#!c:\perl\bin\perl.exe  

#Assign signal handlers
$SIG{'NUM12'} = 'handler';
$SIG{'CHLD'} = 'handler';

print "List current SIG handlers...\n";
while ( my ($key, $value) = each(%SIG) ) {
        print "$key => $value\n" if ($value ne '');
}

print "My PID is $$. I go sleep and wait for signals and ...\n";
while(1) {
   sleep;
}

sub handler{
  local ($sig) = @_;
  # Problem: This line never printed.
  print "I am doing something for SIG $sig....\n"; 
}