Mam ten kod, który ma stworzyć trzy procesy potomne i każdy wykona małą operację matematyczną. Następnie rodzic powinien użyć wyników z całego procesu potomnego ”i uzyskać ostateczną odpowiedź, ale nie mogę znaleźć sposobu, aby faktycznie odczytać wynik z dziecka w rodzicu. Czy istnieje sposób, aby to zrobić?

#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>

int main(void)
{
   int pid1, pid2, pid3, status;
   int a=1, b=2, c=5, d=4, e=6, f=3, g;
   int t1, t2, t3;

   printf("Hello World!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!\n");
   printf("Here I am  before use of forking\n");
   printf("I am the PARENT process and pid is : %d\n",getpid());

   pid1 = fork( );
   if (pid1 == 0)
   {      
    printf("\n\nHere I am just after child forking1\n");
    printf("I am the Child process and pid1 is :%d\n",getpid());      
    printf("My parent's pid is :%d\n",getppid());   
    t1 = a+b;
    printf("The answer for t1 is: %d\n", t1);       
    exit(0);
   }
   else
   {
    wait(&status);
        printf("\nHere I am just after parent forking1\n");
        printf("I am the Parent process and pid is: %d\n",getpid());
   }

   pid2 = fork( );
   if (pid2 == 0)
   {      
    printf("\n\nHere I am just after child forking2\n");
    printf("I am the Child process and pid2 is :%d\n",getpid());      
    printf("My parent's pid is :%d\n",getppid());   
    t2 = c+d;
    printf("The answer for t2 is: %d\n", t2);   
    exit(0);    
   }
   else
   {
    wait(&status);
        printf("\nHere I am just after parent forking2\n");
        printf("I am the Parent process and pid is: %d\n",getpid());
   }

   pid3 = fork( );
   if (pid3 == 0)
   {      
    printf("\n\nHere I am just after child forking3\n");
    printf("I am the Child process and pid3 is :%d\n",getpid());      
    printf("My parent's pid is :%d\n",getppid());   
    t3 = e/f;   
    printf("The answer for t3 is: %d\n", t3);   
    exit(0);
   }
   else
   {
    wait(&status);
        printf("\nHere I am just after parent forkingALL\n");
        printf("I am the Parent process and pid is: %d\n",getpid());
   }


   printf("\n\nThe final answer for t1 is: %d\n", t1);
   printf("The final answer for t2 is: %d\n", t2);
   printf("The final answer for t3 is: %d\n", t3);


   g = t1*t2-t3;
   printf("The final answer for g is: %d\n", g);
}