diff --git a/ap/libc/glibc/glibc-2.23/libio/setbuf.c b/ap/libc/glibc/glibc-2.23/libio/setbuf.c
new file mode 100644
index 0000000..ae8ca8a
--- /dev/null
+++ b/ap/libc/glibc/glibc-2.23/libio/setbuf.c
@@ -0,0 +1,34 @@
+/* Copyright (C) 1993-2016 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.
+
+   As a special exception, if you link the code in this file with
+   files compiled with a GNU compiler to produce an executable,
+   that does not cause the resulting executable to be covered by
+   the GNU Lesser General Public License.  This exception does not
+   however invalidate any other reasons why the executable file
+   might be covered by the GNU Lesser General Public License.
+   This exception applies to code released by its copyright holders
+   in files containing the exception.  */
+
+#include "libioP.h"
+#include "stdio.h"
+
+void
+setbuf (_IO_FILE *fp, char *buf)
+{
+  _IO_setbuffer (fp, buf, _IO_BUFSIZ);
+}