How do I get the file HANDLE from the fopen FILE structure?

Question

The fopen function returns a pointer to a FILE structure,

Answer 1

Use _fileno followed by _get_osfhandle. Don't forget to _close it when you are done.

EDIT: it's not clear to me that _get_osfhandle is supported on WinCE. However the docs for WinCE _fileno say it returns a "file handle" rather than "descriptor". YMMV but this suggests that you can maybe just use _fileno return value directly as a handle on WinCE.

EDIT: #2 That theory is supported by this person's experience.

"If you take a look at the header files that I posted to the list on Jan 29 you can see how I handled the file creation/handle problem. I didn't have to replace all FILE* items with HANDLEs. See the following snippet from fileio.cpp:

#ifndef q4_WCE

  FlushFileBuffers((HANDLE) _get_osfhandle(_fileno(_file)));
  HANDLE h = ::CreateFileMapping((HANDLE)
_get_osfhandle(_fileno(_file)),
                        0, PAGE_READONLY, 0, len, 0);
#else

  FlushFileBuffers((HANDLE) _fileno(_file));
  HANDLE h = ::CreateFileMapping((HANDLE) _fileno(_file),
                    0, PAGE_READONLY, 0, len, 0);
#endif //q4_WCE

It turns out that _fileno returns a handle. You just have to cast it."

Answer 2

For C, try this

HANDLE foo = (HANDLE)_get_osfhandle(fileno(fopen("bar.txt", "w")));

Answer 3

On Linux, there's the int fileno(FILE *); function that returns the file descriptor (the one that was returned by the low-level open function) from the FILE*.

I don't know if it applies to Windows and returns the HANDLE though?