Question

我必须编写一个程序来分叉3个子进程。

父进程只显示一次自己的PID信息，然后等待其子进程死掉。

在所有子进程终止后，主进程显示“主进程终止”，然后退出。

#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <unistd.h>
#include <sys/wait.h>

int main( int argc, char *argv[], char *env[] )
{
       pid_t my_pid, parent_pid, child_pid;
       int status;

    /* get and print my pid and my parent's pid. */

       my_pid = getpid();    parent_pid = getppid();
       printf("\n Parent: my pid is %d\n\n", my_pid);
       printf("Parent: my parent's pid is %d\n\n", parent_pid);

    /* print error message if fork() fails */
       if((child_pid = fork()) < 0 )
       {
          perror("fork failure");
          exit(1);
       }

    /* fork() == 0 for child process */

       if(child_pid == 0)
       {
          execl("/bin/date", "date", 0, 0);


          printf("This print is after execl() and should not have been executed if execl were successful! \n\n");

          _exit(1);
       }
    /*
     * parent process
     */
       else
       {
          printf("\nParent: I created a child process.\n\n");
          printf("Parent: my child's pid is: %d\n\n", child_pid);
          wait(&status); /* can use wait(NULL) since exit status
                            from child is not used. */
          printf("\n Parent: my child is dead. I am going to leave.\n \n ");
       }

       return 0;
}

Answer 1

对不起，我想写评论，但我没有足够的声誉。如果您想首先显示父pid。然后您可以在getpid()之前使用fork()，那么您可以使用waitpid进行收割。可能需要一个循环来收获所有这三个孩子

分叉多个孩子并等到孩子处理死亡

1 个答案: