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Re: Setup patch to keep test version if test version installed

On Feb  6 12:25, Achim Gratz wrote:
> Corinna Vinschen writes:
> > On Feb  5 22:57, Achim Gratz wrote:
> >> 
> >> Oh, and while you are so deep in the bowels of setup.exe, would it be
> >> possible to somehow fake a pty to shell scripts and a console to cmd so
> >> that the scripts run by setup.exe produce their output in line-buffered
> >> instead of fully buffered mode?
> >
> > Er... uh... *cough*... PTC?
> I was hoping you had an idea of how to do this.  I'm coming up empty.
> > For Cygwin processes this would require to duplicate lots of the pty
> > code from Cygwin to Setup.  For native commands it might be enough to
> > play with the process creation flags in the call to CreateProcess, but
> > that might lead to a flickering taskbar entry for a hidden console.
> I've tried to look for recipes, but have not found any that look promising.
> I notice the lack of both unbuffer and stdbuf in Cygwin packagesâ

Unbuffer should be in the expect package, stdbuf in coreutils.  In both
cases I don't know why they are missing in Cygwin.

Yaakov?  Eric?

> IÂdon't think it's possible to ask another application to flush their
> buffers or is there?

If the application isn't prepared to do that (e.g. via signal), no.

> > The other problem is that the stdio handles are redirected to a file
> > and thus, even if you have a console or pty, the output from the command
> > will use fully buffered mode.
> >
> > The only way around that, afaics, is some sort of global setting (env
> > var?) for the buffering mode which is honored by native processes and
> > which may be read by the Cygwin DLL as well to enforce line buffering.
> > But I'm not aware such a setting exists.
> Doesn't sound appealing.  Maybe we just have to live with it.

Looks like it, sorry.


Corinna Vinschen                  Please, send mails regarding Cygwin to
Cygwin Maintainer                 cygwin AT cygwin DOT com
Red Hat

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