xref: /freebsd/lib/libc/string/wcslcat.c (revision 9829d36a8683ded23a8c7cbc12dac15ceb045e0a)
1 /*	$NetBSD: wcslcat.c,v 1.1 2000/12/23 23:14:36 itojun 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  * $FreeBSD$
31  */
32 
33 #include <sys/cdefs.h>
34 #if defined(LIBC_SCCS) && !defined(lint)
35 __RCSID("$NetBSD: wcslcat.c,v 1.1 2000/12/23 23:14:36 itojun Exp $");
36 #endif /* LIBC_SCCS and not lint */
37 
38 #include <sys/types.h>
39 #include <assert.h>
40 #include <wchar.h>
41 
42 /*
43  * Appends src to string dst of size siz (unlike wcsncat, siz is the
44  * full size of dst, not space left).  At most siz-1 characters
45  * will be copied.  Always NUL terminates (unless siz == 0).
46  * Returns wcslen(initial dst) + wcslen(src); if retval >= siz,
47  * truncation occurred.
48  */
49 size_t
50 wcslcat(dst, src, siz)
51 	wchar_t *dst;
52 	const wchar_t *src;
53 	size_t siz;
54 {
55 	wchar_t *d = dst;
56 	const wchar_t *s = src;
57 	size_t n = siz;
58 	size_t dlen;
59 
60 	_DIAGASSERT(dst != NULL);
61 	_DIAGASSERT(src != NULL);
62 
63 	/* Find the end of dst and adjust bytes left but don't go past end */
64 	while (*d != '\0' && n-- != 0)
65 		d++;
66 	dlen = d - dst;
67 	n = siz - dlen;
68 
69 	if (n == 0)
70 		return(dlen + wcslen(s));
71 	while (*s != '\0') {
72 		if (n != 1) {
73 			*d++ = *s;
74 			n--;
75 		}
76 		s++;
77 	}
78 	*d = '\0';
79 
80 	return(dlen + (s - src));	/* count does not include NUL */
81 }
82