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

Oh wise monks, stop the voices in my head, I beg of you.
My problem :
Establish a telnet connection to a device's alarming port. Change the mode of the alarming connection from 'GUI' to clear text (i.e. no control characters creating garbage in the data stream). This is done by pressing F-11 in a simple telnet session. According to xev, F-11 = "\0xffc8". Now, how does one pass this via perl using Net::Telnet?

Solution (or beginnings thereof):
sub openport{
my ($name,$ip,$port)= @_ ;
    print "Connecting to $name @ $ip:$port  " if $debug > 1;
    my $nameport = $name.$port;
    $$nameport = new Net::Telnet (Timeout => 120);
    $$nameport->errmode("return");
    $$nameport->open(Host => $ip,
                 Port => $port);
    if (($error = $$nameport->errmsg) ne ""){
        return $error;
    } else {
        return "OK";
        # Now we send F-11 change the session to clear text.
        $$nameport->cmd("[Here's the problem]");
    }
}

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$$nameport->cmd needs to emmulate the F-11 keystroke. Any input would be greatly appreciated.

Thank you.

Replies are listed 'Best First'.
Re: Out of control in Net::Telnet
by pg (Canon) on Nov 24, 2002 at 19:45 UTC
    Try sprintf, say: 
    $cmd = sprintf("%c%c", 0xff, 0xc8);

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[d/l]
      Don't need sprintf when the same thing can be accomplished with a string literal. "\xff\xc8"
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[d/l]
      That almost fixed it. Result was it definitely changed the interface but still getting of the gui control chars. I'm going to play with some ENV vars and see if I can finish the clean up.

      Thank you so much for the pointer!!!
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Re: Out of control in Net::Telnet
by dakkar (Hermit) on Nov 25, 2002 at 14:08 UTC

    I think that you are going to have to find a bit more about the terminal settings of your device.

    What xev tells you is the X11 keysym of F11. It also tells you the keycode (95).

    In my rxvt, if I say:

    $ cat >a

    and press F11, the resulting file is:

    $ hexdump a
0000000 5b1b 3332

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    In general, what codes to send to a terminal to emulate a keystroke (usually apart from the trivial ones) depends on the type of terminal.

    If you know the terminal type, you can use Term::Cap:

    use Term::Cap;

$terminal = Tgetent Term::Cap { TERM => 'vt100' };
$f11=$terminal->Tputs('F1',1);

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    replacing vt100 with the appropriate terminal type.

    Note: the termcap(5) manpage says that the capability called F1 is "The string sent by function key f11". Alternatively, you can try FB.

    -- 
        dakkar - Mobilis in mobile
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