xref: /openbsd/lib/libc/string/wcslcat.c (revision 17df1aa7)
1 /*	$OpenBSD: wcslcat.c,v 1.3 2005/08/08 08:05:37 espie Exp $	*/
2 /*	$NetBSD: wcslcat.c,v 1.2 2001/01/03 14:33:02 lukem Exp $	*/
3 /*	from OpenBSD: strlcat.c,v 1.3 2000/11/24 11:10:02 itojun Exp 	*/
4 
5 /*
6  * Copyright (c) 1998 Todd C. Miller <Todd.Miller@courtesan.com>
7  * All rights reserved.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  * 3. The name of the author may not be used to endorse or promote products
18  *    derived from this software without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
21  * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
22  * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL
23  * THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
24  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
25  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
26  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
27  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
28  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
29  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30  */
31 
32 #include <sys/types.h>
33 #include <wchar.h>
34 
35 /*
36  * Appends src to string dst of size siz (unlike wcsncat, siz is the
37  * full size of dst, not space left).  At most siz-1 characters
38  * will be copied.  Always NUL terminates (unless siz == 0).
39  * Returns wcslen(initial dst) + wcslen(src); if retval >= siz,
40  * truncation occurred.
41  */
42 size_t
43 wcslcat(wchar_t *dst, const wchar_t *src, size_t siz)
44 {
45 	wchar_t *d = dst;
46 	const wchar_t *s = src;
47 	size_t n = siz;
48 	size_t dlen;
49 
50 	/* Find the end of dst and adjust bytes left but don't go past end */
51 	while (*d != '\0' && n-- != 0)
52 		d++;
53 	dlen = d - dst;
54 	n = siz - dlen;
55 
56 	if (n == 0)
57 		return(dlen + wcslen(s));
58 	while (*s != '\0') {
59 		if (n != 1) {
60 			*d++ = *s;
61 			n--;
62 		}
63 		s++;
64 	}
65 	*d = '\0';
66 
67 	return(dlen + (s - src));	/* count does not include NUL */
68 }
69