xref: /freebsd/contrib/blocklist/port/strlcpy.c (revision 48e64ca13d4f36795ac718911b805e3e9a726f1b)
1 /*	$NetBSD: strlcpy.c,v 1.2 2025/02/11 17:48:30 christos Exp $	*/
2 /*	$OpenBSD: strlcpy.c,v 1.7 2003/04/12 21:56:39 millert Exp $	*/
3 
4 /*
5  * Copyright (c) 1998 Todd C. Miller <Todd.Miller@courtesan.com>
6  *
7  * Permission to use, copy, modify, and distribute this software for any
8  * purpose with or without fee is hereby granted, provided that the above
9  * copyright notice and this permission notice appear in all copies.
10  *
11  * THE SOFTWARE IS PROVIDED "AS IS" AND TODD C. MILLER DISCLAIMS ALL
12  * WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
13  * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL TODD C. MILLER BE LIABLE
14  * FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
15  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
16  * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
17  * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
18  */
19 
20 #if !defined(_KERNEL) && !defined(_STANDALONE)
21 #if HAVE_CONFIG_H
22 #include "config.h"
23 #endif
24 
25 #ifdef HAVE_SYS_CDEFS_H
26 #include <sys/cdefs.h>
27 #endif
28 
29 #if defined(LIBC_SCCS) && !defined(lint)
30 __RCSID("$NetBSD: strlcpy.c,v 1.2 2025/02/11 17:48:30 christos Exp $");
31 #endif /* LIBC_SCCS and not lint */
32 
33 #ifdef _LIBC
34 #include "namespace.h"
35 #endif
36 #include <sys/types.h>
37 #include <assert.h>
38 #include <string.h>
39 
40 #ifdef _LIBC
41 # ifdef __weak_alias
__weak_alias(strlcpy,_strlcpy)42 __weak_alias(strlcpy, _strlcpy)
43 # endif
44 #endif
45 #else
46 #include <lib/libkern/libkern.h>
47 #endif /* !_KERNEL && !_STANDALONE */
48 
49 
50 #if !HAVE_STRLCPY
51 /*
52  * Copy src to string dst of size siz.  At most siz-1 characters
53  * will be copied.  Always NUL terminates (unless siz == 0).
54  * Returns strlen(src); if retval >= siz, truncation occurred.
55  */
56 size_t
57 strlcpy(char *dst, const char *src, size_t siz)
58 {
59 	char *d = dst;
60 	const char *s = src;
61 	size_t n = siz;
62 
63 	/* Copy as many bytes as will fit */
64 	if (n != 0 && --n != 0) {
65 		do {
66 			if ((*d++ = *s++) == 0)
67 				break;
68 		} while (--n != 0);
69 	}
70 
71 	/* Not enough room in dst, add NUL and traverse rest of src */
72 	if (n == 0) {
73 		if (siz != 0)
74 			*d = '\0';		/* NUL-terminate dst */
75 		while (*s++)
76 			;
77 	}
78 
79 	return(s - src - 1);	/* count does not include NUL */
80 }
81 #endif
82