string/strndup.c

   1 /* Copyright (C) 1996-2017 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 #ifdef HAVE_CONFIG_H
  19 # include "config.h"
  20 #endif
  21
  22 #include <stdio.h>
  23 #include <sys/types.h>
  24
  25 #if defined _LIBC || defined STDC_HEADERS
  26 # include <stdlib.h>
  27 # include <string.h>
  28 #else
  29 char *malloc ();
  30 #endif
  31
  32 #undef __strndup
  33 #undef strndup
  34
  35 #ifndef weak_alias
  36 # define __strndup strndup
  37 #endif
  38
  39 char *
  40 __strndup (const char *s, size_t n)
  41 {
  42   size_t len = __strnlen (s, n);
  43   char *new = (char *) malloc (len + 1);
  44
  45   if (new == NULL)
  46     return NULL;
  47
  48   new[len] = '\0';
  49   return (char *) memcpy (new, s, len);
  50 }
  51 #ifdef libc_hidden_def
  52 libc_hidden_def (__strndup)
  53 #endif
  54 #ifdef weak_alias
  55 weak_alias (__strndup, strndup)
  56 #endif