Re: getch() waits even nodelay is set

[Fangtu Qiu]

RedHat 7.3 uses gcc 2.96-110.

More testing:

Same code works fine on RedHat 7.2 with both gcc and g++. The binary 
compiled by g++ on RedHat 7.2 didn't work on 7.3.

Replacing ncurses 5.2-26 on RedHat 7.3 with version 5.2-12 from 7.2 
distribution corrects the problem.

I checked the document of stream I/O. It says one should not mix with 
stdio. But there is no stream I/O routine in the code I provided. This 
confuses me.

-Fangtu

On Sat, 20 Jul 2002, Thomas Dickey wrote:

> On Fri, Jul 19, 2002 at 11:53:34PM -0400, Fangtu Qiu wrote:
> > Hi, Thomas,
> > 
> > The problem appears after I upgraded my linux to RedHat 7.3 from RedHat 
> > 7.2. If you only have 7.2, you may not be able to see the problem.
> 
> I generally do re-installs (upgrades aren't reliable enough for my tastes).
> If 7.4 doesn't come along shortly, I'll probably look into 7.3 in a month
> or so.  (I've a 6.2 and 7.2, for testing).
>  
> > The following code will wait if compiled with g++. It won't wait if 
> > compiled by gcc.
> 
> g++ is a different case - its support for stdio and termio is philosophically
> opposed to allowing mixes of C and C++ code.  So natural combinations fail to
> work because someone decides that because the standard does not assert that 
> the
> facilities _must_ work together, then they're free to implement things in a 
> way
> that prevents them from doing so.
> 
> Usually (this isn't an faq, comes up 1-2 times a year) the problem surfaces
> when someone tries mixing stream I/O with stdio.
>  
> However...
> 
> It's not clear where the problem lies.  Some more information might help
> guess.  I don't think it's purely the compiler - I just now tweaked things
> to make all of ncurses build with g++ using the gcc 3.1 distribution. That
> (running on Slackware 7.1 with glibc 2.1.3) doesn't hang.  (I modified the
> config.status after running configure - autoconf 2.52's check for libstdc
> blew up - and also added an extern-C ifdef to nc_alloc.h).  iirc, Redhat
> 7.2 uses one of the 2.96 series.  Does 7.3 also?
> 
> > =====  cut here =====
> > 
> > #include <curses.h>
> > 
> > int main()
> > {
> >         WINDOW * pwin = initscr();
> >         nodelay(pwin, TRUE);
> >         getch();
> >         endwin();
> > }
> > 
> > ===== cut here =====
> > 
> > Regards,
> > 
> > Fangtu Qiu
> > 
> > 
> > On Fri, 19 Jul 2002, Thomas E. Dickey wrote:
> > 
> > > On Fri, 19 Jul 2002, Fangtu Qiu wrote:
> > > 
> > > > Bug description:
> > > >
> > > > The getch() function waits for the input when nodelay is set.
> > > >
> > > > Bug or new behaviour? Or I missed something?
> > > 
> > > I'm not sure what you are seeing - I use nodelay in several of the test
> > > programs.  (Will check later, in case it's a Redhat bug - I have a 7.2
> > > for testing those).
> > > 
> > > > Platform tested: RedHat linux 7.3
> > > >
> > > > ncurses version: 5.2-26 from RedHat 7.3 (getch WAITS when nodelay is 
> > > > set)
> > > > ncurses version: 5.2-28 from RawHide (getch WAITS when nodelay is set)
> > > > ncurses version: 5.2-20020713 from ftp://dickey.his.com (getch WAITS 
> > > > when
> > > > nodelay is set)
> > > >
> > > > ncurses version: 5.2-12 from RedHat 7.2 (getch doesn't wait when nodelay
> > > > is set)
> > > >
> > > > -Fangtu
> > > >
> > > >
> > > >
> > > > _______________________________________________
> > > > Bug-ncurses mailing list
> > > > address@hidden
> > > > http://mail.gnu.org/mailman/listinfo/bug-ncurses
> > > >
> > > 
> > > 
> 
>