#include "kernel/types.h"
#include "user/user.h"

int main(int argc, char *argv[]) {
  int proc_f2s[2], proc_s2f[2];
  char buffer[8];
  pipe(proc_f2s);
  pipe(proc_s2f);

  if (fork() == 0) {
    read(proc_s2f[0], buffer, 4);
    printf("%d: received %s\n", getpid(), buffer);
    write(proc_f2s[1], "pong", strlen("pong"));
  } else {
    write(proc_s2f[1], "ping", strlen("ping"));
    read(proc_f2s[0], buffer, 4);
    printf("%d: received %s\n", getpid(), buffer);
  }

  exit(0);
}