The obligatory simple (untested) solution: 

use Term::ReadKey;
use threads;
...
my $flag = 0;
async{ 
    $modem->hangup(), $flag = -1 if ReadKey 0.25;
    redo unless $flag
};

if( $modem->dial( $number ) and not $flag ) {
     print "Modem connected";
     $flag = 1; ## terminate thread
}
else {
     print "Dial failed:", $flag == -1 ? ' Terminated by user' : '';
}

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Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
Lingua non convalesco, consenesco et abolesco. -- Rule 1 has a caveat! -- Who broke the cabal?
"Science is about questioning the status quo. Questioning authority".
In the absence of evidence, opinion is indistinguishable from prejudice.

In reply to Re: Device::Modem Help by BrowserUk
in thread Device::Modem Help by strange1

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