Watching a modem.

I'm trying to create an event to wait for a modem to ring.

I'm using the Device::SerialPort from CPAN.

I can detect a ring with the following :

use Device::SerialPort qw(:STAT);
use Event qw(loop unloop);

$Port = new Device::SerialPort("/dev/ttyS0", 0) or die "Can't create port
object";

# Set up modem.
...
blah
blah
blah
...

while (1) {
    print "RING Detected\n" if ($Port->modemlines &
            $Port->MS_RING_ON);
}

All it does obviously is enter an infinate loop and print when it detects a
ring.

How can I use Event->var to watch for a change in $Port->modemlines?

I've tried this, and it doesn't work :

Event->var(
    var=>\$Port->modemlines ,
    cb=>\&checkring,
    poll=>'rw');

loop();

undef $Port;

sub checkring {
 if($Port->modemlines & $Port->MS_RING_ON) {
  print "Ring Detected\n";
  unloop();
 }
}

---------------------------------------
 Stuart Grimshaw         |
 Schoolsnet LTD          |   Special
 www.schoolsnet.com      |   Projects
                         |   Developer
 [email protected] |
---------------------------------------