#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/mman.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>

main(int argc, char *argv[])
{
  int s, *m;

  s = shm_open(argv[1], O_CREAT | O_RDWR, S_IRWXU | S_IRGRP | S_IROTH);

  if( s == -1 ){
    fprintf(stderr, "failed to open shared memory %s\n", argv[1]);
    exit(1);
  }

  m = mmap(0, sizeof(int), PROT_READ | PROT_WRITE, MAP_SHARED, s, 0);

  sleep( atoi(argv[2]) );
  *m = getpid();
  fprintf(stderr, "I'm %d, m is %d\n", getpid(), *m);

  fprintf(stderr, "sleeping...\n");
  sleep(5);
  fprintf(stderr, "I'm %d, m is %d\n", getpid(), *m);
}