C++ do_child函数代码示例

int main(int argc, char **argv) {
  int forkres, i;

  /* Get subtest number */
  if(argc != 2) {
    printf("Usage: %s subtest_no\n", argv[0]);
    exit(-2);
  } else if(sscanf(argv[1], "%d", &subtest) != 1) {
    printf("Usage: %s subtest_no\n", argv[0]);
    exit(-2);
  }
  
  /* Fork off a bunch of children */
  for(i = 0; i < NUMCHILDREN; i++) {
      forkres = fork();
      if(forkres == 0) do_child(i);
      else if(forkres < 0) {
	perror("Unable to fork");
	exit(-1);
      }
  }
  /* do_child always calls exit(), so when we end up here, we're the parent. */
  do_parent();

  exit(-2); /* We're not supposed to get here. Both do_* routines should exit.*/
}

int main(int ac, char **av)
{
	pid_t pid;
	int status;

	tst_parse_opts(ac, av, options, NULL);

	if (sflag)
		hugepages = SAFE_STRTOL(NULL, nr_opt, 0, LONG_MAX);

	setup();

	switch (pid = fork()) {
	case -1:
		tst_brkm(TBROK | TERRNO, cleanup, "fork");
	case 0:
		/* set  the user ID of the child to the non root user */
		if (setuid(ltp_uid) == -1)
			tst_brkm(TBROK | TERRNO, cleanup, "setuid");
		do_child();
		tst_exit();
	default:
		if (waitpid(pid, &status, 0) == -1)
			tst_brkm(TBROK | TERRNO, cleanup, "waitpid");
	}
	cleanup();
	tst_exit();
}

int main(void)
{
  pid_t r;
  subtest = 1;

#ifdef __GNUC__
	printf("Test 52 (GCC) ");
#else
	printf("Test 52 (ACK) ");
#endif
  fflush(stdout);

  if (pipe(pipefdc) == -1) err(1);
  if (pipe(pipefdp) == -1) err(2);

  r = fork();
  if(r < 0) {
	err(3);
  } else if(r == 0) {
	/* Child */
	do_child();
  } else {
	/* Parent */
	do_parent();
  }

  return(0); /* Never reached */

}

int main(int argc, char **argv) {
  int forkres;

  /* Get subtest number */
  if(argc != 2) {
    printf("Usage: %s subtest_no\n", argv[0]);
    exit(-2);
  } else if(sscanf(argv[1], "%d", &subtest) != 1) {
    printf("Usage: %s subtest_no\n", argv[0]);
    exit(-2);
  }
  
  /* Set up anonymous pipe */
  if(pipe(fd_ap) < 0) {
    perror("Could not create anonymous pipe");
    exit(-1);
  }

  forkres = fork();
  if(forkres == 0) do_child();
  else if(forkres > 0)  do_parent(forkres);
  else { /* Fork failed */
    perror("Unable to fork");
    exit(-1);
  }

  exit(-2); /* We're not supposed to get here. Both do_* routines should exit*/
  
}

pid_t
start_server(struct sockaddr_in *ssin, struct sockaddr_un *ssun)
{
    pid_t pid;

    sfd = socket(PF_INET, SOCK_STREAM, 0);
    if (sfd < 0)
	return -1;
    if (bind(sfd, (struct sockaddr *)ssin, sizeof(*ssin)) < 0)
	return -1;
    if (listen(sfd, 10) < 0)
	return -1;

    /* set up UNIX-domain socket */
    ufd = socket(PF_UNIX, SOCK_STREAM, 0);
    if (ufd < 0)
	return -1;
    if (bind(ufd, (struct sockaddr *)ssun, sizeof(*ssun)))
	return -1;
    if (listen(ufd, 10) < 0)
	return -1;

    switch (pid = fork()) {
    case 0:		/* child */
	do_child();
	break;
    case -1:			/* fall through */
    default:			/* parent */
	(void)close(sfd);
	return pid;
    }

    return -1;
}

int main(int ac, char **av)
{
	int pid;
	void do_child(void);

	tst_parse_opts(ac, av, NULL, NULL);

	setup();		/* global setup */

	if ((pid = FORK_OR_VFORK()) == -1) {
		tst_brkm(TBROK, cleanup, "could not fork");
	}

	if (pid == 0) {		/* child */
		/* set  the user ID of the child to the non root user */
		if (setuid(ltp_uid) == -1) {
			tst_resm(TBROK, "setuid() failed");
			exit(1);
		}

		do_child();
	} else {
		/* wait for the child to return */
		SAFE_WAITPID(cleanup, pid, NULL, 0);

