Re: [GD-General] OT: Checking if any chars available on stdin under Windows

[Mark W. <ma...@aw...>]

Ok, the solution appears to be to check _eof(0); - If it returns -1, there's
nothing on stdin.

I *think* that's the answer you're looking for.

Mark Webster

> ----- Original Message ----- 
> From: "Colin Fahey" <cp...@ea...>
> To: <gam...@li...>
> Sent: Friday, April 23, 2004 3:31 PM
> Subject: [GD-General] OT: Checking if any chars available on stdin under
> Windows
>
>
> >
> > 2004 April 22nd
> > Friday
> >
> > Off-Topic question here...but I just spent an hour doing Google
> > searching and reading other online documentation, and I'm not
> > finding any answers to the following:
> >
> > QUESTION:  How can I check if stdin (standard input) has any
> > characters available for reading under WINDOWS (not Linux)?
> >
> > I thought (cin.rdbuf()->in_avail()) would be the cool hacked
> > solution -- but even after doing Sleep(1000), cin.sync_with_stdio(),
> > and wackier and wackier things to try to make "cin" up-to-date,
> > so to speak, the expression above ALWAYS yields zero, whether or
> > not there are characters available on the input stream.
> > (Compiled using Visual C++ 6.0 under Windows 2000)
> >
> > If I have a command line like the following:
> >
> >         testapp
> >
> > then the following code blocks indefinitely:
> >
> >         int c = cin.peek();
> >
> > but if the command line is as follows:
> >
> >         more textfile.txt | testapp
> >
> > then the application does not block.  But in both
> > cases (cin.rdbuf()->in_avail()) is zero.
> >
> > How can "testapp" in the two command line examples
> > above DETECT which scenario (piped input or not) is
> > involved?  That, I guess, is my real goal.  I want to
> > know if the command line lacks the piping from
> > another app, since this means I shouldn't wait
> > forever for stdin data.
> >
> > I'd be willing to use a Win32 function to solve this
> > problem, but if it is really tricky, like creating a
> > thread, or something nutty, then it's probably not
> > worth it.  Bleah, under Linux one can actually use
> > fnctl() to change stdin to non-blocking mode (but,
> > I assume, still buffered), which makes this problem
> > go away -- but no fnctl() under Windows.
> >
> > Anyhow, probably avoiding piping data through stdin
> > is the REAL solution to all of this mess, but that
> > decision is not mine to make.
> >
> > --- Colin
> >
> >
> >
> >
> > -------------------------------------------------------
> > This SF.net email is sponsored by: The Robotic Monkeys at ThinkGeek
> > For a limited time only, get FREE Ground shipping on all orders of $35
> > or more. Hurry up and shop folks, this offer expires April 30th!
> > http://www.thinkgeek.com/freeshipping/?cpg=12297
> > _______________________________________________
> > Gamedevlists-general mailing list
> > Gam...@li...
> > https://lists.sourceforge.net/lists/listinfo/gamedevlists-general
> > Archives:
> > http://sourceforge.net/mailarchive/forum.php?forum_id=557
> >
> >
>