descriptor « windows « C File Q&A

1. Duplicate file descriptor with its own file offset    stackoverflow.com

How can one create a new file descriptor from an existing file descriptor such that the new descriptor does not share the same internal file structure/entry in the file table? Specifically ...

2. Detect NUL file descriptor (isatty is bogus)    stackoverflow.com

The following C file gives a bogus result when NUL is piped to it:

int main()
{
  printf("_isatty = %d\n", _isatty(0));
}

C:\Users\Edward\Dev\nulltest> test.exe < NUL
_isatty = 64

3. On Windows/mingw, what is the equivalent of `fcntl(fd, F_GETFL) | O_ACCMODE`?    stackoverflow.com

I am compiling a program on Windows with Mingw. How can I get the access mode for an open file descriptor?

4. Is there way to make file descriptor non blocking in windows?    stackoverflow.com

I want to port my code from linux to windows. It is something like this:

void SetNonBlocking( int filehandle )
{
    int fhFlags;

    fhFlags = fcntl(filehandle,F_GETFL);
  ...