🚀 go-pugleaf

Brian D. Schieber writes:
> I get this error when I try to bring up XBOARD-3.1.pl1 and gnuchessx
> on my SGI (IRIX 5.2):
...
> Received from first: FIONREAD: Operation not applicable
> Received from first: You probably have a non-ANSI <ioctl.h>; see README. -1 89 4 004667f
> xboard: Error: first chess program (gnuchessx) exited unexpectedly

This question is answered in the FAQ.  (The FAQ question should include 
running without the book.)

    --Tim

[25] I get an error message about FIONREAD when trying to build the GNU Chess
  book (or ECO database).  What do I do?

The message looks something like this:

> FIONREAD: Operation not supported on socket
> You probably have a non-ANSI <ioctl.h>; see README. -1 45 4004787f

If you are using gcc to compile, the solution to this error message is usually
to go to the GNU Chess Makefile, find the line that starts "CFLAGS=" (with no
# character in front of it), and append the flag "-traditional-cpp" to the end
of the line.  Then do

	rm dspcom*.o gnuan.o
	make
	make install

to rebuild gnuchess.

If you aren't using gcc, we don't really understand why this should happen,
but we do have a brute-force workaround: You can simply disable the gnuchess
feature that uses FIONREAD.  Find all the places in dspcom.c (and gnuan.c)
where the line "#ifdef FIONREAD" occurs.  Change each of them to "#ifdef
NOTDEF".  Then recompile gnuchess.

With this code disabled, if you tell gnuchess to think on your time ("hard"
mode), you will have to type ^C to make it stop thinking when you want to make
your move.  The current version of XBoard does this automatically, so
disabling the code has no effect on XBoard.