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 * $OpenBSD: strlcat.c,v 1.2 1999/06/17 16:28:58 millert Exp $
28 * $FreeBSD: src/lib/libc/string/strlcat.c,v 1.2.4.2 2001/07/09 23:30:06 obrien Exp $
29 * $DragonFly: src/sys/libkern/strlcat.c,v 1.5 2007/06/07 23:45:02 dillon Exp $
30 */
31
32 #include <sys/types.h>
33 #include <sys/libkern.h>
34
35 /*
36 * Appends src to string dst of size siz (unlike strncat, 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 <= strlen(dst)).
39 * Returns strlen(initial dst) + strlen(src); if retval >= siz,
40 * truncation occurred.
41 */
42 size_t
strlcat(char * dst,const char * src,size_t siz)43 strlcat(char *dst, const char *src, size_t siz)
44 {
45 char *d = dst;
46 const char *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 (n-- != 0 && *d != '\0')
52 d++;
53 dlen = d - dst;
54 n = siz - dlen;
55
56 if (n == 0)
57 return(dlen + strlen(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