strlcat.c revision 126274 
1/* OPENBSD ORIGINAL: lib/libc/string/strlcat.c */
2
3/*	$OpenBSD: strlcat.c,v 1.11 2003/06/17 21:56:24 millert Exp $	*/
4
5/*
6 * Copyright (c) 1998 Todd C. Miller <Todd.Miller@courtesan.com>
7 *
8 * Permission to use, copy, modify, and distribute this software for any
9 * purpose with or without fee is hereby granted, provided that the above
10 * copyright notice and this permission notice appear in all copies.
11 *
12 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
13 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
14 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
15 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
16 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
17 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
18 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
19 */
20
21#include "includes.h"
22#ifndef HAVE_STRLCAT
23
24#if defined(LIBC_SCCS) && !defined(lint)
25static char *rcsid = "$OpenBSD: strlcat.c,v 1.11 2003/06/17 21:56:24 millert Exp $";
26#endif /* LIBC_SCCS and not lint */
27
28#include <sys/types.h>
29#include <string.h>
30
31/*
32 * Appends src to string dst of size siz (unlike strncat, siz is the
33 * full size of dst, not space left).  At most siz-1 characters
34 * will be copied.  Always NUL terminates (unless siz <= strlen(dst)).
35 * Returns strlen(src) + MIN(siz, strlen(initial dst)).
36 * If retval >= siz, truncation occurred.
37 */
38size_t
39strlcat(char *dst, const char *src, size_t siz)
40{
41	register char *d = dst;
42	register const char *s = src;
43	register size_t n = siz;
44	size_t dlen;
45
46	/* Find the end of dst and adjust bytes left but don't go past end */
47	while (n-- != 0 && *d != '\0')
48		d++;
49	dlen = d - dst;
50	n = siz - dlen;
51
52	if (n == 0)
53		return(dlen + strlen(s));
54	while (*s != '\0') {
55		if (n != 1) {
56			*d++ = *s;
57			n--;
58		}
59		s++;
60	}
61	*d = '\0';
62
63	return(dlen + (s - src));	/* count does not include NUL */
64}
65
66#endif /* !HAVE_STRLCAT */
67