How can I add message passing from parent to child using a pipe and if an interrupt from the keyboard (ctrl+c) is issued, then the program must have interrupt message?

How can I add message passing from parent to child using a pipe and if an interrupt from the keyboard (Ctrl+C) is issued, 

b)then the program must have interrupt message?

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

int main()
{
    int pid, pid1, pid2;
  
   
    pid = fork();
  
    
    if (pid == 0) {
  
        
        sleep(3);
  
       
        printf("child[1] --> pid = %d and ppid = %d\n",
               getpid(), getppid());
    }
  
    else {
        pid1 = fork();
        if (pid1 == 0) {
            sleep(2);
            printf("child[2] --> pid = %d and ppid = %d\n",
                   getpid(), getppid());
        }
        else {
            pid2 = fork();
            if (pid2 == 0) {
               
                printf("child[3] --> pid = %d and ppid = %d\n",
                       getpid(), getppid());
            }
  
           
            else {
                
                sleep(3);
                printf("parent --> pid = %d\n", getpid());
            }
        }
    }
    
    
    

    return 0;
}