xref: /freebsd/contrib/file/src/strlcpy.c (revision 4b9d605768acabc460aa6dcfe8a1f8db35b16794)
1 /*	$OpenBSD: strlcpy.c,v 1.10 2005/08/08 08:05:37 espie 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 /* OPENBSD ORIGINAL: lib/libc/string/strlcpy.c */
20 #include "file.h"
21 #ifndef lint
22 FILE_RCSID("@(#)$File: strlcpy.c,v 1.5 2022/09/24 20:30:13 christos Exp $")
23 #endif
24 
25 #include <sys/types.h>
26 #include <string.h>
27 
28 /*
29  * Copy src to string dst of size siz.  At most siz-1 characters
30  * will be copied.  Always NUL terminates (unless siz == 0).
31  * Returns strlen(src); if retval >= siz, truncation occurred.
32  */
33 size_t
34 strlcpy(char *dst, const char *src, size_t siz)
35 {
36 	char *d = dst;
37 	const char *s = src;
38 	size_t n = siz;
39 
40 	/* Copy as many bytes as will fit */
41 	if (n != 0 && --n != 0) {
42 		do {
43 			if ((*d++ = *s++) == 0)
44 				break;
45 		} while (--n != 0);
46 	}
47 
48 	/* Not enough room in dst, add NUL and traverse rest of src */
49 	if (n == 0) {
50 		if (siz != 0)
51 			*d = '\0';		/* NUL-terminate dst */
52 		while (*s++)
53 			;
54 	}
55 
56 	return(s - src - 1);	/* count does not include NUL */
57 }
58