posted at 9:40am on Monday, September 24th, 2007

For those who are confused reading the comments so far -- it appears to me that the commenting system is eating backslashes. Compare what's being displayed in the comments from bdizzel and others (i.e.: '/$ $/i') with what's in the code box in the article above -- you will find that in the latter there is an extra backslash character present before the first "$" to escape its special meaning as an end-of-line anchor in the pattern match. What the author is trying to match is the sequence (dollar sign)(space)(end-of-line). What the version without the backslash tries to match is (end-of-line)(space)(end-of-line), which is obviously much different.

Also, keep in mind that the prompt string that they're trying to match only makes sense if your prompt ends with a dollar sign ($) -- if you use a csh derivative, for example, and use the convention that your prompt ends in a percent sign (%) or if you like to feel importantly root-like and end your prompt with an octothorpe (aka (in US usage) pound sign, aka "#") -- well, then, you'll have to change your match expression.

Does that clear it up, bdizzel?

bdizzle   

Posted at 8:02am on Thursday, September 27th, 2007

excellent work McNally, i appreciate you taking the time to respond to my question, the prompt was confusing but this pretty much clears it up- thanks again

tez   

Posted at 3:43am on Friday, September 28th, 2007

Hi

I too am having problems with the sequence match. I am using TACACS on my Cisco equipment and have a multi line banner message that finishes with "Usercode:". I have tried all sorts of variations but I stil lfail to get it to work. For example.. waitfor('/[: ]*$/i'); I have tried a number of variations, can anyone help me at all?

sumant chhunchha   

Posted at 7:25am on Monday, October 8th, 2007

Hello,
I tried the things as above...I am trying to telnet with application port which is 2101..when i directly try from dos prompt as >telnet 2101.....it opens a telnet connection and I can fire command for that application however ere it is not showing any prompt to me..it shows blank scree and then i fire commands related to that. however using script it shows error "timed-out waiting for login prompt at telnet2.pl line 18"..... what can be the solution?
[code]
$telnet = new Net::Telnet ( Port=> 2101, Timeout=>10, Errmode=>'die');
$telnet->open('ps4131');
$telnet->login('administrator', 'password');
peint $telnet;
[/code]

Sumit   

Posted at 7:47pm on Friday, October 26th, 2007

hi my prompt is someting like
host:user:dir>
please help me setting the prompt =>'' pattern
I tried alot but nothing doing :(

Sumit   

Posted at 7:48pm on Friday, October 26th, 2007

hi my prompt is someting like
host:user:dir>
please help me setting the prompt =>'' pattern
I tried alot but nothing doing :(

Mikael   

Posted at 7:23pm on Friday, November 2nd, 2007

I think host:user:dir> would be as simple as:
$telnet->waitfor('/^host:user:dir>$/');

Salih   

Posted at 11:47am on Tuesday, November 20th, 2007

I have tried the code above several times . The steps of code are run succesfully untill it reaches line 8 where waitfor() is.

here is my command prompt during connection.

login:

Password:


switch8-12>


The perl script i coded.

1-use Net::Telnet;
2-$telnet = new Net::Telnet ( Timeout=>2, Errmode=>'die');
3-$telnet->open('192.168,0,12');
4-$telnet->waitfor('/login:/');
5-$telnet->print('salih');
6-$telnet->waitfor('/Password:/');
7-$telnet->print('S132A13');
8-$telnet->waitfor('/switch8-12>/');
9-$telnet->print('who');
10-output=$telnet->waitfor('/switch8-12>/');
11-print $output;


Wating for your comments.
Thanks in advance.
Cheers...
All for one, one for all.
(i think that is enough :)))) )

duke74s   

Posted at 4:42am on Monday, December 3rd, 2007

hi my prompt is like this
"[root@z1 ~]# "
- root : user, z1 : hostname, ~ : directory
I've never find the pattern. Please, help me!!

ptg   

Posted at 9:31am on Monday, December 3rd, 2007

I need to run the telnet script against devices with differnt login methods (individual useraccounts and direct password accounts).

Method1:

Username:xxx
Password:xxx
router#

Method2:
Password:xxx
router>enable
Password:xxx
router#

can we do a if and else using telnet->waitfor?

if ($telnet->waitfor('/Password: $/i')) {
$telnet->print("$ARGV[3]");
$telnet->waitfor('/>$/i');
$telnet->print('enable');
$telnet->waitfor('/Password: $/i');
$telnet->print("$ARGV[4]");
$telnet->waitfor('/#$/i');
$output = $telnet->print('');
}
else {
$telnet->waitfor('/Username: $/i');
$telnet->print("$ARGV[3]");
$telnet->waitfor('/Password: $/i');
$telnet->print("$ARGV[4]");
$telnet->waitfor('/#$/i');
$output = $telnet->print('');
}

Any help would be must appreciated!!! thanks!!!

