Telnet: cmd command

You need to set the prompt that Net::Telnet should look for.  Otherwise it's waiting for something it'll never get.

See "perldoc Net::Telnet" or here: http://search.cpan.org/~jrogers/Net-Telnet-3.03/lib/Net/Telnet.pm

I am launching an exe application, which does some file writing and returns.

And yes I am issuing a $telnet->waitfor command after calling the cmd command. All the commands I issued prior to cmd, worked fine...they were issued with the $telnet->print(' ') format. I need to use cmd for this as the command to be issued has variables substituted at runtime. I am waiting for the correct prompt. It just does not return.  

You must use $telnet->prompt() to set the correct prompt before using $telnet->cmd().
$telnet->cmd() is waiting for a prompt in order to return the output.
Your $telnet->waitfor() isn't even being reached until $telnet->cmd() times out.

Use $telnet->print() instead of $telnet->cmd() if you want to use $telnet->waitfor().

Adding to what Tim said

You can set the prompt using $telnet->prompt(), or when you create the object
$telnet = new Net::Telnet (Prompt => YOUR_PROMPT_HERE);


$telnet->cmd(<command>) will send <command>  (followed by the output record seperator, normally "\n") and wait for the prompt (as you told it the prompt should look like).  The $telnet->print(<command>) will not wait for the prompt.

What is your prompt set to in your telnet object, and what does the prompt actually look like?

The prompt windows gives back is
D:\failover>

And I am setting the Prompt => '/D:\\failover>$/i'
But the command from cmd still does not return and times out. What am I doing wrong?

You need four backslashes to represent a literal backslash, according to "perldoc Net::Telnet"

Does new lines or spaces make a difference? Instead od D:\failover, I am now trying just D:\> and I am using /D:\\>$/ for the Prompt regex. I tried a space between the > and $ too...Nothing works...I only get command timed out error...
BTW with 4 backslashes for a single one in the Prompt regex, the program just exits without even running the remote command. Help please.

Maybe the login process didn't swallow the original prompt, so $telnet->cmd(...) sends the command, and reads the prompt and closes the connection before the command gets executed.

Try setting the prompt when you create your Net::Telnet object like Adam314 said...

$telnet = new Net::Telnet (
    Prompt => '/[A-Z]:\\\\.*>\s*$/i'
);

My prompt was always in the telnet object create statement...Now I put the exact same prompt regex, in the telnet object create statement, as above and the same thing happens...with 2 backslashes, the command executes remotely but the perl script times out...and with 4 backslashes, the command does not execute, no timing out, the script just exits without doing anything...no error message is generated either.

Try this pattern, see if this is any better

$telnet = new Net::Telnet (
    Prompt => '^[A-Z]:.*>\s*$/i'
);

Can you post your entire script?

#!/usr/bin/perl
 use Net::Telnet;

 open (fp,"vserver");
 $vip = <fp>;
 chomp($vip);
 
 $telnet = new Net::Telnet ( Timeout=>500,
                             Errmode=>'return',
                             Prompt=>'/^[A-Z]:.*>\s*$/i',
                             Dump_Log => 'dump.txt',
                             Input_log => 'input.txt');

 $telnet->open('10.51.1.19');
 $telnet->waitfor('/login: $/i');
 $telnet->print('Administrator');
 $telnet->waitfor('/password: $/i');
 $telnet->print('acopia');
 $telnet->waitfor('/Documents/i');
 $telnet->print('D:');
 $telnet->waitfor('/D/i');

 $com="failover\\failovertime.exe -path \\\\$vip\\vol0_0 -user engsmoke\lab -pass labtest1 -loud > failover\\test1.txt";

 $res=$telnet->cmd(String=>$com);
 $emsg=$telnet->errmsg;
 print "\nErrMsg: $emsg";

The scripty times out at the $telnet->cmd line. I tried $telnet->cmd($com) too. Didn't work. The prompt from the remote machine is "D:\>".

Using Prompt => '/[A-Z]:\\\\.*>\s*$/i'

Awesome dude...Beautiful.
I am still not clear what was wrong...would you plz explain?

The beginning of line problem could be caused by what windows uses as a new line?  Not sure, glad you got it working though.

>I am still not clear what was wrong...would you plz explain?

Since $telnet->waitfor('/D/i') returned immediately, the comamnd was sent before the Winders shell was ready to accept another command, and probably just ate the command and discarded it.

So it was the waitfor prompt that was the culprit all this time??? and not the telnet->new prompt ???

Well...I saw 2 different behaviors when using 2 and 4 slashes in the prompt attribute of the telnet obj create statement. When I used 2, the remote command would execute but the perl script would time out. When I used 4 slashes, the remote command did not execute and the perl script just ran to the end of the script and exited. I can imagine the 'just eating the command and discarding' situation happenning in the second case...

but again, how would this be linked to the waitfor prompt??

>but again, how would this be linked to the waitfor prompt??

It wouldn't be.

Given what you have now told me, I would say that with the correct prompt (using four backslashes) matched something which $telnet->waitfor('/D/i') didn't remove from the buffer.  So it sent the command and immediately read what the last waitfor didn't swallow, and disconnected, and Windows discarded any data waiting to be sent to the shell.