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