Anonymous Monk has asked for the wisdom of the Perl Monks concerning the following question:

I am writing a program, to telnet to a server and perfrom certain tasks (tasks -> unimportant). When I try to telnet to a server remotely, I can access the server with a certain login name/password, but when i enter another valid login name/password, it times out. Do you know why it worked for a screen name but yet it didn't work for another one. Is there something wrong with the code?? Here is some of the code. Thank you. 

  #!/usr/bin/perl 
  # file: telnet_a.pl 
  
     use Net::Telnet; 
     use Term::ReadKey; 
  
     #connects to the server of your choice 
     $telnet = Net::Telnet->new('osf1.gmu.edu'); 

     #asks for login name with password 
     print "Login Name : "; 
     $HOST = <STDIN> or die print "not a valid name"; 
          
     #reads in the password without showing the character  
     #being typed in 
     ReadMode("noecho",STDIN); 
     print "Password   : "; 
     $USER = <>; 
     print "\n"; 
     
     #restor to normal settings 
     ReadMode("original",STDIN); 
     
     #connects to server 
     $telnet->login($HOST,$USER) or die print "can't access server"; 

     $telnet->cmd('ls');

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Re: login remotely through telnet
by Elijah (Hermit) on Apr 01, 2004 at 17:43 UTC
    Well the following worked fine for me: 
    #!/usr/bin/perl  
use Net::Telnet; 
$telnet = Net::Telnet->new('192.168.1.65');

print "Login Name : "; 
$HOST = <STDIN>; 

print "Password : "; 
$USER = <>; 

$telnet->login($HOST,$USER) or die print "can't access server"; 
@ls = $telnet->cmd('ls');
for(@ls){print;}

    [download]
    I do not have the Term::ReadKey module installed on my system so I removed that. There could be your problem. Or at least I had no problem not using this module and that was the only difference between your code and mine. It would also be a good idea to chomp your variables before using them incase a user enters a whitespace at the end of their user or pass or if a newline sneaks through somehow.

    Edit:

    Ok I installed that module to try and give you some better advice but alas mine runs perfectly. 

    #!/usr/bin/perl  
use Net::Telnet;
use Term::ReadKey;
$telnet = Net::Telnet->new('192.168.1.65');

print "Login Name : "; 
$HOST = <STDIN>; 

ReadMode("noecho",STDIN); 
print "Password : "; 
$USER = <>;
print "\n"; 
ReadMode("original",STDIN); 

$telnet->login($HOST,$USER) or die print "can't access server"; 
@ls = $telnet->cmd('ls');
for(@ls){print;}

    [download]
    Could it be an issue with the telnet server? Does the second user you are trying actually exist on the system?
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Re: login remotely through telnet
by iburrell (Chaplain) on Apr 01, 2004 at 22:36 UTC
    What does it say when you turn on debugging? Deadlock with telnet is common when unexpected responses come from the server.

    For example, the login() docs say: "If any of those prompts sent by the remote side don't match what's expected, this method will time-out, unless timeout is turned off."

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