#include <fcntl.h>
#include <stdio.h>
#include <unistd.h>
int main(int argc, char *argv[]) {
  if (argc != 2) {
    fprintf(stderr, "Usage: ./opener [FILENAME]");
    return 1;
  }

  int fd = open(argv[1], O_RDWR | O_CREAT);
  if (fd == -1) {
    perror("Cannot open file");
    return 1;
  }
  close(fd);

  return 0;
}