toolchain/gcc/newlib/libc/string/wcslcat.c

   1 /*
   2 FUNCTION
   3         <<wcslcat>>---concatenate wide-character strings to specified length
   4
   5 ANSI_SYNOPSIS
   6         #include <wchar.h>
   7         size_t wcslcat(wchar_t *<[dst]>, const wchar_t *<[src]>, size_t <[siz]>);
   8
   9 TRAD_SYNOPSIS
  10         #include <wchar.h>
  11         size_t wcslcat(<[dst]>, <[src]>, <[siz]>
  12         wchar_t *<[dst]>;
  13         const wchar_t *<[src]>;
  14         size_t <[siz]>;
  15
  16 DESCRIPTION
  17         The <<wcslcat>> function appends wide-characters from <[src]> to
  18         end of the <[dst]> wide-character string so that the resultant
  19         wide-character string is not more than <[siz]> wide-characters
  20         including terminating null wide-character code.  A terminating
  21         null wide-character is always added unless <[siz]> is 0.  Thus,
  22         the maximum number of wide-characters that can be appended from
  23         <[src]> is <[siz]> - 1. If copying takes place between objects
  24         that overlap, the behaviour is undefined.
  25
  26 RETURNS
  27         Wide-character string length of initial <[dst]> plus the
  28         wide-character string length of <[src]> (does not include
  29         terminating null wide-characters).  If the return value is
  30         greater than or equal to <[siz]>, then truncation occurred and
  31         not all wide-characters from <[src]> were appended.
  32
  33 PORTABILITY
  34 No supporting OS subroutines are required.
  35 */
  36
  37 /*      $NetBSD: wcslcat.c,v 1.1 2000/12/23 23:14:36 itojun Exp $       */
  38 /*      from OpenBSD: strlcat.c,v 1.3 2000/11/24 11:10:02 itojun Exp    */
  39
  40 /*
  41  * Copyright (c) 1998 Todd C. Miller <Todd.Miller@courtesan.com>
  42  * All rights reserved.
  43  *
  44  * Redistribution and use in source and binary forms, with or without
  45  * modification, are permitted provided that the following conditions
  46  * are met:
  47  * 1. Redistributions of source code must retain the above copyright
  48  *    notice, this list of conditions and the following disclaimer.
  49  * 2. Redistributions in binary form must reproduce the above copyright
  50  *    notice, this list of conditions and the following disclaimer in the
  51  *    documentation and/or other materials provided with the distribution.
  52  * 3. The name of the author may not be used to endorse or promote products
  53  *    derived from this software without specific prior written permission.
  54  *
  55  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
  56  * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
  57  * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL
  58  * THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  59  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  60  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
  61  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
  62  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
  63  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
  64  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  65  */
  66
  67 #include <_ansi.h>
  68 #include <wchar.h>
  69
  70 /*
  71  * Appends src to string dst of size siz (unlike wcsncat, siz is the
  72  * full size of dst, not space left).  At most siz-1 characters
  73  * will be copied.  Always NUL terminates (unless siz == 0).
  74  * Returns wcslen(initial dst) + wcslen(src); if retval >= siz,
  75  * truncation occurred.
  76  */
  77 size_t
  78 _DEFUN (wcslcat, (dst, src, siz),
  79         wchar_t * dst _AND
  80         _CONST wchar_t * src _AND
  81         size_t siz)
  82 {
  83   wchar_t *d = dst;
  84   _CONST wchar_t *s = src;
  85   size_t n = siz;
  86   size_t dlen;
  87
  88   /* Find the end of dst and adjust bytes left but don't go past end */
  89   while (*d != '\0' && n-- != 0)
  90     d++;
  91   dlen = d - dst;
  92   n = siz - dlen;
  93
  94   if (n == 0)
  95     return (dlen + wcslen (s));
  96   while (*s != '\0')
  97     {
  98       if (n != 1)
  99         {
 100           *d++ = *s;
 101           n--;
 102         }
 103       s++;
 104     }
 105   *d = '\0';
 106
 107   return (dlen + (s - src));    /* count does not include NUL */
 108 }