RRP   

Posted at 5:10am on Thursday, January 3rd, 2008

HI Dear,
I found the following error message while trying to connect via telnet. I do not understand what is INC and what it does. I serched but did not find anything. Please help me on this. I am using windows XP. Is there any setting needs to be done for INC.
C:PerlsitelibURI>perl test2.pl
Can't locate Net/Telnet.pm in @INC (@INC contains: C:/Perl/lib C:/Perl/site/lib .) at test2.pl line 4.
BEGIN failed--compilation aborted at test2.pl line 4.

kwatkins   

Posted at 1:27pm on Thursday, January 3rd, 2008

Great, thanks

John Ryan   

Posted at 11:11am on Tuesday, January 8th, 2008

use Net::Telnet;
$telnet = new Net::Telnet ( Timeout=>10, Errmode=>'die');
$telnet->open('168.54.24.155');
$telnet->waitfor('/login: $/i');
$telnet->print('jryan');
$telnet->waitfor('/Password: $/i');
$telnet->print('5JKD223WER1');
$telnet->waitfor('/# $/i');
$telnet->print('uname -a');
$output = $telnet->waitfor('/# $/i');
print $output;
----------
doesn't matter what command I use (in the case above it is uname -a) it always return "1". what does it mean and how to fix it?

sujith   

Posted at 1:17am on Wednesday, January 9th, 2008

when i run this same program to connect to my server it return some error..
The error seems to be like this....

problem connecting to "192.168.1.100", port 23: Connection refused

Can any one help me out ..
cheers

Rami   

Posted at 1:08am on Tuesday, January 15th, 2008

Great ! :) now how to compile it ??

Thommy   

Posted at 6:52am on Tuesday, January 22nd, 2008

My Problem:

setting up a couple of devices via a Cisco Terminal Server.
I want to plug for example 5 Switches to this terminalserver 10.1.1.1 Port 2002 up to 2007

Then i want to set up the Vlan Interface and getting the configuration file from a tftp server.

But my main Problem is to execute commands on the terminal line because i have no login with a terminal server console.

My code:
my $session = Net::Telnet::Cisco::IOS->new(Host => '10.1.1.1', Port => 2002);

$session->cmd("nn"); # for getting a promt without login
@output = $session->cmd('sh run');
print @output;

but command ($session->cmd("nn");)timed-out at test.pl

I tried the same with a regular telnet session to a router and a login, this works
Can u help me?

Serge   

Posted at 6:50am on Wednesday, January 23rd, 2008

Thanks a lot!

shree   

Posted at 3:09am on Tuesday, January 29th, 2008

Actually i tried the below program:
use Net::Telnet;

$telnet = new Net::Telnet ( Timeout=>10,
Errmode=>'die');
$telnet->open('180.15.24.13');

# change this according to your telnet prompt
$telnet->waitfor('/login:/');
$telnet->print('root');

#change this according to your telnet password prompt
$telnet->waitfor('/Password:/');
$telnet->print('siemens');


# $telnet->waitfor('/sun4#/'); #change this to the prompt of the user you are testing
#print $telnet->cmd('./testing.sh');
#print $telnet->cmd('echo " hello " >> hello.csv');

$telnet->close();


but got an error in the command prompt saying:

Can't locate Net/Telnet.pm in @INC (@INC contains: d:/Perl/lib d:/Perl/site/lib .) at telnet.pl line 24.
BEGIN failed--compilation aborted at telnet.pl line 24.

Dave   

Posted at 11:08pm on Wednesday, January 30th, 2008

attn John Ryan.

I have the same problem, I had to do this:

$telnet->print('uname -a');
@output = $telnet->waitfor('/# $/i');
$output = "@output";
print $output;

It bugs me that it's note "right" but it works for now.

skipo   

Posted at 1:17pm on Thursday, February 14th, 2008

I have written a script to connect to a firewall and then telnet to a box on aht other side of that firewall (thaat's the way I have to connect). The purpose was to be able to telnet to a box without manually going thru teh intermediate steps. My code will run commands and return the results to me...until I tried to run vi. The $telnet->cmd('vi bob') just sits but never shows me the vi screen. (I assume because the comand has not completed.) is there a more interactive way to use the Net::Telnet on a character by character basis? to allow me to see the vi screen and interact with it?

