lib/libc/string/wcslcat.c

   1 /*      $NetBSD: wcslcat.c,v 1.3 2012/06/25 22:32:46 abs Exp $  */
   2 /*      from OpenBSD: strlcat.c,v 1.3 2000/11/24 11:10:02 itojun Exp    */
   3
   4 /*
   5  * Copyright (c) 1998 Todd C. Miller <Todd.Miller@courtesan.com>
   6  * All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  * 3. The name of the author may not be used to endorse or promote products
  17  *    derived from this software without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
  20  * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
  21  * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL
  22  * THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  23  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  24  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
  25  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
  26  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
  27  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
  28  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  29  */
  30
  31 #include <sys/cdefs.h>
  32 #if defined(LIBC_SCCS) && !defined(lint)
  33 __RCSID("$NetBSD: wcslcat.c,v 1.3 2012/06/25 22:32:46 abs Exp $");
  34 #endif /* LIBC_SCCS and not lint */
  35
  36 #include <sys/types.h>
  37 #include <assert.h>
  38 #include <wchar.h>
  39
  40 /*
  41  * Appends src to string dst of size siz (unlike wcsncat, siz is the
  42  * full size of dst, not space left).  At most siz-1 characters
  43  * will be copied.  Always NUL terminates (unless siz == 0).
  44  * Returns wcslen(initial dst) + wcslen(src); if retval >= siz,
  45  * truncation occurred.
  46  */
  47 size_t
  48 wcslcat(wchar_t *dst, const wchar_t *src, size_t siz)
  49 {
  50         wchar_t *d = dst;
  51         const wchar_t *s = src;
  52         size_t n = siz;
  53         size_t dlen;
  54
  55         _DIAGASSERT(dst != NULL);
  56         _DIAGASSERT(src != NULL);
  57
  58         /* Find the end of dst and adjust bytes left but don't go past end */
  59         while (*d != '\0' && n-- != 0)
  60                 d++;
  61         dlen = d - dst;
  62         n = siz - dlen;
  63
  64         if (n == 0)
  65                 return(dlen + wcslen(s));
  66         while (*s != '\0') {
  67                 if (n != 1) {
  68                         *d++ = *s;
  69                         n--;
  70                 }
  71                 s++;
  72         }
  73         *d = '\0';
  74
  75         return(dlen + (s - src));       /* count does not include NUL */
  76 }