Determine between socket and fd

Question

On unix everything is a file approach of function read(), write(), close() is not supported on Win32.

I

Answer 1

I suppose you can use select to query the status of a socket.

http://msdn.microsoft.com/en-us/library/ms740141%28VS.85%29.aspx

I would recommend grouping your file desc and sockets in a single struct. You can declare an enum to tell if the descriptor is a file or socket. I know this might not be as dynamic as you want, but generally when you create portable applications, its best to abstract those details away.

Example:

enum type { SOCKET, FILE };

typedef struct
{
    unsigned int id;
    type dataType;
} descriptor_t;

int close(descriptor_t sock)
{
#if WIN32
    if (sock.dataType == SOCKET)
        return closesocket(sock.id);
    else
        return _close(sock.id);
#else
    return close(sock.id);
#endif
}