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      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 (at) 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 }
     77