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

char buf[1024];
int main() {
  char *s;
  int fds[2];
  int size;

  s = "hello world\n";
  pipe(fds);
  if (fork() == 0) {
    write(fds[1], s, 12); close(fds[1]);
    size = read(fds[0], buf, 12);
    printf("child process, csize = %d, cbuf = %s\n", size, buf);
    sleep (5);
    exit(0);
  }
  close(fds[1]);
  size = read(fds[0], buf, 12);
  printf("parent process, pbuf = %s, psize = %d\n", buf, size);
}