Unix FD to Windows File Handles mapping.

[Bruno Albuquerque]

I am new to writing wine specific things so bear with me for a while. Is
there a header file that I can include to get access to those ntdll
functions (a cursory look only  resulted in me finding the associated c
file)? If not, do I have to use LoadLibrary() or some other trick?

Thanks again for all your help so far. It is much appreciated.



On Sun, Dec 22, 2019 at 8:04 AM Zebediah Figura <z.figura12 at gmail.com>
wrote:

>
>
> On 12/22/19 6:40 AM, Gabriel Ivăncescu wrote:
> > On 12/21/19 5:34 PM, Bruno Albuquerque wrote:
> >> Thanks. That led me to the init_user_process_params() where it seems
> >> stdin/stdout/stderr are mapped to the running Windows program. I could
> >> not find any code that would do anything with other inherited opened
> fds
> >> and that led me to think that there is really no special handling and
> it
> >> somehow just happens to work with a winelib program (most
> likely because
> >> it has a bigger Linux surface to it).
> >>
> >> Based on this, I guess what I really want to know is:
> >>
> >> 1 - Does a non-winelib Windows program have access to opened fds
> >> inherited during a fork/exec of Wine?
> >> 2 - If so, is there a way to actually use those fds in the Windows
> program?
> >>
> >>
> >
> > Hi Bruno,
> >
> > I'm not sure if this is feasible to you, but keep in mind that "Windows
> > programs" ran under Wine are technically still running on Linux. So you
> > still have access to Linux syscalls (but not libraries, unless you load
> > them manually, which is not worth it).
> >
> > One possible hack to do this in a "generic" way would be:
> >
> > 1) Use an exception handler in your app.
> >
> > 2) Call the 'uname' system call to make sure the returned sysname is
> > 'Linux'. If the syscall results in an exception, then it's obviously not
> > running on Linux (it could be running on Windows), so do the necessary
> > thing there.
>
> There's also wine_get_host_version(), exported from ntdll, which would
> probably be easier.
>
> In order to get access to file descriptors in the first place, you can
> use the counterpart wine_server_handle_to_fd() [also exported from ntdll].
>
> >
> > 3) If it's 'Linux' then mark it so and simply use Linux syscalls to use
> > the fd and read or write to it. You can use inline assembly for this
> > purpose.
> >
> > If your program is not intended to run on non-Linux environments then
> > you can skip the first two steps. I realize it's a hack but without
> > winelib I don't think there's much else you can do.
> >
>
>
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