[RESOLVED] _stprintf_s - Out of bound access

[hypheni]

  WORD iDay;
  TCHAR text[3];
   _stprintf_s(text, sizeof(text), _T("%d"), iDay);

The above piece of code giving some out of bound access error by some Static code analyser. The iDay is used for Date: ie: 1 - 31.

What should be the proper check to avoid this instead of using a CString in place or TCHAR. ?

[VictorN]

1. It should be _countof(text) instead of sizeof(text).
From MSDN:

sizeOfBuffer
Maximum number of characters to store.

2. WORD means unsigned short and its max value is 65535 which requires at least 6-character buffer for formatting (5 for digits + 1 for terminating NULL)

[hypheni]

Another quick solution would be

WORD iDay;
  TCHAR text[3];
  if(iDay <= 31)
    _stprintf_s(text, sizeof(text), _T("%d"), iDay);

Correct ?

[Paul McKenzie]

Another quick solution would be

No, that is not a solution. Read up on what a TCHAR is and what sizeof(TCHAR) gives you. That sizeof(text) isn't what you think it is.

Regards,

Paul McKenzie

[VictorN]

Correct ?

Still wrong!

I wonder why you are searching for "quick" solution instead of a correct and clean one!
What is wrong with MFC CString?
Why do you pass in a wrong value of the text buffer size?

[hypheni]

Okay, Correct I missed it.