xref: /dragonfly/lib/libc/string/wcslcat.c (revision 0720b42f)
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  * $FreeBSD: head/lib/libc/string/wcslcat.c 188080 2009-02-03 17:58:20Z danger $
29  */
30 
31 #include <sys/types.h>
32 #include <wchar.h>
33 
34 /*
35  * Appends src to string dst of size siz (unlike wcsncat, siz is the
36  * full size of dst, not space left).  At most siz-1 characters
37  * will be copied.  Always NUL terminates (unless siz == 0).
38  * Returns wcslen(initial dst) + wcslen(src); if retval >= siz,
39  * truncation occurred.
40  */
41 size_t
42 wcslcat(wchar_t *dst, const wchar_t *src, size_t siz)
43 {
44 	wchar_t *d = dst;
45 	const wchar_t *s = src;
46 	size_t n = siz;
47 	size_t dlen;
48 
49 	/* Find the end of dst and adjust bytes left but don't go past end */
50 	while (*d != '\0' && n-- != 0)
51 		d++;
52 	dlen = d - dst;
53 	n = siz - dlen;
54 
55 	if (n == 0)
56 		return(dlen + wcslen(s));
57 	while (*s != '\0') {
58 		if (n != 1) {
59 			*d++ = *s;
60 			n--;
61 		}
62 		s++;
63 	}
64 	*d = '\0';
65 
66 	return(dlen + (s - src));	/* count does not include NUL */
67 }
68