printf(" SIGALRM = %d\n", sigismember(&mask, SIGALRM));
printf(" SIGINT = %d\n", sigismember(&mask, SIGINT));
printf(" SIGPROF = %d\n", sigismember(&mask, SIGPROF));
printf(" SIGALRM = %d\n", sigismember(&mask, SIGALRM));
printf(" SIGINT = %d\n", sigismember(&mask, SIGINT));
printf(" SIGPROF = %d\n", sigismember(&mask, SIGPROF));