unless (fork) { # this is the child
    unless (fork) { # this is the child's child
	sleep 1 until getppid == 1;
	_L_O_N_G_O_P_E_R_A_T_I_O_N;
	exit 0;
    }
    # first child exits quickly
    exit 0;
}
wait; # parent reaps first child quickly

# or...

fork && exit;
setpgrp(0,$$);
