xref: /freebsd/lib/libc/string/wcslcat.c (revision 17d6c636720d00f77e5d098daf4c278f89d84f7b)
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  *	from OpenBSD: strlcat.c,v 1.3 2000/11/24 11:10:02 itojun Exp
28  */
29 
30 #include <sys/cdefs.h>
31 #if defined(LIBC_SCCS) && !defined(lint)
32 __RCSID("$NetBSD: wcslcat.c,v 1.1 2000/12/23 23:14:36 itojun Exp $");
33 #endif /* LIBC_SCCS and not lint */
34 __FBSDID("$FreeBSD$");
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 	/* 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