// Start of tuning.h

static char* load_tuning_file(const char *fname,
                              void *cfg,
                              int (*set_size)(void*, const char*, size_t)) {
  const int max_line_len = 1024;
  char* line = malloc(max_line_len);

  FILE *f = fopen(fname, "r");

  if (f == NULL) {
    snprintf(line, max_line_len, "Cannot open file: %s", strerror(errno));
    return line;
  }

  int lineno = 0;
  while (fgets(line, max_line_len, f) != NULL) {
    lineno++;
    char *eql = strstr(line, "=");
    if (eql) {
      *eql = 0;
      int value = atoi(eql+1);
      if (set_size(cfg, line, value) != 0) {
        strncpy(eql+1, line, max_line_len-strlen(line)-1);
        snprintf(line, max_line_len, "Unknown name '%s' on line %d.", eql+1, lineno);
        return line;
      }
    } else {
      snprintf(line, max_line_len, "Invalid line %d (must be of form 'name=int').",
               lineno);
      return line;
    }
  }

  free(line);

  return NULL;
}

// End of tuning.h