Pipes bug when spawning non-cygwin processes

[Takashi Yano]

On Fri, 21 Feb 2020 10:01:21 +0900
Takashi Yano wrote:
> On Thu, 20 Feb 2020 14:33:27 -0500
> Edward Lam wrote:
> > On Tue, Feb 18, 2020 at 2:43 PM Takashi Yano wrote:
> > > Could you please provide a simple test case?
> > 
> > Here you go:
> > 
> > // pipes.cpp
> > //
> > // Compile in a  Visual Studio x64 Native Tools Command Prompt:
> > //     cl pipes.cpp /link /subsystem:windows
> > //
> > // Run from inside a Cygwin shell, the produced pipes.exe
> > //
> > 
> > #include <stdio.h>
> > #include <windows.h>
> > 
> > INT WinMain(HINSTANCE, HINSTANCE, PSTR, INT)
> > {
> >     printf("This message used to show up in mintty cygwin v.2.11.2 shell!
> > or from ssh session\n");
> >     return 0;
> > }
> > // end of pipes.cpp
> 
> Thanks for the test case. Indeed, this works upto cygwin 3.0.7,
> and does not work in cygwin 3.1.0 or later.
> 
> However, I wonder what platform is your program for. This test
> case does not work also in native windows command prompt.
> Your test case works only in old cygwin pty.
> 
> If you want to make a program which works in cygwin pty, you
> can use cygwin g++ like:
> g++ -mwindows pipes.cpp -o pipes
> The binary built by above command works in cygwin pty, but does
> not work in cygwin console (cygwin in command prompt) even with
> cygwin 3.0.7.
> 
> If you want to make a program which works with windows console,
> you should change the code like:
> 
> INT WinMain(HINSTANCE, HINSTANCE, PSTR, INT)
> {
>     if (!AttachConsole(ATTACH_PARENT_PROCESS)) AllocConsole();
>     freopen("CONOUT$", "w", stdout);
>     printf("This message used to show up in mintty cygwin v.2.11.2 shell! or from ssh session\n");
>     return 0;
> }

Or just compile with:
cl pipes.cpp /link /subsystem:console

-- 
Takashi Yano <takashi.yano@nifty.ne.jp>

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