// // fileno.cpp // // Copyright (c) Microsoft Corporation. All rights reserved. // // Defines _fileno(), which returns the lowio file handle for the given stdio // stream. // #include extern "C" int __cdecl _fileno(FILE* const public_stream) { __crt_stdio_stream const stream(public_stream); _VALIDATE_RETURN(stream.valid(), EINVAL, -1); return stream.lowio_handle(); }