diff --git a/ap/libc/glibc/glibc-2.23/libio/iosetbuffer.c b/ap/libc/glibc/glibc-2.23/libio/iosetbuffer.c
new file mode 100644
index 0000000..fcdb125
--- /dev/null
+++ b/ap/libc/glibc/glibc-2.23/libio/iosetbuffer.c
@@ -0,0 +1,47 @@
+/* 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"
+
+void
+_IO_setbuffer (_IO_FILE *fp, char *buf, _IO_size_t size)
+{
+  CHECK_FILE (fp, );
+  _IO_acquire_lock (fp);
+  fp->_flags &= ~_IO_LINE_BUF;
+  if (!buf)
+    size = 0;
+  (void) _IO_SETBUF (fp, buf, size);
+  if (_IO_vtable_offset (fp) == 0 && fp->_mode == 0 && _IO_CHECK_WIDE (fp))
+    /* We also have to set the buffer using the wide char function.  */
+    (void) _IO_WSETBUF (fp, buf, size);
+  _IO_release_lock (fp);
+}
+libc_hidden_def (_IO_setbuffer)
+
+#ifdef weak_alias
+weak_alias (_IO_setbuffer, setbuffer)
+#endif