+
+dnl *** Can we open files in binary mode? ***
+dnl
+AC_DEFUN(FPTOOLS_O_BINARY,
+[
+AC_REQUIRE([AC_PROG_CC])
+AC_MSG_CHECKING(whether we can open files in binary mode)
+AC_CACHE_VAL(fptools_cv_have_o_binary,
+[
+AC_LANG_SAVE
+AC_LANG_C
+AC_TRY_COMPILE(,
+[#ifdef HAVE_FCNTL_H
+#include <fcntl.h>
+#endif
+int x = O_BINARY;],
+fptools_cv_have_o_binary=yes,
+fptools_cv_have_o_binary=no)
+AC_LANG_RESTORE
+])
+AC_MSG_RESULT($fptools_cv_have_o_binary)
+if test "$fptools_cv_have_o_binary" = yes; then
+AC_DEFINE(HAVE_O_BINARY)
+fi
+])
+