1 /* $NetBSD: strlcat.c,v 1.1.1.5 2023/08/18 18:36:49 christos Exp $ */
2
3 /* $OpenBSD: strlcat.c,v 1.13 2005/08/08 08:05:37 espie 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 /* OPENBSD ORIGINAL: lib/libc/string/strlcat.c */
22 #include "file.h"
23 #ifndef lint
24 #if 0
25 FILE_RCSID("@(#)$File: strlcat.c,v 1.5 2022/09/24 20:30:13 christos Exp $")
26 #else
27 __RCSID("$NetBSD: strlcat.c,v 1.1.1.5 2023/08/18 18:36:49 christos Exp $");
28 #endif
29 #endif
30
31 #include <sys/types.h>
32 #include <string.h>
33
34 /*
35 * Appends src to string dst of size siz (unlike strncat, siz is the
36 * full size of dst, not space left). At most siz-1 characters
37 * will be copied. Always NUL terminates (unless siz <= strlen(dst)).
38 * Returns strlen(src) + MIN(siz, strlen(initial dst)).
39 * If retval >= siz, truncation occurred.
40 */
41 size_t
strlcat(char * dst,const char * src,size_t siz)42 strlcat(char *dst, const char *src, size_t siz)
43 {
44 char *d = dst;
45 const char *s = src;
46 size_t n = siz;
47 size_t dlen;
48
49 /* Find the end of dst and adjust bytes left but don't go past end */
50 while (n-- != 0 && *d != '\0')
51 d++;
52 dlen = d - dst;
53 n = siz - dlen;
54
55 if (n == 0)
56 return(dlen + strlen(s));
57 while (*s != '\0') {
58 if (n != 1) {
59 *d++ = *s;
60 n--;
61 }
62 s++;
63 }
64 *d = '\0';
65
66 return(dlen + (s - src)); /* count does not include NUL */
67 }
68