xref: /freebsd/lib/libc/string/wcslcat.c (revision b52b9d56d4e96089873a75f9e29062eec19fabba)
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 0
32 #if defined(LIBC_SCCS) && !defined(lint)
33 __RCSID("$NetBSD: wcslcat.c,v 1.1 2000/12/23 23:14:36 itojun Exp $");
34 #endif /* LIBC_SCCS and not lint */
35 #endif
36 __FBSDID("$FreeBSD$");
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 	/* Find the end of dst and adjust bytes left but don't go past end */
61 	while (*d != '\0' && n-- != 0)
62 		d++;
63 	dlen = d - dst;
64 	n = siz - dlen;
65 
66 	if (n == 0)
67 		return(dlen + wcslen(s));
68 	while (*s != '\0') {
69 		if (n != 1) {
70 			*d++ = *s;
71 			n--;
72 		}
73 		s++;
74 	}
75 	*d = '\0';
76 
77 	return(dlen + (s - src));	/* count does not include NUL */
78 }
79