Question

我需要捕获CTRL + C并完成孩子，主要过程必须等到完成它的东西，然后程序必须完成。这是我的代码：

 void sigint_handler()
{
    /*do something*/
    printf("killing process %d\n",getpid());
    exit(0);
}

int main ()
{
  signal(SIGINT, sigint_handler);


  printf ("This is the parent. PID=%d\n",getpid ());

  int num_children = 4;

  int i;

  while (1){

  for (i=0; i<num_children ;i++){

   if (fork()==0){

    printf ("This is children %d\n",getpid()); 

    sleep(1);

    exit(0);

   }

  }

  //Rest Parent code
  sleep (1);

  printf ("This is the parent again %d, children should have finished\n",getpid());

  //Do stuff

  }

}

这是输出：

This is the parent. PID=19317
This is children 19318
This is children 19319
This is children 19321
This is children 19320
^Ckilling process 19321
killing process 19320
killing process 19317
killing process 19318
killing process 19319

我该如何处理？我不想杀死父母，只是孩子，提前谢谢你！

Answer 1

现在好多了：

    void sigint_handler()
    {
        /*do something*/
        printf("killing process %d\n",getpid());
        exit(0);
    }

    int main ()
    {
        int num_children = 4;
        int i, pid, status;
        printf ("This is the parent. PID=%d\n", getpid());

        while (1) {
            for (i = 0; i < num_children; i++) {
                if ((pid = fork()) == 0) {
                    signal(SIGINT, sigint_handler);
                    printf("This is children %d\n", getpid()); 
                    sleep(1);
                    exit(0);
                }
            }

            // Rest Parent code
            sleep (1);
            waitpid(pid, &status, 0); 
            printf ("This is the parent again %d, children should have finished\n", getpid());
        }
    }

它首先杀死了孩子，但waitpid似乎什么也没做，这是输出：

This is the parent. PID=20048
This is children 20049
This is children 20050
This is children 20051
This is children 20052
This is the parent again 20048, children should have finished
This is children 20053
This is children 20054
This is children 20056
This is children 20055
^Ckilling process 20056
killing process 20055
killing process 20053
killing process 20054

我想要的是在最后打印：这是20048的父母，孩子们应该完成然后完成。非常感谢你

Answer 2

在信号处理程序kill中，子进程仅处理。在父进程wait中，子进程在退出之前退出。

Answer 3

进行此更改，

  for (i=0; i<num_children ;i++){

   if (fork()==0){
signal(SIGINT, sigint_handler);
    printf ("This is children %d\n",getpid()); 

    sleep(1);

    exit(0);

   }

  }

仅对子进程满足if (fork()==0)条件，因此只会注册子进程以捕获信号并退出。

用C捕获信号并杀死所有孩子

3 个答案: