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Re: Net::Telnet blocks

by BrowserUk (Pope)
on Jul 18, 2010 at 18:34 UTC ( #850170=note: print w/replies, xml ) Need Help??

in reply to Net::Telnet blocks

Did you read this bit in the pod?:

The methods login() and cmd() use the prompt setting in the object to determine when a login or remote command is complete. Those methods will fail with a time-out if you don't set the prompt correctly.

Use a combination of print() and waitfor() as an alternative to login() or cmd() when they don't do what you want.

Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
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Re^2: Net::Telnet blocks
by kp2a (Sexton) on Jul 19, 2010 at 03:38 UTC


      I just tried it out, and had a similar problem. Using the following code, I tried to connect to a local box:

      #!/usr/bin/perl use strict; use warnings; use Net::Telnet; my @lines; my $t = new Net::Telnet( Timeout=>10, Prompt=>'/# $/', Dump_Log=>'NetTelnet_x.log' ); $t->open(""); $t->login("foo", undef); @lines = $t->cmd("ls"); print @lines;

      It was hanging on the login, as you described. When it finally timed out, I got the message:

      timed-out waiting for password prompt at ./ line 13

      Well, my local box doesn't have a password on the foo account[1], so it never prompts for password. I just changed the login line to read:


      and it started to work. Perhaps you have the same problem? (I notice that you don't quote the error message anywhere, so I can't tell. The one error message you *did* give was a match timeout from when you were playing with regular expressions.)

      You might try logging in step by step with the cmd() function and verify that the login process is working as you expect. Then you can fix the login() call if you find a surprise.



      [1] I don't run Telnet servers (except for the few minutes for this test), so 733t h@X0r2[1] need not get their hopes up...

      [1] Synonym for "script kiddie".

      tried $telnet->print and $telnet>waitfor rather that $telnet->login

      same results: sucessful login but blocked for timeout seconds

      while playing with pompts I got this message which never appeared before as I had always had the correct prompt

      This indicates to me that the block until timeout has nothing to do with prompt matching:

      error => telnet: pattern match timed-out

        Well, this is exactly the error message you would get when Net::Telnet times out while waiting for a prompt:

        ## Check for failure. return $self->error("pattern match timed-out") if $s->{timedout};

        So, something changed with your remote end. You need to debug this, see the methods mentioned previously to you.

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