Tor  0.4.6.0-alpha-dev
strlcat.c
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
45 strlcat(char *dst, const char *src, size_t siz)
46 {
47  register char *d = dst;
48  register const char *s = src;
49  register size_t n = siz;
50  size_t dlen;
51 
52  /* Find the end of dst and adjust bytes left but don't go past end */
53  while (n-- != 0 && *d != '\0')
54  d++;
55  dlen = d - dst;
56  n = siz - dlen;
57 
58  if (n == 0)
59  return(dlen + strlen(s));
60  while (*s != '\0') {
61  if (n != 1) {
62  *d++ = *s;
63  n--;
64  }
65  s++;
66  }
67  *d = '\0';
68 
69  return(dlen + (s - src)); /* count does not include NUL */
70 }