Thanks,

redhatrak   

Posted at 12:16am on Wednesday, February 20th, 2008

I have tried this script and am getting an error when connecting to a box which actually one can ping to but cannot telnet. the telnet output of such a box is as below:
======
login: patqa1
patqa1's Password:
3004-010 Failed setting terminal ownership and mode.
======
For this error i get perl error as:
pattern match read eof at tt.pl line 24

How can this be handled? Help appreciated.

Thanks,

pepsi   

Posted at 11:43am on Wednesday, March 12th, 2008

Hi,

I am trying to telnet to a windows 2000 machine which has SLNet installed. I am using the following script

$telnet->open('addr1');
$telnet->login('Administrator', 'pass1');
$telnet->print('who');
@output = $telnet->waitfor('/>/');
$output = "@output";
print $output;

But the output is interspersed with junk characters. How do I ensure that these junk characters are not included in the result?

Ideally the result should be as shown below
********************************************
Administrator CONIN$ Mar 12 13:40

C:DOCUME~1ADMINI~1>
*********************************************

But when executed via script shown above, the output is displayed as shown below
*********************************************************
←[4;22H←[4;22Hwh←[4;23H←[4;24Ho←[5;1H←[5;1HAdministrator←[5;21HCONIN$←[5;34HMar
12 12:27←[7;1HC:DOCUME~1ADMINI~1 >
**********************************************************

Thanks

topepsi   

Posted at 4:04am on Wednesday, March 19th, 2008

i think you need to traverse the array @output per element. each element will contain per line.

might look something like this.
$output[0] = "********************************************"
$output[1] = "Administrator CONIN$ Mar 12 13:40";
... and so on

you might need a while or foreach to traverse the array

pepsi   

Posted at 8:51am on Wednesday, March 19th, 2008

topepsi, Thanks for your response. But it didn't work. Each array element still contains junk characters. Any other idea?

Shankar Kundargi   

Posted at 2:02am on Monday, March 24th, 2008

Hi,
I found the following error message while trying to connect via telnet. I am using windows XP. Is there any setting needs to be done for INC.
C:PerlsitelibURI>perl connect.pl
Can't locate Net/Telnet.pm in @INC (@INC contains: C:/Perl/lib C:/Perl/site/lib .) at connect.pl line 3.
BEGIN failed--compilation aborted at connect.pl line 3.
Please help me on this.

Tayyab   

Posted at 5:10am on Monday, March 24th, 2008

Hi Shankar,
May be you need to make a 'Net' repository in C:Perl/lib and then copy Telnet.pm there. I hope it helps.

Shankar Kundargi   

Posted at 7:09am on Monday, March 24th, 2008

Thanks Thayyab,
But the thing I already installed it and now I am getting Timed out error even if the login name and password are correct

Cisco_lad   

Posted at 11:25pm on Tuesday, April 8th, 2008

I am using below and it works fine, but only for one host.
how do I refernce host to a file of hosts. this might be trivial for u guys bit I am worse than a beginner.

Thanks in advance !

Cisco_lad

use Net::Telnet::Cisco;

my $session = Net::Telnet::Cisco->new(Host => '192.168.158.2');
$session->login('login', 'abc123');



# Enable mode
if ($session->enable("abc123") ) {


} else {
warn "Can't enable: " . $session->errmsg;
}

# Execute a command
my @output = $session->cmd('sh start | inc hostname');
print @output;
# Execute a command
@output = $session->cmd('sh ver | inc System image file is');
print @output;

$session->close;

Thai Tuan Anh   

Posted at 11:28pm on Wednesday, April 9th, 2008

I need to telnet to a sunser via 9023 port.
Normally, I can telnet directly as below:
telnet 10.2.4.9 9023
Trying 10.2.4.9...
Connected to 10.2.4.9.
Escape character is '^]'.
900 Login required.
login username passwd
login username passwd
102 2 records.
Lucent NavisRadius Radius Server, Version 4.5.8 (Build 551-060)
Copyright (c) 1998-2005 Lucent Technologies Inc. All Rights Reserved.
==>

I tried to use Net::Telnet with the code following:

#!/usr/bin/perl -w
use Net::Telnet ();
$t = new Net::Telnet (Timeout => 10,Port => 9023,Prompt => '/==> $/');
$t->open("10.2.4.9");
$t->waitfor("900 Login required. $/i");
$t->print("login username passwd");


But it's not successful. This is the error message:

missing opening delimiter of match operator in argument "900 Login required.i" given to Net::Telnet::waitfor() at ./try line 5

How can i fix it ?

PuneetKhurana   

Posted at 5:55am on Monday, April 21st, 2008

Really cool stuff