Re: Stack getting corrupted

"Ketchup" <>
Fri, 12 Dec 2008 14:40:01 -0500
Giovanni, thanks. I am actually on VS.NET2002, so CString is out. Maybe I
can use std::string. I am assuming all I need is to include <string.h> for
that, right? I still would love to get this to work, even if it is just
for my understanding. I hate to just walk away from the problem, you know?

Here is the function I mentioned below. I am basically calling this
function like this:

info->sSubject = readStreamText(&statstg);

I reworked my code just in the last few lines of the function. I added the
following lines. I am still getting some junk in the strings, but not as
much. At least the actual text is still there. All I have done though,
is moved my structure members onto the heap from the stack. Now, I must
manually manage memory allocation, and I am sure I will create memory leaks
with this. I do delete the members elsewhere in the code, but this looks

sReturn = new char[dwValSize];
strncpy(sReturn, strData, dwValSize);
return sReturn;

All I have done is moved each one of these values onto the stack.

char* CmsgtestDlg::readStreamText(STATSTG* pStorage)
 CComPtr<IStream> pIStream;
 char strData[4096];
 strData[0] = 0;
 char* sReturn;

 hr = pIStorage->OpenStream(pStorage->pwcsName, 0, STGM_READ |
  throw hr;
  return false;
  DWORD dwRead = 0;
  DWORD dwValSize = 0;
  char buff = 0;
  //remove NULL characters between every character in the stream data
  while (((pIStream->Read(&buff, 1, &dwRead)) == S_OK) && (!bEOF))
   if (dwRead != 1)
    bEOF = TRUE;
   if (buff != 0)
    strData[dwValSize] = buff;
    dwValSize ++;
    buff = 0;
  strData[dwValSize] = 0;
  sReturn = new char[dwValSize];
  strncpy(sReturn, strData, dwValSize);
  return sReturn;

"Giovanni Dicanio" <> wrote in message

Ketchup wrote:

I noticed that when I set the members of the structure, all but the last
char* member gets corrupted on the stack. (Junk in the strings).


how can I avoid the issues I am experiencing. Is there a better way of
doing this? Can I avoid using MFC CString or std::string types here?

I think that your junk-strings problems are caused by incorrect string
management done by you.
It would be interesting to see some actual code you use to set the
strings, to give better help.

However, believe me: do yourself a favour and use some robust C++ string
class, be it std::string/wstring or CString/A/W.

Note that since VS.NET2003, CString is part of ATL and you can use this
class also without using the whole MFC.

Of course, you can write C++ code in a "C-like" way, using raw char*
pointers, but you have to pay much more attention, and considering that
you said that you are kind of C++ beginner, it is better to make your life
easier and use a robust C++ class.

My 2 cents,

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