Question

I have the code:

wchar_t* temp = HeapAlloc(GetProcessHeap(), HEAP_ZERO_MEMORY, 1000 * sizeof(wchar_t));
wchar_t* temp2 = HeapAlloc(GetProcessHeap(), HEAP_ZERO_MEMORY, 1000 * sizeof(wchar_t));

GetTempPathW(1000, temp);

GetTempFileNameW(temp, L"vdr", GetCurrentProcessId(), temp2);

HeapFree(GetProcessHeap(), 0, temp2);

MessageBoxW(0,temp2,0,0);

It should make a file “vdrXXXX.tmp” with XXXX to be the processs id. But it returns strange things. Like unicode symbols and then part of the path. What I’m doing wrong?

Answer 1

You are freeing the memory before calling MessageBox().

In any case, there’s no need to use HeapAlloc(), just use malloc(). In fact, since GetTempFileName() has a maximum buffer size of MAX_PATH, it’s easiest to do this with stack allocated buffers.