#define CHILD_GID 1000

void parentHandler(int sig) {
  //send SIGHUP to all members of CHILD_GID

  killpg(CHILD_GID, SIGHUP);
}

void childHandler(int sig) {
  printf("SIGHUP received\n");
  exit(0);
}

int main(void) {


//lots of code before this

//set hte parent''s signal handler

signal(SIGINT, parentHandler);

//spawn 3 children

for(int i = 0; i < 3; i++) {
  if(fork() == 0) {
    //set the group gid for the child

    setgid(CHILD_GID);
    //set the  child''s signal handler

    signal(SIGHUP, childHandler);
  }
}

//other code follows