1 /* $OpenBSD: strlcat.c,v 1.13 2005/08/08 08:05:37 espie Exp $ */
2
3 /*
4 * Copyright (c) 1998 Todd C. Miller <Todd.Miller@courtesan.com>
5 *
6 * Permission to use, copy, modify, and distribute this software for any
7 * purpose with or without fee is hereby granted, provided that the above
8 * copyright notice and this permission notice appear in all copies.
9 *
10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17 */
18
19 /* OPENBSD ORIGINAL: lib/libc/string/strlcat.c */
20
21 #include "openbsd-compat.h"
22
23 #if !defined(HAVE_STRLCAT)
24
25 #include <sys/types.h>
26 #include <string.h>
27
28 /*
29 * Appends src to string dst of size siz (unlike strncat, siz is the
30 * full size of dst, not space left). At most siz-1 characters
31 * will be copied. Always NUL terminates (unless siz <= strlen(dst)).
32 * Returns strlen(src) + MIN(siz, strlen(initial dst)).
33 * If retval >= siz, truncation occurred.
34 */
35 size_t
strlcat(char * dst,const char * src,size_t siz)36 strlcat(char *dst, const char *src, size_t siz)
37 {
38 char *d = dst;
39 const char *s = src;
40 size_t n = siz;
41 size_t dlen;
42
43 /* Find the end of dst and adjust bytes left but don't go past end */
44 while (n-- != 0 && *d != '\0')
45 d++;
46 dlen = d - dst;
47 n = siz - dlen;
48
49 if (n == 0)
50 return(dlen + strlen(s));
51 while (*s != '\0') {
52 if (n != 1) {
53 *d++ = *s;
54 n--;
55 }
56 s++;
57 }
58 *d = '\0';
59
60 return(dlen + (s - src)); /* count does not include NUL */
61 }
62
63 #endif /* !defined(HAVE_STRLCAT) */
64