		/* if it exists, remove the shared memory resource */
		rm_shm(shm_id_1);

		tst_rmdir();
	}

	cleanup();
	tst_exit();
}

pid_t
start_server(struct sockaddr_in *sin0)
{
    struct sockaddr_in sin1 = *sin0;
    pid_t pid;

    sfd = socket(PF_INET, SOCK_STREAM, 0);
    if (sfd < 0)
	return -1;
    if (bind(sfd, (struct sockaddr *)&sin1, sizeof(sin1)) < 0)
	return -1;
    if (listen(sfd, 10) < 0)
	return -1;

    switch (pid = fork()) {
    case 0:		/* child */
	do_child();
	break;
    case -1:			/* fall through */
    default:			/* parent */
	(void)close(sfd);
	return pid;
    }

    return -1;
}

int main(int ac, char **av)
{
	const char *msg;
	int status;
	pid_t pid;

	msg = parse_opts(ac, av, options, &help);
	if (msg != NULL)
		tst_brkm(TBROK, NULL, "OPTION PARSING ERROR - %s", msg);

	if (sflag)
		hugepages = SAFE_STRTOL(NULL, nr_opt, 0, LONG_MAX);

	setup();

	switch (pid = fork()) {
	case -1:
		tst_brkm(TBROK | TERRNO, cleanup, "fork");
	case 0:
		if (setuid(ltp_uid) == -1)
			tst_brkm(TBROK | TERRNO, cleanup, "setuid");
		do_child();
		tst_exit();
	default:
		if (waitpid(pid, &status, 0) == -1)
			tst_brkm(TBROK | TERRNO, cleanup, "waitpid");
	}
	cleanup();
	tst_exit();
}

/*
 * do_child_uclinux() - capture signals again, then run do_child()
 */
void
do_child_uclinux()
{
	tst_sig(FORK, sighandler, cleanup);

	do_child();
}

int main(int argc, char **argv) {
    int forkres;
    int master, slave;

    /* Get subtest number */
    if(argc != 2) {
        printf("Usage: %s subtest_no\n", argv[0]);
        exit(-1);
    } else if(sscanf(argv[1], "%d", &subtest) != 1) {
        printf("Usage: %s subtest_no\n", argv[0]);
        exit(-1);
    }

    open_terminal(&master, &slave);

    forkres = fork();
    if(forkres == 0) do_child(master);
    else if(forkres > 0)  do_parent(forkres, slave);
    else { /* Fork failed */
        perror("Unable to fork");
        exit(-1);
    }

    exit(-2); /* We're not supposed to get here. Both do_* routines should exit*/

}

int main(void)
{
	int sp[2];

	if (-1 == socketpair(AF_UNIX, SOCK_STREAM, 0, sp)) {
		fprintf(stderr, "socketpair(): %s\n", strerror(errno));
		exit(EXIT_FAILURE);
	}

	switch (fork()) {
	case -1:
		fprintf(stderr, "fork(): %s\n", strerror(errno));
		exit(EXIT_FAILURE);
	case 0:
		close(sp[0]);
		do_child(sp[1]);
		break;
	default:
		close(sp[1]);
		do_parent(sp[0]);
		break;
	}

	exit(EXIT_SUCCESS);
}

int main(int ac, char **av)
{
	int lc;
	int i;

	tst_parse_opts(ac, av, NULL, NULL);
	setup();

	for (lc = 0; TEST_LOOPING(lc); lc++) {
		tst_count = 0;

		for (i = 0; i < TST_TOTAL; ++i) {
			pid2 = tst_fork();

			if (pid2 == -1)
				tst_brkm(TBROK, cleanup, "fork failed");

			if (!pid2)
				do_child(&test_cases[i]);
			else
				tst_record_childstatus(cleanup, pid2);
			tst_count++;
		}
	}

	cleanup();
	tst_exit();
}

int main(int ac, char **av)
{
	int lc;				/* loop counter */
	char *msg;			/* message returned from parse_opts */

	/* parse standard options */
	if ((msg = parse_opts(ac, av, (option_t *)NULL, NULL)) != (char *)NULL){
		tst_brkm(TBROK, cleanup, "OPTION PARSING ERROR - %s", msg);
	}

#ifdef UCLINUX
	maybe_run_child(&do_child_uclinux, "d", &msg_q_1);
#endif

	setup();			/* global setup */

	/* The following loop checks looping state if -i option given */

	for (lc = 0; TEST_LOOPING(lc); lc++) {
		/* reset Tst_count in case we are looping */
		Tst_count = 0;

		/*
		 * fork a child that will attempt to read a non-existent
		 * message from the queue
		 */
		if ((c_pid = FORK_OR_VFORK()) == -1) {
			tst_brkm(TBROK, cleanup, "could not fork");
		}

		if (c_pid == 0) {		/* child */
			/*
			 * Attempt to read a message without IPC_NOWAIT.
			 * With no message to read, the child sleeps.
			 */
#ifdef UCLINUX
			if (self_exec(av[0], "d", msg_q_1) < 0) {
				tst_brkm(TBROK, cleanup, "could not self_exec");
			}
#else
			do_child();
#endif
		} else {			/* parent */
			usleep(250000);

			/* send a signal that must be caught to the child */
			if (kill(c_pid, SIGHUP) == -1) {
				tst_brkm(TBROK, cleanup, "kill failed");
			}

			waitpid(c_pid, NULL, 0);
		}
	}

	cleanup();

	/*NOTREACHED*/
	return(0);
}

/*
 * do_child_uclinux() - as above, but mallocs rdbuf first
 */
void do_child_uclinux()
{
	if ((rdbuf = (char *)malloc(szcharbuf)) == (char *)0) {
		tst_brkm(TBROK, cleanup, "malloc of rdbuf failed");
	 }

	do_child();
}

/*
 * do_child_uclinux() - as above, but mallocs rdbuf first
 */
void do_child_uclinux(void)
{
	if ((rdbuf = malloc(szcharbuf)) == NULL) {
		tst_brkm(TBROK, cleanup, "malloc of rdbuf failed");
	}

	do_child();
}