1 12042ad7 2021-01-21 op /*
 2 12042ad7 2021-01-21 op  * Copyright (c) 1998, 2015 Todd C. Miller <millert@openbsd.org>
 3 12042ad7 2021-01-21 op  *
 4 12042ad7 2021-01-21 op  * Permission to use, copy, modify, and distribute this software for any
 5 12042ad7 2021-01-21 op  * purpose with or without fee is hereby granted, provided that the above
 6 12042ad7 2021-01-21 op  * copyright notice and this permission notice appear in all copies.
 7 12042ad7 2021-01-21 op  *
 8 12042ad7 2021-01-21 op  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 9 12042ad7 2021-01-21 op  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10 12042ad7 2021-01-21 op  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11 12042ad7 2021-01-21 op  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12 12042ad7 2021-01-21 op  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13 12042ad7 2021-01-21 op  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14 12042ad7 2021-01-21 op  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15 12042ad7 2021-01-21 op  */
16 12042ad7 2021-01-21 op 
17 12042ad7 2021-01-21 op #include <sys/types.h>
18 12042ad7 2021-01-21 op #include <string.h>
19 12042ad7 2021-01-21 op 
20 12042ad7 2021-01-21 op /*
21 12042ad7 2021-01-21 op  * Appends src to string dst of size dsize (unlike strncat, dsize is the
22 12042ad7 2021-01-21 op  * full size of dst, not space left).  At most dsize-1 characters
23 12042ad7 2021-01-21 op  * will be copied.  Always NUL terminates (unless dsize <= strlen(dst)).
24 12042ad7 2021-01-21 op  * Returns strlen(src) + MIN(dsize, strlen(initial dst)).
25 12042ad7 2021-01-21 op  * If retval >= dsize, truncation occurred.
26 12042ad7 2021-01-21 op  */
27 12042ad7 2021-01-21 op size_t
28 12042ad7 2021-01-21 op strlcat(char *dst, const char *src, size_t dsize)
29 12042ad7 2021-01-21 op {
30 12042ad7 2021-01-21 op 	const char *odst = dst;
31 12042ad7 2021-01-21 op 	const char *osrc = src;
32 12042ad7 2021-01-21 op 	size_t n = dsize;
33 12042ad7 2021-01-21 op 	size_t dlen;
34 12042ad7 2021-01-21 op 
35 12042ad7 2021-01-21 op 	/* Find the end of dst and adjust bytes left but don't go past end. */
36 12042ad7 2021-01-21 op 	while (n-- != 0 && *dst != '\0')
37 12042ad7 2021-01-21 op 		dst++;
38 12042ad7 2021-01-21 op 	dlen = dst - odst;
39 12042ad7 2021-01-21 op 	n = dsize - dlen;
40 12042ad7 2021-01-21 op 
41 12042ad7 2021-01-21 op 	if (n-- == 0)
42 12042ad7 2021-01-21 op 		return(dlen + strlen(src));
43 12042ad7 2021-01-21 op 	while (*src != '\0') {
44 12042ad7 2021-01-21 op 		if (n != 0) {
45 12042ad7 2021-01-21 op 			*dst++ = *src;
46 12042ad7 2021-01-21 op 			n--;
47 12042ad7 2021-01-21 op 		}
48 12042ad7 2021-01-21 op 		src++;
49 12042ad7 2021-01-21 op 	}
50 12042ad7 2021-01-21 op 	*dst = '\0';
51 12042ad7 2021-01-21 op 
52 12042ad7 2021-01-21 op 	return(dlen + (src - osrc));	/* count does not include NUL */
53 12042ad7 2021-01-21 op }