lib/libc/string/wcslcat.c

   1 /*      $NetBSD: wcslcat.c,v 1.2 2001/01/03 14:33:02 lukem 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 1.2 2001/01/03 14:33:02 lukem 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(dst, src, siz)
  49         wchar_t *dst;
  50         const wchar_t *src;
  51         size_t siz;
  52 {
  53         wchar_t *d = dst;
  54         const wchar_t *s = src;
  55         size_t n = siz;
  56         size_t dlen;
  57
  58         _DIAGASSERT(dst != NULL);
  59         _DIAGASSERT(src != NULL);
  60
  61         /* Find the end of dst and adjust bytes left but don't go past end */
  62         while (*d != '\0' && n-- != 0)
  63                 d++;
  64         dlen = d - dst;
  65         n = siz - dlen;
  66
  67         if (n == 0)
  68                 return(dlen + wcslen(s));
  69         while (*s != '\0') {
  70                 if (n != 1) {
  71                         *d++ = *s;
  72                         n--;
  73                 }
  74                 s++;
  75         }
  76         *d = '\0';
  77
  78         return(dlen + (s - src));       /* count does not include NUL */
  79 }