new file mode 100644
--- /dev/null
+++ b/m4/fpending.m4
@@ -0,0 +1,70 @@
+#serial 1
+
+dnl From Jim Meyering
+dnl Using code from emacs, based on suggestions from Paul Eggert
+dnl and Ulrich Drepper.
+
+AC_DEFUN(jm_FUNC_FPENDING,
+[
+  AC_CHECK_HEADERS(stdio_ext.h)
+  AC_FEPLACE_FUNCS([__fpending])
+  if test $ac_cv_func___fpending = no; then
+    AC_REPLACE_FUNCS(__fpending)
+    AC_CACHE_CHECK(
+	      [how to determine the number of pending output bytes on a stream],
+		   ac_cv_sys_pending_output_n_bytes,
+      [
+        fp_save_DEFS=$DEFS
+	for ac_expr in 						\
+								\
+	  '# glibc2'						\
+	  'fp->_IO_write_ptr - fp->_IO_write_base' 		\
+								\
+	  '# traditional Unix'					\
+	  'fp->_ptr - fp->_base' 				\
+								\
+	  '# BSD'						\
+	  'fp->_p - fp->_bf._base' 				\
+								\
+	  '# SCO, Unixware'					\
+	  'fp->__ptr - fp->__base' 				\
+								\
+	  '# old glibc?'					\
+	  'fp->__bufp - fp->__buffer' 				\
+								\
+	  '# old glibc iostream?'				\
+	  'fp->_pptr - fp->_pbase' 				\
+								\
+	  '# VMS'						\
+	  '(*fp)->_ptr - (*fp)->_base' 				\
+								\
+	  '# e.g., DGUX R4.11; the info is not available'	\
+	  1 							\
+	  ; do
+	    # Skip each embedded comment.
+	    case "$ac_expr" in '#'*) continue;; esac
+'
+
+	    DEFS="$DEFS -DPENDING_OUTPUT_N_BYTES=$ac_expr"
+	    AC_TRY_COMPILE(
+	      [#include <stdio.h>
+	      ],
+	      [long unsigned int n = $ac_expr;],
+	      fp_done=yes
+            )
+	    DEFS=$fp_save_DEFS
+	    test "$fp_done" = yes && break
+	done
+	AC_DEFINE_UNQUOTED(PENDING_OUTPUT_N_BYTES, $ac_expr,
+	  [the number of pending output bytes on stream `fp'])
+      ])
+  fi
+
+
+
+
+  if test $fu_cv_sys_struct_timespec = yes; then
+    AC_DEFINE_UNQUOTED(HAVE_STRUCT_TIMESPEC, 1,
+		       [Define if struct timespec is declared in <time.h>. ])
+  fi
+])