After an error occurs, I call perror(), naturally. But I'm getting a segmentation fault when I do this or printf("error: %s\n", strerror(errno)); I have no idea what is happing.

  int fd;
  if((fd = open(FILENAME, O_RDONLY)) == -1) {
    perror("fbi");
    exit(1);
  }

  for(;;) {

    readed = read(fd, buffer, BUFSIZE);

    if(readed == 0)
      break;

    if(readed == -1) {
      perror("fbi"); // <- here's the error
      exit(1);
    }

How to fix this?