xref: /openbsd/lib/libc/string/wcslcat.c (revision 898184e3)
1 /*	$OpenBSD: wcslcat.c,v 1.4 2011/07/24 15:21:28 millert Exp $	*/
2 /*	$NetBSD: wcslcat.c,v 1.2 2001/01/03 14:33:02 lukem Exp $	*/
3 
4 /*
5  * Copyright (c) 1998 Todd C. Miller <Todd.Miller@courtesan.com>
6  *
7  * Permission to use, copy, modify, and distribute this software for any
8  * purpose with or without fee is hereby granted, provided that the above
9  * copyright notice and this permission notice appear in all copies.
10  *
11  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
12  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
13  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
14  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
15  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
16  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
17  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
18  */
19 
20 #include <sys/types.h>
21 #include <wchar.h>
22 
23 /*
24  * Appends src to string dst of size siz (unlike wcsncat, siz is the
25  * full size of dst, not space left).  At most siz-1 characters
26  * will be copied.  Always NUL terminates (unless siz <= wcslen(dst)).
27  * Returns wcslen(src) + MIN(siz, wcslen(initial dst)).
28  * If retval >= siz, truncation occurred.
29  */
30 size_t
31 wcslcat(wchar_t *dst, const wchar_t *src, size_t siz)
32 {
33 	wchar_t *d = dst;
34 	const wchar_t *s = src;
35 	size_t n = siz;
36 	size_t dlen;
37 
38 	/* Find the end of dst and adjust bytes left but don't go past end */
39 	while (n-- != 0 && *d != '\0')
40 		d++;
41 	dlen = d - dst;
42 	n = siz - dlen;
43 
44 	if (n == 0)
45 		return(dlen + wcslen(s));
46 	while (*s != '\0') {
47 		if (n != 1) {
48 			*d++ = *s;
49 			n--;
50 		}
51 		s++;
52 	}
53 	*d = '\0';
54 
55 	return(dlen + (s - src));	/* count does not include NUL */
56 }
57