xref: /freebsd/contrib/libpcap/missing/strlcpy.c (revision 96190b4fef3b4a0cc3ca0606b0c4e3e69a5e6717)
1 /*	$OpenBSD: 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 #include <config.h>
20 
21 #include <stddef.h>
22 #include <string.h>
23 
24 #include "portability.h"
25 
26 /*
27  * Copy string src to buffer dst of size dsize.  At most dsize-1
28  * chars will be copied.  Always NUL terminates (unless dsize == 0).
29  * Returns strlen(src); if retval >= dsize, truncation occurred.
30  */
31 size_t
32 pcapint_strlcpy(char * restrict dst, const char * restrict src, size_t dsize)
33 {
34 	const char *osrc = src;
35 	size_t nleft = dsize;
36 
37 	/* Copy as many bytes as will fit. */
38 	if (nleft != 0) {
39 		while (--nleft != 0) {
40 			if ((*dst++ = *src++) == '\0')
41 				break;
42 		}
43 	}
44 
45 	/* Not enough room in dst, add NUL and traverse rest of src. */
46 	if (nleft == 0) {
47 		if (dsize != 0)
48 			*dst = '\0';		/* NUL-terminate dst */
49 		while (*src++)
50 			;
51 	}
52 
53 	return(src - osrc - 1);	/* count does not include NUL */
54 }
55