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
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