1 bbcba3ed 2022-01-10 op /*	$OpenBSD: strlcat.c,v 1.19 2019/01/25 00:19:25 millert Exp $	*/
 2 bbcba3ed 2022-01-10 op 
 3 bbcba3ed 2022-01-10 op /*
 4 bbcba3ed 2022-01-10 op  * Copyright (c) 1998, 2015 Todd C. Miller <millert@openbsd.org>
 5 bbcba3ed 2022-01-10 op  *
 6 bbcba3ed 2022-01-10 op  * Permission to use, copy, modify, and distribute this software for any
 7 bbcba3ed 2022-01-10 op  * purpose with or without fee is hereby granted, provided that the above
 8 bbcba3ed 2022-01-10 op  * copyright notice and this permission notice appear in all copies.
 9 bbcba3ed 2022-01-10 op  *
10 bbcba3ed 2022-01-10 op  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11 bbcba3ed 2022-01-10 op  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12 bbcba3ed 2022-01-10 op  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13 bbcba3ed 2022-01-10 op  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14 bbcba3ed 2022-01-10 op  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15 bbcba3ed 2022-01-10 op  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16 bbcba3ed 2022-01-10 op  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17 bbcba3ed 2022-01-10 op  */
18 bbcba3ed 2022-01-10 op 
19 bbcba3ed 2022-01-10 op #include <sys/types.h>
20 bbcba3ed 2022-01-10 op #include <string.h>
21 bbcba3ed 2022-01-10 op 
22 bbcba3ed 2022-01-10 op #include "compat.h"
23 bbcba3ed 2022-01-10 op 
24 bbcba3ed 2022-01-10 op /*
25 bbcba3ed 2022-01-10 op  * Appends src to string dst of size dsize (unlike strncat, dsize is the
26 bbcba3ed 2022-01-10 op  * full size of dst, not space left).  At most dsize-1 characters
27 bbcba3ed 2022-01-10 op  * will be copied.  Always NUL terminates (unless dsize <= strlen(dst)).
28 bbcba3ed 2022-01-10 op  * Returns strlen(src) + MIN(dsize, strlen(initial dst)).
29 bbcba3ed 2022-01-10 op  * If retval >= dsize, truncation occurred.
30 bbcba3ed 2022-01-10 op  */
31 bbcba3ed 2022-01-10 op size_t
32 bbcba3ed 2022-01-10 op strlcat(char *dst, const char *src, size_t dsize)
33 bbcba3ed 2022-01-10 op {
34 bbcba3ed 2022-01-10 op 	const char *odst = dst;
35 bbcba3ed 2022-01-10 op 	const char *osrc = src;
36 bbcba3ed 2022-01-10 op 	size_t n = dsize;
37 bbcba3ed 2022-01-10 op 	size_t dlen;
38 bbcba3ed 2022-01-10 op 
39 bbcba3ed 2022-01-10 op 	/* Find the end of dst and adjust bytes left but don't go past end. */
40 bbcba3ed 2022-01-10 op 	while (n-- != 0 && *dst != '\0')
41 bbcba3ed 2022-01-10 op 		dst++;
42 bbcba3ed 2022-01-10 op 	dlen = dst - odst;
43 bbcba3ed 2022-01-10 op 	n = dsize - dlen;
44 bbcba3ed 2022-01-10 op 
45 bbcba3ed 2022-01-10 op 	if (n-- == 0)
46 bbcba3ed 2022-01-10 op 		return(dlen + strlen(src));
47 bbcba3ed 2022-01-10 op 	while (*src != '\0') {
48 bbcba3ed 2022-01-10 op 		if (n != 0) {
49 bbcba3ed 2022-01-10 op 			*dst++ = *src;
50 bbcba3ed 2022-01-10 op 			n--;
51 bbcba3ed 2022-01-10 op 		}
52 bbcba3ed 2022-01-10 op 		src++;
53 bbcba3ed 2022-01-10 op 	}
54 bbcba3ed 2022-01-10 op 	*dst = '\0';
55 bbcba3ed 2022-01-10 op 
56 bbcba3ed 2022-01-10 op 	return(dlen + (src - osrc));	/* count does not include NUL */
57 bbcba3ed 2022-01-10 op }