our $zombies = 0; $SIG{CHLD} = sub { $zombies++ }; sub reaper { my $zombie; our %Kid_Status; # store each exit status $zombies = 0; while (($zombie = waitpid(-1, WNOHANG)) != -1) { $Kid_Status{$zombie} = $?; } } while (1) { reaper() if $zombies; ... }