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


int main(int argc, char **argv)
{
  pid_t pid;

  pid = fork();

  if (pid < 0) {
    fprintf(stderr,"Error: can't fork a process\n");
    perror("fork()");
    exit(1);

  } else if (pid) { // I am the parent and I do whatever

    while(1) ; // infinite loop

  } else {  // I am the child
    pid_t pid;

    fprintf(stderr,"I am the child and my pid is: %d\n",getpid());

    // forking a grandchild
    pid = fork();

    if (pid < 0) {
      fprintf(stderr,"Error: can't fork a process\n");
      perror("fork()");
      exit(1);
    } 

    if (!pid) {  // grandchild
      fprintf(stderr,"I am the grandchild and my parent's pid is: %d\n",
 		getppid());
      sleep(2);
      fprintf(stderr,"I am the grandchild and my parent's pid is: %d\n",
 		getppid());
      exit(0);
    } else { // child
      sleep(1);
      exit(0);
    }
  }
}