signal             21 gameio.c           signal(SIGHUP, signal_handler);
signal             22 gameio.c           signal(SIGINT, signal_handler);
signal             23 gameio.c           signal(SIGILL, signal_handler);
signal             24 gameio.c           signal(SIGTERM,signal_handler);
signal             25 gameio.c           signal(SIGQUIT,signal_handler);