The fdopen test is bogus for a lot of reasons:

* "if !" is a bashism.
* The test tests the wrong things, really.

Use the new gnumeric test instead.



AC_MSG_CHECKING([whether to -D_POSIX_SOURCE for the fdopen prototype])
need_posix=no
echo '#include <stdio.h>' > conftest.h
if ! $CPP $CFLAGS conftest.h | grep '\<fdopen\>' > /dev/null ; then
	if $CPP $CFLAGS -D_POSIX_SOURCE conftest.h | grep '\<fdopen\>' > /dev/null
; then
		need_posix=yes
	fi
fi
AC_MSG_RESULT($need_posix)
rm -f conftest.h