1 // SPDX-License-Identifier: BSD-3-Clause
2 /* This file is copied from newlib-1.19 */
3
4 /* $OpenBSD: strlcat.c,v 1.8 2001/05/13 15:40:15 deraadt Exp $ */
5
6 /*
7 * Copyright (c) 1998 Todd C. Miller <Todd.Miller@courtesan.com>
8 * All rights reserved.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 3. The name of the author may not be used to endorse or promote products
19 * derived from this software without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
22 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
23 * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
24 * THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
25 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
26 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
27 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
28 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
29 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
30 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
31 */
32
33 #if defined(LIBC_SCCS) && !defined(lint)
34 static char *rcsid =
35 "$OpenBSD: strlcat.c,v 1.8 2001/05/13 15:40:15 deraadt Exp $";
36 #endif /* LIBC_SCCS and not lint */
37
38 #include <types_ext.h>
39 #include <string_ext.h>
40 /* #include <string.h> */
41
42 size_t strlen(const char *s);
43 /*
44 * Appends src to string dst of size siz (unlike strncat, siz is the
45 * full size of dst, not space left). At most siz-1 characters
46 * will be copied. Always NUL terminates (unless siz <= strlen(dst)).
47 * Returns strlen(src) + MIN(siz, strlen(initial dst)).
48 * If retval >= siz, truncation occurred.
49 */
strlcat(char * dst,const char * src,size_t siz)50 size_t strlcat(char *dst, const char *src, size_t siz)
51 {
52 register char *d = dst;
53 register const char *s = src;
54 register size_t n = siz;
55 size_t dlen;
56
57 /* Find the end of dst and adjust bytes left but don't go past end */
58 while (n-- != 0 && *d != '\0')
59 d++;
60 dlen = d - dst;
61 n = siz - dlen;
62
63 if (n == 0)
64 return dlen + strlen(s);
65
66 while (*s != '\0') {
67 if (n != 1) {
68 *d++ = *s;
69 n--;
70 }
71 s++;
72 }
73 *d = '\0';
74
75 return dlen + (s - src); /* count does not include NUL */
76 }
77