newlib/libc/string/wcsncat.c

   1 /*
   2 FUNCTION
   3         <<wcsncat>>---concatenate part of two wide-character strings
   4
   5 SYNOPSIS
   6         #include <wchar.h>
   7         wchar_t *wcsncat(wchar_t *__restrict <[s1]>,
   8                         const wchar_t *__restrict <[s2]>, size_t <[n]>);
   9
  10 DESCRIPTION
  11         The <<wcsncat>> function appends not more than <[n]> wide-character
  12         codes (a null wide-character code and wide-character codes that follow
  13         it are not appended) from the array pointed to by <[s2]> to the end of
  14         the wide-character string pointed to by <[s1]>. The initial
  15         wide-character code of <[s2]> overwrites the null wide-character code
  16         at the end of <[s1]>.
  17         A terminating null wide-character code is always appended to the result.
  18         If copying takes place between objects that overlap, the behaviour is
  19         undefined.
  20
  21 RETURNS
  22         The <<wcsncat>> function returns <[s1]>; no return value is reserved to
  23         indicate an error.
  24
  25 PORTABILITY
  26 <<wcsncat>> is ISO/IEC 9899/AMD1:1995 (ISO C).
  27
  28 No supporting OS subroutines are required.
  29 */
  30
  31 /*      $NetBSD: wcsncat.c,v 1.1 2000/12/23 23:14:36 itojun Exp $       */
  32
  33 /*-
  34  * Copyright (c)1999 Citrus Project,
  35  * All rights reserved.
  36  *
  37  * Redistribution and use in source and binary forms, with or without
  38  * modification, are permitted provided that the following conditions
  39  * are met:
  40  * 1. Redistributions of source code must retain the above copyright
  41  *    notice, this list of conditions and the following disclaimer.
  42  * 2. Redistributions in binary form must reproduce the above copyright
  43  *    notice, this list of conditions and the following disclaimer in the
  44  *    documentation and/or other materials provided with the distribution.
  45  *
  46  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  47  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  48  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  49  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  50  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  51  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  52  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  53  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  54  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  55  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  56  * SUCH DAMAGE.
  57  *
  58  *      citrus Id: wcsncat.c,v 1.1 1999/12/29 21:47:45 tshiozak Exp
  59  */
  60
  61 #include <_ansi.h>
  62 #include <wchar.h>
  63
  64 wchar_t *
  65 wcsncat (wchar_t *__restrict s1,
  66         const wchar_t *__restrict s2,
  67         size_t n)
  68 {
  69   wchar_t *p;
  70   wchar_t *q;
  71   const wchar_t *r;
  72
  73   p = s1;
  74   while (*p)
  75     p++;
  76   q = p;
  77   r = s2;
  78   while (*r && n)
  79     {
  80       *q++ = *r++;
  81       n--;
  82     }
  83   *q = '\0';
  84   return s1;
  85 }