Re: [PATCH 0/2] Return appropriate handle by _get_osfhandle() and GetStdHandle().

[Corinna Vinschen <corinna-cygwin@cygwin.com>]

On Mar 23 22:51, Takashi Yano wrote:
> On Tue, 23 Mar 2021 14:32:39 +0100
> Corinna Vinschen wrote:
> > On Mar 23 21:52, Takashi Yano via Cygwin-patches wrote:
> > > On Tue, 23 Mar 2021 21:42:06 +0900
> > > Takashi Yano wrote:
> > > > On Tue, 23 Mar 2021 21:32:12 +0900
> > > > Takashi Yano wrote:
> > > > > I try to check run.exe behaviour and noticed that
> > > > > run cmd.exe
> > > > > and
> > > > > run cat.exe
> > > > > does not work with cygwin 3.0.7 and 3.2.0 (TEST) while these
> > > > > work in 3.1.7.
> > > > 
> > > > In obove cases, cmd.exe and cat.exe is running in *hidden* console,
> > > > therefore nothing is shown. Right?
> > > 
> > > In what situation are
> > >   psi->cb = sizeof (STARTUPINFO);
> > >   psi->hStdInput  = GetStdHandle (STD_INPUT_HANDLE);
> > >   psi->hStdOutput = GetStdHandle (STD_OUTPUT_HANDLE);
> > >   psi->hStdError  = GetStdHandle (STD_ERROR_HANDLE);
> > > these handles used?
> > 
> > Hmm, trying to make sense from the code, I'd say, these handles are used
> > by default, unless run.exe is already attached to a console.  In  the
> > latter case, it calls CreateFile( "CONIN$") etc. to attach the new
> > process to that console.
> 
> "if (!bForceUsingPipes && bHaveConsole)"
> then handles are replaced by CreateFile("CONIN$", ...) etc.
> else replaced by pipe handle. If so, handles returned by
> GetStdHandle() are never used.
> 
> Do I overlook something?

AFAICS, bForceUsingPipes is always FALSE.  bHaveConsole is only TRUE if
run.exe is started from a console.  If run.exe is started from the GUI
(which was the primary idea, IIRC), bHaveConsole is FALSE.  So the
GetStdHandle() handles are used when started from thre GUI, isn't it?


Corinna