use Tk;
$mw = tkinit;
for(1..4){
    $mw->Checkbutton(
        -text => qq/check it $_/,
        -command => \&f,
    ) ->pack;
}
MainLoop;
sub f {
    my $b = $Tk::event->W;
    warn join q/ /, $b->{Value}, $b->cget(q/-text/);
}
__END__
1 check it 3 at - line 14.
0 check it 3 at - line 14.
1 check it 3 at - line 14.
0 check it 3 at - line 14.
1 check it 3 at - line 14.
0 check it 3 at - line 14.
1 check it 3 at - line 14.
0 check it 3 at - line 14.