$SIG{INT} = sub {syswrite(STDERR, "$$:\tChild has signaled.\n", 27);
};

$parent = $$;
print "$$:\tI am the parent.\n";

unless($pid = fork){
  print "$$:\tI am the child.\n";
  print "$$:\tSending SIGINT to $parent.\n";
  kill INT, $parent;
  exit;
}

print "$$:\tWaiting for the child to signal.\n";
print "." for(1..100);
print "Did I catch it?";