QueryDosDevices

>>What kind of system does The Buffer growes larger, May be say larger then 8192 Bytes.

Strange question, oddly worded.
I think you are asking if it would be possible for this function to return more than 8192 bytes.  I don't know the answer to that, but my system returns 5552 bytes, so it could easily be possible.

Perhaps you are asking if there is a way to determine if you have gotten all of the information, after all, there is no error message if your buffer is too small.  Here is how I would do it:

Start with a small buffer and, in a loop, keep calling, using a larger and larger buffer until the return value does not change twice in a row:

char* pBuf;
DWORD nLastSize= -1;
for (int j=1000; j< 100000; j+= 1000 ) {
    pBuf=new char[j];
    DWORD nRet= QueryDosDevice( 0, szBuff, j );
    if (nRet == 0 ) break; // and handle the error
    if ( nLastSize == nRet ) {
        break; // all done
    }
    delete[] pBuf;  // get ready for next pass
    nLastSize == nRet;
}

Note: I did not test this code.

-- Dan

Hi Dan

I also thought twice or thrice how to frame the question but that was the best I could do that point in time

Actually I know that buffer could be more than 8192 bytes as I have seen system where this was 15000 bytes

As far as code was concerned my buffer was 8192 only for this system also. It actually wrote past the buffer successfully.

I came to know only at a latter point so it may happen that even when your size is 1000 in your code it will succeed and you wont get 0 as the return value as in my case.

I have here reworded the question
My question was not regarding the coding aspect it was rather theorytical .

"I wanted to know what actually governs NO of dosdevices on the system."