1 /*	$OpenBSD: strlcpy.c,v 1.11 2006/05/05 15:27:38 millert Exp $	*/
2 
3 /*
4  * Copyright (c) 1998 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 <sys/types.h>
20 #include <string.h>
21 
22 /*
23  * Copy src to string dst of size siz.  At most siz-1 characters
24  * will be copied.  Always NUL terminates (unless siz == 0).
25  * Returns strlen(src); if retval >= siz, truncation occurred.
26  */
27 size_t
strlcpy(char * dst,const char * src,size_t siz)28 strlcpy(char *dst, const char *src, size_t siz)
29 {
30 	char *d = dst;
31 	const char *s = src;
32 	size_t n = siz;
33 
34 	/* Copy as many bytes as will fit */
35 	if (n != 0) {
36 		while (--n != 0) {
37 			if ((*d++ = *s++) == '\0')
38 				break;
39 		}
40 	}
41 
42 	/* Not enough room in dst, add NUL and traverse rest of src */
43 	if (n == 0) {
44 		if (siz != 0)
45 			*d = '\0';		/* NUL-terminate dst */
46 		while (*s++)
47 			;
48 	}
49 
50 	return(s - src - 1);	/* count does not include NUL */
51 }
52