lib/libc/string/wcslcat.c

   1 /*
   2  * Copyright (c) 1998 Todd C. Miller <Todd.Miller@courtesan.com>
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. The name of the author may not be used to endorse or promote products
  14  *    derived from this software without specific prior written permission.
  15  *
  16  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
  17  * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
  18  * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL
  19  * THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  20  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  21  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
  22  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
  23  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
  24  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
  25  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  26  *
  27  * $OpenBSD: strlcat.c,v 1.3 2000/11/24 11:10:02 itojun Exp $
  28  * $NetBSD: wcslcat.c,v 1.1 2000/12/23 23:14:36 itojun Exp $
  29  * $FreeBSD: src/lib/libc/string/wcslcat.c,v 1.3.2.1 2001/07/11 23:48:38 obrien Exp $
  30  * $DragonFly: src/lib/libc/string/wcslcat.c,v 1.3 2005/09/18 16:32:34 asmodai Exp $
  31  */
  32
  33 #include <sys/types.h>
  34 #include <assert.h>
  35 #include <wchar.h>
  36
  37 /*
  38  * Appends src to string dst of size siz (unlike wcsncat, siz is the
  39  * full size of dst, not space left).  At most siz-1 characters
  40  * will be copied.  Always NUL terminates (unless siz == 0).
  41  * Returns wcslen(initial dst) + wcslen(src); if retval >= siz,
  42  * truncation occurred.
  43  */
  44 size_t
  45 wcslcat(wchar_t *dst, const wchar_t *src, size_t siz)
  46 {
  47         wchar_t *d = dst;
  48         const wchar_t *s = src;
  49         size_t n = siz;
  50         size_t dlen;
  51
  52         /* Find the end of dst and adjust bytes left but don't go past end */
  53         while (*d != '\0' && n-- != 0)
  54                 d++;
  55         dlen = d - dst;
  56         n = siz - dlen;
  57
  58         if (n == 0)
  59                 return(dlen + wcslen(s));
  60         while (*s != '\0') {
  61                 if (n != 1) {
  62                         *d++ = *s;
  63                         n--;
  64                 }
  65                 s++;
  66         }
  67         *d = '\0';
  68
  69         return(dlen + (s - src));       /* count does not include NUL */
  70 }