#include <stdio.h>  
#include <unistd.h>   /* for fork, getpid */
#include <poll.h>     /* for the poll call */
#include <stdlib.h>   /* for rand*/


void sleepabit(pid_t mypid, int fd) {
    int  naptime;
    char abuf[200];
    int len;

    naptime = rand() % 5+1;
    len = sprintf(abuf,"%d is sleeping %d written to %d",mypid,naptime,fd);
/*    printf("%d is sleeping %d, written to %d\n",mypid,naptime,fd);  */
    write(fd,abuf,len);
    sleep(naptime);
}

main() {
   pid_t mypid,pid;
   int fd[2];
   char buf[200];
   int len;
   int i,j,count;
   struct pollfd lines[3];
   int pollres;


   for (i=0;i<3;i++){
       if (0 !=  pipe(fd) ) {
          printf("We had an error making the pipe\n");
          exit (-1);
       }

       if ( 0 == (pid = fork())) {
	  
          /* the child code for child i */

          mypid=getpid();
          printf("After the fork-child, I am %d\n",mypid); 

	  srand(mypid);

          close(fd[0]);
          sleep(1);
          for (j=0;j<3;j++) {
  	     sleepabit(mypid,fd[1]);
          }
/*	  printf("good by from pid %d\n",mypid); */
          exit(1);
       } else {
          mypid=getpid();
          printf("After the fork-parent, I am %d\n",mypid); 

	  close(fd[1]);
          lines[i].fd = fd[0];
          lines[i].events = POLLIN;
          lines[i].revents = 0;

       }
   }

   printf("Parent here:\n\n");

   count = 0;

   for (i=0;i<3;i++) {
       printf("We will check fd=%d\n",lines[i].fd);
   }

   printf("\n");
   while (count < 9) {
      pollres=poll(lines,3,-1);

      switch (pollres) {
	  case 0:
		printf("A timeout has occured, Not likely but here it is\n");
		break;
	  case -1:
		printf("An error has occured, exiting \n");
		exit(-1);
	  default:
		for (j=0;j<3;j++) {
		    if (lines[j].revents & POLLIN) {
                        count ++;
		        len = read(lines[j].fd,buf,sizeof(buf));
                        buf[len]=0;
		        printf("A child says: <<%s>>, event %d\n",buf,count);
			lines[j].revents=0;
			buf[0]=(char)0;
		    }
		    lines[j].revents=0;
		}
      }
   }
}