c - 此代码是否会导致从父进程成功创建两个子进程？

Question

这是我的 C 代码，用于从父进程创建两个子进程。 这样能创建成功吗？我当前的输出是:

You are in parent process whose id is 29509
you are in child process 1 and your parent id is 29509
You are in parent process whose id is 29511
you are in child process 2 and your parent id is 29509

为什么在我输出的第三行中父 ID 不同？？

    #include<stdio.h>
    #include<unistd.h>
    int main(){
            pid_t child1,child2;
            int c,d,e;
            child1=fork();
            if(child1==0){
                    c=getppid();
                    printf("you are in child process 1 and your parent id is %d\n",c);

            }
            else{
                    child2=fork();
                    e=getpid();
                    printf("You are in parent process whose id is %d\n",e);
            }
            if(child2==0){
                    d=getppid();
                    printf("you are in child process 2 and your parent id is %d\n",d);
            }
    }

输出是

You are in parent process whose id is 29509
you are in child process 1 and your parent id is 29509
You are in parent process whose id is 29511
you are in child process 2 and your parent id is 29509 

Answer 1

在您的第二个fork 之后，父进程和第二个子进程都执行“父进程”printf。