如何在C中设置变量类型char数组的格式说明符的宽度？

I have a function --

我有一个功能 -

bool DataPersistence::persistUIDetails (const char *data, quint32 len)
{
  TLOG_FUNC_ENTER();
  bool retVal = true;

  char tmp[len+1];
  strncpy (tmp, data, len);

  //Working on persisting the UI details.
  char type[len];
  char uiVers[len];
  char mwVers[len];
  char ts[len];

  sscanf (tmp, "%s %s %s %s", type, uiVers, mwVers, ts);

}
bool DataPer