strlcpy.c revision 356341 
1/*	$OpenBSD: pcap_strlcpy.c,v 1.12 2015/01/15 03:54:12 millert Exp $	*/
2
3/*
4 * Copyright (c) 1998, 2015 Todd C. Miller <Todd.Miller@courtesan.com>
5 *
6 * Permission to use, copy, modify, and distribute this software for any
7 * purpose with or without fee is hereby granted, provided that the above
8 * copyright notice and this permission notice appear in all copies.
9 *
10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17 */
18
19#ifdef HAVE_CONFIG_H
20#include <config.h>
21#endif
22
23#include <stddef.h>
24#include <string.h>
25
26#include "portability.h"
27
28/*
29 * Copy string src to buffer dst of size dsize.  At most dsize-1
30 * chars will be copied.  Always NUL terminates (unless dsize == 0).
31 * Returns strlen(src); if retval >= dsize, truncation occurred.
32 */
33size_t
34pcap_strlcpy(char * restrict dst, const char * restrict src, size_t dsize)
35{
36	const char *osrc = src;
37	size_t nleft = dsize;
38
39	/* Copy as many bytes as will fit. */
40	if (nleft != 0) {
41		while (--nleft != 0) {
42			if ((*dst++ = *src++) == '\0')
43				break;
44		}
45	}
46
47	/* Not enough room in dst, add NUL and traverse rest of src. */
48	if (nleft == 0) {
49		if (dsize != 0)
50			*dst = '\0';		/* NUL-terminate dst */
51		while (*src++)
52			;
53	}
54
55	return(src - osrc - 1);	/* count does not include NUL */
56}
57