1 /* $OpenBSD: strlcat.c,v 1.8 2001/05/13 15:40:15 deraadt Exp $ */
2
3 /*
4 * Copyright (c) 1998 Todd C. Miller <Todd.Miller@courtesan.com>
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. The name of the author may not be used to endorse or promote products
16 * derived from this software without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
19 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
20 * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
21 * THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
22 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
23 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
24 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
25 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
26 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
27 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28 */
29
30 #if defined(LIBC_SCCS) && !defined(lint)
31 static char *rcsid = "$OpenBSD: strlcat.c,v 1.8 2001/05/13 15:40:15 deraadt Exp $";
32 #endif /* LIBC_SCCS and not lint */
33
34 #include <sys/types.h>
35 #include <string.h>
36
37 /*
38 * Appends src to string dst of size siz (unlike strncat, siz is the
39 * full size of dst, not space left). At most siz-1 characters
40 * will be copied. Always NUL terminates (unless siz <= strlen(dst)).
41 * Returns strlen(src) + MIN(siz, strlen(initial dst)).
42 * If retval >= siz, truncation occurred.
43 */
44 size_t
strlcat(dst,src,siz)45 strlcat(dst, src, siz)
46 char *dst;
47 const char *src;
48 size_t siz;
49 {
50 register char *d = dst;
51 register const char *s = src;
52 register size_t n = siz;
53 size_t dlen;
54
55 /* Find the end of dst and adjust bytes left but don't go past end */
56 while (n-- != 0 && *d != '\0')
57 d++;
58 dlen = d - dst;
59 n = siz - dlen;
60
61 if (n == 0)
62 return(dlen + strlen(s));
63 while (*s != '\0') {
64 if (n != 1) {
65 *d++ = *s;
66 n--;
67 }
68 s++;
69 }
70 *d = '\0';
71
72 return(dlen + (s - src)); /* count does not include NUL */
73 }
74