xref: /freebsd/lib/libc/string/wcslcat.c (revision eda14cbc264d6969b02f2b1994cef11148e914f1)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1998 Todd C. Miller <Todd.Miller@courtesan.com>
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. The name of the author may not be used to endorse or promote products
16  *    derived from this software without specific prior written permission.
17  *
18  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
19  * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
20  * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL
21  * THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
22  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
23  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
24  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
25  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
26  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
27  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28  *
29  *	from OpenBSD: strlcat.c,v 1.3 2000/11/24 11:10:02 itojun Exp
30  */
31 
32 #include <sys/cdefs.h>
33 #if 0
34 #if defined(LIBC_SCCS) && !defined(lint)
35 __RCSID("$NetBSD: wcslcat.c,v 1.1 2000/12/23 23:14:36 itojun Exp $");
36 #endif /* LIBC_SCCS and not lint */
37 #endif
38 __FBSDID("$FreeBSD$");
39 
40 #include <sys/types.h>
41 #include <wchar.h>
42 
43 /*
44  * Appends src to string dst of size siz (unlike wcsncat, siz is the
45  * full size of dst, not space left).  At most siz-1 characters
46  * will be copied.  Always NUL terminates (unless siz == 0).
47  * Returns wcslen(initial dst) + wcslen(src); if retval >= siz,
48  * truncation occurred.
49  */
50 size_t
51 wcslcat(wchar_t *dst, const wchar_t *src, 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 (n-- != 0 && *d != '\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