xref: /freebsd/contrib/openbsm/compat/strlcat.h (revision ec65e4f8d0654361df5e97d4de3518edebf76b46)
1 /*-
2  * Copyright (c) 1998 Todd C. Miller <Todd.Miller@courtesan.com>
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. The name of the author may not be used to endorse or promote products
14  *    derived from this software without specific prior written permission.
15  *
16  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
17  * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
18  * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL
19  * THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
20  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
21  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
22  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
23  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
24  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
25  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26  *
27  * dollar OpenBSD: strlcat.c,v 1.2 1999/06/17 16:28:58 millert Exp dollar
28  */
29 
30 /*
31  * Appends src to string dst of size siz (unlike strncat, siz is the
32  * full size of dst, not space left).  At most siz-1 characters
33  * will be copied.  Always NUL terminates (unless siz <= strlen(dst)).
34  * Returns strlen(src) + MIN(siz, strlen(initial dst)).
35  * If retval >= siz, truncation occurred.
36  */
37 static size_t
38 strlcat(dst, src, siz)
39 	char *dst;
40 	const char *src;
41 	size_t siz;
42 {
43 	char *d = dst;
44 	const char *s = src;
45 	size_t n = siz;
46 	size_t dlen;
47 
48 	/* Find the end of dst and adjust bytes left but don't go past end */
49 	while (n-- != 0 && *d != '\0')
50 		d++;
51 	dlen = d - dst;
52 	n = siz - dlen;
53 
54 	if (n == 0)
55 		return(dlen + strlen(s));
56 	while (*s != '\0') {
57 		if (n != 1) {
58 			*d++ = *s;
59 			n--;
60 		}
61 		s++;
62 	}
63 	*d = '\0';
64 
65 	return(dlen + (s - src));	/* count does not include NUL */
66 }
67