debug/stpncpy_chk.c

   1 /* Copyright (C) 1993-2017 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, see
  16    <http://www.gnu.org/licenses/>.  */
  17
  18 /* This is almost copied from strncpy.c, written by Torbjorn Granlund.  */
  19
  20 #include <string.h>
  21
  22
  23 /* Copy no more than N characters of SRC to DEST, returning the address of
  24    the terminating '\0' in DEST, if any, or else DEST + N.  */
  25 char *
  26 __stpncpy_chk (char *dest, const char *src, size_t n, size_t destlen)
  27 {
  28   if (__builtin_expect (destlen < n, 0))
  29     __chk_fail ();
  30
  31   return __stpncpy (dest, src, n);
  32 }