xref: /freebsd/contrib/tcpdump/missing/strlcpy.c (revision 2b15cb3d0922bd70ea592f0da9b4a5b167f4d53f)
1 /*	$NetBSD: strlcpy.c,v 1.5 1999/09/20 04:39:47 lukem Exp $	*/
2 /*	from OpenBSD: strlcpy.c,v 1.4 1999/05/01 18:56:41 millert Exp 	*/
3 
4 /*
5  * Copyright (c) 1998 Todd C. Miller <Todd.Miller@courtesan.com>
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. The name of the author may not be used to endorse or promote products
17  *    derived from this software without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
20  * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
21  * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL
22  * THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
23  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
24  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
25  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
26  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
27  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
28  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29  */
30 
31 #ifdef HAVE_CONFIG_H
32 #include <config.h>
33 #endif
34 
35 #include <tcpdump-stdinc.h>
36 
37 #include <string.h>
38 
39 #include "interface.h"
40 
41 /*
42  * Copy src to string dst of size siz.  At most siz-1 characters
43  * will be copied.  Always NUL terminates (unless siz == 0).
44  * Returns strlen(src); if retval >= siz, truncation occurred.
45  */
46 size_t
47 strlcpy(char *dst, const char *src, size_t siz)
48 {
49 	register char *d = dst;
50 	register const char *s = src;
51 	register size_t n = siz;
52 
53 	/* Copy as many bytes as will fit */
54 	if (n != 0 && --n != 0) {
55 		do {
56 			if ((*d++ = *s++) == 0)
57 				break;
58 		} while (--n != 0);
59 	}
60 
61 	/* Not enough room in dst, add NUL and traverse rest of src */
62 	if (n == 0) {
63 		if (siz != 0)
64 			*d = '\0';		/* NUL-terminate dst */
65 		while (*s++)
66 			;
67 	}
68 
69 	return(s - src - 1);	/* count does not include NUL */
70 }
71