diff --git a/ap/libc/glibc/glibc-2.23/string/argz-append.c b/ap/libc/glibc/glibc-2.23/string/argz-append.c
new file mode 100644
index 0000000..e8d3812
--- /dev/null
+++ b/ap/libc/glibc/glibc-2.23/string/argz-append.c
@@ -0,0 +1,49 @@
+/* Routines for dealing with '\0' separated arg vectors.
+   Copyright (C) 1995-2016 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Written by Miles Bader <miles@gnu.ai.mit.edu>
+
+   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/>.  */
+
+#include <argz.h>
+#include <string.h>
+#include <stdlib.h>
+
+/* Add BUF, of length BUF_LEN to the argz vector in ARGZ & ARGZ_LEN.  */
+error_t
+__argz_append (char **argz, size_t *argz_len, const char *buf, size_t buf_len)
+{
+  size_t new_argz_len = *argz_len + buf_len;
+  char *new_argz = realloc (*argz, new_argz_len);
+  if (new_argz)
+    {
+      memcpy (new_argz + *argz_len, buf, buf_len);
+      *argz = new_argz;
+      *argz_len = new_argz_len;
+      return 0;
+    }
+  else
+    return ENOMEM;
+}
+weak_alias (__argz_append, argz_append)
+
+/* Add STR to the argz vector in ARGZ & ARGZ_LEN.  This should be moved into
+   argz.c in libshouldbelibc.  */
+error_t
+__argz_add (char **argz, size_t *argz_len, const char *str)
+{
+  return __argz_append (argz, argz_len, str, strlen (str) + 1);
+}
+weak_alias (__argz_add, argz_add)